FINISHED FORGED SPROCKET SEGMENT METHOD AND APPARATUS

摘要

A finished toothed sprocket segment (14) is forged in a cavity (76) of a first die (70) by a second die (82) having a protrusion (88) which extends into the cavity (76). The sprocket segment (14) has first and second spaced datum pads (60, 62) formed on a first curved surface (46) of a rim (40) of the sprocket (14) which locates the sprocket segment (14) on a hub (12). The first and second datum pads (60, 62) and first and second apertures (67, 73) are located relative to each other so that distortion of the sprocket segment (14) during final heat treatment does not effect the relative position. As a result the apertures (24, 26) in the hub (12) and sprocket segment (28) are easily aligned during attachment of the sprocket segment (14) to the hub (12). Since the first die (70) requires no draft angles, the critical surfaces on the sprocket segment (14) are forged to final finish, flatness and tolerance.