Patent GB-190818496-A (GB)
Title: Improvements in or relating to Sole Sewing Machines.
Inventor: PLANT THOMAS GUSTAVE
Filed: 1908-09-03
Granted: 1908-12-17
Abstract: 18,496. Plant, T. G. Feb. 4, [date applied for under Section 91 of Patents &c. Act, 1907]. Boot - sole sewing - machines; presser lifted automatically ; stopping, automatic. - Relates to machines having pressers which during the intervals between the feeding movements are forced towards the work by an increased pressure and locked in position, and consists in means interposed between the presser mechanism and the operating-cam whereby at any time the operative can release the presser from the extra pressure, unlock it, and raise it from the work, and also in means for perf orming the same operations automatically, operated in stopping the machine by the stopping gear. The presser 10 is operated by a cam-actuated lever 23 pivoted at 24 which carries a ratchet pawl 22 and a toe 29. In its upward movement, it raises the lever 16, pivoted at 12, which carries one abutment 17 of the spring 18. The other abutment 19 being attached to the presser by the rod 14, this movement applies the increased pressure to the presser for clamping the work. A spring-pressed detent 26, pivoted to the machine frame. locks the presser in the clamping position. In the downward movement of the lever 23, first a fixed pin 30 arrests the front of the pawl 22 and, canting it, releases the lever 16 and reduces the pressure on the presser to that continuously applied by the spring 33, and then the toe 29 removes the detent 26 and unlocks the presser. The bowl which runs in the cam-groove 39 is carried by a lever 36, Fig. 7, pivoted at 24. In between this lever 36 and the lever 23 is placed a slotted plate 41 supported at the rear by a pin 48 which rides in a slot in the lever 23, and in the front by bowls 44, 45 on the levers 36 and 23 respectively, which ride in their respective portions of the slot in the plate. The side of the slot engaged by the bowl 44 is inclined downwards in the forward portion and the part engaged by the bowl 45 upwards so that when the plate is moved rearwardly and the bowls enter the forward portions of the slot the lever 23 is given an upward movement relative to the camlever 36. This movement is sufficient for the releasing and unlocking of the presser as previously described. The pin 48 projects beyond the lever 23 and is embraced by the slotted end of a lever 50. For hand-operation, the lever is connected by a link 54 to a hand-lever 52. For automatic operation, the lever is connected by a link 102 to a lever 100 operated by the stop-gear. A spring attached at one end to the lever 50 and at the other to the pin 58 is strong enough to return the parti when released. The end of the link 102.which embraces the pin 104 on the lever 50 is open towards the front to permit the operation of the devices by the hand-gear independently of the stop-gear. The rear portions of the slot in the plate 41 coincide so that further motion of the plate 41 and lever 50 is inoperative. This is utilized to permit further movement of the hand-lever 52 in which it engages a projection 59 on the presser and raises the latter entirely from the work. The stop-gear is substantially the same as that described in Specification No. 17,857, A.D. 1908, in which the machine is brought to rest by causing it to wind up a spring, and is then given a short reverse movement by the spring to bring the machine to a stand-still in a predetermined position. The presser gear is operated automatically during this reverse movement. For this purpose, the lever 100 carries a trip lever 106 at its upper end, which is normally kept by a spring in the position shown in Fig. 2 in full lines. In the normal clockwise running of the cam 108 the lever 106 yields to the cam projection ; but in the final reverse movement, the cam projection acts on the under side of the lever 106 and consequently tilts the lever 100, causing the latter to release and unlock the presser, and, through the agency of the hand-lever 52, to lift the presser from the work.