Patent GB-289142-A (GB)
Title: Improvements in or relating to machines for use in the manufacture of shoes
IPC: D05B15/00
Filed: 1927-01-20
Abstract: 289,142. British United Shoe Machinery Co., Ltd., (United Shoe Machinery Corporation). Jan. 20, 1927. Boot-sole sewing-machines.-In machines for operating on boots and shoes in which automatically acting mechanism is provided for changing the relative positions of the shoe and the operating means to transfer the point of operation about the shoe means are provided whereby (1) a reverse movement is automatically imparted to the position-changing mechanism upon a failure of the operating means to function, as upon the occurrence of a mis-stitch or the breakage of a thread in sewing; (2) the freely movable jack supporting the shoe is mounted so that the lateral movements imparted to it tip the shoe about the operating devices as a fulcrum; (3) the mechanism for imparting shoe-feeding movements to the shoe-supporting jack is automatically controlled in accordance with the size of the shoe being operated upon, in order to maintain correct timing relationship between the movement of the jack and the movement imparted by the feeding mechanism which engages the shoe directly; and (4) the welt is severed automatically upon the completion of the seam. The general organization of the machine described is similar to that set out in Specifications 114,842 and 215,772. Chain - stitching; welting. - The stitch-forming mechanism and associated parts, Fig. 14, are actuated by cams on a cross-shaft 40 which is driven by a main shaft 126, Fig. 5, through a clutch 130,132, and gearing 136,138. A curved hook needle 2 is clamped in a carrier which is oscillated by a cam through a link and lever connection, and is also reciprocated axially by other cams to assist in feeding the work. A needle guide is oscillated by a rock-bar 62. A looper 6, and a channel guide roll 10, which assists in feeding the work, are actuated as described in Specification 268,885, and a thread-measuring finger operating as described in Specification 268,888 is provided. The thread is governed by a braked tension wheel 116, a reciprocating take-up 14, and retaining plates 16. A welt guide 12 is yieldingly pressed against the work during part of each cycle so that it will accommodate itself to varying thicknesses, and is then locked in position. It is also mounted for movement in the direction of feed to enable it to co-operate with the channel guide roll and needle in feeding the work. The carrier 68 for the welt guide is supported by a ball 70 on an arm 72 pivoted at 74, the yielding pressure being applied by a spring 82. Locking is effected by a cam-operated lever 86, an eccentric face of which engages a segment 84 on the arm 72. The carrier 68 is swung horizontally about the support 72 to impart feeding movements to the welt guide by a cam lever 104 pivoted at 106. The connection between this lever and the carrier comprises a slide 78 in which is housed a ball 76 through which the end of the carrier passes. Welt severing. The devices for severing the welt at the conclusion of an operation are actuated by a shaft 566 which is rocked, by driving mechanism described below, after the sewing mechanism has been stopped. A toothed segment 602 on the shaft 566 engages rack teeth 604 on a bar 600, Fig. 29, carrying the knife, and advances the knife and welt supporting jaws 594 into positions upon opposite sides of the welt. The knife bar slides in the slide 596 carrying the jaws 594. and towards the end of the movement a pin 610 working in an inclined slot 612 causes the knife to move obliquely towards the welt and sever it. Lasts, mounting.-The shoe-supporting jack 140, 142, Fig. 1, which is mounted for universal movement, is constructed as described in Specification 160,274, [Class 89 (iii), Nailing &c.]. The tipping and turning movements imparted to it are caused to move the shoe about the point: of operation at which it is engaged by the needle, welt guide, and channel guide roll. Lateral tipping movements are imparted to the jack by swinging the jack support 160 by means of a cam lever 164 pivoted on a shaft 166 and having an arm carrying a cam roll 170 arranged to engage a cam on a pattern cam-shaft 172. Longitudinal tipping movements are imparted by swinging the support 158 by means of a cam lever 174 actuated by a cam on the pattern cam-shaft. Turning movements are imparted to the jack spindle wheel 148 by a weighted cable 182, one end of which passes round a pulley 188 which is actuated by a cam lever 204 through segmental gearing. Feeding movement of jack. The mechanism for imparting feeding movements to the jack is adjusted automatically in accordance with the size of the shoe, so that the feed corresponds with that imparted by the shoe engaging devices. The feeding lever 210, Figs. 1, 2 and 26, is pivoted at 212 and connected to the end of the jack by a link 214. It is rocked through