The Counterfeit Coin Detector Patent Archive

Every device ever patented to catch a bad coin

Anti-fraud device

Patent line drawing showing a tall coin-operated cabinet mechanism (Fig. 1) with a hinged coin slide, magnet, push-handle, camera and dash-pan assembly, alongside a detail front view of the money-box (Fig. 3) and a partial side view (Fig. 2) of the slide linkage.COIN FREED OR ACTUATED MACHINE.Helen Alicia Burt · March 29, 1892Patent drawing showing a coin-detector ejector mechanism with a pivoted horseshoe magnet, bent rod, incline bar, and push-off plate mounted on a bracket, with five labeled cross-sectional figures illustrating the mechanism in normal and coin-actuated positions.EJECTOR FOR COIN-DETECTORS FOR MONEY-CONTROLLED MACHINES.Otto Jaeger and Alexander Jaeger · December 12, 1899Patent drawing showing a coin slot mechanism with a support plate, sliding coin-carrying strip with handle, housing with lateral flanges, ridges and studs for anti-fraud protection, and a magnet-equipped trigger arm, illustrated in seven labeled figures including top, side, and cross-sectional views.COIN CONTROLLED DEVICELouis M. Hall · February 14, 1933Patent drawing of a rectangular slot-machine coin box showing an inclined coin slide leading to a metallic bouncing block, with side sections illustrating the paths taken by genuine coins versus thin or soft metal slugs into a slug pocket.FRAUD PREVENTATIVE DEVICE FOR SLOT MACHINESGust Poulas · October 16, 1934Patent drawing showing a coin chute leading to a pivoted balance arm mechanism with weighted counterlevers that tips one way to accept or another way to reject a check based on its weight.CHECK SELECTING APPARATUSRalph D. Lynch · July 23, 1935Patent drawing of a coin-operated payphone front panel showing coin slots labeled 25¢, 10¢, and 5¢, a rotary dial, warning text about felony slug use, and internal mechanical diagrams of a spring-loaded plunger device for detecting slugs.SLUG ELIMINATOR FOR COIN OPERATED MECHANISMSRussell J. Hall · March 17, 1936Exploded and sectioned patent drawings of a rectangular coin-detector housing showing sliding gauge levers, a knurled sizing disc, a pivoted weight-measuring pendulum with jaws, and numerous numbered pins, screws, and channels for sorting coins from slugs.COIN DETECTING APPARATUSJohn F. Lindberg · September 23, 1941