Patent ES-368846-A1 (ES)
Title: Apparatus for feeding and cutting strip material
IPC: D05B23/00
Filed: 1969-06-26
Abstract: A sewing-machine is adapted to sew strips 24a, 24b alternately and sequentially along a common strip by apparatus including means individual to each of the first mentioned strips to advance the latter one after another to the sewing position and means for severing the advanced strip at a predetermined length. Fabric strips 24a, 24b are drawn from rolls 26a, 26b, and pass through respective passages (36a, 36b, Fig. 7, not shown) in a block 35 and then through respective tubes 22a, 22b attached to a fixed bar 110. The strips then pass through respective passages (131), (132) in bar 110 and are finally directed by a tubular guide 61, spaced from and attached to bar 110, under the presser foot 14 of a sewing machine 10. The outlet of guide 61 is wider than a strip and is formed at its left hand side with a finger 63 against which a strip is held by an inwardlybiased finger 65a of a lever 65 engaging the right hand edge of the strip. A knife 154, formed with opposed cutting edges 154a, 154b co-operating with corresponding edges on block 110 at the outlet ends of the passages (131), (132) for severing the strips thereat, is connected to a lever 162 which is connected to the piston rod 153 of a double-acting air cylinder 151. Block 35 carries on its opposed sides respective double-acting cylinders 42a, 42b, to the piston rods 47 of which are pivoted respective support members 48 for pins (51) which pass through slots in block 35 to engage the strips in the respective channels (36a), (36b). The piston rods are normally retracted by reduced air pressure permanently applied via respective lines 58a, 58b. In operation, one of the strips, e.g. strip 24b, terminates at bar 110, having been severed thereat by the prior actuation of knife 154, and strip 24a passes under presser foot 14 to be stitched to a workpiece, such as a waistband assembly for trousers. when a required length of strip 24a has been attached, a treadle is momentarily depressed, whereby compressed air is supplied simultaneously to one end of cylinder 151 for actuating knife 154 to sever strip 24a, to a cylinder 75 for projecting the piston rod 84 thereof against lever 65 to move finger 65a outwardly, and via a line 56b and delay valve 55b to cylinder 42b for extending the piston rod and thereby feeding strip 24b through the. freed outlet of guide 61 and under the presser foot 14. On release of said treadle line 56b and cylinders 75 and 151 are de-pressurised, whereby the piston rod of cylinder 42b is retracted, and finger 65a engages the right hand edge of strip 24b. When said treadle is next depressed knife 154 moves in the reverse direction to sever strip 24b, finger 65a moves outwardly, and air is supplied via a line 56a and delay valve 55a to cylinder 42a for extending the piston rod to feed strip 24a under presser foot 14. A spring strip (171, Fig. 19, not shown) may project from bar 110 to engage the right hand edge of a strip adjacent the needle 13. In a modification, cylinder 75 is eliminated and a lever (180), equivalent to lever 65, co-operates with a cam (185) fixed to bar 166 for shifting the strip-engaging finger lever (180) outwardly of guide 61 during the stroke of knife 154.