GB1433553A - Automatic feeding of workpieces of limp sheet material - Google Patents

Abstract

1433553 Workpiece guides SAMCO-STRONG Ltd 13 April 1973 [14 April 1973] 17907/73 Heading DIG A work guidance mechanism for feeding limp sheets in a sewing machine comprises sensing means for determining the edge contour of the workpiece, and workpiece orientating means actuable in response to the sensing means to maintain a workpiece edge in contact with a workpiece edge guide and having a workpiece clamp rotatable about an axis normal to the worktable and a workpiece engaging member movable about an arc about said axis, means to move the members towards and away from the table and to rotate them to maintain the workpiece edge in contact with the guide. As a workpiece is fed along below an adjustable plate 72 by a normal feed arrangement 20 parallel to edge guides 36, 38 until photocell 28 detects the end of the workpiece. The rotatable member 34 is then lowered until it touches the top of the workpiece, this being achieved by means of a solenoid 52 operated by the photocell. Clutch parts 46, 48 engage to rotate the member 34 and with it the attached work engaging finger 32 to rotate the workpiece to bring the next seam into line. At this point the work guide 36 is retracted to allow the corner of the workpiece to move outwards as it turns. At this point a downwardly directed air jet 79 is is released to keep the corner in contact with the work surface. Stitching then continues until all four sides are stitched. As the termination of stitching nears work guide 38 is moved towards the needle to move the line of stitching away from the workpiece. A thread cutter 152 slidably mounted in a slidable holder 150 on a frame 142 is urged downwardly by a piston and cylinder arrangement 144 the holder 150 being connected to the piston rod 146 by a spring 158. A lever 162 is pivoted on the slide 150 and has a work engaging foot 160. The arrangement can be moved downwardly until the holder 150 is stopped by an abutment 168. Lever 170 pivoted on the slide 154 then moves a link 180 downmards and the knife and foot 100 move the last amount. At this point the plate 72 is moved down to clamp the workpiece with the thread tensioned. The thread is cut the plate 72 released and the foot 160 acts to remove the finished workpiece. Attaching labels:-Labels L placed in a hole 120 in plate 72 are moved by a cranked finger 126 acted on by two pneumatic rams 106, 116 to feed them to a point below the plate 72 and into the line of stitching where they are attached to the workpiece. Work supports:-When the stitching operation is nearly completed an additional support surface 200 may be raised by a pneumatic piston 212 through a chain 204 and sprocket 202 under the signal from the counting device, described in the parent application, which determines when the stitching operation has been completed.