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Steam Shovel

Steam shovel

.]] A steam shovel is a large steam powered excavating machine designed for lifting and moving material such as snow and soil. It was invented by William Otis who received a patent for his design in 1839. Basically a steam shovel consists of a caterpillar track or rail track mounted steam engine which is used to drive pulleys that move a hinged boom and bucket-shaped scoop under the control of an engineer. During the early 20th Century steam shovels lost out to the more powerful Diesel powered excavating machines that we still see today. Although many have been scrapped some can still be found in industrial museums and are popular restoration projects for steam enthusiasts.

External links

- http://members.tripod.com/dsmdonaldson/id59.htm
- http://www.copperrange.org/shovel.htm Category:Industrial equipment

Machine

For other uses of the term Machine, see Machine (disambiguation) Machine (disambiguation)A machine is any mechanical or organic device that transmits or modifies energy to perform or assist in the performance of tasks. It normally requires some energy source ("input") and accomplishes some sort of work. People have used mechanisms and machines to amplify their abilities since before written records were available. Generally these devices decrease the amount of force required to do a given amount of work, alter the direction of the force, or transform one form of motion or energy into another. The mechanical advantage of a simple machine is the ratio between the force it exerts on the load and the input force applied. This does not entirely describe the machine's performance, as force is required to overcome friction as well. The mechanical efficiency of a machine is the ratio of the actual mechanical advantage (AMA) to the ideal mechanical advantage (IMA). Functioning physical machines are always less than 100% efficient. Modern power tools, automated machine tools, and human-operated power machinery complicate the definition of "machine" greatly. Machines used to transform heat or other energy into mechanical energy are known as engines.

Simple machines or mechanical components

- Gear
- Lever
- Pulley
- Wedge
- Spring
- Wheel and Axle
- Bearings
- Belts
- Seals
- Chains

Clock

- Atomic clock
- chronometer
- Pendulum clock
- Quartz clock

Compressors and Pumps

- Archimedes screw
- Eductor-jet pump
- Hydraulic ram
- Tuyau
- Vacuum pump

Internal combustion engine

- Gasoline engine
- Diesel engine
- Four-stroke cycle
- Two-stroke cycle
- Wankel engine

External combustion engine

- Steam engine
- Stirling engine

Linkages

- Pantograph
- Peaucellier-Lipkin

Turbine

- Gas turbine
- Jet engine
- Steam turbine
- Water turbine
- Wind generator, Windmill (Air turbine)

Airfoil

- Sail
- Wing
- Rudder
- Flap
- Damper
- Propeller

Rocket

Computing machines

- Calculator
- Analog computer
- Wind tunnel
- Digital computer
- Turing machine

Automated machines

Biological machines

- Virus, Bacterium
- Cell (biology)
- Plant and animal
- Human being
- The mind - controversially Category:Mechanical engineering Category:Manufacturing Category:Electro mechanical engineering Category:Production and manufacturing ja:機械 simple:Machine

Snow

) high forests.]] Snow is precipitation in the form of crystalline water ice, consisting of a multitude of snowflakes. Since it is composed of small rough particles it is a granular material. It has an open and therefore soft structure, unless packed by external pressure. Snow is commonly formed when water vapor undergoes deposition high in the atmosphere at a temperature of less than 0°C (32°F), and then falls to the ground.

Types

Flurries are similar to rainshowers and only last for short periods of time. Snow which has partially thawed while falling is called sleet; if this re-freezes on further descent, the resulting small icy pellets or granules of snow are called soft hail. A related phenomenon is freezing rain, where rain falls on ground sufficiently cold for it to freeze on contact, forming black ice on the ground. A snow squall is a brief, very intense snowstorm while a blizzard is a long-lasting snow storm with intense snowfall and usually high winds. Particularly severe storms can create whiteout conditions where visibility is reduced to less than 1 m, while blizzards can also create large snowdrifts. A ground blizzard occurs when a strong wind drives already fallen snow to create drifts and whiteouts. Snow can be also manufactured using snow cannons, which actually create tiny granules more like soft hail (this is sometimes called "grits" by those in the southern U.S. for its likeness to the texture of the food). In recent years, snow cannons have been produced that create more natural looking snow, but these machines are very expensive and are found only on the most prestigious places.

Occurrence

Snowfall varies by time and location, including geographic latitude, elevation and other factors which affect weather in general. In latitudes closer to the equator, there is less chance of snow fall, 35° N and 40°S are often quoted as a rough delimiter. The western coasts of the major continents remain snowless to much higher latitudes. As temperature decreases with altitude, high mountains, even at or near the Equator, have permanent snow cover on their top. Examples include Mount Kilimanjaro in Tanzania and the Tropical Andes in South America; the only snow actually on the Equator is at 4,690 m altitude on the south slope of Volcán Cayambe in Ecuador (Google Earth images). Conversely, many regions of the Arctic and Antarctic receive very little precipitation and therefore little snow despite the bitter cold (below a certain temperature, air essentially loses its ability to carry water vapor). Although density of fresh snow varies widely, a guide is that the depth of snowfall is 10 times that of a rainfall containing the same mass of water. Substantial snowfall sometimes disrupts infrastructure and services even in regions that are accustomed to them. Traffic may be snarled or even completely stop. Basic infrastructure such as electricity, phones and gas supply can be shut down. This can lead to a snow day, a day on which school or other services are cancelled owing to unusually heavy snowfall. In areas that normally have very little snow, this may occur even with light accumulation — something often made fun of by those people used to colder climates, where streets would remain passable given the same amount of snow. The highest seasonally cumulative precipitation of snow ever measured in the world was on Mount Baker, Washington, U.S.A during 1998–1999 season when they received 28.96 meters (1,140 in); this surpassed the previous record holder, Mount Rainier, Washington, U.S.A which during 1971–1972 season received 28.5 meters (1,122 in) of snow; and the world record daily precipitation was recorded in Silver Lake, Colorado, U.S.A in 1921 1.93 meters (76 in). See also: List of Countries receiving snowfall

Recreation

List of Countries receiving snowfall Forms of recreation dependent on snow:
- Many winter sports, such as skiing, snowmobiling, snowshoeing and snowboarding
- Playing with a sled or riding in a sleigh
- Building a snowman or snow fort
- Throwing snowballs mutually in a snowball fight or at others to tease them. (Humans seem to be the only animal that throw their snowballs. Pygmy chimpanzees have been known to carry snowballs around, but never to throw them.) Where snow is scarce but the temperature is low enough, snow cannons may be used to produce an adequate amount for such sports. Tightly packed snow may be used as a construction material in, for example, Inuit snow houses. The world´s biggest snowcastle is built in Kemi, Finland, every winter.

Geometry

Finland An interesting question is why the arms of snowflakes are symmetrical, and why no two snowflakes appear to be identical. The answer is believed to be due to the fact that the distances between snowflakes are much greater than the distances across snowflakes. The symmetry of snowflake arms is always six-fold, which arises from the hexagonal crystal structure of ordinary ice (known as ice I_h) along its 'basal' plane. There are, broadly, two possible explanations for the symmetry of snowflakes. Firstly, there could be communication (information transfer) between the arms, such that growth in each arm affects the growth in each other arm. Surface tension or phonons are among the ways that such communication could occur. The other explanation, which appears to be the prevalent view, is that the arms of a snowflake grow independently in an environment that is believed to be rapidly varying in temperature, humidity and so on. This environment is believed to be relatively spatially homogenous on the scale of a single flake, leading to the arms growing to a high level of visual similarity by responding in identical ways to identical conditions, much in the same way that unrelated trees respond to environmental changes by growing near-identical sets of tree rings. The difference in the environment in scales larger than a snowflake leads to the observed lack of correlation between the shapes of different snowflakes. tree ring However, the concept that no two snowflakes are alike is incorrect; it is entirely possible, but unlikely, that a pair of snowflakes may be visually identical if their environments were similar enough, either because they grew very near one another, or simply by chance. The American Meteorological Society has reported that matching snow crystals were discovered by Nancy Knight of the National Center for Atmospheric Research. The crystals were not flakes in the usual sense but rather hollow hexagonal prisms. ;High-resolution gallery Image:Snow crystals.png Image:Snow crystals 2.png Image:Snow crystals 2b.png Image:LT-SEM snow crystals.jpg Image:LT-SEM snow crystal magnification series-3.jpg

Media

External links

- [http://www.nsdl.arm.gov/Library/glossary.shtml#snowflake National Science Digital Library - Snowflake]
- [http://www.its.caltech.edu/~atomic/snowcrystals/faqs/faqs.htm Kenneth G. Libbrecht's Snowflake FAQ]
- http://www.its.caltech.edu/~atomic/snowcrystals/photos/photos.htm Category:Snow ko:눈 (날씨) ja:雪 simple:Snow th:หิมะ

Invented

:In music, an invention is a short composition with two or three part counterpoint. See Invention (music) In general terms, an invention is an object, process or technique which displays an element of novelty. In certain circumstances, legal protection may be granted to an invention by way of a patent.

What drives the process of invention?

Over time, humanity has invented objects and methods for accomplishing tasks which fulfill some purpose in a new or different manner, usually with the objective of realising that purpose in a faster, more efficient, easier or cheaper way. Although it is evident that people do invent, the circumstances which facilitate or optimise the development of inventions is less clear. One school of thought, popularized in the phrase "necessity is the mother of invention", argues that in essence, lack of resources leads to invention, while the opposing school of thought argues that it is only an excess of resources which has this result. However, the actual position may not be understood simply by reference to one or the other of these perspectives.

From idea to invention

Although a new or useful object or method may be developed to fulfill a specific purpose, the original idea may never be fully realised as a working invention, perhaps because the concept is in some way unrealistic or impractical. A "castle in the air" or a "pie in the sky" (or "castles in Spain") may refer to a creative idea which does not reach fruition due to practical considerations. The history of invention is full of such castles, as inventions are not necessarily invented in the order that is most useful. For example, the design of the parachute was worked out before the invention of powered flight. Other inventions simply solve problems for which there is no economic incentive to provide a solution. On the other hand, any barriers to implementation may simply be an issue of engineering or technology which can be overcome in time with scientific advances. History is also replete with examples of ideas which have taken some time to reach physical reality, as demonstrated by various ideas originally attributed to Leonardo da Vinci which are now expressed in everyday physical form.

