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The Counterfeit Coin Detector Patent Archive

Every device ever patented to catch a bad coin

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Washington d.c. patent

Patent drawing of a cabinet-style coin-operated lung testing machine showing a tall glowing lamp array, an internal air cylinder and piston with a coin chute and switch mechanism below, plus a detailed diagram of the wiring connections for the lamps.

COIN-CONTROLLED TESTING-MACHINE.Santley M. Taylor · October 13, 1903

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