US Patent 7687022 Method for manufacturing a synchronizing ring

To manufacture a synchronizing ring of a synchronizing device for a variable-ratio gear transmission, this synchronizing ring having a ring body having locking teeth on an outer circumference and a friction lining made of a carbon nonwoven material bonded to a duroplastic resin on the conical inner circumference, the ring body is compressed from a sintering powder and sintered before the sintered ring body is axially compressed in a die at least in the region of the conical inner circumference. The friction lining is then glued onto the conical inner circumference of the ring body and secured in a mold under pressure while supplying heat.