Zeppo, the Mechanical one of the “Marx Brothers”.

Zeppo Marx was the most mechanically inclined of the family. It is even said that he kept the family car in running order.
After leaving the group in the early 1930s, Marx met a Douglass Aircraft executive at the racetrack. The executive told the vaudevillian and movie star that he was short on machinists and was, therefore, short on machine parts.
Zeppo started work on those parts out of his garage and soon formed the company, Marman Products, known for marketing the Marman clamp, which is still commonly used in the aviation and aerospace industries.
Thus began Zeppo’s second successful career. A Day At The Races indeed!
Zeppo also received a total of three patents.
The first was in 1952 for a Vapor Delivery Pad for Distributing Moist Heat (also known as a heating pad), a common item still in use to this day.
The other two patents were received in 1969 for “Cardiac pulse rate monitor” and “method and watch mechanism for actuation by a cardiac pulse.”
When used together, they were meant to alert people with heart problems.
The watch part had two dials. One was driven by the wearer’s pulse and the other operated at a normal heartbeat rate. So, if the pulse-driven part ā€“ which was run by an electric powered magnet ā€“ started to go too fast or too slow, it would trigger an audible alarm. In other words, it was an early heart rate monitor.
via 10 People You Might Not Know Were Inventors (inventions, inventors, innovations) – ODDEE.