GB1480769A - Manufacture of multi-groove pulleys - Google Patents

Abstract

1480769 Making pulleys; spinning ASPRO Inc 18 Oct 1974 [19 Oct 1973] 45163/74 Headings B3A and B3J A multi V-groove sheet-metal pulley, Fig. 4 (not shown), is made from a cup-shaped blank in two spinning operations, two grooves being formed in the cylindrical side wall adjacent the base in the first operation and at least a third groove being formed in the side wall in the second operation. Formed by pressing and trimming operations, the starting blank has a hub 83 and a reinforcing ring 84 both attached as by welding. Apparatus for spinning the first pair of grooves comprises a known machine in which the headstock spindle and possibly also the tailstock spindle are driven and relatively movable axially. The machine is provided with headstock and tailstock dies and rolls for spinning the grooves. A third groove is spun in a second machine similar to the first but with different dies and rollers. The headstock dies for the first machine include a sleeve 13, Fig. 6, on which the blank is supported with its free end 86 lodged in a groove 51. Within the sleeve 13 is a spool 17, 15, 18 formed with radial slots 26, Fig. 13, to receive the shanks 35 of die elements 34 expanded, against the action of return springs 45, by an hydraulically-operated mandrel 54. Springs 22 press the spool towards the tailstock which has ring dies 61, 62, 63 bearing on the blank. During spinning by rolls 72, 73 the tailstock moves towards the headstock, and roll 73 moves into engagement with roll 72, Fig. 7. As the rolls 72, 73 are withdrawn from the roughly-formed grooves 93, finishing rolls 77, 78, Fig. 8, are moved into the grooves and the spool 17, 15, 18 moved by the tailstock against a stop collar 11, collapsing springs 22 and completing the first two V-grooves 99. For the second spinning operation the intermediate blank is mounted on a sleeve 105, Fig. 16, in which there is a spool 109, 107, 110, similar to the spool for the first operation, and carrying radially expansible die segments 125. A single rough-forming roll 159 is used, followed by a finish-forming operation, Fig. 17, in which three rolls 164, 165, 166 are used two of which maintain the shape of the previously-formed grooves and the third 164 displaces a clampsleeve 140 to expose the retained margin of the workpiece during the forming operation.