Patent GB-936715-A (GB)
Title: Improvements in or relating to sewing installations
IPC: D05B23/00
Filed: 1962-05-31
Abstract: 936,715. Sewing machines. G. M. PFAFF A.G. May 31, 1962 [Oct. 2, 1961], No. 20945/62. Class 112. [Also in Group VIII] A sewing installation comprises a sewing machine, a device adapted to fold over the edges of a workpiece, and a device comprising a pair of co-operating jaws adapted to grip the workpiece while leaving its folded over edges exposed, and to convey the workpiece to the sewing machine. As shown, a pair of work-clamping devices 5, 6 alternately convey a pocket patch 7, having an edge fold 34, from a folding device 2 to a sewing machine 1, where the patch is laid upon a garment for being sewn thereto around the folded edge. Clamp 5 comprises a body 14 slidable on a horizontal rail 3 carried by columns 12, 13. A pair of vertical rods 16, slidable in body 14, are connected together at their upper ends by a bar 17 and carry a plate 18 slidably supporting a carriage 27 to which is fixed an upper clamp plate 29. A lower clamp plate 31 is hinged to plate 29 by a pin 30 and is biased thereagainst by a spring 37. Pin 30 is rigid with plate 31 and has a squared outer end 32. A spring 22 connected between frame 14 and plate 18 biases a roller 21 journalled on the latter against a track 8 on a guide member 10 rigid with rail 3. A motor 23 mounted on plate 18 drives a friction wheel 24 engaging a friction track 26 on carriage 27 for traversing the latter. Frame 14 is connected by a bar 40 to the upper run of an endless driven chain 43 carried by sprockets 42 on the columns 12, 13. Clamp 6 is similar to clamp 5 but its frame 14 is slidable on a rail 4, its roller 21 is biased against a track 9 on a guide member 11 rigid with rail 4, and a member 41 connects its frame 14 to the lower run of chain 43. The arrangement is such that when one clamp is at the sewing machine the other clamp is at the folding device. The latter comprises a base-plate 52 having a U-shaped opening 51 and supported by legs 50. A U-shaped plate 54, arranged around opening 51, is separated from plate 52 by plates 53 and has an inner edge 56 overlying opening 51. Two L-shaped plates 57, slidably supported between plates 52 and 54, have their inner edges normally aligned with the edges of opening 51, and have corner extensions 59 which pass through gaps in the plates 53 and are coupled at their free ends to the plungers of respective solenoids 61 mounted on plate 54. A U-shaped pressure plate 63, supported on plate 53 by springs 68, has a downwardlyprojecting rib 66 slidably engaging edge 56, and carries a bridge 72 connected to the plunger 71 of an hydraulic cylinder 70 mounted on a bridge 69 carried by plate 54. A track 73. situated between the legs 50, supports a carriage 75 traversed thereon via a connection 84 and chain 83 by a motor 82. A column 74, mounted on carriage 75, contains a slidable bar 76 biased upwardly by a spring 78 and carrying a plate 77 for supporting a patch 7. Plate 72 is normally held in the lowered position by a chain 79 connected to a solenoid. In operation, when clamp 5 arrives at the sewing machine, its carriage 27 is traversed to position the patch 7 correctly, and bar 17 is engaged by a bar 44 on an hydraulic plunger 45 to lower the patch on to the garment. When clamp 6 arrives at the folding device, its carriage 27 is traversed to position the plates 29, 31 within the opening 51 and to position the squared end 32 of pivot 30 within a groove 89 at the free end of the shaft of a motor 87 mounted on plate 52. On operation of motor 87, plate 31 is thereby swung outwardly till it is held by a nose 46 on a spring latch 48 fixed to column 13. Carriage 75 is then traversed to position plate 77, carrying a patch 7, beneath the opening 51, when the solenoid connected to chain 79 is de-energized to allow plate 77 to ascend for positioning patch 7 against plate 29. Solenoids 61 are then energized to move plates 57 inwardly, whereby the free edge 33 of patch 7 is folded under plate 77 to form fold 34 adjacent edge 56. Plate 63 then descends to grip fold 34 between plate 57 and rib 66, and carriage 75 is traversed to move plate 77 out of the folding device, when a lug 86 on column 74 engages a cam surface 49 on latch 48 to release plate 31, which then swings inwards to engage plate 29 for holding the edge 33 of patch 7 thereagainst. Plate 63 then applies very heavy pressure to render the fold 34 permanent, whereupon plates 57 and 63 are released, and carriage 27 is traversed to withdraw the folded patch from the folding device. At the end of the sewing operation, carriage 27 of clamp 5 is traversed to withdraw the clamp plates 29, 31 from the sewn pocket. Clamps 5 and 6 are then traversed to exchange their positions, the plates 18 respectively rising and falling as they pass each other, under the influence of the guide tracks 8, 9, to prevent obstruction therebetween.