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34-633: The WC was the Model W variant tailored to cultivating , thus the W + C (for "cultivating") name. Other W variants, such as the WD and WF, followed later (in lower numbers). The WC was popular in the Great Depression for its good value, affordable price, and frugal design elements. Two factors that lowered its cost of manufacture, and thus its sales price, were that it was made partially from off-the-shelf components, and that its steel channel iron frame eliminated

68-419: A pull-type clutch, pressing the pedal pulls the release bearing to disengage the clutch. In a push-type clutch, pressing the pedal pushes the release bearing to disengage the clutch. A multi-plate clutch consists of several friction plates arranged concentrically. In some cases, it is used instead of a larger diameter clutch. Drag racing cars use multi-plate clutches to control the rate of power transfer to

102-486: A common material being an organic compound resin with a copper wire facing or a ceramic material. In an automatic transmission , the role of the clutch is performed by a torque converter . However, the transmission itself often includes internal clutches, such as a lock-up clutch to prevent slippage of the torque converter, in order to reduce the energy loss through the transmission and therefore improve fuel economy. Older belt-driven engine cooling fans often use

136-517: A composite paper material. A centrifugal clutch automatically engages as the speed of the input shaft increases and disengages as the input shaft speed decreases. Applications include small motorcycles , motor scooters , chainsaws , and some older automobiles . A cone clutch is similar to dry friction plate clutch, except the friction material is applied to the outside of a conical shaped object. This conical shape allows wedging action to occur during engagement. A common application for cone clutches

170-413: A fixed fraction of a revolution per operation. Fast action friction clutches replaced dog clutches in some applications, eliminating the problem of impact loading on the dogs every time the clutch engaged. In addition to their use in heavy manufacturing equipment, single-revolution clutches were applied to numerous small machines. In tabulating machines , for example, pressing the operate key would trip

204-447: A heat-activated clutch, in the form of a bimetallic strip . When the temperature is low, the spring winds and closes the valve, which lets the fan spin at about 20% to 30% of the crankshaft speed. As the temperature of the spring rises, it unwinds and opens the valve, allowing fluid past the valve, making the fan spin at about 60% to 90% of crankshaft speed. A vehicle's air-conditioning compressor often uses magnetic clutches to engage

238-424: A single revolution clutch to process the most recently entered number. In typesetting machines , pressing any key selected a particular character and also engaged a single rotation clutch to cycle the mechanism to typeset that character. Similarly, in teleprinters , the receipt of each character tripped a single-revolution clutch to operate one cycle of the print mechanism. In 1928, Frederick G. Creed developed

272-421: A single-turn wrap spring clutch that was particularly well suited to the repetitive start-stop action required in teleprinters . In 1942, two employees of Pitney Bowes Postage Meter Company developed an improved single turn spring clutch. In these clutches, a coil spring is wrapped around the driven shaft and held in an expanded configuration by the trip lever. When tripped, the spring rapidly contracts around

306-418: Is an accepted version of this page A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor , while the clutch's output shaft is connected to the mechanism that does the work . In a motor vehicle , the clutch acts as a mechanical linkage between the engine and transmission . By disengaging

340-411: Is the synchronizer ring in a manual transmission. A dog clutch is a non-slip design of clutch which is used in non-synchronous transmissions . The single-revolution clutch was developed in the 19th century to power machinery such as shears or presses where a single pull of the operating lever or (later) press of a button would trip the mechanism, engaging the clutch between the power source and

374-411: Is usually mounted directly to the face of the engine's flywheel , as this already provides a convenient large-diameter steel disk that can act as one driving plate of the clutch. Some racing clutches use small multi-plate disk packs that are not part of the flywheel. Both clutch and flywheel are enclosed in a conical bellhousing for the gearbox. The friction material used for the clutch disk varies, with

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408-494: The Teletype Model 28 and its successors, using the same design principles. IBM Selectric typewriters also used them. These are typically disc-shaped assemblies mounted on the driven shaft. Inside the hollow disc-shaped drive drum are two or three freely floating pawls arranged so that when the clutch is tripped, the pawls spring outward much like the shoes in a drum brake . When engaged, the load torque on each pawl transfers to

