Nut punching apparatus

A nut punching apparatus comprising:

• a striking punch for thrusting a nut onto a metal plate;
• a caulking die facing the punch through the metal plate;
• a nut feeding guide having a punch passage and a nut delivery opening;
• the passage accommodating the punch to be slidable therein;
• the opening extending perpendicular to the passage;
• and
• a driving means for moving the nut feeding guide fore and aft along the punch longitudinally thereof, such that the nut having advanced through the delivery opening is pushed into a transfer zone located ahead a fore end of the striking punch while the nut feeding guide is at its foremost position, and
• such that the nut feeding guide is retracted to its rearmost position so as to allow the striking punch to cooperate with the caulking die to punch the nut onto the metal plate,
• the apparatus further comprising a positioning pin that extends through the striking punch along an axis thereof so that a fore end portion of the pin reciprocates between its projected position ahead the fore end of the punch and its retracted position behind this fore end, such that the pin penetrates a threaded bore of the nut which has arrived at the transfer zone ahead the punch,
• whereby the projected fore end portion of the positioning pin passing through the nut is brought into engagement with a positioning aperture previously formed in the metal plate at its portion to which the nut is to be punched.