The Counterfeit Coin Detector Patent Archive

Every device ever patented to catch a bad coin

Knife-edge pivot

Patent 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 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, 1877