Internally toothed sleeve ring for synchromesh gears

摘要

To manufacture a coupling sleeve for the synchromesh unit of a change-speed gear, a green powder pressing is sintered, producing an undercut (6) subsequently, behind both ends of each internal tooth. In the novel process the green pressing (7) has continuous internal teeth (4) running through, with the required, final reduced cross-section (11), at least near one end face of the collar, running up to the ends of the teeth. This is first pressed and sintered, and then, to form the undercuts (6), the teeth are upset-forged or jolted inwardly, from the end faces. Pref. there is a simultaneous reduction in the wedge angle included by the endfaces (5) of the teeth. The sintering is first carried out in tried and tested manner, without the complication of un undercut. At little expense, upsetting then forms the undercut, actually by generating an overhang. The tooth has the required reduced thickness over the intervening length, and the press tool, operating only on the ends, is small, simple and inexpensive to make. Upsetting the end angle of the tooth produces an advantageous flow of the metal, for the intended coupling application.