Patent ID: 7157650

Claim:
An electrical switch comprising a casing ( 1 ) having a base( 21 ), first, second and third conductive tracks ( 31 , 27 , 34 ) on said base, and first and second conductive domes ( 3 , 5 ) supported on the base and in contact, respectively, with said first and third tracks ( 31 , 34 ), the domes being initially out of engagement with each other, the second dome ( 5 ) being downwardly depressable against the first dome ( 3 ) and the first dome being downwardly depressable against said second contact ( 27 ), wherein: said base has a lower surface with said first track ( 31 ) lying threreat, and said base has a raised surface lying above said lower surface with said third track ( 34 ) lying thereat; said first dome ( 3 ) has opposite first edges ( 51 ) spaced apart by a first length, said opposite first edges lying on said lower surface and one of said first edges lies on said first track ( 31 ); said second dome ( 5 ) has opposite second edges ( 57 ) spaced apart by a second length that is greater than said first length, said opposite second edges lying on said raised surface and one of said second edges lying on said second track ( 34 ).