Joseph J. Zimmermann Jr., 92, who in 1948 invented one of the first telephone answering machines, died March 31 in Brookfield, Wis. The cause of death was not announced.
Zimmermann was running his own heating and air-conditioning firm and didn't have enough money for a secretary, so he invented an answering machine to take calls when he was out of the office.
According to an obituary in the Milwaukee Journal-Sentinel, the answering machine, called the Electronic Secretary Model R1, weighed 80 pounds and responded to the phone's ring by lifting the receiver from its cradle, playing a 78-rpm record with a message, then tripping a wire recorder to record the caller's response.
Zimmermann went into business with a partner, George W. Danner, to manufacture the devices. By 1957, their firm, Electronic Secretary Industries, had sold more than 6,000 of the machines. General Telephone purchased the company and its patent rights that year.
A Milwaukee native, Zimmermann earned an electrical engineering degree from Marquette University. He served in the Army Signal Corps in World War II and was among the first soldiers to land on Omaha Beach in Normandy, France, on D-day.