Rankin Handcuffs

Rankin handcuffs patented by Andrew Rankin Feb 20 1866 #52,745. The dip in the bow is to allow the jailor to insert his thumb since the cuffs need a hard pull to open when unlocked. Complicated to operate: to unlock, screw in key a few turns, then pull key outwards and release it, then pull cuffs open. To lock: pull key out, close cuffs lightly, then slam them closed, push key inwards and unscrew it. Incorrect operation can damage the cuffs.