Invention and innovation

Following the terminology of political economist Joseph Schumpeter, an invention differs from an innovation. While an invention is merely theoretical (even though the legal protection of a patent may have been sought), an innovation is an invention that has been put into practice. However, this conflicts with the theory of social anthropologists and other social sciences researchers. In social sciences, an innovation is anything new to a culture. The innovation does not need to have been adopted. The theory for adoption (or non-adoption) of an innovation is called diffusion of innovations. This theory, first put forth by Everett Rogers, considers the likelihood that an innovation will ever be adopted and the taxonomy of persons likely to adopt it or spur its adoption. Gabriel Tarde also dealt with the adoption of innovations in his Laws of Imitation.

External links

- [http://www.websters-online-dictionary.org/browse/inventions/ Inventions] in [http://www.websters-online-dictionary.org Webster's Dictionary] - the Rosetta Edition
- [http://www.wipo.int/pct/en/inventions/inventions.html List of PCT (Patent Cooperation Treaty) Notable Inventions] (on the WIPO web site)
- [http://www.inventionindex.com/ Invention Index]
- [http://www.inventions.org/ Inventors Assistance League] (Non-profit organization operating since 1963) Category:History of technology Category:Technology ja:発明

William Otis

William Otis was an inventor who invented the steam shovel. Otis received a patent for the steam shovel on February 24, 1839. Otis, William

Patent

:This article relates to the intellectual property right. A land grant is also called a patent. A patent is a set of exclusive rights granted by a state to a person for a fixed period of time in exchange for the regulated, public disclosure of certain details of a device, method, process or composition of matter (substance) (known as an invention) which is new, inventive and useful. The exclusive right granted a patentee is the right to prevent others from making, using, selling, offering to sell or importing the claimed invention, not the right to make, use, or sell the invention themselves. The patentee may have to comply with other laws and regulations to make use of the claimed invention. So, for example, a pharmaceutical company may obtain a patent on a new drug but will be unable to market the drug without regulatory approval. The term "patent" originates from the Latin word patere which means "to lay open" (ie. make available for public inspection) and the term letters patent, which originally denoted royal decrees granting exclusive rights to certain individuals or businesses.

Economic rationale and criticisms

There are two primary justifications for granting patents. First, in accordance with the original definition of the term "patent," it is argued that awarding patents facilitates and encourages disclosure of innovations into the public domain for the common good. Without patents, an inventor may prefer to keep his invention a secret. Disclosure of an invention allows other inventors to improve upon it and patent their improvements. Furthermore, when a patent's term has expired, the public record ensures that the patentee's idea is not lost to mankind. Second, it is broadly believed that patents incentivise economically-efficient research and development (R&D). Many corporations have annual R&D budgets of hundreds of millions or even billions of dollars. In a society without patents, it is conceivable that each corporation would lower or eliminate R&D spending, because each could reap what another had sown. This second justification closely parallels fundamental arguments underlying traditional property rights--who would build a house if another could freely occupy it? However, there are arguments in opposition to patent rights. Most fundamentally, granting a patent confers a monopoly of sorts upon an owner, because he may legally exclude competitors from using or exploiting the invention (though strictly speaking, the word "monopoly" requires that there is no viable alternative in the marketplace). In this way, patent rights differ from traditional property rights--building a house does not prevent one's neighbor from building a house, but patenting an invention bars anyone in the country of filing from producing the invention for the term of the patent. Indeed, patents have historically been granted by sovereigns to non-inventing parties in favor merely so they could profit from monopoly power. The stifling of competition due to patent rights may result in higher prices, lower quality, and shortages--characteristic problems with monopolies. Historically, countries with effective patent regimes have experienced greater economic growth and technological advances than countries where intellectual property is not protected by law. But in such countries there are many problems with the difference between rich and poor classes. People from poor classes often have no ability to initiate new business. Furthermore, industry specific experiences differ. For example, the mid-19th century dyestuffs industry faltered in Britain despite patent protections and flourished in Germany despite the absence of such protections. A more subtle problem with patent rights was put forth by law professors Michael Heller and Rebecca Eisenberg in a 1998 Science article. Building from Heller's theory of the tragedy of the anticommons, the professors postulated that useful innovations that build on earlier patented inventions can be inhibited by the high transaction costs from negotiating with the earlier patentees. According to Heller and Eisenberg, intellectual property rights may become so widely fragmented that, effectively, no one can take advantage of them. As one potential example, the professors identify therapeutic proteins and genetic diagnostic tests that would require the use of numerous patented gene fragments. In analogy to traditional property rights, it would be as if six different parties owned a house's two bedrooms, living room, kitchen, dining room, and bathroom--the utility of the house would be wasted until the parties could either negotiate an arrangement in which some or all of the parties were free to use each other's areas of the house or one party acquired ownership of the entirety of the house. Because of the difficulty in balancing the benefits and drawbacks of patent grants, there is ongoing debate over the extent to which patents should be conferred. This controversy is manifested in the ways different jurisdictions decide whether to grant patents. But recent years have seen a global embrace and augmentation of the scope of patents, as evidenced by the WTO Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPs). One interesting side effect of modern day patent usage is that the small-time inventor can use the monopoly status to become a licensor. This allows the inventor to accumulate capital quickly from just licensing and may allow rapid innovation to occur because he/she may choose to not manage a manufacturing buildup for the invention. Thus, time and energy can be spent on pure innovation and allow others concentrate on manufacturability.

Legal implementation

A modern patent provides the right to exclude others from making, using, selling, offering for sale, or importing the patented invention. Generally, patents are enforced only through civil lawsuits. Patent licensing agreements are effectively contracts in which the patent owner (the licensor) agrees not to sue the licensee for infringement of the licensor's patent rights. Governments typically reserve the right to suspend or cancel a patent at will. A patent application, for a utility patent in the United States (as opposed to a design patent), must explain how to work (i.e., make and/or use) the invention(s) and must also include claims that particularly point out the invention(s) and define the scope of the subject matter for which exclusive rights are sought by the patent applicant. The exclusive rights are limited to the subject matter encompassed by the patent's claims. Patent claims are typically of the form of a long noun phrase, e.g.:
- "An apparatus for catching mice, comprising a base member for placement on a flat surface, a spring member..."
- "A chemical for cleaning windows, comprising approximately 10–15% ammonia, ..."
- "A method for computing future life expectancies, the method comprising gathering personal data including X, Y, Z, ..." Each word of a claim is considered an "element" or "limitation" of the claim. In order to exclude someone from using your patented invention in a court, you will have to demonstrate to the court that what the other person is using is included within the scope of at least one claim of the patent. For this reason, it is more valuable to obtain patent claims that include the absolute minimal set of limitations that differentiate a new invention over what came before. While the United States is moving towards more rigid claim interpretations, "equivalents" of claim elements or limitations may be permitted in determining patent infringement. The practice elsewhere in the world differs.

Example

If an inventor takes an existing patented mouse trap design, adds a new feature to make an improved mouse trap, and obtains a patent on the improvement, he or she can legally build his or her improved mouse trap only with permission from the patent holder of the original mouse trap, assuming the original patent is still in force. On the other hand, the owner of the improved mouse trap can exclude the original patent owner from using the improvement. Under these circumstances, patent owners sometimes engage in cross-licensing agreements.

Governing laws

Although patents are fundamentally territorial in their nature, there are currently a number of significant international treaties governing some important aspects of patent law. The most universal of these is the WTO TRIPs Agreement, to which almost all countries are a party. The United States, the countries of the European Union, and Japan, are parties to all of the significant treaties. This has led to significant harmonization of patent law worldwide, particularly in the last decade of the 20th century and continuing into the 21st. Despite recent harmonization, the United States patent laws are unique in several significant respects. The biggest difference is that, if two people apply for a patent on the same invention, the US system awards the patent to the "first to invent", whereas in the rest of the world the "first to file" is awarded the patent. A contest between different inventors over priority is called "interferences". Another unique aspect of U.S. patent law is that an inventor has a one-year grace period after publication or sale to file a patent application, whereas in most other countries patent rights are lost if an application is not on file when a public disclosure, publication or sale takes place. As mentioned above, patents are territorial in nature. Thus, to obtain patents in multiple countries it is required to separately file patent applications in each country, or region, where a patent is sought. The Patent Cooperation Treaty (PCT), however, allows applicants to initially file a single international application, which later can be entered into separate countries or regions. Similarly, within Europe, a single patent application procedure is available through the European Patent Office, but successful applications result in multiple patents (up to 36) rather than a single European-wide patent. Such a European-wide unitary patent, or "community patent", has been the subject of discussion at the EU level since the 1970s, with no result so far. Many of the international treaties are designed to afford some recognition of filing dates to patent applications previously filed in another country. In this respect, the most important treaty is the Paris Convention, dating back to 1883. Typically, inventors are allowed one year (the priority year) from the date of their filing (in a first country) to file the application in other countries. The authority for patent statutes in different countries varies. In the United States, the Patent and Trademark Office gets its authority from statutes in Title 35 of the United States Code, which in turn is based on Article One, Section 8 of the U.S. Constitution.

Patent prosecution

Typically, an application for a patent is prepared by a professional agent known as a patent attorney or patent agent, who files the application with a patent office. The person applying for a patent generally does not need to be the inventor who created or authored the invention. However, in the United States a patent application must be filed in the name of the actual inventor or inventors, although the application can be assigned to another party, such as the employer of the inventor. At the patent office an examiner will consider the invention's patentability and whether it is otherwise eligible for grant. The entire legal process of examination and obtaining grant is called patent prosecution. Some countries do not formally review patent applications while others accept the determination of other patent offices. For example, some smaller countries, such as Belgium and the Netherlands grant a patent almost automatically or with minimal examination. This may be contrasted with the strict requirements of the United States Patent and Trademark Office, the Japanese Patent Office and the European Patent Office. The patent prosecution process typically involves: # Filing a patent application by inventor or applicant. # Formalizing of application (signatures by inventors or applicant), often filed at the same time as the application. # Establishing of a prior art search report by the patent office. # Publication at 18 months from earliest claimed filing date. US applicants can request non-publication if the application is not filed outside the United States. # Review by the examiner or the Examining Division, including communication with applicant to modify the claim language, if needed. # Grant of the patent (if it the patentability criteria are met) and publication of the issued patent. # Opposition period, during which anybody (e.g., other companies) can challenge the patent grant. This is not applicable for the US where other procedures are available, namely the reissue and reexamination procedure. In several countries, oppositions can be filed before the grant of the patent. The specifics of the examination process include: # Verifying that claims are for a patentable subject matter. # Ensuring unity of invention, since each patent application can only be for one invention (called "restriction" practice in the United States). # Formalities. Ensure that the drawings, description, and claims meet all formal requirements. # Utility or industrial applicability. # Novelty (newness) # Non-obviousness or inventive step. Different patent systems use different terms and different standards for these concepts, of which the most important probably are: patentable subject matter, novelty, non-obviousness and sufficient disclosure.

