Abstract:
A push button assembly including an operating unit and a switch unit having an enclosure. The operating unit is comprised of a housing, fastened to the switch unit enclosure, and having a hollow interior section. The operating unit is further comprised of a collar member having one end positioned within the interior section of the housing and another end extending outward therefrom, and a mushroom head fixed to the other end of the collar member. Also provided is an actuating plunger having one end mechanically coupled to the one end of the collar member and having another end coupled to the switch unit. Further provided are means for maintaining the collar member in a first position and means for maintaining the collar member in a second position. The first position maintaining means is comprised of means for biasing the collar member in the direction outward from the interior of the housing, a projection having an upper and lower wall extending from an exterior surface of the collar member and joining at an apex distal from the exterior surface, and the interior section of the housing having a portion in juxtaposition with the upper wall of the projection to limit the outward movement of the collar member. The second position maintaining means is comprised of a washer member, a rigid spring seat, and a spring member biased toward the exterior surface of the collar member and positioned between the planes formed by the respective flat surfaces of the washer member and the spring seat, whereby the collar member is maintained in the second position when the spring member is squeezed between the upper wall of the projection and the flat surface of the washer member.