Hole punch for plastics, paper, metal or textile - has spring loaded cutting ram provided with slight twist by balls operating in helical grooves

摘要

The cutting rams are mounted on a holder (2) and each ram (20) is rotatable to a limited extent. Following punching, the ram is allowed to retract slightly against the force of a spring (27) in an enlarged part of the housing (29). The rotary movement of the ram is induced by a number of steep spiral grooves (32) in which run sets of steel balls (33) seated in a bush (34a). The cutting ram has a reduced diameter end (24) with a shoulder (25) for the spring to rest on.