Workpiece holding clamp mechanism of a forging machine

Abstract

A workpiece holding clamp mechanism includes first and second clamp arms associated with respective clamp jaws. The first clamp arm is mounted on a transmission shaft, and has a sleeve part sleeved onto the transmission shaft, a first prong extending axially from the sleeve part and having a shaft receiving recess, a second prong extending axially from the sleeve part and spaced apart transversely from the transmission shaft, and a connection part bridging the first and second prongs. The first and second prongs cooperate with the sleeve part and the connection part to confine a receiving space which is aligned with a key groove of the transmission shaft into which a key is inserted. The connection part reduces an incidence of crack formation due to stresses in the first clamp arm.

1 . A workpiece holding clamp mechanism comprising: 
 first and second clamp arms which have first and second clamp jaws, respectively, and which are turnable to open or close said first and second clamp jaws;    a transmission shaft having a key groove; and    said first clamp arm being mounted on said transmission shaft, and including a sleeve part sleeved onto said transmission shaft proximate to said key groove and having a shaft receiving hole, a first prong extending axially from said sleeve part and having a shaft receiving recess which extends axially from said shaft receiving hole, a second prong extending axially from said sleeve part and spaced apart transversely from said transmission shaft, and a connection part bridging said first and second prongs, said first and second prongs cooperating with said sleeve part and said connection part to confine a receiving space which is aligned with said key groove;    said first clamp arm further having a key disposed within said receiving space and inserted into said key groove, and a fastener that extends through said second prong and that locks said key in said key groove.    
   
   
       2 . The workpiece holding clamp mechanism as claimed in  claim 1 , wherein said connection part is formed as one piece with said first and second prongs and said sleeve part.  
   
   
       3 . The workpiece holding clamp mechanism as claimed in  claim 1 , wherein said first clamp arm further has a lower extension that projects downward from said sleeve part and that is connected to said first clamp jaw.  
   
   
       4 . The workpiece holding clamp mechanism as claimed in  claim 3 , further comprising a returning spring, said first clamp arm further including an upper extension that projects upward from said sleeve part to be biased by said returning spring.  
   
   
       5 . A workpiece holding clamp mechanism comprising: 
 a transmission shaft having a first key groove;    a driven shaft parallel to and driven by said transmission shaft;    a swing arm mounted on said transmission shaft, said swing arm including a sleeve part sleeved onto said transmission shaft proximate to said first key groove and having a shaft receiving hole, a first prong extending axially from said sleeve part and having a shaft receiving recess which extends axially from said shaft receiving hole, a second prong extending axially from said sleeve part and spaced apart transversely from said transmission shaft, and a connection part bridging said first and second prongs, said first and second prongs cooperating with said sleeve part and said connection part to confine a receiving space which is aligned with said first key groove, said swing arm further having a key disposed within said receiving space and inserted into said first key groove, and a fastener that extends through said second prong and that locks said key in said first key groove;    a first clamp arm mounted on said transmission shaft opposite to said swing arm; and    a second clamp arm mounted on said driven shaft.    
   
   
       6 . The workpiece holding clamp mechanism as claimed in  claim 5 , wherein said connection part is formed as one piece with said sleeve part and said first and second prongs.  
   
   
       7 . The workpiece holding clamp mechanism as claimed in  claim 5 , wherein said swing arm further includes a pair of spaced apart lugs projecting radially from said sleeve part, and a roller mounted between said lugs.  
   
   
       8 . The workpiece holding clamp mechanism as claimed in  claim 5 , wherein said transmission shaft further includes a second key groove, said first clamp arm including a sleeve part sleeved onto said transmission shaft proximate to said second key groove and having a shaft receiving hole, a first prong extending axially from said sleeve part of said first clamp arm and having a shaft receiving recess which extends axially from said shaft receiving hole of said first clamp arm, a second prong extending axially from said sleeve part of said first clamp arm and spaced apart transversely from said transmission shaft, and a connection part bridging said first and second prongs of said first clamp arm, said first and second prongs of said first clamp arm cooperating with said sleeve part and said connection part of said first clamp arm to confine a receiving space which is aligned with said second key groove, said first clamp arm further having a key disposed within said receiving space of said first clamp arm and inserted into said second key groove, and a fastener that extends through said second prong of said first clamp arm and locks said key of said first clamp arm in said second key groove.