John Herkenhoff (1905-1996)
Minster Machine was started as a machine shop in 1896 by Anton Herkenhoff and built its first press in 1926. The following year Anton’s son John graduated from the University of Dayton in mechanical engineering and started work for the company. He worked on the design of a large double-crank straight-side press to stamp bases for gasoline pumps that greatly expanded the company’s capability. Starting with clutch patents for oil-drilling equipment developed by Anton, Minster introduced presses with multiple disk air friction clutch and brake on the same shaft. John Herkenhoff became General Manager in 1935 and President in 1939. Under his management, researchers at Minster obtained 61 patents, including the straight-side single-crank press, the transfer press, a series of improvements in air friction clutches that culminated in1947 with one that fitted in the flywheel of open-back-inclinable presses and doubled the speed possible with mechanical clutches.