A parking meter includes a timing unit, a coin receiver which can receive coins of different diameters, and a first and a second normally blocked lever which are biased for movement in mutually opposite directions about a joint axis of rotation into detecting engagement with a plurality of angularly...http://www.google.de/patents/US3961695?utm_source=gb-gplus-sharePatent US3961695 - Manually activated apparatus for timing intervals of different magnitude
