Patent GB-1315001-A (GB)
Title: Apparatus and method of edge stitching workpieces
IPC: D05B23/00
Filed: 1970-04-14
Abstract: 1315001 Feeding and delivering sheets BATA SHOE FINANCIAL CORP OF CANADA Ltd 14 April 1970 [14 April 1969] 17581/70 Heading B8R [Also in Division D1] Irregularly shaped workpieces such as quarters, vamps and tongues of shoe uppers are fed automatically to a sewing machine. General arrangement.-Workpieces are lifted one at a time from a storage bin 32, Fig. 1, by suction cups carried by swinging bar 15 and delivered on to a conveyer 16 (if necessary via a turn-over mechanism 18) which feeds them into contact with retractable aligning pins 20 on the work-table 12. Suction grippers 286, 288, on a travelling arm 24 lift the correctly aligned workpieces, turn them through approximately 90 degrees, move them inwards or outwards to a predetermined position determined by a photoelectric cell PR411, Fig. 22 and translate them towards the stitching head. The workpieces are moved through the stitching station, along with an edging tape folded over the edge, by the motion of the stitching needle and a feed dog, the path of the stitching being curved to follow the edge of the workpieces by the presser wheel 340, guide member 360 and holding pins 358, 322, which are controlled by photoelectric devices PR 711F, PR 711B and PR 712, Fig. 22. After completion of stitching the thread and tape are severed by a chopper 28, Fig. 2 and the completed workpieces are lifted by suction grippers 392, Fig. 2, carried by a travelling arm 30 and delivered into storage bins. The whole sequence of operations is controlled by a switching device associated with an electrical circuit. Feed arrangements.-The workpieces are stored in bins 32, 34, Fig. 1, and automatically fed upwardly to a predetermined position, controlled by a photocell by a screw and nut elevator 80. The bins 32, 34 are mounted on a sliding carriage and upon emptying of one bin it is automatically moved sideways for reloading and replaced by the other bin. The nut of the elevator 80 is split and is disengaged when the bin is empty to permit quick return to the bottom position for engagement with the bottom of the stack in the replacement bin. The suction grippers on the bar 15 may be arranged to move inwards slightly after engaging the top workpiece in the bin 32 to bend the workpiece and thereby ensure that only one workpiece is lifted. The arm 24, Fig. 3, carrying the suction grippers 286, 288, Fig. 1 which lift a workpiece from the gauging station 20 and move it into correct position for stitching comprises a main part 260 attached to a sliding carriage 362 and a secondary part 278 movable inwardly and outwardly along arm 260 by a motor 270. After lifting the workpiece the grippers are turned by a compressed air motor 280 through an angle of approximately 90 degrees so as to be aligned in the general direction of stitching, and then carried by motion of the carriage 362 towards the needle until over a row of small holes under one of which is positioned photoelectric cell PR 411, Fig. 22. Carriage 362 is stopped by a limit switch and motor 270 moves arm 278 inwards until the workpiece is in the correct position determined by cell PR 411. The carriage 362 then resumes its motion to move the workpiece towards the needle at a speed approaching that at which it moves during stitching. As the workpiece enters the stitching area, limit switches stop the slide 362, cut off the suction from the lifting cups, and cause the slide to return arm 24 to its initial position. After completion of stitching and cutting off of thread by the chopper 28, Fig. 2, a suction discharge device 30, Figs. 2 and 3, similar to the first device 24 and mounted on a slide 382 lifts the workpiece, turns it through 90 degrees, and carries it to a delivery bin. The chopper 28, comprising a cutter blade actuated by a compressed air piston, is controlled by a photocell PR 81, Fig. 22.