GB191224331A - Improvements in or relating to Sewing Machines. - Google Patents

Abstract

24,331. Topham, L. E. Oct. 25, 1911, [Convention date]. Sewing-machines; stopping-gear, non-automatic.-Relates to a stopping - mechanism for high-speed sewing-machines comprising the combination with the main driving-mechanism adapted to be thrown into and out of operation by the operator, of a slow-speed driving-mechanism which, when thrown into operation acts first as a brake to retard the movement of the machine, and then drives the machine at a, reduced speed to stopping position all as described in Specifications 5453/12, and consists in mechanism whereby the machine is stopped at a predetermined point in its cycle, the presser is raised and the thread tension is released. The pin 43, which, in the operation of stopping the machine, is moved upwards to engage and hold the normally free end of the cranked clutch lever 40, as described in the Specification referred to above, is held inoperative during the working of the machine by a catch 50 pivoted upon a cross-head fixed upon the pin 43. When the rod 57 rises upon the release of the starting- treadle, a lever 54, linked to the rod 57 by the parts 55, 56, presses upon the toe of the catch 50, pushes the catch outwards, and releases the pin 43, which is afterwards moved upwards to engage the clutch lever as the end of the slot 58 in the rod 57 engages the pivot pin of the catch 50. The slotted end 74 of a link 71 embraces a second pin on the cross-head, but the link is prevented from rising with the cross-head and pin 43 by a spring catch 76, which engages a stop-piece 77. When, however, the clutch is thrown into gear, the clutch-lever 40, pin 43, and slide 44 are moved against the spring 45 to compress it and the catch 76 is carried away from its stop. The link 71 thereupon rises and an associated lever 70 is turned under pressure of a pin 69 forming the end of a bifurcated lever 68 which is pivoted transversely at 67 upon a revoluble sleeve 61 and is pulled downwards by a spring 72. The rotation of the lever 68 carries an arm 59 upon it into the path of a cam 60 on the main-shaft of the sewing- machine, and it is first moved outwards by the cam and then is engaged by a radial surface upon the same and serves to stop the machine in a predetermined position. The outward movement of the lever arm 59 rotates the sleeve 61 to which it is pivoted and a second arm 62 integral with the sleeve. This arm is connected positively to a lever 13 which through a wire 15 operates a tension-release device such as described in Specification 23,478/10 and also, when moved as described above impinges upon a screw 65 on a lever 9 connected to the presser and thereby raises the same. The pin 43 is of such a length that the rod 57 can be depressed sufficiently to remove the lever 59 from the cam 60 without withdrawing the pin 43 from the recess in the lever 40. By this arrangement, the presser can be lowered on to the work before the machine is started.