442-504: The belt . Its "snappy governor […] seemed to sense a heavy load, even before the load arrived." Ignition was by magneto . The WC was the first farm tractor to have rubber tires as standard equipment, and the first tractor tested on rubber in the Nebraska tractor tests . The pneumatic-rubber-tire-on-steel-wheel combination was more expensive to make than a steel wheel with cleats . To make rubber tires standard equipment while also keeping

476-507: The WC became one of the earliest farm tractors (to Buescher's knowledge, the first) to have starter and lights as standard equipment. A belt pulley was standard equipment on the WC, while a power take-off (PTO) and a mechanical power lift for the cultivator were optional. In 1936 the PTO option's list price was USD $ 50, the power lift option's, $ 35. The PTO was necessary if the buyer was planning to use

510-483: The WC could be ordered in both tricycle (narrow tread) and wide tread (that is, wide front track ) versions, with the tricycle configuration by far the most popular. The tractor could be ordered as "air front", meaning rubber tires in front and steel wheels in back. In 1939 Harry Merritt, an Allis-Chalmers executive, decided that, with over 90 percent of WCs selling with the optional electric starter and lights , these features would henceforth be standard equipment. Thus

544-480: The WC to pull the Allis-Chalmers All-Crop Harvester , a pull-type combine . The combination of a WC tractor pulling an All-Crop Harvester combine was a huge commercial success for Allis from the mid-1930s through mid-1940s. Various design changes occurred over the model's lifespan: The WC, with many good features and various first-to-market attributes, had at least a few drawbacks. Its clutch

578-414: The clutch, the engine speed (RPM) is no longer determined by the speed of the driven wheels. Another example of clutch usage is in electric drills . The clutch's input shaft is driven by a motor and the output shaft is connected to the drill bit (via several intermediate components). The clutch allows the drill bit to either spin at the same speed as the motor (clutch engaged), spin at a lower speed than

612-455: The clutch. This can provide smoother engagement and a longer lifespan of the clutch, however wet clutches can have a lower efficiency due to some energy being transferred to the oil. Since the surfaces of a wet clutch can be slippery (as with a motorcycle clutch bathed in engine oil), stacking multiple clutch discs can compensate for the lower coefficient of friction and so eliminate slippage under power when fully engaged. Wet clutches often use

646-414: The compressor as required. Motorcycles typically employ a wet clutch with the clutch riding in the same oil as the transmission. These clutches are usually made up of a stack of alternating friction plates and steel plates. The friction plates have lugs on their outer diameters that lock them into a basket that is turned by the crankshaft. The steel plates have lugs on their inner diameters that lock them to

680-449: The cost of the tractor low, the WC's designers, C.E. Frudden and Walter Strehlow, gave the WC drop gearing at the rear (bull-gear-with-pinion final drives), which allowed row-crop ground clearance while having smaller-diameter drive wheels. Drop gearing had appeared many times before on earlier tractors, but never yet for this new reason—to minimize the amount of rubber needed for the tires. Like other row-crop tractors from various makers,

714-475: The default state is for the transmission to be connected to the engine. A "neutral" gear position is provided, so that the clutch pedal can be released with the vehicle remaining stationary. The clutch is required for standing starts and in vehicles whose transmissions lack synchronising means, is used to assist in matching the speeds of the engine and transmission during gear changes to avoid gear “crashing,” which can cause serious damage to gear teeth. The clutch

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748-439: The friction disk is moved away from the flywheel by means of a lever mechanism. The majority of automotive clutches on manual transmissions are dry clutches. Slippage of a friction clutch (where the clutch is partially engaged but the shafts are rotating at different speeds) is sometimes required, such as when a motor vehicle accelerates from a standstill; however the slippage should be minimised to avoid increased wear rates. In

782-562: The late 30s, when various brands moved both brake pedals to the right foot. [REDACTED] Media related to Allis-Chalmers WC at Wikimedia Commons Cultivator Too Many Requests If you report this error to the Wikimedia System Administrators, please include the details below. Request from 172.68.168.150 via cp1114 cp1114, Varnish XID 437741680 Upstream caches: cp1114 int Error: 429, Too Many Requests at Fri, 29 Nov 2024 06:53:54 GMT Clutch This

