Patent GB-235438-A (GB)
Title: Machine for straightening needles light bars and the like
IPC: B21G1/12
Filed: 1924-09-29
Abstract: 235,438. Fairweather, W., (Singer Manufacturing Co.). Sept. 29, 1924. Needles.-In a machine of the type described in Specifications 28625/10 and 26094/11, [both in Class 83 (iv), Metals, Working], for straightening light bars, wires, and particularly sewing- machine needles, the needle support is fed beneath the impact-straightener and returned at the end of the operation, the needle being then automatically removed from the support and an unstraightened needle fed into the support while the parts are in the initial straightening position. The base plate 1 carries a bed 5 having bearings for a cam-shaft 7 driven from a transverse mainshaft 10 through worm-gearing 9, the mainshaft being belt driven from a shaft S. Clutch mechanism operated from a hand lever 25 is embodied in the main shaft drive. The hammer actuating-shaft 21 is also belt driven from the shaft S and carries a cam-wheel 29 actuating the hammer rock-shaft 34. The latter is integral with a block 40 provided with a striking shoulder 42, and adjustably carrying the hammer hedve 45 which terminates in the head 48 having a hardened operative portion 49. The anvil is fitted in a block 56 adjustably secured to the bed 5. In order to move the needle axially past the hammer a sliding carriage 65 is traversed by means of a cam 70, the cam groove being shaped so as first to give a slight dwell while a series of blows is delivered adjacent to the needle shank, then a progressive feed to hammer the blade, then a second dwell to hammer the blade near the eye, and finally a quick return movement. The needle shank is supported in a groove in a block 74 having a stop-plate 81, and the hammer is arranged to operate at a point intermediate between the anvil and the shanksupport. To rotate the needle during its passage under the hammer an inclined shaft 83 carries a friction wheel 82 and is driven through gearing 100 from the cam shaft, the friction wheel being resiliently pressed into engagement with the needle by a spring 91. In order to permit the introduction or removal of needles from the pocket the friction wheel is intermittently lifted by means of lever mechanism actuated by a cam 108 on the shaft 7. The hammer impact is regulated by means of a wedge block 118, Fig. 12, interposed between a striking shoulder 42 of the striker 41 and a curved shoulder 117 on a support 116. The wedge block is resiliently connected to a vibratory lever 120 adjustably secured to a control shaft 126. The latter carries an arm 137 provided with a feeler block 139 held by a spring against the underside of the needle n to be straightened so that the stroke of the hammer is automatically adjusted according to the amount of deflection of the needle. The ejector for a finished needle comprises a lever 150 having pins 153 straddled by forks carried on a plate 154 which is provided with hooked rods 158, the plate 154 being normally held down by a spring 163. The lever 150 is operated from a cam 170 on the shaft 7 acting through further adjustable lever devices (Fig. 3), the action being timed so that on completion of a straightening operation the hooks 158 are advanced over a needle and then withdrawn. The finished needles pass down an inclined surface 171 into a shoot 172 and thence to a receptacle. The needle hopper 174 is provided with an adjustable transverse plate 179 to accommodate needles of different lengths, and the lower end is closed by a segment 183 whose upper end is provided with shallow grooves 186 and a deeper groove 187 which is of the same depth as the diameter of the needle shank. The segment is rocked by means of a cam 191 acting through a lever 183'. The needles are agitated in order to ensure the positioning of a needle in the groove by means of small cam-recesses 193, and the segment is then fed forward by a larger cam-projection 194. The segment is normally held retracted by a spring 195. An adjustable transverse bar 198 is adapted to bear upon the top of the pile of needles. The needle-transfer mechanism comprises a slide bar 202, Fig. 2, connected to a lever 209 operated by a cam 214 on the shaft 7. The forward end of the slide-bar carries a cam 220 contacting with a head on a pin 221 operated from a cam 223 on the shaft 7 while a block 225 is provided with a needle-receiving groove. The upper surface of the slide bar also carries a pivoted spring finger 230 adapted to bear upon the upper surface of the needle blade. A guard is provided for the gears 100, 101, 102 and a second guard protects the slide bar 202. A plate 268 is secured over the slideway for the carriage 65 to prevent the ingress of dirt when the carriage is advanced. In operation the carriage is moved backward during the reciprocating of the hammer, the blows of which are controlled by the feeler mechanism. When the carriage reaches its extreme position the hammer is automatically held inoperative by a cam 258 operating through a lever 253 and plunger 249. The hopper segment is simultaneously operated to bring the needle in the recess 187 into alignment with the transfer jaws 234, 225. The carriage is then moved forward, whereupon the gripping-jaws are automatically closed and the shank of the needle lifted from the hopper segment. At the end of the forward carriage movement the ejector hooks are advanced to remove the finished needle, the friction wheel 82 being raised by its cam. The slide bar 202 is thereupon immediately advanced to position a fresh needle in the block 74, where it is clamped by the descent of the frction wheel.