The Counterfeit Coin Detector Patent Archive

Every device ever patented to catch a bad coin

Anti-slug device

Patent drawing showing eight figures of a coin-slot mechanism with spring-loaded pivoting catches, a bridge and tongue guide, and a hooked washer-diverting chute, labeled with lowercase letters a through n.APPARATUS FOR PREVENTING FRAUD IN VENDING-MACHINESEdward Phipps Appleyard and James Johnson · July 23, 1889Patent drawing showing six figures of a coin-slot protection mechanism with a reciprocating slide, spring-loaded ejector, magnet, and coin chute, plus hand-operated views of a coin being inserted.MEANS FOR PROTECTING RECEIVING-OPENINGS OF COIN-CONTROLLED MACHINES.Almy Le Grand Peirce · March 20, 1894Patent drawing of a coin-tester showing two upright posts holding a crank-operated shaft with paired slotted heads that grip and test a coin between them, mounted on a rectangular wooden base with a spring and adjusting screw beneath.COIN-TESTER FOR SLOT-MACHINES.Morgan D. Sadtler · July 31, 1906Patent drawing of a mechanical gum vending machine cabinet showing an internal coin chute, pivoted testing gate with counterweight, discharging arm with numbered fingers, and separate compartments for genuine coins and rejected slugs.COIN-CONTROLLED SLOT OR VENDING MACHINE AND COIN-TESTING MECHANISM THEREFOR.Louis J. Disser · November 13, 1906Patent drawing showing a long sliding guide plate and strip mechanism with coin apertures, spring trigger, magnet, and abutment arm, illustrated in eight cross-sectional and plan views labeled Fig. 1 through Fig. 8.COIN CONTROLLED DEVICELouis M. Hall · May 16, 1933Patent drawing of a mechanical coin and slug selector showing a vertical housing with internal chutes, rollers, and a counter-balanced pivoting arm with adjustable stop screw that sorts coins from light and heavy slugs into separate discharge paths.COIN OR SLUG SELECTOR DEVICE OR ATTACHMENTWilliam M. Christopher · June 22, 1937Patent drawing showing a coin chute assembly with a magnet mounted beside an entrance slot, a beveled shoulder, and a retrieval slot for dislodging trapped slugs, illustrated across six labeled figures.COIN DETECTING APPARATUSAlbert E. Gebert and Floyd C. Black · December 15, 1942