Patent GB-1420711-A (GB)
Title: Aparatus for forming wire links
IPC: B21F37/00
Filed: 1974-01-09
Abstract: 1420711 Forming links; shearing CRAFFORD TOOL & DIE CO 9 Jan 1974 [24 Jan 1973] 00998/74 Headings B3E and B3W In apparatus for forming wire links, each wire element is preformed and then passes through a magazine of elements before being  fed to engage a lower die member which raises the element to a link forming station where a descending die forms the link, and the clearance between the dies is adjustable to allow for using different size wire elements to form different size links. In the embodiments described, further preforming of the elements takes place in the magazine. Fig. 5 shows part of a machine driven through an operator controlled one revolution clutch 30 and shaft 22. The various actions of the machine are timed and performed by cams such as 58 on shaft 22. Cam 58 raises rod 56 through roller 59, and a latch mechanism 105, 106 (see also Fig. 6, not shown) ensures positive lowering of rod 56. Rod 56 controls lowering of a head 72 through further cam and roller mechanism 54, 55, 64, 76. Head 72 supports upper link forming die 51 and part of the further preforming apparatus 49. Further cams (not shown) on shaft 22 operate a wire feed device (not shown), a wire element cutting and preforming device 46 upstream of the magazine 48, and the lower die assembly 50. Fig. 12 is an exploded view of the cutting and preforming and feeding devices, and of the magazine and lower die assembly. Wire is fed intermittently from an aperture 209 in a guide 153. A cut-off and forming device 46 rises to shear the wire between surfaces 240, 246 so that a length of wire rests on the grooved upper surfaces of members 206, 208, which as device 46 rises further form the wire about projection 220 into an upwardly open U-shape as at W1. Meanwhile a feeder device 254 has been withdrawn through co-operating inclined faces 256, 250 as feed device 47 rises. As device 254 returns under spring force, channel 257 pushes the element, through a tapered slot 224 which inhibits return of the element, into a magazine defined between channel 228 and arbor 234. Part way along the magazine, the elements are deformed into an upwardly open C-shape, as at W2, to embrace the arbor, as described below. From the magazine the elements pass through aperture 270 to rest on lower die surface 268 of rod 266 in slot 264. Rod 266 then rises as upper die 51, Fig. 5, descends to form the element W2 into a link joined to a chain or other item which the operator has suitably positioned. Rod 266 is operated by a cam having a replaceable part, see Fig. 10 (not shown), to vary the lift of the rod so that different sized elements may be formed into different sized links. The cut-off and forming elements will also be suitably replaced. The further preforming apparatus is shown in Fig. 7, and includes two jaws 122 biased apart by resilient material 128, and passing through slots 236 (Fig. 12) in the magazine. Cam members 118 are adjustably secured to the head 72 (Fig. 5) and move through slots 238 (Fig. 12) so as to pivot the jaws together and further preform the wire elements. In another embodiment, the wire elements are preformed to C-shape as described above, and then, e.g. after plating placed in a hopper from which a flexible arbor of cross-section like arbor 234 extends to the link forming station. The hopper vibrates to feed the elements on to and along the arbor.