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Jockey Wheel
A jockey wheel is a wheel-based mechanical system used for steering or guidance, either: * a guide wheel - usually operating as a pair - which is used to move, retain, locate and (usually) add tension to a chain, rope or cable which is then fed into the groove of another wheel, toothed wheel, cog or sprocket; * a (frequently) retractable, smaller, height-adjustable wheel located on the front of a trailer or caravan for the low-speed manoeuvring or manual steering of said trailer-based unit when decoupled from the powered vehicle to which it was attached. On trailers A jockey wheel for vehicular use is a retractable adjustable-height wheel used on the front of trailers (or caravans) with either a single axle (two running wheels) or more close-coupled axles at or near the centre of gravity whereby without additional support, the trailer would not remain level. The jockey wheel is close to the towing hitch and has a built-in screw jack to enable the trailer nose to be lifted over th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicycle Chain
A bicycle chain is a roller chain that transfers power from the pedals to the drive-wheel of a bicycle, thus propelling it. Most bicycle chains are made from plain carbon or alloy steel, but some are nickel-plated to prevent rust, or simply for aesthetics. History Obsolete chain designs previously used on bicycles included the block chain, the skip-link chain, and the Simpson lever chain. The first chains were of a simple, bushing-less design. These had inherent reliability problems and a bit more friction (and mechanical efficiency losses) than modern chains. With these limitations in mind, the Nevoigt brothers, of the German Diamant Bicycle Company, designed the roller chain in 1898, which uses bushings. More recently, the "bushingless roller chain" design has superseded the bushed chain. This design incorporates the bearing surface of the bushing into the inner side plate, with each plate creating half of the bushing. This reduces the number of parts needed to assemble ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sprocket
A sprocket, sprocket-wheel or chainwheel is a profiled wheel with teeth that mesh with a chain, track or other perforated or indented material. The name 'sprocket' applies generally to any wheel upon which radial projections engage a chain passing over it. It is distinguished from a gear in that sprockets are never meshed together directly, and differs from a pulley in that sprockets have teeth and pulleys are smooth except for timing pulleys used with toothed belts. Sprockets are used in bicycles, motorcycles, tracked vehicles, and other machinery either to transmit rotary motion between two shafts where gears are unsuitable or to impart linear motion to a track, tape etc. Perhaps the most common form of sprocket may be found in the bicycle, in which the pedal shaft carries a large sprocket-wheel, which drives a chain, which, in turn, drives a small sprocket on the axle of the rear wheel. Early automobiles were also largely driven by sprocket and chain mechanism, a practice la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trailer (vehicle)
A trailer is an unpowered vehicle towed by a powered vehicle. It is commonly used for the transport of goods and materials. Sometimes recreational vehicles, travel trailers, or mobile homes with limited living facilities where people can camp or stay have been referred to as trailers. In earlier days, many such vehicles were towable trailers. United States In the United States, the term is sometimes used interchangeably with travel trailer and mobile home, varieties of trailers and manufactured housing designed for human habitation. Their origins lay in utility trailers built in a similar fashion to horse-drawn wagons. A trailer park is an area where mobile homes are placed for habitation. In the United States trailers ranging in size from single-axle dollies to 6-axle, high, long semi-trailers are commonplace. The latter, when towed as part of a tractor-trailer or "18-wheeler", carries a large percentage of the freight that travels over land in North America. Types ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caravan (towed Trailer)
A caravan, travel trailer, camper, tourer or camper trailer is a trailer towed behind a road vehicle to provide a place to sleep which is more comfortable and protected than a tent (although there are fold-down trailer tents). It provides the means for people to have their own home on a journey or a vacation, without relying on a motel or hotel, and enables them to stay in places where none is available. However, in some countries campers are restricted to designated sites for which fees are payable. Caravans vary from basic models which may be little more than a tent on wheels to those containing several rooms with all the furniture and furnishings and equipment of a home. Construction of the solid-wall trailers can be made of metal or fiberglass. Travel trailers are used principally in North America, Europe, Australia and New Zealand. History In Europe, the origins of travel trailers and caravanning can be traced back to the travelling Romani people, and showmen who spent mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centre Of Gravity
In physics, the center of mass of a distribution of mass in space (sometimes referred to as the balance point) is the unique point where the weighted relative position of the distributed mass sums to zero. This is the point to which a force may be applied to cause a linear acceleration without an angular acceleration. Calculations in mechanics are often simplified when formulated with respect to the center of mass. It is a hypothetical point where the entire mass of an object may be assumed to be concentrated to visualise its motion. In other words, the center of mass is the particle equivalent of a given object for application of Newton's laws of motion. In the case of a single rigid body, the center of mass is fixed in relation to the body, and if the body has uniform density, it will be located at the centroid. The center of mass may be located outside the physical body, as is sometimes the case for hollow or open-shaped objects, such as a horseshoe. In the case of a distri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Towing Hitch
