Bobbin Wound Coil for an Electromagnetic Coupling

Abstract

A bobbin wound coil for an electromagnetic coupling includes a bobbin having a cylindrical body disposed about a central axis, end flanges disposed at each axial end of the body and a terminal connector on an exterior side of one of the end flanges. The terminal connector includes a body defining a central cavity and a post extending from an exterior surface of the body of the terminal connector. A coil includes a beginning portion extending through the body of the terminal connector and the end flange on which the terminal connector is located, an end portion extending through the body of the terminal connector and the end flange, and a center portion extending between the beginning portion and the end portion and wound about the cylindrical body of the bobbin. One of the beginning portion and the end portion of the coil is wound about the post.

What is claimed is: 
     
         1 . A bobbin wound coil for an electromagnetic coupling, comprising:
 a bobbin including
 a cylindrical body disposed about a central axis; 
 a first end flange disposed at a first axial end of the cylindrical body and extending radially outwardly therefrom, the first end flange defining an interior side facing the cylindrical body and an exterior side facing away from the cylindrical body; 
 a second end flange disposed at a second axial end of the cylindrical body and extending radially outwardly therefrom, the second end flange defining an interior side facing the cylindrical body and an exterior side facing away from the cylindrical body; and, 
 a terminal connector on an exterior side of the first end flange, the terminal connector including
 a body defining a central cavity; and, 
 a first post extending from an exterior surface of the body of the terminal connector; and, 
 
 a coil having a beginning portion extending through the body of the terminal connector and the first end flange, an end portion extending through the body of the terminal connector and the first end flange, and a center portion extending between the beginning portion and the end portion and wound about the cylindrical body of the bobbin
 wherein one of the beginning portion and the end portion of the coil is wound about the first post. 
 
   
     
     
         2 . The bobbin wound coil of  claim 1 , further comprising a locking tab extending from the exterior surface of the body of the terminal connector and wherein the first post is radially aligned with the locking tab. 
     
     
         3 . The bobbin wound coil of  claim 2  wherein the locking tab is triangular in cross-section and includes a radially extending edge along the exterior surface of the body of the terminal connector, an axially extending edge extending away from the exterior surface of the body of the terminal connector and an inclined edge extending between the radially extending edge and axially extending edge. 
     
     
         4 . The bobbin wound coil of  claim 1  wherein the terminal connector further includes a second post extending from the exterior surface of the body of the terminal connector and another of the beginning portion and the end portion of the coil is wound about the second post. 
     
     
         5 . The bobbin wound coil of  claim 4  wherein the terminal connector includes third and fourth posts extending from the exterior surface of the body of the terminal connector, the beginning portion of the coil wound about two of the first, second, third and fourth posts and the end portion of the coil wound about another two of first, second, third and fourth posts. 
     
     
         6 . The bobbin wound coil of  claim 1  wherein the beginning portion of the coil extends through a first opening in the terminal connector and a first opening in the first end flange and the end portion of the coil extends through a second opening in the terminal connector and a second opening in the first end flange, the second opening in the terminal connector forward of the first opening in the terminal connector in a first circumferential direction and the second opening in the first end flange rearward of the first opening in the first end flange in the first circumferential direction, the beginning portion of the coil including a first section extending from the first opening in the terminal connector to the first opening in the first end flange and the end portion of the coil including a first section extending from the second opening in the terminal connector to the second opening in the first end flange, the first section of the end portion of the coil crossing over the first section of the beginning portion of the coil. 
     
     
         7 . The bobbin wound coil of  claim 1  wherein the body of the terminal connector includes axially spaced inner and outer walls, first and second circumferentially spaced side walls extending between the inner and outer walls and a radially inner side wall extending between the inner and outer walls, the inner wall of the body of the terminal connector including first and second circumferential end sections and a center section disposed between the first and second circumferential end sections and separated from the first and second circumferential end sections by first and second openings in the terminal connector, and a portion of one of the first circumferential end section, the second circumferential end section, and the center section is spaced from the radially inner side wall to define a first recess configured to receive one of the beginning portion and the end portion of the coil. 
     
     
         8 . The bobbin wound coil of  claim 1  wherein an axial thickness of the first end flange varies to define a first recess in the exterior side of the first end flange bordered by a radially inner wall, a radially outer wall and first and second side walls extending radially between the radially inner wall and the radially outer wall, the radially outer wall including a first opening extending therethrough and in communication with the first recess. 
     
