Grinder and method for controlled edge break production

Abstract

A robust grinding assembly is provided for grinding cooling holes in a dovetail groove by offsetting the drive shaft of the cutting assembly with respect to the center axis of the bar in which it is housed, whereby a larger sized collet can be accommodated.

1 . A grinding tool comprising: 
 a main body;    a drive shaft passage defined from a proximal end of said main body along at least a part of the length of said main body, said drive shaft passage having an axis disposed in parallel to a longitudinal center axis of said main body and laterally offset therefrom;    a cross bore defined generally transverse to said longitudinal axis at least part way through said main body to intersect said drive shaft passage;    a drive shaft disposed to extend through said drive shaft passage of said main body;    a cross head assembly disposed in said cross bore for selectively receiving and holding a cutter and for being driven to rotate said cutter by said drive shaft; and    a bearing handle detachably secured to a distal end of said main body, said bearing handle having a free distal end,    wherein said drive shaft passage is laterally offset from the longitudinal center axis of the main body in a direction away from a projecting direction of said cutter out of said main body.    
   
   
       2 . A grinding tool comprising: 
 a main body;    a drive shaft passage defined along at least a part of the length of said main body, said drive shaft passage having an axis disposed in parallel to a longitudinal center axis of said main body and laterally offset therefrom;    a cross bore defined generally transverse to said longitudinal axis at least part way through said main body to intersect said drive shaft passage;    a drive shaft disposed to extend through said drive shaft passage of said main body; and    a cross head assembly disposed in said cross bore for selectively receiving and holding a cutter and for being driven to rotate said cutter by said drive shaft;    wherein said drive shaft passage is laterally offset from the longitudinal center axis of the main body in a direction away from a projecting direction of said cutter out of said main body, and    wherein said cross head assembly includes a ⅛″ collet for receiving a ⅛″ cutter.    
   
   
       3 . A grinding tool as in  claim 1 , further comprising a torque motor operatively coupled to said drive shaft.  
   
   
       4 . A grinding tool as in  claim 3 , wherein a speed reducer is interposed between said torque motor and said drive shaft.  
   
   
       5 . A grinding tool as in  claim 3 , wherein said torque motor is axially aligned with said drive shaft and axially offset with respect to the center axis of said main body.  
   
   
       6 . A grinding tool as in  claim 2 , wherein said drive shaft passage is defined from a proximal end of the main body along at least a part of the length of the main body, and further comprising a bearing handle detachably secured to a distal end of said main body, said bearing handle having a free distal end.  
   
   
       7 . A grinding tool comprising: 
 a main body;    a drive shaft passage defined from a proximal end of said main body along at least a part of the length of said main body, said drive shaft passage having an axis disposed in parallel to a longitudinal center axis of said main body and laterally offset therefrom;    a cross bore defined generally transverse to said longitudinal axis at least part way through said main body to intersect said drive shaft passage;    a drive shaft disposed to extend through said drive shaft passage of said main body;    a cross head assembly disposed in said cross bore for selectively receiving and holding a cutter and for being driven to rotate said cutter by said drive shaft; and    wherein said drive shaft passage is defined from a proximal end of the main body along at least a portion of the length of the main body and further comprising a bearing handle detachably secured to a distal end of said main body,    wherein said bearing handle is selectively operatively coupled to said main body so as to be axially aligned with the center axis thereof.    
   
   
       8 . A grinding tool as in  claim 1 , wherein said bearing handle has a bore defined therethrough for selectively receiving an attachment rod and wherein said attachment rod is selectively coupled to said main body to secure said bearing handle thereto.  
   
   
       9 . A grinding tool as in  claim 8 , wherein said attachment rod is coupled with said main body through the utilization of a threaded fastener.  
   
   
       10 . A method of grinding an edge of a cooling hole of a dovetail groove, comprising: 
 providing a tool including a main body, a drive shaft passage defined along at least a part of the length of said main body, said drive shaft passage having an axis disposed in parallel to a longitudinal center axis of said main body and laterally offset therefrom, a cross bore defined generally transverse to said longitudinal axis at least part way through said main body to intersect said drive shaft passage, a drive shaft disposed to extend through said drive shaft passage of said main body, and a cross head assembly disposed in said cross bore for selectively receiving and holding a cutter and for being driven to rotate the cutter by said drive shaft;    securing a cutter to said cross head assembly;    operatively coupling a torque motor to said drive shaft;    inserting said main body into a dovetail groove so that the main body is disposed in a base portion of the dovetail groove and the cutter is disposed adjacent the edge to be ground;    actuating the motor; and    displacing the cutter about and along the edge to grind the same.    
   
   
       11 . A method as in  claim 10 , wherein said cross head assembly includes a ⅛″ collet and wherein said securing comprises securing ⅛″ cutter to said cross head assembly.  
   
   
       12 . A method as in  claim 10 , wherein a speed reducer is selectively interposed between said torque motor and said drive shaft.  
   
   
       13 . A method as in  claim 10 , wherein said torque motor is axially aligned with said drive shaft and axially offset with respect to the center axis of said main body.  
   
   
       14 . A method as in  claim 10 , wherein said torque motor is attached to said drive shaft at a first, proximal end of said main body and further comprising: providing a bearing handle and attaching the bearing handle to a second, distal end of the tool main body.  
   
   
       15 . A method as in  claim 14 , wherein said bearing handle is attached to said main body so as to be axially aligned with the center axis thereof.  
   
   
       16 . A method as in  claim 14 , wherein said bearing handle has a bore defined therethrough for selectively receiving an attachment rod and wherein said attachment rod is coupled to said main body.  
   
   
       17 . A method as in  claim 16 , wherein said attachment rod is threaded to said main body.  
   
   
       18 . A grinding tool as in  claim 7 , wherein said bearing handle has a bore defined therethrough for selectively receiving an attachment rod and wherein said attachment rod is selectively coupled to said main body to secure said bearing handle thereto.  
   
   
       19 . A grinding tool as in  claim 18 , wherein said attachment rod is coupled with said main body through the utilization of a threaded fastener.  
   
   
       20 . A grinding tool as in  claim 6 , wherein said bearing handle is selectively operatively coupled to said main body so as to be axially aligned with the center axis thereof.