GB747332A - Improvements in lock-stitch sewing machines - Google Patents

Abstract

747,332. Sewing-machines. DURKOPPWERKE AKT.-GES. Aug. 25, 1954 [Sept. 14, 1953], No. 24684/54. Class 112. A lock-stitch sewing-machine in which one needle may be held out of action temporarily, as for turning sharp corners, has means operable at will for re-winding on to the bobbin below-the needle which has been inoperative, thread which has been drawn from said bobbin during continued operation of the other needle. The loop-taker 7 for the inoperative needle is journalled in a bracket 8 situated under the throatplate 3. A bearing sleeve 12 carried by bracket 8 contains a vertical hollow shaft 14 formed at its upper end with a plate 15 and having coupled to its lower end by means of a slip friction clutch 17 a hand-operable crank 16. A spindle 20 journalled in shaft 14 carries at its upper end a milled-edge wheel 21, and has coupled to its lower end by means of a slip friction clutch 22 an arm 23 engageable by the crank 16. Wheel 21 is permanently engaged with a resilient wheel 29 journalled in plate 15. Initial movement of crank 16 rotates shaft 14 against the bias of a torsion spring 24 to move wheel 29 through an opening in the bobbin case 10 and into driving engagement with a flange of the bobbin 11, said movement being adjustably limited by means of an abutment screw 27 carried by plate 15. Continued movement of crank 16 serves to rotate spindle 20 and thereby the bobbin for re-winding the loop of thread. The clutches are respectively set to slip when wheel 29 engages the bobbin and when the taut bobbin thread arrests further driving of the bobbin.