The Counterfeit Coin Detector Patent Archive

Every device ever patented to catch a bad coin

Specific gravity test

Patent drawing of an 1853 coin tester showing a rectangular gage plate with five graduated slots labeled D through H mounted on two posts above a base, with hidden dotted lines revealing internal pivoting levers and a rod I running beneath the plate; a second elevation view shows a single lever swinging a coin through the gage into a collection area below.COUNTERFEIT-COIN DETECTOR.Gideon B. Smith · September 6, 1853Technical patent drawing showing a long pivoting lever balance with multiple circular coin-sized cavities labeled E, F, G, H, L, and M along its length, mounted on a base with two pillars, alongside a small separate weight piece labeled J and K.BALANCE FOR DETECTING SPURIOUS COIN.John Allender · November 27, 1855Patent drawing of an 1857 coin balance showing a triangular graduated scale beam mounted on uprights with a lever, index pointer, and a plate with slots sized for different U.S. gold coin denominations.BALANCE FOR DETECTING COUNTERFEIT MONEYFerdinand J. Herpers · December 29, 1857Patent drawing showing a rectangular brass plate with a sliding scale marked for gold and silver coins, numbered diameter and thickness scales, and studs for testing coin weight and size, alongside a perspective view and cross-section.Coin-DetectorH. Maranville · February 14, 1860Patent drawing showing a mechanical coin-counting apparatus with paired vertical guide channels, a central tilting balance plate, adjustable counterweights on threaded arms, and swinging vanes directing coins to separate receptacles, shown in top view and two cross-sectional views.IMPROVEMENT IN COIN-COUNTERSAron Bernstein · October 31, 1876A flat elongated metal plate resembling a paper-knife, bent at a right angle near the middle, with graduated slots labeled 10, 20, 25, and 50 near one end for testing coins of different denominations, shown in perspective and in two side views balancing a coin.IMPROVEMENT IN DETECTERS OF COUNTERFEIT COINJohn A. Thompson · February 27, 1877Patent drawing showing a small tilting platform device with hooked gages that hold a fifty-cent coin in place, a knife-edge pivot beneath the platform, and a hidden balance-weight chamber, illustrated in level and tipped positions plus a top-down view of the coin secured by the gages.IMPROVEMENT IN COUNTERFEIT-COIN DETECTERSJohn Wiarda · March 20, 1877Six circular diagrams of a metal coin-testing disk showing concentric slots labeled a, c, and diameter markings 10, 25, and 50, with a pivoting knife-edge rod extending from the side, illustrating coins tilting up or down depending on weight.IMPROVEMENT IN COUNTERFEIT-COIN DETECTERSJohn W. Sutton · March 27, 1877Technical patent drawing showing a bent metal bar with flanges and paired clasping lugs used as a tipping balance to test coin weight, alongside cross-section and alternate frame views.IMPROVEMENT IN COUNTERFEIT-COIN DETECTERSJohn A. Thompson · April 3, 1877Technical patent drawing of a balance-lever coin detector showing a gage-arm A with cross-pieces B, D, and K on one side, an elongated weighted arm E on the other, pivoted atop a stand G, with additional detail views of the pivot mechanism and gage cross-section.IMPROVEMENT IN COIN-DETECTERSPatrick Doherty · June 19, 1877Patent drawing of a rectangular metal case with two longitudinal slots in its top plate, an internal curved balance bar visible in cross-section, a projecting handle arm, and guide bars beneath the slots, shown from side, top, and end views.IMPROVEMENT IN COUNTERFEIT-COIN DETECTERSEdward Kronenberg · September 25, 1877Patent drawing showing five figures of a pocket coin-testing device with labeled tubes (A), a weighted trip-lever (B), and casing (C), including top views and cross-sections, and a version mounted to a counter or money-drawer.IMPROVEMENT IN COUNTERFEIT-COIN DETECTERS.William H. Rice · October 16, 1877Patent drawing of a combined postal scale and counterfeit-coin detector showing a plan view (Fig. 1) with a large graduated disk marked for gold, silver, and postage rates, and a side cross-section (Fig. 2) showing the beam, counterweight box with shot, and coin pan.IMPROVEMENT IN POSTAL-SCALE AND COUNTERFEIT-COIN DETECTER.Harvey Maranville · April 30, 1878Patent drawing showing a rectangular cabinet divided into rows of labeled coin-detector cases (A) with inlet slots (a) for coin denominations, feeding into a series of adjacent boxes (D), plus a cross-sectional view revealing an internal tilting poise mechanism (B) inside a detector case.IMPROVEMENT IN COUNTERFEIT-COIN DETECTER AND COIN-RECEIVER.Samuel A. Field · May 14, 1878Patent drawing of a 19th-century counterfeit coin detector showing a slotted measuring table above a coin box, with internal cylinders, floats, and trays for weighing coins using quicksilver.COUNTERFEIT-COIN DETECTOR.John B. Atwater · September 19, 1882Patent drawing of a folding pocket coin balance, showing a slotted metal plate pivoting on knife-edge bearings between two hinged standards mounted in a shallow box, with a small counterweight at one end and a removable supplemental plate with smaller slots for testing gold coins.COIN-TESTER.Merritt Clarke · March 6, 1883Patent drawing of a countertop coin-detector showing a boxed housing with three coin slots and internal balance beams mounted on a turned pedestal base, plus detail views of individual pivoting coin-rest balances and their adjustable weighted arms.COIN-DETECTORThomas I. Porter · March 13, 1900Technical patent drawing showing a complex mechanical coin-testing apparatus with multiple gears, levers, springs, and pivoting arms arranged within a rectangular housing frame, including a knob-topped shaft and numbered reference points identifying individual components.APPARATUS FOR DISTINGUISHING GENUINE FROM SPURIOUS COINSJohn E. Evard · December 17, 1901Mechanical schematic of a vending-machine coin selector showing gears, pivoted levers, a weighted balancing arm, and chutes for accepting or returning coins.AUTOMATIC FRAUD PREVENTIVE MEANS FOR CHECK CONTROLLED APPARATUSAaron A. Knee · October 11, 1932Patent drawing of a rectangular glass-windowed coin detector casing with a circuitous internal track, showing pivoted selector wheels, a counterweighted trap door, and coin recesses labeled with numbered reference lines.DEVICE FOR REJECTING SPURIOUS COINSCecil H. Underwood · March 5, 1935