Thumbwheel switch with improved thumbwheel camming structure for resilient contacts

Claim 1

A switch comprising in combination a housing; a sole rotatable digit wheel disposed in said housing; stationary spring contacts disposed in said housing; means for presetting a predetermined program of direct and inverse commutation of circuits by said spring contacts; a partly embedded contact member of said presetting means being mounted on said wheel; insulating rings of said presetting means, having shaped projections, which are intermediate portions of said contact member, and disposed concentrically therewith; and a stationary plate secured in said housing for supporting said spring contacts; a part of said spring contacts being made in the form of U-shaped contacts; the other part of said spring contacts being made in the form of a comb-shaped spring contact having blades corresponding in number to at least that of said U-shaped contacts; said comb-shaped contact and said U-shaped contacts being Arranged so that non-contacting surfaces of said U-shaped contacts, corresponding to said rings, slidingly interact with said projections of the rings; a first contacting surface of each U-shaped contact being also in contact with a blade portion of said comb-shaped contact while a second contacting surface of each U-shaped contact interacts with said contact member; said non-contacting surfaces slidingly engaging said shaped projections and being alternately moved thereby to selectively provide a contact path, and to interrupt the same, between respective ones of said U-shaped contacts and said contact member in accordance with the predetermined program of circuit commutation.