A tow hitch (or tow bar or trailer hitch in North America) is a device attached to the chassis of a vehicle for towing, or a towbar to an aircraft nose gear. It can take the form of a tow ball to allow swiveling and articulation of a trailer, or a tow pin, or a tow hook with a trailer loop, often used for large or agricultural vehicles where slack in the pivot pin allows similar movements. Another category is the towing pintle used on military vehicles worldwide. To tow safely, the correct combination of vehicle and trailer must be combined with correct loading horizontally and vertically on the tow ball. Advice should be heeded (see references) to avoid problems. Regional variations North America Trailer hitches for conventional passenger cars, light-duty commercial vehicles, light trucks, and multipurpose passenger vehicles come in two main OEM or aftermarket types: receiver and bumper/fixed-drawbar. Receiver-type hitches consist of a portion with a rearward-facing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Screw Jack
A jackscrew, or screw jack, is a type of jack that is operated by turning a leadscrew. It is commonly used to lift moderately and heavy weights, such as vehicles; to raise and lower the horizontal stabilizers of aircraft; and as adjustable supports for heavy loads, such as the foundations of houses. Description A screw jack consists of a heavy-duty vertical screw with a load table mounted on its top, which screws into a threaded hole in a stationary support frame with a wide base resting on the ground. A rotating collar on the head of the screw has holes into which the handle, a metal bar, fits. When the handle is turned clockwise, the screw moves further out of the base, lifting the load resting on the load table. In order to support large load forces, the screw is usually formed with Acme threads. Advantages An advantage of jackscrews over some other types of jack is that they are ''self-locking'', which means when the rotational force on the screw is removed, it will remai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tow Ball
A tow hitch (or tow bar or trailer hitch in North America) is a device attached to the chassis of a vehicle for towing, or a towbar to an aircraft nose gear. It can take the form of a tow ball to allow swiveling and articulation of a Trailer (vehicle), trailer, or a tow pin, or a tow hook with a trailer loop, often used for large or agricultural vehicles where slack in the pivot pin allows similar movements. Another category is the towing pintle used on military vehicles worldwide. To tow safely, the correct combination of vehicle and trailer must be combined with correct loading horizontally and vertically on the tow ball. Advice should be heeded (see references) to avoid problems. Regional variations North America Trailer hitches for conventional passenger cars, light-duty commercial vehicles, light trucks, and multipurpose passenger vehicles come in two main OEM or aftermarket types: receiver and bumper/fixed-drawbar. Receiver-type hitches consist of a portion with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caster
A caster (or castor) is an undriven wheel that is designed to be attached to the bottom of a larger object (the "vehicle") to enable that object to be moved. Casters are used in numerous applications, including shopping carts, office chairs, toy wagons, hospital beds, and material handling equipment. High capacity, heavy duty casters are used in many industrial applications, such as platform trucks, carts, assemblies, and tow lines in plants. Types Casters may be fixed to roll along a straight line path, or mounted on a pivot or pintle such that the wheel will automatically align itself to the direction of travel. Rigid casters A basic, rigid caster consists of a wheel mounted to a stationary fork. The orientation of the fork, which is fixed relative to the vehicle, is determined when the caster is mounted to the vehicle. An example of this is the wheels found at the rear of a shopping cart in North America. Rigid casters tend to restrict vehicle motion so that the vehicle t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicycle Rear Derailleur Pulley Wheels
A bicycle, also called a pedal cycle, bike or cycle, is a human-powered or motor-powered assisted, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A is called a cyclist, or bicyclist. Bicycles were introduced in the 19th century in Europe. By the early 21st century, more than 1 billion were in existence. These numbers far exceed the number of cars, both in total and ranked by the number of individual models produced. They are the principal means of transportation in many regions. They also provide a popular form of recreation, and have been adapted for use as children's toys, general fitness, military and police applications, courier services, bicycle racing, and bicycle stunts. The basic shape and configuration of a typical upright or "safety bicycle", has changed little since the first chain-driven model was developed around 1885. However, many details have been improved, especially since the advent of modern m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dérailleur
file:14-06-20-shimano-600-RalfR-N3S 7903-05.jpg, Shimano 600 front derailleur (1980) A derailleur is a variable-ratio bicycle gearing system consisting of a bicycle chain, chain, multiple sprockets of different sizes, and a mechanism to move the chain from one sprocket to another. Modern front and rear derailleurs typically consist of a moveable chain-guide that is operated remotely by a Bowden cable attached to a Shifter (bicycle part), shifter mounted on the bicycle frame, down tube, handlebar Stem (bike), stem, or Bicycle handlebar, handlebar. When a rider operates the lever while pedalling, the change in cable tension moves the chain-guide from side to side, "derailing" the chain onto different sprockets. Etymology ''Dérailleur'' is a French word, derived from the derailment of a train from its tracks. Its first recorded use was 1930. History file:Derailleur Bicycle Drivetrain.svg, A modern racing bicycle, road bicycle drivetrain with front and rear derailleurs Vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cogset
On a bicycle, the cassette or cluster is the set of multiple sprockets that attaches to the hub on the rear wheel. A cogset works with a rear derailleur to provide multiple gear ratios to the rider. Cassettes come in two varieties, freewheels or cassettes, of which cassettes are a newer development. Although cassettes and freewheels perform the same function and look almost the same when installed, they have important mechanical differences and are not interchangeable. Freewheels A freewheel (also known as a block) consists of either a single sprocket or a set of sprockets mounted on a body which contains an internal ratcheting mechanism and mounts on a threaded hub. Threaded rear hubs were available in different thread patterns depending on the country of manufacture, French and British threads being the most common. British C.E.I. (Cycle Engineers Institute) thread was adopted as the international standard and is now known as B.S.C. (British Standard Cycle). It is a standar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
