Patent ID: 7000319

Claim:
A method of manufacturing an outer race used in a constant velocity universal joint of a tripod type, said constant velocity universal joint comprising a cup body and a shaft extending axially outwardly from a bottom of the cup body in a direction opposite to an open end thereof, said cup body having an inner peripheral surface formed with three axially extending track grooves, said cup body further including a radially outwardly protruding wall portion, aligned with each of the track grooves, and a radially inwardly depressed wall portion aligned with a reduced diameter portion of a peripheral wall of the cup body between each of the track grooves, said protruding and depressed wall portions being so defined as to alternate with each other in a direction substantially circumferentially of the cup body, each of the reduced diameter portions of the peripheral wall of the cup body adjacent the open end of the latter having a chamfered portion defined at a peripheral lip region of the open end of the cup body, said method comprising: in an upsetting operation, forming a reduced diameter portion of a substantially cylindrical member, which eventually defines the shaft, and a large diameter portion of the substantially cylindrical member with an axially inwardly depressed recess defined in an end face of the large diameter portion, the recess having a tapered peripheral wall face, which eventually defines a general shape of each of the chamfered portions, using an upsetting technique; in a cup forming operation, forming a cup in the substantially cylindrical member by a combined pushing including a forward pushing and a rearward container pushing; and in a drawing operation, shaping the large diameter portion to a final design dimension and shape using a drawing technique, said upsetting operation being carried out prior to the cup forming operation, and said cup forming operation being carried out prior to said drawing operation.