Patentable subject matter

The standard for what is patentable subject matter in the United States is "anything under the sun made by man" that is new (novel), useful, and non-obvious. Similar standards for patentability apply in Japan. Higher standards exist under the European Patent Convention (EPC), where for example computer programs as such are not patentable. Under US law, a claimed invention is deemed useful if, at the time of filing, it is capable of providing some identifiable benefit (to a person of ordinary skill in the art of the invention). The benefit must be specific, substantial, and practical. Generally speaking, there are three broad categories of patentable subject matter: processes, machines and articles of manufacture and use. A process could be a method for making something, a method for using something, or a method for doing something. Processes include business methods, most software, medical techniques, sports techniques and the like. Machines include devices and apparatuses. Articles of manufacture include mechanical devices, electrical/electronic devices and compositions of matter such as chemicals, medicines, DNA, RNA, etc. However, laws of nature, physical phenomena, and abstract ideas are not patentable. Software inventions implementing algorithms are not patentable for this reason unless it produces a "useful, concrete, and tangible result" (US law) or technical effect (European law). The US standard for the patentability of software is more liberal than that in Europe. Japanese patent law lies between the US and Europe. The patentability of software (and business methods) is quite controversial from a global perspective. Case law in the United States permits patents for software and business methods. Yet computer programs as such are not patentable in Europe, although some inventions that use software can be patented in Europe. Patents related to natural compounds (e.g. items found in rainforests) as well as medicines, medical treatment techniques, and genetic sequences are also controversial. There are significant country-by-country differences in handling these subject matters. For example, in the United States you can get a patent for a surgical method but you cannot exclude physicians from performing the surgical method.

Novelty

Novelty relates to whether something existed before its invention by the applicant or was disclosed to the public before the patent application's filing date. For public disclosures of the invention by the inventor, the United States and Canada permit a one year grace period, but most other countries provide no grace period, instead requiring "absolute novelty". An invention is not novel if there is a previously existing or disclosed device or process that includes all of the elements of the claimed invention. Identifying such "prior art" by the patent examiner is accomplished by a search of literature (technical journals, published patent applications and issued patents, etc.) that predate the filing date of the particular patent application.

Inventive step and non-obviousness

prior art Even if an applicant's claim for an invention is novel (i.e. not taught by a single prior art reference), a patent can still be denied to the applicant if the claimed subject matter would have been obvious to someone else skilled in the technical field of the invention. The purpose of forbidding patents on obvious technologies is to prevent a person from obtaining exclusive rights to what is effectively already in the possession of the public, even if documentation of the exact form of the applicant's embodiment happens to be lacking. Accordingly, obviousness asks the question whether all previously known technology related to the invention would teach a "person having ordinary skill in the art", e.g. someone who does the type of things relating to the technical field of the invention, how to make the invention. Many patent applications in the United States, Europe and Japan are initially rejected as being obvious. The standard of obviousness and its application are more subjective and controversial than that of novelty. If the requirements are set very high, virtually nothing is patentable. Similarly if the requirements are very low, all kinds of trivial inventions can receive patents. Generally, the patent laws make it difficult for patent examiners to employ hindsight reasoning in rejecting a claim as obvious, by requiring some teaching that would motivate a person of ordinary skill in the art to modify the technology found in the prior to arrive at the claimed invention. In the United States, objective evidence or secondary considerations of non-obviousness can overcome a proper obviousness rejection. Such secondary considerations can include unexpected results, commercial success, long-felt need, failure of others, copying by others, licensing, and skepticism of experts. As a practical matter, during examination the patent examiner will attempt to locate two or more references that when combined show all of the features of the claimed invention and indicate that one of ordinary skill would make that combination. The threshold for the obviousness or inventive step standard can be particularly ambiguous in genus-species situations. For example, if an inventor finds two species of a particular genus, e.g. two particular chemical compositions out of 10,000 in the broader genus, should the inventor be entitled to a patent on the entire genus? Further, if someone has discovered the genus already, but not isolated any of the species, are the species obvious in light of the genus? Under US law, the species may still be patentable if they produce results that are unexpectedly different from those of other previously known members of the genus. For example, suppose a software inventor unveils the quicksort sorting algorithm to the world but only discloses it using integers (this is the species). Can someone else then obtain a patent on an "improved" quicksort suitable for use on any partially ordered set (this is the genus)? Under US law, this is not a question of obviousness since a claim to the genus lacks novelty as the species is known. Finally, in spite of all precautions, some patents still give a general impression of triviality. An example is given by the "combover" patent (, filed December 1975), which has also been awarded the 2004 Ig Nobel Prize in engineering for its apparently unintentional ridiculousness.

Term of patent

As TRIPS agreement declares, the maximum term of an issued patent is 20 years from earliest claimed filing date. In the United States, for applications filed after to June 8, 1995, the patent term is 20 years from the earliest claimed filing date (see also: Term of patent in the United States). Also, in several countries there are multiple types of patents, and the 20 year term frequently only applies to utility patents and not design, petit, or other kinds of less heavily examined patents. For example, the term of a U.S. design patent, which covers the ornamental shape of objects, lasts 14 years from its issue date.

Example

If the better mousetrap patent is filed on January 1, 1996 and is issued or granted on January 1, 2000, it will lapse twenty years from filing: January 1, 2016. However, if the inventor comes up with a second improvement and claims priority to her first patent when filing the second patent on January 1, 1998, that second patent, after grant, would lapse 20 years from the earliest claimed priority: January 1, 2016.

Miscellaneous

While a patent grants an exclusive right on the invention claimed, many national laws provide for special rules on granting compulsory license to requesting third parties when the invention is not put into practice within a specified amount of time or is put into practice in a manner that is deemed to be insufficient for the needs of the country. The licensee must pay reasonable compensation, to be fixed by an independent tribunal if not agreed. In practice, obtaining a compulsory license is not easy. Secrecy provisions are also present in many national laws in case the invention for which a patent is filed is deemed to have military interest. A patent might also be seized by the State under grounds of public utility. This is akin to the state's power of eminent domain. Again, as for compulsory licensing, an obligation to pay reasonable compensation, to be fixed by an independent tribunal if not agreed, is invariably provided. For example, during the 2001 anthrax attacks, it was rumoured that the US had considered seizing the patent on the Cipro antibiotic from the Bayer Corporation. However, the anthrax attacks did not continue and the patent was not seized. The World Trade Organization Agreement 1994 imposes restrictions on both compulsory licensing and seizure (TRIPs Agreement, article 31).

History of patents

Bayer Corporation Although there is evidence suggesting that something like patents was used among some ancient Greek cities, patents in the modern sense originated in Italy. The first patent law was a Venetian Statute of 1474 in which the Republic of Venice issued a decree by which new and inventive devices, once they had been put into practice, had to be communicated to the Republic in order to obtain legal protection against potential infringers. England followed with the Statute of Monopolies in 1623 under King James I. Prior to this time, the crown would issue letters patent providing any person with a "monopoly" to produce particular goods or provide particular services. The first of them was granted by Henry VI in 1449 to a Flemish man a 20 year monopoly on the manufacture of stained glass. This was the start of a long tradition by the English Crown of the granting of "letters patent" (meaning 'open letter', as opposed to a letter under seal) which granted "monopolies" to favoured persons (or people who were prepared to pay for them). This became increasingly open to abuse as the Crown granted patents in respect of all sorts of known goods (salt, for example). This power, which was to raise money for the crown, was widely abused, and court began to limit the circumstances in which they could be granted. After public outcry, James I was forced to revoke all existing monopolies and declare that they were only to be used for 'projects of new invention'. This was incorporated into the Statute of Monopolies in which Parliament restricted the crown's power explicitly so that the King could only issue letters patents to the inventors or introducers of original inventions for a fixed number of years. In the reign of Queen Anne the rules were changed again so that a written description of the article was given. Section 6 of the Statute refers to "manner[s] of new manufacture... [by] inventors", and this section remains the foundation for patent law in New Zealand and Australia. The Statute of Monopolies was later developed by the courts to produce modern patent law; this innovation was soon adopted by other countries. The Patent Commission of the U.S. was created in 1790. Its first three members were Secretary of State Thomas Jefferson, Secretary of War Henry Knox, and Attorney General Edmund Randolph. On July 31, 1790 inventor Samuel Hopkins of Pittsford, Vermont became the first person to be issued a patent in the United States. His patented invention was an improvement in the "making of Pot Ash by a new apparatus & process". The earliest patent law required that a working model of each invention be produced in miniature. The Patent Law was revised for the first time in 1793. It adopted a simple registration system where a patent would be granted for a $30 fee. The Patent Board was replaced by a clerk in the Department of State. James Madison, Secretary of State, created a separate Patent Office within the State Department and he appointed Dr. William Thornton as its first superintendent in May 1802. On May 5th, 1809 Mary Dixon Kies became the first woman to be awarded a U.S. patent. Later, in 1810, the Patent Office moved from the Department of State to Blodgetts Hotel. In the same year, they opened the patent model storage to the general public. The first 10,000 patents issued by the USPTO from July 1790 to July 1836 were destroyed in a fire in December 1836. About 2800 of them were later recovered, but the majority of them are still missing. The recovered patents are now called X-Patents because their patent numbers end with an "X."

Patent models

One of the most interesting early features of the U.S. patent system was the requirement of patent models. A patent model was a scratch-built miniature model no larger than 12" by 12" that showed how the patent works. Since most early inventors were ordinary people without technological or legal training, it was difficult for them to submit formal patent applications, due to the required small-scale models. However, to some degree, it was beneficial for these amateur inventors to submit a model. This is because their inventions might not be fully comprehended otherwise. Patent models were required since 1790. The Congress of the U.S. abolished the legal requirement for them in 1870. The U.S. Patent Office kept this requirement until 1880. However, some inventors still willingly submitted models at the turn of the 20th century. A working model, or other physical exhibit, may be required by the U.S. patent office if deemed necessary. This is not done very often. A working model may be requested in the case of applications for patent for alleged perpetual motion devices (Source: USPTO web site).

