Abstract: Manufacturing method for a tubular shell of a constant velocity universal-joint for flexibly coupling two rotary shafts, to one of which the shell is fixed at a flange thereof. The method comprises a groove and preliminary flange forming process and a flange forming process. In the former process a hollow cylindrical blank is applied pressing in a radial direction for forming plural grooves therein and forming at the same time a preliminary flange at one end of the cylindrical blank by expanding it into a funnel shape, and in the latter process the preliminary flange formed on a semi-finished article in the former process is formed into a completed flange by a flange forming die, while holding the semi-finished article in a restrained status under pressure from either side, external and internal, by means of restraining dies. An apparatus suitable for performing the method is also disclosed.

Abstract: A shell for a universal joint for flexibly coupling two rotary shafts. The shell is constructed using a manufacturing technique to produce a shell of light weight and excellent strength. The shell generally has a hollow cylindrical configuration and is secured at one end to a rotary shaft and formed to have a plurality of grooves extending parallel to its cylindrical axis. A second rotary shaft includes portions which engage the plurality of grooves for transmitting movement from one shaft to the other through the shell. The shell may be formed using a tubular work piece or a planar work piece, and may be provided in substantially complete form by use of a machine press prior to subjecting the material to an ironing process to make the grooves of accurate shape and dimension. The process is performed such that no machining is required to form the grooves and produce the shell.