Nut punching apparatus

Abstract

A nut punching apparatus has a striking punch ( 1 ), a caulking die ( 2 ), a nut feeding guide ( 10 ) having a punch passage ( 11 ) and a nut delivery opening ( 12 ) perpendicular to the passage, and a driving means ( 14 ) moving the guide along the punch. The nut ‘N’ fed through the opening is pushed into a transfer zone located ahead the punch ( 1 ) while the guide ( 10 ) is at its foremost position. This guide is retracted to its rearmost position to allow the punch to cooperate with the die ( 2 ) to punch the nut ‘N’ onto a metal plate ‘W’. The apparatus has a positioning pin ( 20 ) through the punch so that its fore end portion reciprocates taking a foraward position ahead the punch and a retracted position. The pin ( 20 ) penetrates a threaded bore of the nut ‘N’ at the transfer zone, such that the projected fore end portion of the pin ( 20 ) passing through the nut ‘N’ engages with a positioning aperture ( 30 ) formed in the metal plate ‘W’.

1 . 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.    
     
     
         2 . A nut punching apparatus as defined in    claim 1   , wherein the positioning pin is held in a bore that is formed through the striking punch, and a pneumatic cylinder is disposed in a basal end of the punch so as to drive the pin to retractably project its fore end portion beyond the fore end of the punch.  
     
     
         3 . A nut punching apparatus as defined in    claim 1    or    2   , wherein a pair of resilient pawls facing one another are disposed on opposite lateral sides of the fore end of the punch so that the nut having arrived at the transfer zone is gripped with these pawls.