Spring biased energy absorber for vacuum switch contact shafts

Claim 1

In an electrical switch including a pair of electrical contacts, soft metal, deformable shafts respectively supporting said contacts, and spring-loaded means for selective opening and closing of the contacts as desired and for creating a predetermined static closing force between said contacts when the contacts are in a closed condition, including opening and closing apparatus operatively coupled to at least one of the shafts, the improvement comprising structure for slowing the relative closing speed of said contacts prior to the instant of impact between said contacts for absorbing a part of the impact force developed during closing of said contacts, and without substantially lessening said static closing force between the contacts when the contacts are closed, said structure including an elongated arm presenting an engagement surface; means supporting said arm for pivoting movement thereof and in a location proximal to said closing apparatus; and means associated with said arm for biasing the arm to a disposition where said surface is in the path of said closing apparatus during closing of said contacts for causing said apparatus to engage and pivot said arm immediately prior to closing of said contacts, the distance between the pivot axis of said arm and said engagement surface being substantially less than the overall length of said arm.