GB787644A - Control device for the needle bar of a zig-zag sewing machine - Google Patents

Abstract

787,644. Sewing-machines. SOC. INTERNATIONALE DE FINANCE. Oct. 25, 1954 [Nov. 7, 1953], No. 30607/54. Class 112 Needles, shifting laterally. In a zig-zag sewing-machine in which the needle-bar gate 29 is oscillated by a connection adjustable along a member 8 oscillated by a cam 5 engaging a forked member, the latter member and the member 8 are rigid or unitary with one another and are pivotally mounted on a movable carrier whereby the neutral position of the needle may be adjusted. In the arrangement shown the cam 5, driven by worm gears from the needle-bar shaft 2 engages a fork formed on the underside of the member 8, and the latter member is pivoted at 10 to a carrier formed by an arm secured on a shaft 11 bearing in a fixed split sleeve which is tightened so that the shaft may be moved angularly by adjusting means, but is not moved by operation of the machine. A member 13, also fixed on the shaft 11 and adjusted during manufacture, is connected by a link 20 to a finger-lever 23, pivoted on a spindle 24, whereby the carrier for the member 8 is adjusted to vary the neutral position of the needle; the member 13 has an end portion with a central groove 15 to be engaged by a spring-pressed pin 16 to locate it in its mid-position and abutments 14 to limit its movement to either side by contact with the pin 16. The link connecting the needle-bar gate 29 with the arm 8 is formed in two parts 26, 27 adjustably fixed together and its inner end is shifted along the arm 8, to vary the width of the zig-zag, by a link connected to an arm 31 fixed to the spindle 24, on which is also fixed an arm 32 forming a hand lever and slidably carrying a knob 37 spring-pressed inwards. A plunger connected to the sliding knob 37 engages a sleeve mounted on the spindle and formed with abutments arranged to engage two adjustable stop screws, so that the range of movement of the arm 32 is limited; by pulling out the knob 37 and turning it the arm is disconnected from the sleeve and the abutments consequently rendered ineffective.