External links

- [http://www.legalmatch.com/law-library/article/patents.html LegalMatch] Patent Legal Resource
- [http://www.ipfrontline.com/ IPFrontline™] PatentCafe's Intellectual Property & Technology Magazine
- [http://www.inventorfraud.com/ National Inventor Fraud Center] - Information about the invention process and invention marketing companies.
- [http://www.patentlawportal.com Patent Law Portal] - Patent Law News, Articles and Resouces
- [http://www.ipnewsflash.com IP Newsflash recent case law and developments regarding patents]

Patent Office Web sites and other regional info

- [http://www.ipaustralia.gov.au/ IP Australia] incorporates the Patent, Designs and Trade Marks offices
- [http://www.uspto.gov U.S. Patent and Trademark Office]
- [http://strategis.ic.gc.ca/sc_mrksv/cipo/ Canadian Intellectual Property Office]
- [http://patents1.ic.gc.ca/ Canadian Patents Database]
- [http://www.jpo.go.jp/ Japan Patent Office]
- [http://www.kipo.go.kr/kpo/ Korean Intellectual Property Office]
- European Patent Office
- [http://gb.espacenet.com/ European Network of Patent Databases]
- [http://www.patent.gov.uk/ UK Patent Office]
- [http://www.nkpal.com/ipr/ NKPAL's IPRs Division] - IPRs information and Patent filing in India.
- [http://www.wipo.int/ World Intellectual Property Organisation]
- [http://www.info-brevetti.org/ Innovation and patent information in Italy]

Patent organizations

- [http://www.pubpat.org/index.html The Public Patent Foundation] PUBPAT Represents the Public's Interests Against Wrongly Issued Patents and Unsound Patent Policy
- [http://www.ipo.org Intellectual Property Owners Association]

Patent searches and downloads

- [http://www.GetThePatent.com GetThePatent.com] - Online patent search database offering instantaneous access to complete multi-page USPTO, EPO, WIPO (PCT), British, French, German, Japanese, and Swiss patent documents received via your printer, email, or web browser.
- [http://www.braindex.com/patent_pdf/ Free US and Worldwide Patent PDFs] - Download patents for free.
- [http://www.pat2pdf.org pat2pdf.org] - Free lookup and download of U.S. patents in PDF form
- [http://www.freepatentsonline.com FreePatentsOnline.com] - Free US and international patent searching database, PDF downloading, list of funny patents.
- [http://nip.blogs.com/patent/2004/09/guide_to_downlo.html The Guide to Downloading Copies of Patents from Internet]
- [http://www.ipdiscover.com/ IP-Discover] - Search and retrieve patents from the public databases.
- [http://www.search4ip.com/ search4ip] - Free patent search.
- [http://www.patentmatic.com/ PatentMatic] - Free patent downloads (US, European & others).
- [http://www.IAMcafe.com PatentCafe's International Patent Database with Semantic / Natural Language Search Engine]

Weird and historical patents

- [http://www.patent.freeserve.co.uk/ Patently Absurd British Patents]
- [http://www.library.umaine.edu/patents/historical.htm Information on Historical Patents]
- [http://www.patentlysilly.com Patently Silly]
- [http://ipfunny.blogs.com IP Funny Blog] Category:Intellectual property
- ja:特許 th:สิทธิบัตร

Caterpillar track

Caterpillar tracks are large (modular) tracks used on tanks, construction equipment and certain other off-road vehicles. Unlike the Kegresse tracks which use a flexible belt, caterpillar tracks are made of a number of rigid units that are joined to each other. The tracks help the vehicle to distribute its weight more evenly over a larger surface area than wheels can, keeping it from sinking in areas where wheeled vehicles of the same weight would sink. For instance, the ground pressure of a car is equal to the pressure of the air in the tires, perhaps 30 psi (207 kPa), whereas the seventy-tonne M1 Abrams tank has a ground pressure of just over 15 psi (103 kPa).

History

A crude caterpillar track was designed in 1770 by Richard Edgeworth. The British polymath Sir George Cayley patented a caterpillar track, which he called a "universal railway" (The Mechanics' Magazine, 28 January 1826). Steam powered tractors using a form of caterpillar track were reported in use during the Crimean War in the 1850s. An effective caterpillar track was invented and implemented by Alvin Lombard, for the Lombard steam log hauler. He was granted a patent in 1901. He built the first steam-powered log hauler at the Waterville Iron Works in Waterville, Maine the same year. In all, eighty-three Lombard steam log haulers were built. In 1903, the founder of the Holt Manufacturing, Benjamin Holt, paid Lombard $60,000 so they could produce vehicles under his patent. At about the same time a British agricultural company Hornsby based in Grantham, UK developed and patented a caterpillar track in 1905. The design differed from modern tracks in that it flexed in only one direction, and the links locked together to form a solid rail on which the road wheels ran. Hornsby's tracked vehicles were used as artillery tractors by the British Army from 1906. Their patent was also purchased by Holt. Following a merger and name change, The Holt Manufacturing Company became the Caterpillar Tractor Company in 1925. Caterpillar tracks have since revolutionized construction vehicles and land warfare. Track systems have been developed and improved during the years. The first tanks to be fielded were developed from Holt tractors which were already in use towing artillery over the difficult terrain of the Western Front of the First World War. Perhaps the oldest implementation of something like tracks is to be found in theories of prehistoric erection of large stone monuments, when megaliths may have been slid atop rounded wooden logs. The logs are carried from the back of the procession to the front in an endless chain, like caterpillar track. Attempts by experimental archaeologists to reconstruct these methods have met with varying success. The system is a pre-cursor to development of the axle which keep a rotating cylinder fixed to its cargo. The Israeli Defence Forces have developed an improved suspension system, called Mazkum מזקו"ם (or זחלים for short), which enables greater mobility than regular tracks. The Mazkum is installed on the Israeli Merkava tank which helps improve mobility and speed, some of the Israeli patents were sold to Caterpillar Tractor.

Engineering

Merkava Merkava Modern tracks are built from modular chain links which compose together a closed chain. These chain links are often broad and made of alloy steel. The links are jointed by a hinge. This allows the track to be flexible and maintain its elliptical shape. The vehicle's weight is suspended from a number of road wheels, or "bogies". Road wheels are typically mounted on some form of suspension to cushion the ride over rough ground. Suspension design is a major area of development; early designs offered only a few inches of travel using springs, whereas modern hydro-pneumatic systems allow several feet of travel and include shock absorbers. Tracks are moved by a toothed drive wheel, or drive sprocket, driven by the motor and engaging with holes in the track links to drive the track. The drive wheel is typically mounted well above the contact area on the ground, allowing it to be fixed in position. Placing a suspension on the driving wheel is possible, but is mechanically more complicated. A non-powered wheel, an idler, is placed at the opposite end of the track, primarily to angle the front (or rear) of the track to allow it to climb over obstacles. Some track arrangements use return rollers to keep the top of the track running straight between the drive sprocket and idler. Others allow the track to droop and run along the tops of large road wheels, called dead track or slack track. Tracked vehicles have better mobility than pneumatic tires over rough terrain. They smooth out the bumps and glide over small obstacles; riding in a fast tracked vehicle feels like riding in a boat over heavy swells. Tracks are tougher than tires since they cannot be punctured or torn. Tracks are much less likely to get stuck in soft ground, mud, or snow, since they distribute the weight of the vehicle over a larger contact area, decreasing its ground pressure. Bulldozers, which are most often tracked, uses this attribute to rescue other vehicles (such as wheel loaders) which have become stuck in or sunk into the ground. The disadvantages of tracks are lower top speed and the damage that they cause to what passes beneath them: they can severely damage lawns, farm fields, and even asphalt pavement. Prolonged use places enormous strain on the drive transmission and the mechanics of the tracks, which must be overhauled or replaced regularly. It is common to see tracked vehicles such as bulldozers or tanks transported long distances by a wheeled carrier such as a semitrailer or train, though technological advances have made this practice less common among tracked military vehicles than it once was. A recent innovation by Caterpillar is a rubber track tractor for agricultural use, such as the Cat™ Challenger Tractor, MT700 and MT800 series. Instead of a track made of linked steel plates, it uses a reinforced rubber belt with chevron treads for improved traction and reduced soil compaction. Having a rubber belt also means that the vehicle can relocate itself on public roads without damaging pavement.

Tracked vehicles

- Bulldozer
- Crawler
- Excavator
- Snowmobile
- Snowcat
- Tank
- Half-track

Steam engine

A steam engine is a heat engine that makes use of the thermal energy that exists in steam, converting it to mechanical work. Steam engines were used in pumps, locomotives, steam ships and steam tractors, and were essential to the Industrial Revolution. They are still used for electrical power generation using steam turbines. A steam engine needs a boiler to boil water to produce steam under pressure. Any heat source can be used, but the most common is a fire fueled by wood, coal, or oil. (However, anything that can be burned can be used as fuel for the fire: paper, trash, used crankcase oil, ground-up corncobs, manure, natural gas, gasoline, high proof alcohol, dry grass, hay, dry weeds, etc). The steam expands and pushes against a piston or turbine, whose motion does the work of turning wheels or driving other machinery. In British English, the term steam engine my also refer to an entire steam locomotive.

Types of steam engine

Steam engines can be classified in two main ways:
- By the technology used. Most steam engines use either piston engines or turbines.
- By the application. Steam engines are used as:
- Stationary engines. Stationary steam engines again divide into two main classes:
- Winding engines, rolling mill engines, and similar applications which need to frequently stop and reverse.
- Engines providing power, which stop rarely and do not need to reverse. These include nearly all thermal power stations, and were also used in mills, factories and to power cable railways and cable tramways before the widespread use of electric power.
- Vehicle engines:
- Steamboats and steamships.
- Land vehicles:
- Steam locomotives.
- Steam cars.
- Steam rollers.
- Steam shovels.
- Traction engines.

Invention

Traction engine Traction engine.]] The first steam device, the aeolipile, was invented by Heron of Alexandria, a Greek, in the 1st century AD, but used only as a toy. Incidently 700 years earlier in Corinth, Greece, rail tracks were invented; however the Greeks never thought of putting the two together. In 1665 Edward Somerset, Marquis of Worcester, installed a steam-powered engine for pumping water in Raglan Castle. Denis Papin, a French physicist, built a working model of a steam engine in about 1687, and he is credited with a number of significant gadgets such as the safety valve. Sir Samuel Morland also developed ideas for a steam engine during the same period, he built a number of steam-engine pumps for Louis XIV in the 1680s. Early industrial steam engines were designed by Thomas Savery (The "fire-engine", 1698) and Thomas Newcomen (1712), and in 1769 James Watt patented what is essentially the modern steam engine - all later developments are refinements of Watt's principle changes rather than new features. Humphrey Gainsborough produced a model condensing steam engine in the 1760s. In 1802 William Symington built the "first practical steamboat", and in 1807 Robert Fulton used the Watt steam engine to power the first commercially successful steamboat. Early engines worked by the vacuum of condensing steam, whereas later types (such as steam locomotives) used the power of expanding steam.

