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* Jacobs Vehicle Systems, Inc. develops and manufacturers commercial vehicle retarding and valve actuation technologies. The company produces light-duty, medium-duty, and heavy-duty engine brakes, recreational vehicle exhaust brakes, aftermarket parts and tune-up kits to heavy-duty diesel engine manufacturers in the United States, Asia and Europe. The company was incorporated in 1990 and is based in Bloomfield, Connecticut. Jacobs Vehicle Systems, Inc. operates as a subsidiary of Danaher Corporation.〔(【引用サイトリンク】url=http://www.hoovers.com/company/Jacobs_Vehicle_Systems_Inc/rfstrki-1.html )〕 == History == The Jacobs Engine Brake has been on the market since 1961, better known as the “Jake Brake”. The value of an engine retarder had been recognised many years earlier. In England in 1905, the motor car manufacturer Rover provided on its "16-20" model an auxiliary camshaft and modified exhaust cams which, when selected via a camshaft pedal, lifted the exhaust valve twice to every revolution of the shaft, causing air to be taken in from the exhaust pipe on every downward movement of the piston, compressed on the upward stroke, and then exhausted. Rover declared that "the braking effect of this device is very pronounced - in fact, for all ordinary purposes it can be used without recourse to the friction brakes". Some 26 years later, and despite the advances in friction braking, the need for such a system was experienced by inventor Clessie L. Cummins. In August 1931, Clessie Cummins, Ford Moyer, and Dave Evans driving a Cummins diesel powered Indiana truck from New York to Los Angeles attempted to set a new truck speed record across the continent. All went well until the descent of the Cajon Pass leading into San Bernardino, CA, a long and steep gravel road which almost led to the demise of the truck and its driver, Clessie Cummins. In 1955, Clessie began studying what might be done to turn his engine into an effective “brake”, or vehicle retarder. An idea for a practical method came to Clessie in 1957. The idea revolved around taking advantage of perfectly timed motion already built into Cummins and Detroit Diesel engines; these engines have a third cam on the main camshaft that activates the fuel injector of each cylinder. A simple retrofit mechanism could transfer motion to open the exhaust valve. A patent was ultimately granted by the U.S. Patent Office. Although the principles were proven by mechanically transferring the injector motion, a more practical method was to use a fully hydraulic motion and force transfer. The first retarder housings of the prototype design were installed on a Cummins diesel engine in a truck owned and operated by the Sheldon Oil Company.〔(【引用サイトリンク】url=http://www.mrsharkey.com/cummins-diesel-history )〕 The initial run with the engine brake was to one of their plants just at the eastern base of the grade, down the Sierras on U.S. Highway 50 near Lake Tahoe. In April 1960, Jacobs Manufacturing Company made the decision to establish its new Clessie L. Cummins Division, (now named Jacobs Vehicle Systems) for the manufacture of the engine brake. The first production units for the Cummins NH series engines left the factory in 1961, followed shortly by a brake for the Detroit 71 series.〔(【引用サイトリンク】url=http://www.overdriveretro.com/2011/04/08/1961-cummins-nh220-855-cubic-in-engine/ )〕 The firm split in 1986 and chuck manufacturing now takes place in Clemson, South Carolina and engine brake production in Bloomfield, CT. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Jacobs Vehicle Systems」の詳細全文を読む スポンサード リンク
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