Sealed push button switch

Claim 1

A sealed self compensating push button switch comprising a hollow support body; a plurality of electrical contacts mounted in fixed positions within said support body; a movable control member mounted slidably on said support body; a resiliently deformable bellows interposed between said support body and said movable control member, said bellows engaging said support body and said movable control member in a fluid-tight manner; resilient means interposed between said support body and said movable control member; and a pluraity of movable electrical contacts carried by said movable control member and movable therewith in relation to said support body and against action of said resilient means from a extended position in which said fixed and movable contacts are electrically connected together to a retracted position in which said fixed and movable contacts are electrically disconnected from one another; said movable control member comprising an outer push button, a contact carrier element supporting said movable contacts and having a radially outwardly elastically deformable portion, and a cylindrical connection member rigidly connected to said push button and telescopically engaging said contact carrier element; said connection member comprising first and second portions, said first portion being provided with a plurality of outer annular grooves, and said second portion being tubular and extending axially from said first portion, said second section further having axial through slots and being radially inwardly elastically deformable; and rib means extending radially inwardly from said deformable portion of said contact carrier element for selective snap-engagement in said outer grooves thereby to axially lock said connection member and said contact carrier element relative to one another in any one of a plurality of distinct relative axial positions whereby, upon the application of a compression force to said push button in excess of a predetermined value, said rib means engages with a successive one of said outer grooves.