Use and development

steam locomotive The first industrial applications of the vacuum engines were in the pumping of water from deep mineshafts. The Newcomen engine operated by admitting steam to the operating chamber, closing the valve, and then admitting a spray of cold water. The water vapor condenses to a much smaller volume of water, creating a vacuum in the chamber. Atmospheric pressure, operating on the opposite side of a piston, pushes the piston to the bottom of the chamber. In mineshaft pumps, the piston was connected to an operating rod that descended the shaft to a pump chamber. The oscillations of the operating rod are transferred to a pump piston that moves the water, through check valves, to the top of the shaft. The first significant improvement, 60 years later, was creation of a separate condensing chamber with a valve between the operating chamber and the condensing chamber. This improvement was invented on Glasgow Green, Scotland by James Watt and subsequently developed by him in Birmingham, England, to produce the Watt steam engine with greatly increased efficiency. The next improvement was the replacement of manually operated valves with valves operated by the engine itself. Such early vacuum, or condensing, engines are severely limited in their efficiency but are relatively safe since the steam is at very low pressure and structural failure of the engine will be by inward collapse rather than an outward explosion. Their power is limited by the ambient air pressure, the displacement of the working chamber, the combustion and evaporation rates, and the condenser capacity. The maximum theoretical efficiency is limited by the relatively low boiling point of water at near atmospheric pressure (100 °C, 212 °F). The next big improvement in efficiency came with Richard Trevithick's use of pressurized steam, which used a far greater pressure, but more importantly (from a thermodynamic standpoint) operates at a higher temperature differential. But with this added pressure came much danger and many disasters due to exploding boilers and machinery. The most important refinement at this point was the safety valve, which releases excess pressure. Reliable and safe operation came only with a great deal of experience and codification of construction, operating, and maintenance procedures.

Boilers

safety valve Supplement, Vol. XIX, No. 470, Jan. 3, 1885. Now on display in the National Museum of Science and Industry (The Science Museum), London.]] Boilers are of two main types:
- Fire tube construction is typical of early maritime installations for boats and ships and the boilers of steam locomotives. In a fire tube boiler, the hot gases from the firebox (a combustion chamber) are passed through tubes connecting perforated end plates. The gases then enter a smokebox or smoke chest and pass on to a smokestack. The boiler may be vertical or horizontal. For an example of a vertical boiler of this type observe the boiler in the small riverboat used in the movie The African Queen. This type is also used in some boilers that provide steam for steam heating of a building and was also used in the steam shovel. Locomotives and early ships used a horizontal orientation and early ships would usually require a tall smokestack to provide draft, not having a fan to provide a forced draft. In a steam locomotive the draft is generally augmented at startup by directing the steam exhaust through the smokestack, which provides a partial vacuum.
- In a water tube boiler the water is heated in multiple tubes exposed to the hot gases. The tubes are joined to a steam collector chamber at the top. A significant advantage of this type is that there is less chance of catastrophic failure, as there is not a great amount of water in the boiler, nor are there large mechanical elements subject to failure. There may be additional tubes above the collector in the upper portion of the hot gas exhaust - this device, called a superheater, provides additional temperature (the pressure being unchanged) and increases the thermal efficiency of the entire mechanism. Superheaters were also used in some of the later versions of the steam locomotive. There are also rarer variants, for example the drum boiler used in some steam cars. There is also another division between boilers: natural aspiration, which is nearly all of them, and forced-draft, or "pressure-fired" boilers. This technology, equivalent to supercharging for an internal combustion engine, was developed by the Germans and acquired by the US Navy to be used in some frigates built after the Second World War. In it, a fan is used to increase the rate of burning; the boiler must be constructed to get that extra heat to the water. An engine using this kind of boiler has the greatest acceleration from a standing start of any marine powerplant.

Engines

High pressure steam engines are of various types but most are either reciprocating piston or turbine devices.

Reciprocating

Double-acting

After the development of pressurized steam technology, the next major advance was the use of double-acting pistons, with pressurized steam admitted alternately to each side while the other side is exhausted to the atmosphere or to a condenser. Most reciprocating engines now use this technology. Power is removed by a sliding rod, sealed against the escape of steam. This rod in turn drives (via a sliding crosshead bearing) a connecting rod connected to a crank to convert the reciprocating motion to rotary motion. An additional crank or eccentric is used to drive the valve gear, usually through a reversing mechanism to allow reversal of the rotary motion. When a pair of double acting pistons is used, their crank phasing is offset by 90 degrees of angle; this is called quartering. This ensures that the engine will always operate, no matter what position the crank is in. Some ferryboats have used only a single double-acting piston, driving paddlewheels on each side by connection to an overhead rocker arm. When shutting down such an engine it was important that the piston be away from either extreme range of its travel so that it could be readily restarted.

Multiple expansion

eccentric Another type uses multiple (typically three) single-acting cylinders of progressively increasing diameter and stroke (and hence volume). High pressure steam from the boiler is used to drive the first and smallest diameter piston downward. On the upward stroke the partially expanded steam is driven into a second cylinder that is beginning its downward stroke. This accomplishes further expansion of the relatively high pressure exhaust from the first chamber. Similarly, the intermediate chamber exhausts to the final chamber, which in turn exhausts to a condenser. The image at the right shows a model of such an engine. The steam travels through the engine from left to right. The valve chest for each of the first two cylinders is to the left of the corresponding cylinder while that of the third is to the right. One modification of the triple-expansion engine is to use two smaller pistons that sum to the area of the third piston to replace it. This results in the more balanced unit of a total of four pistons arranged in a vee-configuration. The development of this type of engine was important for its use in steamships, for the condenser would, by taking back a little of the power, turn the steam back to water for its reuse in the boiler. Land-based steam engines could exhaust much of their steam and be refilled from a fresh water tower, but at sea this was not possible. This sort of engine dominated merchant marine applications prior to and during World War II. It even was used in warships before the HMS Dreadnought of 1905. Multiple expansion can also result in greater efficiency, as the steam expends more of its energy driving pistons before leaving the engine. Some steam locomotives used double expansion. The most common arrangement was two sets of driving wheels. A set of high pressure cylinders drove one set and the low pressure cylinders drove the other set. A rarer arrangement was called the tandem compound, in which the high and low pressure cylinders were coaxial and had a common piston rod. Other steam locomotives were simple, or single, expansion only. Most compound steam locomotives had a "simpling valve" which fed high pressure steam to all cylinders to help start a train.

Uniflow

Another type of reciprocating steam engine is the "uniflow' type. In this, valves (which act similarly to those used in internal combustion engines) are operated by cams. The inlet valves open to admit steam when minimum expansion volume has been reached at the top of the stroke. For a period of the crank cycle steam is admitted and the poppet inlet are then closed, allowing continued expansion of the steam during the downstroke. Near the bottom of the stroke the piston will expose exhaust ports in the side of the cylindrical chamber. These ports are connected by a manifold and piping to the condenser, lowering the pressure in the chamber to below that of the atmosphere. Continued rotation of the crank moves the piston upward. Engines of this type always have multiple cylinders in an inline arrangement and may be single or double acting. A particular advantage of this type is that the valves may be operated by the effect of multiple camshafts, and by changing the relative phase of these camshafts, the amount of steam admitted may be increased for high torque at low speed and may be decreased at cruising speed for economy of operation, and by changing the absolute phase the engine's direction of rotation may be changed. The uniflow design also maintains a constant temperature gradient through the cylinder, avoiding passing hot and cold steam through the same end of the cylinder. (The uniflow concept is also employed in two stroke supercharged diesel engines used for marine, locomotive, and stationary applications. Such diesels do not need the economizer feature and use a simpler sliding camshaft for reversing.)
Turbine type
Steam turbines for high power applications use a number of rotating disks containing propeller-like blades at their outer edge. These moving "rotor" disks alternate with stationary "stator" blade rings affixed to the turbine case that serve to redirect the steam flow for the next stage. Owing to the high speed of operation such turbines are usually connected to a reduction gear to drive another mechanism such as a ship's propeller. Steam turbines are more durable, and require less maintenance than reciprocating engines. They also produce smoother rotational forces on their output shaft, which contributes to their lower maintenance requirements and lower wear on the machinery they power. The main use for steam turbines is in electricity generation stations where their high speed of operation is an advantage and their relative bulk is not a disadvantage. They are also used in marine applications, powering large ships and submarines. Virtually all nuclear power plants generate electricity by heating water and powering steam turbines. A limited number of steam locomotives were manufactured that used turbine technology. While they met with some success for long haul freight operations in Sweden and elsewhere, steam turbine technology did not last long in the railway world and was rapidly replaced by diesel locomotives.
Rotary type
In theory, it might be possible to use a mechanism based on a pistonless rotary engine such as the Wankel engine in place of the cylinders and valve gear of a conventional reciprocating steam engine. Lack of control of the cutoff is a major problem with such designs, and none has been demonstrated in practice.
Steam powered vehicles
cutoff Nicolas-Joseph Cugnot demonstrated the first functional self-propelled steam vehicle, his "fardier" (steam wagon), in 1769. Arguably, this was the first automobile. While not generally successful as a transportation device, the self-propelled steam tractor proved very useful as a self mobile power source to drive other farm machinery such as grain threshers or hay balers. Steam engine powered automobiles continued to compete with other motive systems into the early decades of the 20th century. However steam engines are less favored for automobiles, which are generally powered by internal combustion engines, because steam requires at least thirty seconds (in a flash boiler) or so to develop pressure. On February 21, 1804 at the Pen-y-Darren ironworks in Wales, the first self-propelled railway steam engine or steam locomotive built by Richard Trevithick was demonstrated.
Advantages
The strength of the steam engine for modern purposes is in its ability to convert heat from almost any source into mechanical work. Unlike the internal combustion engine, the steam engine is not particular about the source of heat. Most notably, without the use of a steam engine nuclear energy could not be harnessed for useful work, as a nuclear reactor does not directly generate either mechanical work or electrical energy - the reactor itself simply heats water. It is the steam engine which converts the heat energy into useful work. Steam may also be produced without combustion of fuel, through solar concentrators. A demonstration power plant has been built using a central heat collecting tower and a large number of solar tracking mirrors, (called heliostats). Similar advantages are found in a different type of external combustion engine, the Stirling engine, which offers efficient power in a compact engine, but which is difficult to operate over a wide range of operating conditions, difficulties which are readily addressed by the modern hybrid vehicle. Steam locomotives are especially advantageous at high elevations as they are not especially adversely affected by the lower atmospheric pressure. This was inadvertently discovered when steam engines operated at high altitudes in the mountains of South America were replaced by diesel-electric engines of equivalent sea level power. They were quickly replaced by much more powerful locomotives capable of producing sufficient power at high altitude. In Switzerland (Brienz Rothhorn) and Austria (Schafberg Bahn) new rack steam locomotives have proved very successful. They were designed based on a 1930s design of Swiss Locomotive and Machine Works (SLM) but with all of today's possible improvements like roller bearings, heat insulation, light-oil firing, improved inner streamlining, one-man-driving and so on. These resulted in 60 percent lower fuel consumption per passenger and massively reduced costs for maintenance and handling. Economics now are similar or better than with most advanced diesel or electric systems. Also a steam train with similar speed and capacity is 50 percent lighter than an electric or diesel train, thus, especially on rack railways, significantly reducing wear and tear on the track. Also, a new steam engine for a paddle steam ship on Lake Geneva, the "Montreux" was designed and built, being the world's first ship steam engine with an electronic remote control. The steam group of SLM in 2000 created a wholly-owned company called DLM to design modern steam engines and steam locomotives.
Efficiency
To get the efficiency of an engine, divide the number of joules of mechanical work that the engine produces by the number of joules of energy input to the engine by the burning fuel. In general, the rest of the energy is dumped into the environment as heat. No pure heat engine can be more efficient than the Carnot cycle, in which heat is moved from a high temperature reservoir to one at a low temperature, and the efficiency depends on the temperature difference. Hence, steam engines should ideally be operated at the highest steam temperature possible, and release the waste heat at the lowest temperature possible. In practice, a steam engine exhausting the steam to atmosphere will have an efficiency (including the boiler) of 5%, but with the addition of a condenser the efficiency is greatly improved to 25% or better. A power station with exhaust reheat, etc. will achieve 30% efficiency. Combined cycle in which the burning material is first used to drive a gas turbine can produce 60% efficiency. It is also possible to capture the waste heat using cogeneration in which the residual steam is used for heating. It is therefore possible to use about 90% of the energy produced by burning fuel - only 10% of the energy produced by the combustion of the fuel goes wasted into the atmosphere. One source of inefficiency is that the condenser causes losses by being somewhat hotter than the outside world, although this can be mitigated by condensing the steam in a heat exchanger and using the recovered heat, for example to pre-heat the air being used in the burner of an external combustion engine. The operation of the engine portion alone is not dependent upon steam; any pressurised gas may be used. Compressed air is sometimes used to test or demonstrate small model "steam" engines.
Festivals and museums