     
         9 . The bobbin wound coil of  claim 1 , further comprising an anti-rotation member extending from one of the cylindrical body, the first end flange and the second end flange and configured to engage a field shell of the electromagnetic coupling. 
     
     
         10 . The bobbin wound coil of  claim 1 , further comprising means for inhibiting rotation of the bobbin relative to a field shell of the electromagnetic coupling. 
     
     
         11 . A method of forming a bobbin wound coil for an electromagnetic coupling, comprising:
 providing a bobbin including
 a cylindrical body disposed about a central axis; 
 a first end flange disposed at a first axial end of the cylindrical body and extending radially outwardly therefrom, the first end flange defining an interior side facing the cylindrical body and an exterior side facing away from the cylindrical body; 
 a second end flange disposed at a second axial end of the cylindrical body and extending radially outwardly therefrom, the second end flange defining an interior side facing the cylindrical body and an exterior side facing away from the cylindrical body; and, 
 a terminal connector on the exterior side of the first end flange, the terminal connector including
 a body defining a central cavity; and, 
 a first post extending from an exterior surface of the body of the terminal connector; 
 inserting the beginning portion of the coil through the terminal connector and the first end flange; 
 winding the coil about the cylindrical body; 
 inserting an end portion of the coil through the first end flange and the terminal connector; and, 
 winding one of the beginning portion and the end portion of the coil about the first post. 
 
   
     
     
         12 . The method of  claim 11  wherein the terminal connector includes a locking tab extending from the exterior surface of the body of the terminal connector and the first post is radially aligned with the locking tab. 
     
     
         13 . The method of  claim 12  wherein the locking tab is triangular in cross-section and includes a radially extending edge along the exterior surface of the body of the terminal connector, an axially extending edge extending away from the exterior surface of the body of the terminal connector and an inclined edge extending between the radially extending edge and axially extending edge. 
     
     
         14 . The method of  claim 11  wherein the terminal connector further includes a second post extending from the exterior surface of the body of the terminal connector and the method includes winding another of the beginning portion and the end portion of the coil about the second post. 
     
     
         15 . The method of  claim 14  wherein the terminal connector further includes third and fourth posts extending from the exterior surface of the body of the terminal connector and the method includes winding the one of the beginning portion and the end portion of the coil about the third post and winding the another of the beginning portion and the end portion of the coil about the fourth post. 
     
     
         16 . The method of  claim 11 , further comprising inserting the beginning portion of the coils through a first opening in the terminal connector and a first opening in the first end flange and inserting the end portion of the coil through a second opening in the terminal connector and a second opening in the first end flange, the second opening in the terminal connector forward of the first opening in the terminal connector in a first circumferential direction and the second opening in the first end flange rearward of the first opening in the first end flange in the first circumferential direction, the beginning portion of the coil including a first section extending from the first opening in the terminal connector to the first opening in the first end flange and the end portion of the coil including a first section extending from the second opening in the terminal connector to the second opening in the first end flange, the first section of the end portion of the coil crossing over the first section of the beginning portion of the coil. 
     
     
         17 . The method of  claim 11  wherein the body of the terminal connector includes axially spaced inner and outer walls, first and second circumferentially spaced side walls extending between the inner and outer walls and a radially inner side wall extending between the inner and outer walls, the inner wall of the body of the terminal connector including first and second circumferential end sections and a center section disposed between the first and second circumferential end sections and separated from the first and second circumferential end sections by first and second openings in the terminal connector, and a portion of one of the first circumferential end section, the second circumferential end section, and the center section is spaced from the radially inner side wall to define a first recess, the method further including:
 inserting the beginning portion of a coil through the first opening in the inner wall of the terminal connector; and, 
 inserting the end portion of the coil through the second opening in the inner wall of the terminal connector
 wherein one of the beginning portion and end portion of the coil extends through the first recess. 
 
 
     
     
         18 . The method of  claim 11  wherein an axial thickness of the first end flange varies to define a first recess in the exterior side of the first end flange bordered by a radially inner wall, a radially outer wall and first and second side walls extending radially between the radially inner wall and the radially outer wall, the radially outer wall including a first opening extending therethrough and in communication with the first recess. 
     
     
         19 . The method of  claim 11  wherein the bobbin further includes an anti-rotation member extending from one of the cylindrical body, the first end flange and the second end flange and configured to engage a field shell of the electromagnetic coupling. 
     
     
         20 . The method of  claim 11  wherein the bobbin further includes means for inhibiting rotation of the bobbin relative to a field shell of the electromagnetic coupling.