Patent GB-1392477-A (GB)
Title: Unit for use in the execution of seams on pieces of sheet material
IPC: D05B39/00
Filed: 1972-04-07
Abstract: 1392477 Sewing machines CENTRE D'ETUDES TECHNIQUES DES INDUSTRIES DE L'HABILLEMENT 7 April 1972 [9 April 1971] 57043/73 Divided out of 1392476 Heading D1G A unit for use when executing seams along a path formed by a succession of straight portions inclined at angles to one another comprises a turntable 37 for supporting a workpiece holder 38, means (such as interen'gaging pegs and apertures) whereby the turntable 37 may be secured in a number of predetermined positions to a rectilinearly movable guide 53 which is movable in both slides on a slide 55 and means (such as rams 86 and 89) for pivotally displacing the turntable through a predetermined angle relative to the guide. In the apparatus shown a detachable workpiece holder 38 is mounted on three columns 41, 42, 43 extending from the turntable 37 which is universally movable on ball mountings 46 under the fixed axis of the needles of a sewing machine 2.  The workpiece holder 38 (Fig. 4) comprises two drawers 221, 222 slidable in the space between middle and lower plates 201, 213 and an upper plate 208 hinged to the middle plate 201. Each drawer (Figs. 19-24, not shown) comprises a generally flat plate with a. shallow recess for a piece of material held in place by a flat plate (235) and a recess (236) at one end for the needle path. One or two locating apertures (237), (238), (239) are provided in each drawer. The workpiece holder is located by two conical pegs (242), (243) (Fig. 7, not shown) movable vertically by a ram 255 and engagement in plugs at the tops of the columns 42 and 43. The Presser Foot 11 (Figs. 2, 3) is a rectangular apertured plate 12 resiliently supported (Fig. 9, not shown) at the ends of arms 13, 14 secured to a shaft 15 which is pivotable by a ram 23.  The plate 37 has apertures (Fig. 14) engageable by pegs 72, 73 (Fig. 10) fixed below a guide 53 which is mounted on a ball slide 55 for the rectilinear movement and which is urged downwardly by a spring 66 on slideways 58, 59 secured to the frame of the apparatus. The plate 37 is rotated by a three-pronged fork 81, which is first raised by a vertical ram 89 when the long prong 82 engages one of the holes 104 in the guide to lift it from the plate 37 and then the two shorter prongs 83 engage further holes in the plate 37 and is then rotated 90 by a ram 86 before lowering the fork 81 when the pegs 72, 73 engage fresh holes of the plate.  The plate 37 and hence a workpiece is fed under the needle 5 by a rod 112 (with a withdrawable stud (116) (Fig. 18 not shown) at its end to permit rotation of the plate 37) driven from the machine mainshaft through a transmission 121-134 which cyclically produces intermittent feed while the needle is raised from the material. The transmission (Fig. 1) includes a drive belt 132, an adjustable crank 127, a link 126 adjustably pivoted to an oscillating lever 125 which actuates a one-way clutch the output from which drives a pinion 122 (Fig. 3) through electro-magnetically clutched forward or reverse gearing, the pinion 122 meshing with a rack 121 on the rod 112. The apparatus may be used for making pockets by the method described in Specification 1392476 when an aperture in a trouser leg 301 (Fig. 34) is mounted between the upper and middle plates 208, 201 of the workpiece holder, an outer pocket portion 307 is mounted in the upper drawer and sewn to the trouser leg by an end seam, a long seam 2AV, and an end seam and an inner pocket portion 304 on the lower drawer slid into position and a double end seam, a long seam 6AR, and a double end seam made. The workpiece is removed and the two pocket portions sewn around.  For Figures see next page