Punch press with automatic tool changer

Claim 1

A punch press comprising a support, a vertically reciprocable ram, a tool holder on the lower end of said ram and having an opening for receiving a punch, a die holder spaced below said tool holder and having means for supporting a die, said die holder having a slug opening extending therethrough, a tool magazine on said support and releasably holding a plurality of tool sets each comprising a punch and a vertically alined die adapted to coact with one another to form a hole in a workpiece, said magazine also releasably holding a dummy set comprising a first shield adapted to cover the opening in said tool holder and further comprising a second shield adapted to cover said die holder and close off said slug opening, means for moving said magazine on said support to advance any selected one of said sets to a tool changing station, means selectively operable to cause the set in said tool changing station to be transferred from said magazine to said tool and die holders and then subsequently back to said magazine, a housing fixed to said support and enclosing said magazine, an access opening in said housing at said tool changing station and exposing the set at said tool changing station, and shield means carried by and movable with said magazine, said shield means being located adjacent the home of said dummy set and being operable, when said home is in said tool changing station, to close off said access opening and protect said tool sets of said magazine from foreign material entering into said housing through said access opening.