Patent GB-926228-A (GB)
Title: Wire bending die mechanism
Inventor: FISHER ANDREW JAY
IPC: B21F35/04
Filed: 1961-05-26
Abstract: 926,228. Wire-bending machines. SAGINAW WIRE PRODUCTS Inc. May 26, 1961, No. 19180/61. Class 83 (4). A machine capable of bending a plurality of spring-wire loops to the general form shown in Fig. 4 includes means for moving the dies, which are spaced apart on both sides of the wire, through non-circular arcs whereby the wire is folded by a die which, at the end of its travel, remains at the point of contact with the wire initially engaged by it. The die-housings may be adjusted to provide for variation in the size and pitch of the loops produced, and the machine may form a plurality of straight lengths of wire simultaneously. The dies a, b, d, e, Fig. 1, on one side of the wire W are pivoted to their respective die-slides 24 at 34 and are each provided with pairs of inset hardened pins 41 around which the wire is bent to form the loops, similar dies g, h, i, j opposing them ; the two end dies f, k have one pin 41 each, and the centre die c, whilst similar in shape to those on either side, is capable only of reciprocating motion, effected by a cam-operated lever 26, Fig. 6, which moves the slide 24 towards the wire or wires against the reaction of a return spring 29, the unformed wires being released from an overhead hopper on to supports 50. The die c is moved forward to clamp the wire against a stationary element 32 whilst the opposed dies h, I on either side are swung inwards about their pivots 34 as an arcuate cam face 46, formed on the edge of each stationary cover 18 of the slide housings 14, is contacted by a roller 45 carried by each moving die. The dies b, d are similarly swung into alignment with their forwardly moving slides followed by g, j, and a, e. When forming is completed by the action of the end dies f, k, the wire has a dove-tailed configuration, arising from over-bending to a required extent to allow for " spring " on the release of die pressure, this release being effected in the reverse sequence. The shaped wire or wires are then dropped to a conveyer or rack below. Adjustable stops 47, 49 limit respectively the cam-actuated forward travel and swing of each die, but in a modification, Fig. 7, the stops 47 are eliminated in an embodiment which introduces additional slides 53, spaced between the die-housings 14, which are reciprocated in timed sequence with the slides 24. In a further modification, Fig. 8, screws 55 are fitted to the sides of the die-heads to assist the bending action ; Fig. 9 (not shown) illustrates the use of die-heads shaped to achieve the same effect by forming one side of the head so that it will contact the wire during bending. A further modification, Fig. 10, shows an embodiment adapted for the formation of wider loops than that above described, in which separately operated dies O and P engage the loop t to form the bends in conjunction with rollers 62, 64 carried by slides 57, 56, the loop being completed by the forward and arcuate movement of a further die n. A projection from the end of the slide 57 overlaps the wire and has a face 57a which engages with the edge 57d of the die P to guide the die into position.