It was a 1931 coast-to-coast journey that nearly ended in a tragedy that first sparked the idea for what is now known as the Jake Brake^®.  In August 1931, Clessie L. Cummins along with Ford Moyer and Dave Evans left New York in a Cummins Diesel-powered Indiana truck for Los Angeles to try to break the speed record for a cross-country trip.  As the men traveled toward San Bernardino, California, one evening, Cummins was at the wheel while the two others slept. 

"About dusk on the fifth day, we reached the top of Cajon Pass west of Barstow, California. Before retiring to the sleeping compartment, Dave had warned me against this thirty-five mile stretch of mountainous downgrade. 'Wake up Ford and me when you get to Kayhone Pass,' I had understood him to say, 'I don’t want to be in this box when you start down that twister with the kind of brakes we’ve got.' I had heard but not seen, my Spanish being nonexistent, the word Cajon failed to register when the sign appeared. Soon, however, I realized my error. The brakes wouldn’t hold. Now running in third gear, I tried desperately to get into a lower speed. Nothing doing. I saw I would just have to ride it out. Well down the long grade by now, I suddenly saw something moving across the road ahead. There was a long dark shadow and then a red glow flared in the sky. I realized with new alarm that a freight train was cutting across our path. The truck roared on. Dave and Ford screamed bloody murder in the compartment behind me. And I clung to that steering wheel like a madman. Had Mack Sennett been on hand with a movie camera, he would have gotten enough footage for one of his famous Keystone Kops features. As we raced inexorably toward the crossing and doom, the train’s caboose loomed out of the darkness. Its red lights cleared the highway just as we reached the tracks. We had escaped certain death by Inches." – Clessie L. Cummins

Over the last 60 years, Jacobs has been through many changes including a few name changes.  In 1961, the Clessie L. Cummins Division of the Jacobs Manufacturing Company in West Hartford, Connecticut, began manufacturing the Model 20 engine brake for the Cummins NH 220 engine and promoted it at an ATA Convention in New York City.  In its first year, 360 Model 20 brakes were sold, but over the next few years, more engine brake models were engineered for Cummins, Detroit Diesel, and Mack engines as aftermarket products, where the brakes were installed after the production of the engine and vehicle.  By the late 1970s and early 1980s, the company was growing and moved to Bloomfield, Connecticut, where it is headquartered today.  Here a state-of-the-art research and development laboratory was established, and the company became the Jacobs Vehicle Equipment Company. 

The company was transformed with a new lean business system based on the Toyota Production System in the second half of the 1980s.  During this time the company began shifting from an aftermarket supplier to supplying engine brakes directly to the OEM’s assembly line.  In the 1990s, Jacobs’ evolution continued.  In addition to becoming Jacobs Vehicle Systems, the traditional “bolt-on” products became integrated engine braking solutions, the company instituted world-class quality systems, began shipping engine brakes to EOMs across the globe, and reached the milestone of one million engine brakes sold. Today, these traditions continue with manufacturing facilities on three continents, over 30 customers around the globe, and trillions of miles on the road.

In 1985, the American Society of Mechanical Engineers (ASME) named the Jacobs Engine Brake the 81^st National Historic Mechanical Engineering Landmark.  For more details on the Jacobs Engine Brake and Clessie Cummins journey to create the engine brake, visit the ASME historical landmark site.

After Clessie Cummins’ terrifying event in 1931, he vowed to create a solution so that an incident like this would not happen in the future.  Fast forward to 2021, and today over 9 million engine brakes have been sold by Jacobs since 1961.  Drivers all over the world have avoided nightmare rides like the one Clessie Cummins experienced 90 years ago thanks to the invention of the engine brake.  It isn’t just added downhill control that the engine brake offers.  In addition to added safety, engine brakes improve the Total Cost of Ownership (TCO) for vehicles by preventing wear and tear on the foundation brakes, saving fleets money and keeping the vehicles on the road and out of the repair shop.  In fact, engine brakes can extend the life of foundation brakes by 2-3 times.

Today’s engine brakes come in various forms such as compression release or bleeder brakes as well as Jacobs next-generation High Power Density, or HPD® engine brake.  Jacobs engineers work with engine OEMs throughout the engine development process to design, test, and optimize the engine brake.  Presently the Jacobs engine brakes are a fully integrated part of the vehicle and not only provide engine brake power going downhill, but are applied during automated shifting, cruise control, aftertreatment thermal management and advanced vehicle safety systems.

Learn more about how your engine brake can lower your Total Cost of Ownership.

Today, Jacobs’ products go beyond engine braking.  Our engineers are working on ways to help reduce emissions with products such as Cylinder Deactivation and Variable Valve Actuation.  Jacobs is working with OEMs across the globe to help them meet upcoming stringent emissions regulations by reducing NOx and CO2 emissions while improving fuel economy.  Jacobs’ emission solutions are in the heart of the vehicle – the engine – using well-established componentry that Jacobs has perfected over the last 60 years with minimal changes to the valvetrain.

You can even find our products in off-highway vehicles or a field or a mine.  Our engine brake products have been utilized in agriculture and mining for years to assist with braking and safety, but now, Jacobs has introduced Fulcrum Technology which is an ideal solution for off-road (or NRMM) applications.  Jacobs Fulcrum Bridge allows an engine brake to work with a lashless valvetrain for the first time.  Because of this, there is no longer a need to set lash, thereby reducing maintenance requirements and vehicle downtime.  Additionally, Fulcrum allows OEMs to optimize the cam design to enhance engine performance and efficiency leading to fewer emissions.

Learn more about Jacobs' New Gear.