GB938654A - Bobbin thread wiping device for lock stitch sewing machines - Google Patents

Abstract

938,654. Sewing machines. SINGER CO. Aug. 8, 1962 [Aug. 25, 1961], No. 30366/62. Class 112. A single-thread lockstitch sewing machine is provided with means for withdrawing the remainder of the thread from the looptaker bobbin at the end of a stitching operation, and comprising a first hook member rotatable with the looptaker and shiftable from a retracted position to an extended position in the path of the locking thread from the bobbin to the work, a second hook member shiftable from a retracted position radially outwards of the cylindrical body portion of the looptaker to an extended position in the path of the locking thread, and a fixed member provided with a surface abutting the second hook member in its retraced position. A rotary hook comprises a cylindrical body portion 16 fixed to a driving shaft 14, and a cylindrical threadcamming portion 18 of greater diameter. A resilient ring 34, fixed by a screw 35 to body 16, is engaged with a notch 36 in a hook member 37 slidably mounted in body 16, ring 34 being sprung away from the latter to retain member 37 normally in a retracted position within body 16. A slidable bar 30 is arranged to be moved to the left during the final stitch-forming cycle, whereby a nose 33 carried by a plate 32 fixed to bar 30 presses on ring 34 to shift hook member- 37 into the path of the bobbin thread Tb, while a hook 41 on the end of a bar 40 carried by plate 32 also moves into the path of the bobbin thread Tb. Bar 30 then returns to its original position, in which hook 41 abuts a surface 44 on a fixed bar 42. Hook member 37 thereby withdraws the thread from the bobbin and winds this thread around the cylindrical portion 18.