Clessie Cummins
Videos
Clessie Lyle Cummins was the founder of the Cummins Engine Co. He was an entrepreneur who improved on existing diesel engines, created new diesel engine designs, was awarded 33 United States patents f
Cummins (left) showing Fred Duesenberg one of his engines
A compression release engine brake, compression brake, or decompression brake is an engine braking mechanism installed on some diesel engines. When activated, it opens exhaust valves to the cylinders,
Clessie Cummins
…problem of vehicle brakes overheating and becoming non-functional during long, steep downhill descents. As a result, he designed and patented the first compression release engine brake. The design was first offered to Cummins, but Jacobs was ultimately the company with which he partnered. In 1960, the product was sold under the Jake…
A compression release engine brake from Jacobs Vehicle Systems, popularly known as a "Jake brake"
A view of engine compression brake rocker arm (the thickest at the right of each set)
Jacobs Engine Brake Division logo
No Jake brakes sign