Pneumatic control systems have long been used in places like mines and grain elevators where a spark could cause an explosion.
Around 1930 there was a burst of patents for pneumatic computers and typewriters, which didn’t seem to be aimed toward safety because most had electric motors and some were ‘adapters’ for electric typewriters.
Most of these devices were by Carlson and McClintic in Pittsburgh, with no company specified in the patent. Several were by American Automatic Typewriter, one by Underwood, and one by McBee. The latter is what steered me into this rabbit mine as I was looking for other applications of the McBee technology.
I won’t try to animate or model these, just show the Rube Goldberg complexity and indirectness of the devices.
The patents cite player piano inspiration, which is clearly visible. The machines are described as ‘reproducing typewriters’, designed to type out a form message as many times as needed by inserting the correct roll of punched paper.
Bigger question: Why wasn’t compressed air the FIRST thought for typewriters? They were using organ-like keyboards from the start. Pneumatic power would have been easier on the fingers than pure mechanical levers. Player pianos and hurdy-gurdys would then have suggested programmable mechanisms.
Hollerith turned the player piano into electric form, but air was available long before electricity. Wheatstone himself “should” have started with air telegraphs since his family made accordions and organs. His first telegraph looked like a concertina.
I guess there’s one unsatisfying answer to all of these questions. Many inventions were just an inch away from development with existing technologies, mechanical or pneumatic or hydraulic, but none of those paths were taken or even SEEN until electric telegraphs opened minds. Wheatstone was the key (lit and fig) that triggered everything else.
Polistra's Mill 