Patent GB-1104750-A (GB)
Title: Improvements in or relating to stencil control apparatus for use with automatic sewing path copying and the like machines
IPC: D05B39/00
Filed: 1967-02-14
Abstract: 1,104,750. Sewing machines. QUICK-ELEKTROMOTOREN-WERKE G.m.b.H. - 14, Feb., 1967 [15, Feb., 1966], No. 7087/67. Heading D1G In a sewing machine in which a work-feed clamp is coupled for movement to a strip-like template the opposite sides of which are frictionally engaged by a driving, roller and a guide roller respectively, the axes of the rollers being parallel and the axis of the guide roller being displaceable in a path concentric with the axis of the drive roller, the driving mechanism comprises differential or planetary gearing, the rotation of the driving roller being derived from one output shaft and the pivotal displacement of the guide roller being derived from a second output shaft, said shafts rotating in opposite directions. In Fig. 2 an upstanding strip 8, corresponding to the desired seam configuration, is secured to a plate 9 coincident with the edge of a recess 10 therein. Strip 8 is engaged on opposite sides by a driving roller 37 and a guide roller 44. The differential or planetary drive gearing 30 comprises a motor-driven worm 25 meshing with a worm gear 27 journalled on a hollow shaft 28. A sun gear 29, journalled on shaft 28 and rigid with gear 27, has internal teeth meshing with a series of planet gears 31 which, in turn, mesh with a sun gear 32 rigid with shaft 28. The planet gears 31 are journalled on a structure 34 rigid with a hollow shaft 35 coaxial with shaft 28. Driving roller 37 is rigid with shaft 35. Shaft 28 is rigid with a block 40 formed with a radial slot 41 slidably housing a block 42 which journals the guide roller 44. A spring 46 acts on block 42 to bias roller 44 against strip 8. A leaf spring 51, secured at one end to block 40 and bearing at its other end against the upper edge of strip 8, is rigid with a rod 50 coaxial with shaft 28. Spring 51 initially engages a notch at the starting end of strip 8, whereby rod 50 depresses the actuating member 52 of a microswitch 53 for switching the latter off. Stitching is initiated by raising spring 51 to allow switch 53 to close for starting the driving motor. Sewing commences at a position 62 and continues along a straight portion 63. shaft 35 and roller 37 rotating counterclockwise and shaft 28 not rotating, until the rotation of roller 37 is stopped at a corner position 65. Shaft 28 then rotates clockwise to carry roller 44 around the corner from position 66 to position 67, when rotation of shaft 28 ceases and rotation of shaft 35 re-commences. After a second corner 69 has been turned and a final straight portion completed, stitching ends at a position 70 when springs 51 enters a second terminal notch in strip 8 to stop the driving motor. Fig. 7 shows an arrangement adapted to sew reverse corners. The strip comprises respective beginning, intermediate and end sections 147. 149, 151 separated from each other, and offset corner sections 148, 150 interposed between respective sections 147, 149 and 149, 151. A driving roller 142 co-operates with a guide roller 132 on sections 147, 149, 151, while a driving roller 138 co-axial with roller 142, cooperates with a guide roller 128 on sections 148, 150.