Home Page American Government Reference Desk Shopping Special Collections About Us Contribute



Escort, Inc.






GM Icons
By accessing/using The Crittenden Automotive Library/CarsAndRacingStuff.com, you signify your agreement with the Terms of Use on our Legal Information page. Our Privacy Policy is also available there.

Jacobs Vehicle Systems


Jacobs Vehicle Systems
Vehicle Systems Manufacturer

Topic Navigation
Official Site: JacobsVehicleSystems.com
Wikipedia: Jacobs Vehicle Systems

Page Sections
History
Article Index
Manufacturers of a system that actuates engine valves to slow a vehicle, commonly known as a Jake Brake.

History

The following section is an excerpt from Wikipedia's Jacobs Vehicle Systems page on 21 December 2020, text available via the Creative Commons Attribution-ShareAlike 3.0 Unported License.

Jacobs Vehicle Systems, Inc. is an American company that engineers, 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 its domestic market in America, as well as in Asia and Europe. The company was incorporated in 1990 and is based in Bloomfield, Connecticut. Jacobs Vehicle Systems, Inc. operates as a subsidiary of Altra Industrial Motion Corporation.

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. 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.

The firm split in 1986 and chuck manufacturing now takes place in Clemson, South Carolina and engine brake production in Bloomfield, CT.


Article Index

DateArticleAuthor/Source
12 June 2004Jacobs Vehicle Systems Wins Hino Motors Award for Technology & Development 2003 TMJacobs Vehicle Systems





The Crittenden Automotive Library