Unlocking mechanism

Claim 1

A rotary switch comprising, a stationary base plate, an electrically non-conductive rotatable setting plate having angularly spaced upstanding projections of equal height on a major surface thereof and having resilient rear extensions resiliently bearing on said base plate, an electrically conductive contact plate mounted on said setting plate for angular positioning thereof in dependence upon the angular position of the setting plate and having means for making an electrical connection therewith, said contact plate having angular spaced contacts upstanding in the same direction as said projections and of lesser height than said projections and angularly spaced therefrom and electrically conductive driven contact gear driven in operation for selectively making and breaking an electrical connection with the upstanding contacts and disposed coaxially with said setting plate seated on tips of said upstanding projections for sliding frictionally thereon in substantial parallelism with the setting plate, resilient means resiliently biasing the driven contact gear into engagement with said upstanding projections, said contact plate having a first set of through openings angularly spaced for receiving the projections therein when in registry therewith thereby allowing axial travel of said contact plate for seating on said upstanding contacts for making electrical connection therewith and having a second set of through openings disposed angularly spaced dispersed intermediate and alternately of the first set of openings for receiving the upstanding contacts when in registry therewith for breaking said electrical connection when said upstanding contacts are received in said second set of openings, said upstanding projections having ramp surfaces on a side thereof for engagement by edges of the first set of through openings for travelling on corresponding ramp surfaces against the force of said resilient means and seating on the tips of said upstanding projections, and means for variably angularly positioning the rotatable setting plate to different angular positions for resting thereat stationarily thereby variably setting the time at which said connection will be made.