GB1084720A - Improvements in or relating to automatic guiding apparatus for sewing machines - Google Patents

Abstract

1,084,720. Seaming non-metallic sheet material. E. M. JUNKINS. Dec. 31, 1964, No. 53097/64. Heading B5K. [Also in Division D1] Apparatus for use with a heat-seaming machine to guide a workpiece along a predetermined path comprises a work-holder capable of free lateral and longitudinal movement, means for sensing deviation of the workholder from the predetermined path as it traverses the path, and means for rotating the work-holder to overcome the deviation. As shown, a work-holder 19 is used in conjunction with a sewing machine 11. The workholder, which is hollow, is carried by and communicates with a vertical hollow shaft 22 journalled in a bearing 23 fast with a hollow horizontal shaft 27 which communicates with shaft 22. Shaft 27 is slidably but non-rotatably supported in a bearing member 25 journalled on a fixed vertical shaft 24 and supported by a collar 26. A spring 42 acts on bearing member 25 to bias a cam plate 32, fast with shaft 22 and having a periphery shaped to the line of stitching, against a driven friction wheel 33 along a line 35 coaxial with the needle bar 12. The respective noses 47, 48 of a pair of spring-biased rods 44, 45 engage the periphery of cam 32 on either side of and closely adjacent to line 35. When the noses project equally, microswitches 51, 52, carried by rod 44 are closed, and a motor 31, coupled by universal joints 29, 30 and a telescopic shaft 28 to shaft 22, is inoperative. Canting of cam-plate 32 to cause one nose to project more than the other results in closing one or the other of switches 51, 52 to drive motor 31 in one direction or the other, whereby camplate 32 and the work-holder 19 are restored to the correct alignment. A workpiece 20 of rectangular form, along three sides of which a line of stitching is to be sewn, is placed in a depression 70 in the top of a table 18, the depression correctly positioning the workpiece in relation to the path of the workholder 19. The apparatus is then started and microswitches 61 and 63 are initially open, whereby a solenoid 16 is de-energized for uncoupling the sewing machine 11 from its driving motor 15 and a motor 39 is energized to drive wheel 33, while a compressed air line 67 is connected to a pipe 69 discharging inwardly into shaft 27 to blow air through work-holder 19. When the work-holder comes above the depression 70, a cam ridge 65 on cam-plate 32 closes switch 63, whereby line 67 is connected to a pipe 68 discharging outwardly into shaft 27 to create a vacuum in work-holder 19. The workpiece is thereby picked up by suction. When the work-holder reaches the stitching position, a cam ridge 62 on cam-plate 32 closes switch 61, whereby motor 39 is de-energized and solenoid 16 is energized for driving sewing machine 11 and wheel 33. At the end of the predetermined path, cam ridge 62 allows switch 61 to close for stoppingthe sewing machine, and cam ridge 65 allows switch 63 to close, whereby the completed work-piece is blown off the work-holder.