- [http://www.dartmouth.org.uk/newcomen.htm The Newcomen Engine House, Dartmouth, Devon, England, UK]
- Steam Era in Milton, Ontario
- Ontario Agricultural Museum in Milton, Ontario
- Missouri River Valley Steam Engine Association [http://www.mrvsea.com/fall_show.htm Back to the Farm Reunion] in central Missouri, USA. This is not a steam-only festival, but it has always had a good showing of running steam engines.
- [http://collections.ic.gc.ca/hamilton/pump.htm Hamilton Museum of Steam and Technology] in Hamilton, Ontario. An old municipal pumphouse dating to 1860 with it's original two Woolf Compound Rotative Beam Engines, one of which still operates.
See also

- Timeline of steam power
- Newcomen steam engine
- Watt steam engine
- Steam power during the Industrial Revolution
- Stationary steam engine
- Steam donkey
- Steam locomotive for details of steam powered railway 'engines'
- Crosshead bearing
- steam car
- Stanley Steamer
- Live steam
- Beam engine
External links

- [http://www.avero.de/?links/dampfmaschine Interactive Steam Engine] See how it works and manipulate the speed
- [http://www.keveney.com/Engines.html Animated engines - Illustrates a variety of steam engines]
- [http://www.fantasyarts.net/nanotechnology-gallery.htm The World's Smallest Steam Engine]
- [http://www.history.rochester.edu/steam/thurston/1878/Chapter5.html A history of the growth of the steam-engine]
- [http://www.dself.dsl.pipex.com/MUSEUM/POWER/uniflow/uniflow.htm Uniflow locomotives]
- [http://www.dself.dsl.pipex.com/MUSEUM/TRANSPORT/mower/mower.htm Steam powered lawn mower]
- [http://www.saunalahti.fi/animato/steam Building Model Steam trains]
- [http://www.cincinnati.com/travel/stories/053099_steamer.html Steamboat revival on Lake Geneva] Category:Energy conversion Category:Engines Category:Piston engines ja:蒸気機関

Pulleys

rightA pulley is a wheel with a groove along its edge, for holding a rope or cable. Pulleys are usually used in sets designed to reduce the amount of force needed to lift a load. However, the same amount of work is necessary for the load to reach the same height as it would without the pulleys. The magnitude of the force is reduced, but it must act through a longer distance. Pulleys are one of the six simple machines.

Types of Pulleys

A fixed or class 1 pulley has a fixed axle. That is, the axle is "fixed" or anchored in place. A fixed pulley is used to redirect the force in a rope (called a belt when it goes in a full circle). A fixed pulley has a mechanical advantage of 1. A movable or class 2 pulley has a free axle. That is, the axle is "free" to move in space. A movable pulley is used to transform forces. A movable pulley has a mechanical advantage of 2. That is, if one end of the rope is anchored, pulling on the other end of the rope will apply a doubled force to the object attached to the pulley. A compound pulley is a combination fixed and movable pulley system. A block and tackle is a compound pulley where several pulleys are mounted on each axle, further increasing the mechanical advantage. Plutarch reported that Archimedes moved an entire warship, laden with men, using compound pulleys and his own strength. Image:Pulley class1.PNG |fixed pulley
(class 1) Image:Polea-simple-movil.jpg|movable pulley
(class 2) Image:Polispasto2.jpg |compound pulley Image:Polispasto4.jpg |tackle category:mechanics ja:滑車

Diesel engine

The diesel engine is a type of internal combustion engine; more specifically, it is a compression ignition engine, in which the fuel is ignited by being suddenly exposed to the high temperature and pressure of a compressed gas containing oxygen (usually atmospheric air), rather than a separate source of ignition energy (such as a spark plug), as is the case in the gasoline engine. This is known as the diesel cycle, after German engineer Rudolf Diesel, who invented it in 1892 and received the patent on February 23, 1893 (1893-02-23). Diesel intended the engine to use a variety of fuels including coal dust. He demonstrated it in the 1900 Exposition Universelle (World's Fair) using peanut oil (see biodiesel).

How diesel engines work

When a gas is compressed, its temperature rises (see the combined gas law); a diesel engine uses this property to ignite the fuel. Air is drawn into the cylinder of a diesel engine and compressed by the rising piston at a much higher compression ratio than for a spark-ignition engine, up to 25:1. The air temperature reaches 700–900 °C, or 1300–1650 °F. At the top of the piston stroke, diesel fuel is injected into the combustion chamber at high pressure, through an atomising nozzle, mixing with the hot, high-pressure air. The resulting mixture ignites and burns very rapidly. This contained explosion causes the gas in the chamber to heat up rapidly, which increases its pressure, which in turn forces the piston downwards. The connecting rod transmits this motion to the crankshaft, which is forced to turn, delivering rotary power at the output end of the crankshaft. Scavenging (pushing the exhausted gas-charge out of the cylinder, and drawing in a fresh draught of air) of the engine is done either by ports or valves. To fully realize the capabilities of a diesel engine, use of a turbocharger to compress the intake air is necessary; use of an aftercooler/intercooler to cool the intake air after compression by the turbocharger further increases efficiency. In very cold weather, diesel fuel thickens and increases in viscosity and forms wax crystals or a gel. This can make it difficult for the fuel injector to get fuel into the cylinder in an effective manner, making cold weather starts difficult at times, though recent advances in diesel fuel technology have made these difficulties rare. A commonly applied advance is to electrically heat the fuel filter and fuel lines. Other engines utilize small electric heaters called glow plugs inside the cylinder to warm the cylinders prior to starting. A small number use resistive grid heaters in the intake manifold to warm the inlet air until the engine reaches operating temperature. Engine block heaters (electric resistive heaters in the engine block) plugged into the utility grid are often used when an engine is shut down for extended periods (more than an hour) in cold weather to reduce startup time and engine wear. A vital component of any diesel engine system is the governor, which limits the speed of the engine by controlling the rate of fuel delivery. Older governors were driven by a gear system from the engine (and thus supplied fuel only linearly with engine speed). Modern electronically-controlled engines achieve this through the electronic control module (ECM) or electronic control unit (ECU) - the engine-mounted "computer". The ECM/ECU receives an engine speed signal from a sensor and then using its algorithms and look-up calibration tables stored in the ECM/ECU, it controls the amount of fuel and its timing (the "start of injection") through electric or hydraulic actuators to maintain engine speed. Controlling the timing of the start of injection of fuel into the pistons is key to minimising their emissions and maximising the fuel economy (efficiency) or the engine. The exact timing of starting this fuel injection into the cylinder is controlled electronically in most of today's modern engines. The timing is usually measured in units of crank angles before Top Dead Center (TDC) that the piston is at. For example, if the ECM/ECU initiates fuel injection when the piston is 10 degrees before TDC, the start of injection or "timing" is said to be 10 deg BTDC. The optimal timing will depend on both the engine design as well as its speed and load. Advancing (injecting when the piston is further away from TDC) the start of injection results in higher in-cylinder pressure and higher efficiency but also results in higher Nitrous Oxide (NOx) emissions. At the other extreme, very retarded start of injection or timing causes incomplete combustion. This results in higher Particulate Matter (PM) emissions and higher smoke.

Fuel injection in diesel engines

Early diesels often employed indirect injection in order to use simple, flat-top pistons, and made the positioning of the early, bulky diesel injectors easier, but all modern diesel engines employ some form of direct injection, coupled with more complicated bowl-in-piston designs. Modern engines also use a very highly pressurised fuel supply line, which replaces the older, noisier, and mechanically more complicated combined pump and selector valve assembly (see below).

