Self-locking three position pressure operated switch construction

Claim 1

A pressure operated switch construction of the type having pressure applying means which operate in response to the influence of the environment surrounding the construction whereby changes in the environment control the switch operation, said switch comprising a movable contact and a physically separate contact, spring means normally holding said movable contact out of engagement with said separate contact, an outwardly extending lip defined by said movable contact, a contact strip carried by said separate contact and extending transversely adjacent said contact lip, an opening defined by said separate contact, said contact strip extending along one side of said opening, said opening being dimensioned to receive said lip, said pressure applying means operating to force said lip into engagement with said strip and to drive said lip over said strip and into said opening, a stop means formed of insulating material positioned on the opposite side of said opening for engaging said lip, said pressure applying means being adapted to move said lip into engagement with said stop means with said lip then being located within said opening and completely out of engagement with said separate contact, and means defined by said lip for locking engagement with said strip whereby said lip is permanently confined within said opening after being driven over said strip, said spring means operating to normally hold said lip out of engagement with said separate contact before said lip is driven over said strip, and said spring means operating to hold said lip in engagement with separate contact when the force of said pressure applying means is removed after said lip is driven over said strip.