GB1200298A - Improvements in or relating to machines for and methods of forming blanks - Google Patents

Abstract

1,200,298. Forging. G.K.N. SCREWS & FASTENERS Ltd. 21 Sept., 1967 [9 Sept., 1966], No. 40271/66. Heading B3H. In the pressing of a workpiece such as a nut blank, bearing cup or a backward extrusion, at a plurality of die stations M, O, P, Fig. 2, the workpiece is transferred between stations by spring-biased gripping fingers 53 on an intermittently rotated turret 27 and is pushed out of the fingers into the die and subsequently returned to the fingers. The turret 27 carries twelve sets of spring-closed gripping fingers 53 with bevelled entry edges and is adjustably mounted on a drive plate 31, Fig. 1, connected by shear pin 36 to a driving member 35 having a tapered fit 37 with a drive spigot 38. The tapered parts 35, 38 are pressed together by a stud 40. Spigot 38 carries a pin 42 engaging a slipper block 43 secured to a plate 47 which is mounted on an indexing device 49 having a scroll cam driven from the main shaft of the press. The dies 19 are secured to a die plate 17 by studs 23 and clamping straps 20. The punches 109 are carried by a punch plate 79 reciprocable through ball guides 82 on a pair of posts 80. Each punch 109 is mounted in a punch holder 102 and is adjustable vertically by a wedge plate 87 actuated by a nut 89. The punch holder is adjustable horizontally about pivot 103 by screws (106), (107), Fig. 5 (not shown), and also radially in the direction X, Fig. 4 (not shown), by nut (99). The punch has thus universal adjustment. For forming nut blanks, hexagonal section workpieces formed by pressing or cropping, are fed into the transfer fingers 53 at a loading station L. They are then transferred to station M, pushed by the punch out of the fingers and into die 19a, and formed into a first shape, Figs. 9, 10 (not shown). An ejector rod 15a then pushes the workpieces out of the die and into the fingers 53 which transfer them first to intermediate station N and then to the next die station O. Between stations M and O the workpieces are turned end to end by engagement of a gear 72 on the finger housing 56, with a fixed rack 75; guide plates (77), (78) at station O ensure that the fingers are located correctly. At station O, the workpieces are pressed into the final outer shape, Figs. 11, 12 (not shown), and at the next station P, a central web is punched out of the bore, Figs. 13, 14 (not shown). The blanks are unloaded at station Q. A further set of workpieces are being processed simultaneously in a set of similar dies at the opposite side of the press, Fig. 2. In an alternative arrangement for a horizontal nut-forming machine, the turret rotates about a horizontal axis.