Internally toothed gear mfr. for sheet metal - uses extrusion to produce teeth thicker than original sheet

摘要

The fitting (2) forming part of the mechanism for adjusting the reclining seat of an automobile has an integrally formed internally toothed gear. The fitting is made from sheet metal 2.55 mm thick and the gear is formed by first making a circular depression with a depth greater than the metal thickness. A circular groove of V cross-section is then formed on both sides of the metal with a dia. greater than that of the depression. an extrusion operation then causes the material to flow into the required final form of the teeth and the V section grooves limit the region of the metal flow.