Ball joint element and method of forming same

Abstract

An improved, light weight ball member for universal connections having a hollow interior both in its ball portion and connecting portion for providing high strength and light weight and method for forming it through an improved forging process, using improved forging dies.

1 . A method of forming a ball member for a ball and joint pivotal connection being formed from a single piece comprised of a ball portion adapted to be pivotally connected within a socket formed by one of the elements to be connected and a shank portion adapted to be fixedly secured in a complimentary opening of the other element to be pivotally connected, comprising the steps of forging a solid cylindrical piece of metal into the integral ball and shank portions with complimentary closed ball shaped and cylindrical shaped cavities by forging steps. 
   
   
       2 . The method as set forth in  claim 1 , wherein the forging steps comprise an initial step of forging a cylindrical cavity opening through one end of the cylindrical piece of metal and subsequently closing its open end through another forging step. 
   
   
       3 . The method as set forth in  claim 1 , wherein the forging steps include steps of forming the ball portion on successive forging steps where the external diameter is progressively increased. 
   
   
       4 . The method as set forth in  claim 1 , wherein the forging steps include steps of progressively decreasing the diameter of an end of the cylindrical portion. 
   
   
       5 . The method as set forth in  claim 4 , wherein the forging steps comprise an initial step of forging a cylindrical cavity opening through one end of the cylindrical piece of metal and subsequently closing its open end through another forging step. 
   
   
       6 . The method as set forth in  claim 5 , wherein the forging steps include steps of forming the ball portion on successive forging steps where the external diameter is progressively increased 
   
   
       7 . The method as set forth in  claim 6 , wherein the forging steps progressively increase the diameter of the cavity in the ball portion. 
   
   
       8 . The method as set forth in  claim 7 , wherein the forging steps further form a cylindrical enlargement between the ends of the cylindrical portion. 
   
   
       9 . The method as set forth in  claim 1 , wherein the forging steps include steps of forming a cavity within the solid cylindrical piece of metal, forming an inner closed end of the cavity having an inner surface defining a hemispherical shape, and forming a cylindrical portion of the cavity extending from the closed end to an open end of the piece of metal, distal from the inner closed end. 
   
   
       10 . The method as set forth in  claim 9  additionally comprising a step of drawing metal forming an inner surface of the cylindrical portion, toward the inner closed end. 
   
   
       11 . The method as set forth in  claim 10 , wherein the step of step of drawing metal additionally comprises drawing the metal inwardly at an upper end of the closed end to thereby transform the hemispherical shape of the closed end to enclose a partial spherical cavity that is more than a hemisphere but less than an entire sphere. 
   
   
       12 . The method as set forth in  claim 11  additionally comprising pressing the single piece until the shape of the inner surface of the closed end is transformed into an approximately spherical shape. 
   
   
       13 . A method of forming a ball member for a ball and joint pivotal connection being formed from a single piece comprised of a ball portion adapted to be pivotally connected within a socket formed by one of the elements to be connected and a shank portion adapted to be fixedly secured in a complimentary opening of the other element to be pivotally connected, the method comprising the steps of:
 forging a cylindrical recess in a single piece of metal such that the cylindrical recess includes an open end at a first end of the single piece of metal and a closed end of the single piece of metal;   forging an inner surface of the closed end to have a hemispherical shape having a terminal end and an open end connecting to the cylindrical recess;   drawing metal from an inner surface of the cylindrical recess into an inwardly protruding portion at the open end of the hemispherical shape;   closing the open end of the cylindrical recess by forging.   
   
   
       14 . The method as set forth in  claim 13  additionally comprising further forging the single piece of metal until the inner closed end has an approximately spherical inner surface. 
   
   
       15 . The method as set forth in  claim 13  additionally comprising forming the outer surface of the ball portion on successive forging steps where the external diameter is progressively increased. 
   
   
       16 . The method as set forth in  claim 13  additionally comprising the steps of progressively decreasing an outer diameter of the portion of the single piece of metal including the cylindrical recess. 
   
   
       17 . The method as set forth in  claim 13  additionally comprising the steps of progressively increasing an outer diameter of the portion of the single piece of metal including the closed end. 
   
   
       18 . The method as set forth in  claim 17 , wherein the steps of progressively increasing the outer diameter comprises forming the outer surface of the closed end into a ball shape. 
   
   
       19 . The method as set forth in  claim 7 , wherein the forging steps further form a cylindrical enlargement between the ends of the cylindrical portion.