GB543512A - Improvements relating to machines for automatically producing pressure-shaped articles, more especially tapered bore rivets - Google Patents

Abstract

543,512. Forging hollow rivets &c. AVIATION DEVELOPMENTS, Ltd., and MUMFORD, R. H. June 24, 1940, No. 10796. [Class 83 (iv)] In a machine 1 for shaping tapered bore rivets or other articles by pressure having a mould 9, Fig. 6, moved step-by-step relative to a shaping tool 25 first to receive a blank at A, then to shape the article at B and finally to eject it at C, the mould has a plunger 11 which serves, in the first position A of the mould, to locate the blank, in the second B, as an anvil and, in the third C, to eject the article. A number of moulds is carried by a drum 2 rotated, step-by-step, about a fixed cam 15 by a ratchet thereof engaged by a pawl 28 during the last part of the up stroke of a slide 22 to which it is pivoted and which carries the tool 25. Hollow blanks fed by a tube and co-axial wire through a slot 32 of a plate 31 are received one in the recess 10 of each mould as it reaches the position A. At the next movement of the drum 2 a mould containing a blank is brought to the position B and the descending tool 25, guided by a skirt 23 engaging a recess 8 in the drum, shapes the blank. In positions A and B the plunger 11, which may have a frusto-conical recess in its active face, is supported by its projection 13 engaging surfaces 19, 20 of the cam, to form a bottom to the recess 10. At the next movement of the drum the mould, containing the shaped article, is brought to the position C, during which movement the projection 13 passes to a high surface of the cam thus lifting the plunger 11, against the action of a spring 14, to eject the article. In a modification a second shaping tool may operate at position E, blanks being fed at D and ejected at F. In further modifications there is more than one mould 9 at each angular face and a corresponding increase in the number of tools 25. The moulds, plungers, and tools may be inter-changeable with others of a different size and shape. The machine 1 may be used with any suitable press and may e.g. be bolted at 36, Fig. 1, to the inclined bed 33 of an eccentric press, driven through variable speed belt gear 46 from an electric motor 45. The press slide 43 may be connected by a yoke 44 to the ends of a rod 26 secured to the slide 22.