GB1285205A - Chain stitch forming device for lock stitch sewing machines - Google Patents

Abstract

1285205 Lock and chain stitch sewing machine BROTHER KOGYO KK 17 Oct 1969 [21 Oct 1968 5 March 1969 1 Sept 1969] 51243/69 Heading D1G A lock stitch sewing machine is converted into a chain stitch machine by a device inserted in place of the bobbin case, the device including a finger which co-operates with a loop holder to hold the needle thread loop taken by the looptaker until the descending needle has passed through that loop. Three embodiments are described. In the first, Figs. 2 and 6, the device comprises a part 71 of plastics material and a plate 68 provided with the finger 69, the end of which co-operates with parts 90 (and 89, Fig. 5 not shown) on a bridge piece 88. The device has an elongated hole 66 having an inclined portion 67, the hole fitting over the bobbin pin 56. A latch lever 78 controlled by plate 82 engages a notch in the pin 56 to retain the device thereon. A spring 81 urges the face 74 on to the cam lip 73 of the looptaker. As the latter revolves the device is moved up and down by the cam lip 73 to first rise, engage and hold the needle loop (Fig. 3 not shown) and later to move downwards and tilt (Fig. 4 not shown) to shed the loop. In a second embodiment (Figs. 9-11, not shown) the finger (104) cooperates with a loopholder (111) formed by a recess in the underside of the throat plate (54). The device itself is of sheet construction. In a third embodiment, Fig. 15, applied to a machine having a rotary looptaker making two revolutions per needle oscilation, the looptaker is fitted with a cam plate 147 engaging a part 136 of the device, the finger 142 co-operating with a restraining number 124 fitted to the looptaker housing. This device is carried in a case (128, Fig. 12, not shown).