Indirect Injection

An indirect injection diesel engine delivers fuel into a chamber off the combustion chamber, called a prechamber, where combustion begins and then spreads into the main combustion chamber. The prechamber is carefully designed to ensure adequate mixing of the atomized fuel with the compression-heated air. This has the effect of slowing the rate of combustion, which tends to reduce audible noise. It also softens the shock of combustion and produces lower stresses on the engine components. The addition of a prechamber, however, increases heat loss to the cooling system and thereby lowers engine efficiency.

Direct injection

Modern diesel engines make use of one of the following direct injection methods:

Common rail direct injection

The common rail system on its prototype was already developed in late sixties with Mr. Hiber in Switzerland. After that, Ganser of the Swiss Federal Institute of Technology focusing on his research the common rail technology was advanced. In mid nineties, Dr. Shohei Itoh and Masahiko Miyaki, Japanese automotive parts manufacturer Denso Corporation, developed the Common Rail Fuel System for Heavy Duty Vehicles and finally turned into its first practical use on their ECD-U2 common Rail system, which was mounted on the HINO RAISING RANGER truck and sold for general use in 1995. Later in 1997 the German automotive parts manufacturer Robert Bosch GmbH extended its use for passenger car. Today the common rail system is responsible for a revolution in diesel engine technology. Delphi Automotive Systems of the US also make common-rail systems. Different car makers refer to their common rail engines by different names, e.g. DaimlerChrysler's CDI, Ford Motor Company's TDCi (most of these engines are manufactured by PSA), Fiat Group's (Fiat, Alfa Romeo and Lancia) JTD, Renault's DCi, GM/Opel's CDTi (most of these engines are manufactured by Fiat, other by Isuzu), PSA Peugeot Citroen's HDI, Toyota's D-4D, and so on. In older diesel engines, a distributor-type injection pump, regulated by the engine, supplies bursts of fuel to injectors which are simply nozzles through which the diesel is sprayed into the engine's combustion chamber. As the fuel is at low pressure and there cannot be precise control of fuel delivery, the spray is relatively coarse and the combustion process is relatively crude and inefficient. In common rail systems, the distributor injection pump is eliminated. Instead an extremely high pressure pump stores a reservoir of fuel at high pressure - up to 1,800 bar (180 MPa) - in a "common rail", basically a tube which in turn branches off to computer-controlled injector valves, each of which contains a precision-machined nozzle and a plunger driven by a solenoid. Driven by a computer (which also controls the amount of fuel to the pump), the valves, rather than pump timing, control the precise moment when the fuel injection into the cylinder occurs and also allow the pressure at which the fuel is injected into the cylinders to be increased. As a result, the fuel that is injected atomises easily and burns cleanly, reducing exhaust emissions and increasing efficiency. In addition, the engine's Electronic Control Unit (ECU) can inject a small amount of diesel just before the main injection event ("pilot" injection) that reduces noise and vibration, as well as optimises injection timing and quantity for variations in fuel quality, cold starting, and so on. Most European automakers have common rail diesels in their model lineups, even for commercial vehicles. Some Japanese manufacturers, such as Toyota, Nissan and recently Honda, have also developed common rail diesel engines.

Unit direct injection

This also injects fuel directly into the cylinder of the engine. However, in this system the injector and the pump are combined into one unit positioned over each cylinder. Each cylinder thus has its own pump, feeding its own injector, which prevents pressure fluctuations and allows more consistent injection to be achieved. This type of injection system, also developed by Bosch, is used by Volkswagen AG in cars, and most major diesel engine manufactures, in large commercial engines (Cat, Cummins, Detroit Diesel). With recent advancements, the pump pressure has been raised to 2,050 bar (205 MPa), allowing injection parameters similar to common rail systems.

Types of diesel engines

There are two classes of diesel engines: two-stroke and four-stroke. Most diesels generally use the four-stroke cycle, with some larger diesels operating on the two-stroke cycle. Normally, banks of cylinders are used in multiples of two, although any number of cylinders can be used as long as the load on the crankshaft is counterbalanced to prevent excessive vibration. The inline-6 is the most prolific in medium- to heavy-duty engines, though the V8 and straight-4 are also common.

Advantages and disadvantages versus spark-ignition engines

Diesel engines are more efficient than gasoline/petrol engines of the same power (by approx. 15%), resulting in lower fuel consumption. Naturally aspirated diesel engines are more massive than gasoline/petrol engines of the same power for two reasons; the first is that it takes a larger capacity diesel engine than a gasoline engine to produce the same power. This is essentially because the diesel cannot operate as quickly - the "rev limit" is lower - because getting the fuel-air mixture into a diesel engine is more difficult than a gasoline engine [http://www.perkins.com/perkins/cda/articleDisplay/1,4094,7___32_____7_10020408,00.html]. The second reason is that a diesel engine must be stronger to withstand the higher combustion pressures needed for ignition. Yet it is this same build quality that has allowed some enthusiasts to acquire significant power increases with turbocharged engines through fairly simple and inexpensive modifications. A gasoline engine of similar size cannot put out a comparable power increase without extensive alterations because the stock components would not be able to withstand the higher stresses placed upon them. Since a diesel engine is already built to withstand higher levels of stress, it makes an ideal candidate for performance tuning with little expense. However it should be said that any modification that raises the amount of fuel and air put through a diesel engine will increase its operating temperature which will reduce its life and service interval requirements. In addition, sending additional fuel to the cylinders will wash away lubricating oil faster. These things are issues with newer, lighter, "high performance" diesel engines which aren't "overbuilt" to the degree of older engines and are being pushed to provide greater power in smaller engines. The addition of a turbocharger or supercharger to the engine (see turbodiesel) greatly assists in increasing fuel economy and power output. Boost pressures can be higher on diesels than gasoline engines, and the higher compression ratio allows a diesel engine to be more efficient than a comparable spark ignition engine, although the calorific value of the fuel is slightly lower at 45.3 megajoules per kilogram to gasoline at 45.8 MJ/kg. The increased fuel economy of the diesel over the petrol engine means that the diesel produces less carbon dioxide (CO₂) per unit distance. The recent development of biofuel alternatives to fossil fuels has unleashed the ability to produce a net-sum of zero emissions of CO₂, as it is re-absorbed into plants and then comes full circle, being used to produce the fuel. Diesel engines can produce black soot from their exhaust. This consists of unburned carbon compounds. Modern diesel engines catch the soot in a particle filter, which when saturated is automatically regenerated by burning the particles. Other problems associated with the exhaust gases (nitrogen oxide, sulfurous fumes) can be mitigated with further investment and equipment. The lack of an electrical ignition system greatly improves the reliability. The high durability of a diesel engine is also due to its overbuilt nature (see above) as well as the diesel's combustion cycle, which creates less-violent changes in pressure when compared to a spark-ignition engine, a benefit that is magnified by the lower rotating speeds in diesels. Unfortunately, due to the greater compression force required and the increased weight of the stronger components, starting a diesel engine is a harder task. More torque is required to push the engine through compression. Either an electrical starter or an air start system is used to start the engine turning. On large engines, pre-lubrication and slow turning of an engine, as well as heating, are required to minimize the possibility of damaging the engine during initial start-up and running. Some smaller military diesels can be started with an explosive cartridge that provides the extra power required to get the machine turning. In the past, Caterpillar and John Deere used a small gasoline "pony" motor in their tractors to start the primary diesel motor. The pony motor heated the diesel to aid in ignition and utilized a small clutch and transmission to actually spin up the diesel engine. Even more unusual was an International Harvester design in which the diesel motor had its own carburetor and ignition system, and started on gasoline. Once warmed up, the operator moved two levers to switch the motor to diesel operation, and work could begin. These engines had very complex cylinder heads (with their own gasoline combustion chambers) and in general were vulnerable to expensive damage if special care was not taken (especially in letting the engine cool before turning it off).

Automobile racing

Although the weight and lower output of a diesel engine tend to keep them away from automotive racing applications, there are many diesels being raced in classes that call for them, mainly in truck racing, as well in types of racing where these drawbacks are less severe, such as land speed record racing. [http://www.cumminsracing.com/ Diesel engined dragsters] even exist, despite the diesel's drawbacks being central to performance in this sport. In 1952, [http://www.cummins.com/eu/pages/en/whoweare/cumminshistory.cfm Cummins Diesel] won the pole at the Indianapolis 500 race with a supercharged 3 liter diesel car, relying on torque and fuel efficiency to overcome weight and low peak power, and led most of the race until the badly situated air intake of the car swallowed enough debris from the track to disable the car.

Dieseling in spark-ignition engines

A gasoline (spark ignition) engine can sometimes act as a compression ignition engine under abnormal circumstances, a phenomenon typically described as "pinging" or "pinking" (during normal running) or "dieseling" (when the engine continues to run after the electrical ignition system is shut off). This is usually caused by hot carbon deposits within the combustion chamber that act as would a "glow plug" within a diesel or model aircraft engine. Excessive heat can also be caused by improper ignition timing and/or fuel/air ratio which in turn overheats the exposed portions of the spark plug within the combustion chamber.

Fuel and fluid characteristics

Diesel engines can operate on a variety of different fuels, depending on configuration, though the eponymous diesel fuel derived from crude oil is most common. Good-quality diesel fuel can be synthesised from vegetable oil and alcohol. Biodiesel is growing in popularity since it can frequently be used in unmodified engines, though production remains limited. Petroleum-derived diesel is often called "petrodiesel" if there is need to distinguish the source of the fuel. The engines can work with thicker, heavier oil, or oil with higher viscosity, as long as it is heated to ease pumping and injection. These fuels are cheaper than clean, refined diesel oil, although they are dirtier. The biofuels straight vegetable oil (SVO) and waste vegetable oil (WVO) can fall into this category. Moving beyond that, use of low-grade fuels can lead to serious maintenance problems. Most diesel engines that power ships like supertankers are built so that the engine can safely use low grade fuels. Ethanol is also used in some cases, since it has a high octane rating which means it can be highly compressed before spontaneously igniting. One way this is used is in E95 fuel which actually contains 5% gasoline along with 95% ethanol. Normal diesel fuel is more difficult to ignite than gasoline because of its higher flash point, but once burning, a diesel fire can be extremely fierce.

