GB1369312A - Method of making annular channelled members - Google Patents

Abstract

1369312 Making annular members; stamping GENERAL MOTORS CORP 28 Sept 1971 [28 Oct 1971] 44782/72 Headings B3A and B3Q A method of making an annular channelled member (10), Fig. 1 (not shown), from a flat rectangular sheet of metal comprises bending the sheet and joining the ends to form a cylindrical workpiece 18, Fig. 4, and flaring one side edge of the workpiece in a cavity between annular concave and convex members and forcing the flared edge of the workpiece into a further cavity between annular concave and convex members to form an annular channelled member having a generally U-shaped configuration. The annular member (10) forms part of a hydrodynamic coupling or converter to which blades are affixed to form a rotor. The ends of the bent rectangular sheet of metal are welded together and the weld is planished. The workpiece 18 is placed on a centre post 58 of a die set 22 and it is held between the lower section 48 of a spring pad assembly 44 and a cylindrical form post 40. When a ram 25 is lowered, a curl ring 32 engages the top of the workpiece 18 and drives down the form post 40, which rests on resiliently supported pins 70. As the curl ring and form post move down, the upper edge 15 of the workpiece enters into a clearance 83 between them to form an annular flange (84), Fig. 5, (not shown). The pre-formed workpiece is then placed in a curl die set 90, Fig. 6, and formed into a channel section between a curl ring 96 and a form post 104, as in the die set 22. As the curl ring is raised after forming, a housing 126 of a stripper 124 strips the channel section member from the form post 104. If additionalforming is required, the member is placed in a restrike die set (138), Fig. 8 (not shown), wherein one limb of the U of the channelled member is made longer than the other.