Joseph W. Rittenhouse received his BSEE degree from Purdue in 1939; after graduation, he joined the James R. Kearney Corporation in St. Louis. War interrupted Rittenhouse's career, in 1943, and he was commissioned a Second Lieutenant. He received the Army Commendation Ribbon for meritorious achievement for his work in the U. S. Army Signal Corps and was released from active duty in 1946. Rittenhouse remained in the Army Reserve until 1954, by which time he had risen to the rank of Major.

After the war, Rittenhouse pursued graduate work in electrical engineering at the University of Missouri School of Mines and Metallurgy in Rolla where he completed his MSEE degree in 1949.

In 1954, Rittenhouse joined the Joslyn Manufacturing & Supply Co. as technical director of the High-Voltage Equipment Division. In this position he was responsible for everything from product design and manufacturing to market analysis and sales promotion. Rittenhouse became general manager of his division in 1965. In 1969, as the newly appointed vice president of electrical products, he assumed responsibility for all Joslyn products.

Rittenhouse was elected to the Board of Directors of Joslyn in 1970, and became president and chairman of the board in 1973. Relinquishing the post of president in 1978 , Rittenhouse continued as chairman of the board until his retirement in 1979.