Tool and method for forming surface features onto a workpiece

Abstract

A tool for forming an annular workpiece, such as a gear, is provided. The tool has a cylindrical inner form member that has a perimeter that is surrounded by the gear. Driver moves axially along a central axis of the inner form member and gear. A plurality of outer form members rest on a support and are slideable with respect to the support. Each outer form member is provided with a tapered surface that corresponds with and engages with a tapered surface of the driver. Axial movement of the driver causes the tapered surfaces to engage, sliding the outer form members radially inwardly toward the gear. The outer form members are provided with surface features that form teeth onto the gear when the driver presses the outer form members against the gear.

What is claimed is: 
     
         1 . A tool for forming an annular workpiece, comprising:
 one or more inner form members defining a perimeter;   a plurality of outer form members collectively disposed in an annular shape about a central axis and radially outward from the perimeter, each outer form member having an inner surface facing the perimeter and an opposing outer surface, each inner surface defining a surface feature for forming a corresponding outer surface feature onto the workpiece; and   a driver member configured to translate along the axis to cause the outer form members to move radially inward toward the workpiece to form the outer surface features onto the workpiece.   
     
     
         2 . The tool of  claim 1 , wherein each outer surface of the outer form members is tapered with respect to the central axis, and the driver member includes an inner surface that is tapered with respect to the central axis. 
     
     
         3 . The tool of  claim 2 , wherein the inner surface of the driver member slides along the outer surfaces of the outer form members to force the outer form members to move radially inward toward the workpiece. 
     
     
         4 . The tool of  claim 1 , wherein the perimeter defines a series of surface features for forming corresponding inner surface features onto the workpiece. 
     
     
         5 . The tool of  claim 4 , wherein the outer form members are radially slidable with respect to the perimeter to form the outer surface features and inner surface features onto the workpiece. 
     
     
         6 . The tool of  claim 1 , further comprising a support member having a generally planar surface for supporting the outer form members. 
     
     
         7 . The tool of  claim 6 , wherein the support member includes a plurality of tracks extending radially from the central axis. 
     
     
         8 . The tool of  claim 7 , wherein each outer form member includes a protrusion extending into one of the tracks to facilitate sliding movement of the outer form members along the support member. 
     
     
         9 . The tool of  claim 1 , wherein each outer form member is biased radially outward as the driver member moves the outer form members radially inward. 
     
     
         10 . A method of forming an annular workpiece, comprising:
 locating the annular workpiece between a generally cylindrical inner form member and a plurality of outer form members, each outer form member being disposed on a support and having an outer surface; and   driving a driver member toward the support and against the outer surfaces to force the outer form members to slide along the support and press against the annular workpiece.   
     
     
         11 . The method of  claim 10 , wherein the outer surfaces are tapered with respect to a central axis of the generally cylindrical inner form member. 
     
     
         12 . The method of  claim 10 , further comprising annularly arranging the outer form members about the inner form member. 
     
     
         13 . The method of  claim 10 , further comprising providing a plurality of surface features on an outer surface of the inner form member, wherein the driving presses the workpiece against the surface features to form corresponding surface features on an inner annular surface of the workpiece. 
     
     
         14 . The method of  claim 10 , further comprising providing a surface feature on each of the outer form members, wherein the driving presses the workpiece against the surface features to form corresponding surface features on an outer annular surface of the workpiece. 
     
     
         15 . The method of  claim 10 , wherein the outer form members collectively define a circumference about the workpiece, wherein the driving reduces the circumference. 
     
     
         16 . A system for forming a gear, the system comprising:
 a support;   a plurality of outer form members supported by the support and arranged annularly about a central axis, the outer form members being configured to move toward and away from the central axis along the support, each outer form member being biased away from the central axis; and   a driver selectively engaged with at least one of the outer form members;   wherein movement of the driver toward the support presses the outer form member toward the central axis to form an outer surface of the gear.   
     
     
         17 . The system of  claim 16 , further comprising an inner form member disposed radially inward from the outer surface of the gear to form inner surface features on the gear. 
     
     
         18 . The system of  claim 17 , wherein the inner form member is moveable along the central axis relative to the support. 
     
     
         19 . The system of  claim 16 , wherein the outer form members collectively define a circumference that is variable when the driver engages the at least one of the outer form members. 
     
     
         20 . The system of  claim 16 , wherein the outer form members each define a tapered outer surface facing away from the central axis that engages with a corresponding tapered surface of the driver.