Diesel applications

The vast majority of modern heavy road vehicles (trucks), ships, large-scale portable power generators, most farm and mining vehicles, and many long-distance locomotives have diesel engines. However, in the U.S. they are not as popular in passenger vehicles as they are in Europe as they are perceived as being heavier, noisier, of having performance characteristics which makes them slower to accelerate, and of being more expensive than petrol vehicles. In addition, before the mandatory reduction of sulphur in on-road diesel fuel to 15 parts per million, which will start at 15 Oct 2006 (2006-10-15) in the U.S. (1 June 2006 (2006-06-01) in Canada), diesel fuel used in North America has higher sulphur content than the fuel used in Europe, effectively limiting diesel use to industrial vehicles. 2006-06-01 In Europe, where tax rates in many countries make diesel fuel much cheaper than petrol, diesel vehicles are very popular and newer designs have significantly narrowed differences between petrol and diesel vehicles in the areas mentioned. One anecdote tells of Formula One driver Jenson Button, who was arrested while driving a diesel-powered BMW coupe at 230 km/h (about 140 mph) in France, where he was too young to have a petrol-engined car hired to him. Button dryly observed in subsequent interviews that he had actually done BMW a public relations service, as nobody had believed a diesel could be driven that fast. The BMW diesel lab in Steyr, Austria is led by Ferenc Anisits and is considered to be a leader in development of automotive diesel engines. Similarly, Mercedes Benz had a successful run of diesel-powered passenger cars in the late 1970s and 1980s. After a hiatus in the 1990s with relatively few diesel cars in its lineup, Mercedes Benz has revived diesel cars in its newer ranges with an emphasis on high performance versus the older models' lack thereof. ;High-Speed :High-speed (approximately 1200 rpm and greater) engines are used to power lorries (trucks), buses, tractors, cars, yachts, compressors, pumps and small generators. ;Medium-Speed :Large electrical generators are driven by medium speed engines, (approximately 300 to 1200 rpm) optimised to run at a set speed and provide a rapid response to load changes. ;Low-Speed : The largest diesel engines are used to power ships. These monstrous engines have power outputs over 80,000 kW, turn at about 60 to 100 rpm, and are up to 15 m tall. They often run on cheap low-grade fuel, which require extra heat treatment in the ship for tanking and before injection due to their low volatility. Companies such as Burmeister & Wain and Wärtsilä (e.g., Sulzer Diesels) design such large low speed engines. They are unusually narrow and tall due to the addition of a crosshead bearing. Today (2005), the Wärtsilä-Sulzer RTA96-C turbocharged two-stroke diesel engine is the most powerful and most efficient prime-mover in the world, with cylinder bores of 960 mm (37.8 in) and stroke of 2500 mm (98.4 in), producing up to 80,080 kW (107,389 hp) in the 14-cylinder configuration. The zeppelins Graf Zeppelin II and Hindenburg were propelled by reversible diesel engines. The direction of operation was changed by shifting gears on the camshaft. From full power forward, the engines could be brought to a stop, changed over, and brought to full power in reverse in less than 60 seconds. This was done before reversible pitch propellers for aircraft had been perfected. A few airplanes have been built that use diesel engines, such as the Junkers-powered Blohm & Voss Ha 139 of the late 1930s. This is quite rare because of the high importance of power-weight ratios in aeronautical applications, and the development of kerosene-powered jet engines and the closely-related turboprop engines. However, this may change in the near future. The newer automotive diesels have power-weight ratios comparable to the ancient spark-ignition designs common in general aviation aircraft, and have better fuel efficiency. Their use of electronic ignition, fuel injection, and sophisticated engine management systems also makes them far easier to operate than mass-produced spark-ignition aircraft engines, most of which still use carburetors. Combined with Europe's very favourable tax treatment of diesel fuel compared to petrol, these factors have led to considerable interest in diesel-powered small general aviation planes, and several manufacturers have recently begun selling diesel engines for this purpose. The Diamond Twin Star is currently one of the very few general aviation aircraft manufactured with diesel engines. It can be twice as efficient as a comparable twin aircraft due to the diesel engines made by Thielert. Another major advantage for aviation users is that diesel engines can be fuelled with jet fuel, which is produced in a much greater quantity than avgas. See aircraft engine. Also, some motorcycles have been built using diesel engines.

Current and future developments

Already, many common rail and unit injection systems employ new injectors using stacked piezoelectric crystals in lieu of a solenoid, which gives finer control of the injection event. Variable geometry turbochargers have flexible vanes, which move and let more fuel into the engine depending on load. This technology increases both performance and fuel economy A technique called accelerometer pilot control (APC) uses a sensor called an accelerometer to provide feedback on the engine's level of noise and vibration and thus instruct the ECU to inject the minimum amount of fuel that will produce quiet combustion and still provide the required power (especially while idling.) The next generation of common rail diesels are expected to use variable injection geometry, which allows the amount of fuel injected to be varied over a wider range, and variable valve timing similar to that on gasoline engines. At least in the US, diesels will slowly face displacement by tougher emissions regulations. Other methods to achieve even more efficient combustion, such as HCCI (homogeneous charge compression ignition), are being studied.

Modern diesel facts

(Source: Robert Bosch GmbH) Fuel passes through the injector jets at speeds of nearly 1500 miles per hour (2400 km/h) – as fast as the top speed of a jet plane. Fuel is injected into the combustion chamber in less than 1.5 milliseconds (one and a half thousandths of a second) – about as long as a camera flash. The smallest quantity of fuel injected is one cubic millimetre – about the same volume as the head of a pin. The largest injection quantity at the moment for automobile diesel engines is around 70 cubic millimetres. If the camshaft of a six-cylinder engine is turning at 4500 rpm, the injection system has to control and deliver 225 injection cycles per second. On a demonstration drive, a Volkswagen 1-liter diesel-powered car used only 0.89 liters of fuel in covering 100 kilometers – making it probably the most fuel-efficient car in the world. Bosch’s high-pressure fuel injection system was one of the main factors behind the prototype’s extremely low fuel consumption. Production record-breakers in fuel economy include the Volkswagen Lupo 3L TDI and the Audi A2 3L 1.2 TDI with standard consumption figures of 3 liters of fuel per 100 kilometers. Their high-pressure diesel injection systems are also supplied by Bosch. In 2001, nearly 36% of newly registered cars in Western Europe had diesel engines. Austria leads the league table of registrations of diesel-powered cars with 66%, followed by Belgium with 63% and Luxembourg with 58%. Germany, with 34.6% in 2001, was in the middle of the league table. By way of comparison: in 1996, diesel-powered cars made up only 15% of the new car registrations in Germany. In 1998, for the very first time in the history of the legendary 24-hour race at the Nürburgring, a diesel-powered car was the overall winner – the BMW works team 320d, fitted with modern high-pressure diesel injection technology from Bosch.

External links

-
- [http://auto.howstuffworks.com/diesel.htm/ HowStuffWorks Article]
- [http://www.bath.ac.uk/~ccsshb/12cyl/ The Most Powerful Diesel Engine in the World]
- [http://www.cumminsracing.com Cummins Racing, home of the world's fastest diesel dragster...]
- [http://www.thedieselstop.com The Diesel Stop - Information on the Power Stroke Diesel]
- [http://www.northtexaspowerstrokes.com North Texas Power Stroke Association - Ford/International Power Stroke Diesel Enthusiasts]
- [http://www.rolls-royce.com/marine/product/diesel/default.jsp Rolls-Royce corporate website - diesel engines]
- [http://www.tdiclub.com TDIClub.com - TDI Enthusiasts]
- [http://www.turbodieselregister.com Turbodiesel Register - Dodge/Cummins Turbodiesel Enthusiasts]
- [http://www.volvo.com/volvopenta/global/en-gb Volvo Penta - manufacturer of marine and industrial diesel engines]
- [http://www.best-generator.com/ Best Engine - Manufacturer of Diesel Engine]
- [http://www.centurion-engines.com Centurion Engines - aeronautical applications]
- [http://www.wartsila.com/ Wärtsilä - manufacturer of diesel power plants]
- [http://www.cat.com/cda/layout?m=37532&x=7 Caterpillar - manufacturer of Caterpiller (Cat) diesel engines as well as construction equipment]
- [http://www.cummins.com Cummins - manufacturer of Cummins diesel engines]
- [http://www.detroitdiesel.com Detroit Diesel - manufacturer of diesel engines]
- [http://www.internationaldelivers.com/ -International/Navistar- manufacturer of International and Ford PowerStroke diesel engines, as well as heavy duty trucks]
- [http://www.perkins.com Perkins - manufacturer of diesel engines]
- [http://www.deutz.de Deutz - manufacturer of esoteric diesel engines]
- [http://www.deere.com John Deere - manufacturer of diesel engines and farm and construction equipment]
- [http://www.yanmar.com Yanmar - manufacturer of diesel engines, specilzing in those for marine use]
- [http://www.komatsu.com/kdl Komatsu Diesel - manufacturer of diesel engines]
- http://www.sisudiesel.com/ - Sisu Diesel
- [http://wagoneers.com/ wagoneers.com - see Mercedes Diesels and DIESELS] Category:Piston engines ko:디젤 엔진 ja:ディーゼルエンジン

Haven

En Haven, (m., pl. Havens), ok Hoben, un Haben schreven, is en Steed an dat Water, de för de Schippfohrt inricht is. En Haven is en Oort, wo Scheep anleggen köönt un mutt darum an't Water liggen, direkt an't Meer, an enen Stroom, an enen Fluss oder an enen See. Dat Över bi enen grötteren Haven is tomehrst besünners muurt to en Kai. Op den Kai sünd de Ümslagsanlagen, Krän, Containerbrüchen, Suuger un anners mehr. För den Transpoort to Land is an de Kaianlaag faken ok en Straat un en Iesenbohn. Dat gifft
- den Seehaven för de grötteren Schipp
- Containerhaven för Containerümslag
- Ölhaven för Erdöl
- Massengoothaven för Massengoot, so as Kahl, Erz, Koorn, Steen
- Passagierhaven för Passagierschipp
- Fährhaven för Fährschipp.
- den Binnenschippshaven för de lütten Binnenschipp
- den Sportboothaven för Seilbööd un anner Bööd. Gröttere Havens sünd
- Hamborg
- Rotterdam
- New York
- Hongkong
- Tokio
- Bremen un Bremerhaven
- Willemshaven (Wilhelmshaven]
- Emden
- Kiel
- Göteborg
- Cuxhaven De gröttste düütsche Binnenschippshaven is in Duisborg an den Rhien. Kategorie:Buwark Kategorie:Verkehr Kategorie:Water [[simple:Harbor

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Types of Pulleys

Diesel engine

How diesel engines work

Fuel injection in diesel engines

Indirect Injection

Common rail direct injection

Unit direct injection

Types of diesel engines

Advantages and disadvantages versus spark-ignition engines

Automobile racing

Dieseling in spark-ignition engines