GB228085A - Needle-bar controlling device for sewing machines - Google Patents

Abstract

228,085. Fairweather, W., (Singer Manufacturing Co.). Oct. 7, 1924. Multiple - needle machines; needle - driving mechanism, disconnecting; needle holders.-In a two-needle sewing-machine in which one needlebar can be thrown out of action, for example when turning a corner in the seam, the disengaged needle-bar is automatically brought into operation again at the end of a predetermined interval. The needle-bar 9 is continuously reciprocated by a crank and pitman 5 and is grooved, Fig. 7, to receive the disconnectable needle-bar 11, which at its upper end carries a yoke 20 and connecting bolt' 21. The eyed end of the bolt slides upon a rod 25 fixed on a slide 26 which can be moved endwise by a lever and pitman 35. When the bolt 21 is withdrawn shoulders 90, Fig. 8, on the needle-bar 9 carry the needle-bar 11 to its highest position and it is retained there by a spring stop 91. A spring buffer 95 prevents the needle-bar 11 from being carried up further by subsequent friction with the needle-bar 9. The needle-holder 18 on the bar 11 is formed with a ring 17 which embraces the bar 9 and the needleholder 14 of the bar 9 has a half ring piece 13. The pitman 35 by which the bolt 21 is actuated is pivoted to a swinging frame 37, Figs. 1 and 3, which is turned against the pull of a spring 76 by a treadle-operated lever 74, 75 when the needle-bar 11 is being disengaged. This movement of the frame carries a ratchet-wheel 47, pivoted on the frame, into engagement with a pawl 78 continuously reciprocated by an eccentricrod 83 and at the same time a latch 66 slips over a pin 73 on the frame to lock it. Thereafter the ratchet-wheel is turned until a lateral lug 61 on the wheel engages a part of the latch 66 and disengages the latch from the pin 61 so that the frame 37 can be drawn back by the spring 76 and by means of the pitman 35, the coupling bolt 21 moved to recouple the needle-bars. The ratchetwheel, when it is carried by the movement of the frame out of engagement with the pawl 78, is returned by a spring until a shoulder engages the underside of a stop 57. The lug 61 is formed on a plate 48 adjustably clamped on the side of the ratchet-wheel and an index 62 on the plate moves over a scale on the wheel which indicates the positions corresponding to the several numbers of stitches during which the needle-bar 11 may be kept out of action.