GB1051083A - - Google Patents

Abstract

1,051,083. Programmed control of sewing. G.M. PFAFF A.G. April 29, 1965 April 29, 1964], No. 18007/65. Heading G3N. [Also in Division D1] Spaced stencil pins 102, conforming to a line of stitching, are carried by a stencil plate rigid with the workholder of a sewing machine. The pins are adapted to be engaged in succession on opposite sides by rotatably driven pinions 52, 57, pinion 52 being mounted co-axially with the needle of the sewing machine and the axis of pinion 57 being rotatable about the axis of pinion 52. The arrangement is such that the pinions initially displace the stencil plate to produce a line of stitching until a first corner I is reached. The pins 103 at the leading leg of corner I and the pins 104 at the trailing leg are larger than the pins 102, the lower portions of pins 103 and the upper portions of pins 104 being cut away on the inside. Pinion 52 is thereby able to move to a position co-axial with the centre of curvature of pins 103, 104, when a cam on the stencil plate actuates a micro-switch. Thereby, operation of the sewing machine and rotation of the pinions is inevitably stopped, the pinions are lowered after a time delay to disengage pinion 52 from pins 103 and to engage pinion 52 with pins 104, and after a further time delay pinion 57 is rotated clockwise about the axis of pinion 52 from engagement with pins 103 to engagement with pins 104, when a second micro-switch is actuated to start the drive to the sewing machine and the pinions 52, 57. When the latter disengage from the trailing pin 104, another microswitch is actuated, whereby the pinions rise to engage the further pins 102, and stitching continues until a change-over point II, intermediate the corner I and a second corner III, is reached. At point II the pinions engage a long pin 107 opposite which at a distance equal to the pitch diameter of pinion 52 is located a long pin 108, the upper part of which is cut away on the inside, and another micro-switch is simultaneously actuated. The drive to the sewing machine and the pinions 52, 57 is thereby stopped, energization of magnetic couplings in the drive to the latter being reversed whereby, on drive being resumed, the pinions 52, 57 will rotate in the reverse directions, the pinions are lowered to engage pinion 52 with pin 108, and pinion 57 is rotated counter-clockwise about the axis of pinion 52 and through 180 degrees into engagement with pin 108. A micro-switch is thereby actuated to lower the pinions still further for disengaging pinion 52 from pin 107 while leaving the pinions engaged with the longer pin 108, and the drive to the sewing machine and pinions is restored to engage the latter with a next long pin 110. Upon disengagement of the pinions from pin 110 a micro-switch is actuated, whereby the pinions rise to engage further pins 102, and sewing continues until corner m is reached, operation of the apparatus thereat being similar to the operation at corner I.