Welding apparatus

Claim 1

In welding apparatus of the class comprising a pair of opposed pressing boards, means to move said pressing boards toward and away from each other for receiving therebetween superposed articles to be welded together, a heated platen for heating the surfaces of said articles, means for reciprocating said heated platen between an operative position defined between said pressing boards and an inoperative position defined outside of the area between said pressing boards, a holding mechanism for holding said articles to be welded upon the opposing surfaces of said pressing boards, and spacer means for defining predetermined gaps between said heated platen and said pressing boards, the improvement comprising: said spacer means is mounted upon either one or both of said pressing boards and said heated platen and has a height smaller than the thickness of the article to be welded so that the surface layer of said article having a thickness equal to the difference between the thickness of said article and the height of said spacer is fused by said heated platen; and said holding mechanism comprises suction disc means made of resilient material and connected to a source of vacuum, and disposed in a recess of said pressing board, and spring means is provided for biasing said suction disc so as to normally protrude beyond the inner surface of said pressing head, yet when said suction disc is actuated so as to attract said article to be welded and said pressing board is actuated toward said platen, said suction disc is retracted into said recess against the biasing force of said spring means.