816-442: The machine's crankshaft for exactly one revolution before disengaging the clutch. When the clutch is disengaged, the driven member is stationary. Early designs were typically dog clutches with a cam on the driven member used to disengage the dogs at the appropriate point. Greatly simplified single-revolution clutches were developed in the 20th century, requiring much smaller operating forces and in some variations, allowing for

850-414: The motor (clutch slipping) or remain stationary while the motor is spinning (clutch disengaged). A dry clutch uses dry friction to transfer power from the input shaft to the output shaft, for example a friction disk presses against a car engine's flywheel by a spring mechanism. The wheels of the vehicle only rotate when the flywheel is in contact with the friction disk. To stop the transfer of power,

884-521: The need for large, heavy castings for the transmission and rear end (as were often used in tractors of the era). Its power was ample for the time and class, allowing it to pull a two-bottom plow . With its minimalist design and low price, about 178,000 WCs were made from 1934 to 1948. The WC was assembled at the West Allis, Wisconsin , plant, near Milwaukee . In 1934, the WC was listed at USD $ 825 on rubber (standard), $ 675 on steel (optional). By 1936,

918-407: The others to keep them engaged. These clutches do not slip once locked up, and they engage very quickly, on the order of milliseconds. A trip projection extends out from the assembly. If the trip lever engaged this projection, the clutch was disengaged. When the trip lever releases this projection, internal springs and friction engage the clutch. The clutch then rotates one or more turns, stopping when

952-568: The power shaft engaging the clutch. At the end of one revolution, if the trip lever has been reset, it catches the end of the spring (or a pawl attached to it), and the angular momentum of the driven member releases the tension on the spring. These clutches have long operating lives—many have performed tens and perhaps hundreds of millions of cycles without the need of maintenance other than occasional lubrication. Cascaded-pawl single-revolution clutches superseded wrap-spring single-revolution clutches in page printers, such as teleprinters , including

986-433: The prices were $ 960 and $ 785, respectively. The tractor could also be ordered as "air front", meaning rubber tires in front and steel wheels in back. The WC had a 201 cubic inches (3,290 cc) , inline-four engine . Like most tractors of the era, the WC offered multifuel capability, running on gasoline , kerosene , or alcohol , and featured a small auxiliary fuel tank in addition to the larger main fuel tank, so that

1020-416: The tractor could be started on gasoline when cold and, once warmed up, switched to kerosene or alcohol. The engine's 4 in (100 mm) bore and 4 in (100 mm) stroke made it one of the first tractor engines (to Buescher's knowledge, the first) to be square or oversquare, that is, to have an equal or shorter stroke than bore. The WC engine tested at 22 horsepower at the drawbar and 30 at

1054-414: The transmission input shaft. A set of coil springs or a diaphragm spring plate force the plates together when the clutch is engaged. On motorcycles the clutch is operated by a hand lever on the left handlebar. No pressure on the lever means that the clutch plates are engaged (driving), while pulling the lever back towards the rider disengages the clutch plates through cable or hydraulic actuation, allowing

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1088-407: The trip lever again engages the trip projection. Most cars and trucks with a manual transmission use a dry clutch, which is operated by the driver using the left-most pedal. The motion of the pedal is transferred to the clutch using mechanical linkage, hydraulics (master and slave cylinders) or a cable. The clutch is only disengaged at times when the driver is pressing on the clutch pedal, therefore

1122-439: The wheels as the vehicle accelerates from a standing start. Some clutch disks include springs designed to change the natural frequency of the clutch disc, in order to reduce NVH within the vehicle. Also, some clutches for manual transmission cars use a clutch delay valve to avoid abrupt engagements of the clutch. In a wet clutch , the friction material sits in an oil bath (or has flow-through oil) which cools and lubricates

1156-438: Was not particularly well designed, and, like other tractors of the 1920s through mid-1930s, it lacked usability in the design of its brake controls, with a hand lever on each side of the tractor, which meant that applying the brakes took the operator's hands away from other controls. Other tractors had foot pedals on both sides, but that meant that the clutch and left brake could not be operated simultaneously. The solution came in

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