GB1417698A - Machines for and methods of forming loops at end portions of coil springs - Google Patents

Abstract

1417698 Forming spring ends BRITISH UNITED SHOE MACHINERY CO Ltd 19 Jan 1973 [21 Jan 1972] 2914/72 Heading B3E A machine for forming a loop at the end of a coil spring comprises looping means and a projection system whereby an image of the end of the spring is projected on to a screen to assist an operator in orientating the spring correctly. Fig. 2 is a longitudinal section of a machine having an aperture 16 through which the operator inserts the spring to rest on a glass plate 18. A light pipe 40 directs light from a lamp 42 (see also Fig. 3) and reflector 44 on to the spring end, and the image is formed on screen 37 by lenses 32 and mirrors 34, 36. A rotatable glass plate 38 bears an engraved pointer corresponding to the desired position of the end of the spring wire, or positions if left and right-handed springs are to be looped. The glass plate 18 is mounted in a plate 12 adjustable for focusing by screw 192. When the spring has been gripped (see below) the glass plate 18 is withdrawn by air motor 22, Fig. 3 (plan), pivotable about support 24 by a screw 26 to adjust the height of the spring relative to the loop forming tools. When the spring has been correctly orientated, it is gripped by three jaws 58, Fig. 5, slidable in grooves 56 by cams 64 and slots 62 in disc 60 rotatable by lever 72 and air motor 86 (see also, Fig. 3). A further arm in the lever works between stops 76 on a slider adjustable and lockable by knob 82, so that the travel of the jaws 58 can be set for various spring sizes. The loop forming mechanism is shown in Fig. 3, and comprises a coil opening tool 168, anvil 106, and striker 132. Each tool is mounted in a block 166, 102, 130 supported by rods 162, 96, 98 and arms 160, 92, 94 on pivots 158, 90. The tools are operated by cam members 172, 110, 138 movable between fixed surfaces 190, 114, 142 and inclined surfaces 188, 112, 140 on the blocks by air motors 170, 108, 136. Return springs 176, 118, 146 are provided. To vary the loop formed, each air motor is bodily movable along its axis by a respective lead screw mechanism operated by screws 184, 126, 154.