links 220, 222, 236, by a cam lever 234 having an arm engaging a cam on the pattern cam shaft 172. To provide the automatic adjustment of the stroke, the common pivot 224 of the links 220, 222 is connected to an arm 240, which swings about an adjustable fulcrum 242 carried by an arm 244 pivoted at 246. A weighted cord is provided to keep the cam lever in contact with its cam. When a shoe is placed in position for the starting of a seam, the feeding lever 210 and the lever 244 are positioned automatically and the lever 244 is locked when the machine is started. To enable different styles of shoes to be sewn upon the machine, a series of sets of cams are mounted on the pattern cam-shaft 172, which may be shifted axially to bring selected cams into operation as described in Specification 215,772. Driving pattern cam-shaft. The speed of the pattern cam-shaft 172 is controlled automatically in accordance with the size of the shoe being sewn. The drive from the main shaft 126, Fig. 5, is through gears 136, 322, shaft 312, clutch 316, a variable-speed pawl-and-ratchet device 288, 292, a sleeve 284, and a train of toothed reduction gearing. The pawls 292 of the variable speed dervice are mounted on pivoted levers 296, the positions of which are controlled by a groove in a plate 304 which is pivoted at 306, Fig. 3. The setting of the plate 304 to determine the speed of the shaft 172 occurs when the treadle 364 is depressed to start the machine, the movement being derived from a bar 332 which is connected to the plate by levers 336, 328 and segmental gearing 326. Before starting, the bar 332 is held up by a spring 350, but when the treadle is depressed it moves a slide 354 so that pins 352 rock a lever 340 which pulls down the bar through a link 338. The bar 332 is positioned by its jaws 344 engaging a stud 348 on the lower end of the lever 244 which, as stated above, is itself positioned in accordance with the size of the shoe. The bar 332 is locked in position by a latch 386 until another shoe is placed on the jack. A rod 384 connected to the bar 332 serves to lock the lever 244 by gripping devices 372, Fig. 2, at its end engaging a rod 366 jointed to the lever. Re-nositioning parts at end of sewing operation. After the sewing mechanism is stopped, the jack and the pattern cam-shaft are restored to initial position by an eccentric as described in Specification 241,235. The eccentric is actuated by a shaft 616, Fig. 5. At the end of an operation it is given one revolution at slow speed as described below. Reversing shoe position-changing mechanism on failure of operating means to function. Upon the occurrence of a mis-stitch or the breaking of a thread, the machine is stopped automatically, and the pattern cam-shaft is driven in a reverse direction through a predetermined distance without, however, the jack &c. being restored to initial position, or the welt-severing mechanism being actuated. The stop gear is tripped, and the reverse clutch thrown in for the purpose by mechanism, Figs. 16 and 17, cooperating with the thread tension wheel 116. An arm 692 is clamped to the wheel spindle 118 so that it is displaced slightly with the spindle at each stitch, but is restored after each stitch against the friction of the clamp by a rod 696 which is actuated by the cam lever 104. If a stitch is missed, the arm 692 is not displaced, but stays in the path of the end of the lever 702, which is pivoted on the end of the rocking cam lever 104. The lever 702 is then rocked about its pivot 704, and the movement is transmitted to the control lever 464, Figs. 3 and 8, of the stop gear by connections 712, 716, 724, in such a way that the machine is stopped and a clutch 744, Figs. 5 and 7 is engaged in order to drive the pattern cam-shaft from a slow speed shaft 616 in a reverse direction. The clutch 316 in the normal drive for the pattern cam-shaft is disengaged at the same time. The extent of the reverse movement is determined by a projection 770 on a ring 758 'which is clutched to the shaft 736 while it is rotating backwards. The projection acts on a lever 664 geared to a lever 658 which re-sets the clutches. The normal position of the ring 758, and therefore the extent of the reverse movement, is varied in accordance with the size of the shoe by a stop arm 764 which is positioned by a link 766 which is connected to the bar 332. Starting and stopping gear.-When the starting treadle 364 is depressed, the slide bar 354 acts on a lever to draw down a rod 448, Fig. 8, which throws in the main clutch 132. The rod is locked in this position by a latch 456 which engages a projection 458 upon it. The latch is controlled by the lever 464, and is adapted to be tripped, in order to disengage the clutch 132 and to apply the brake, when either (1) the lever is swung in one direction by the rod 724 upon the occurrence of a mis-stitch as described above, or (2) the lever is swung in the other direction upon the completion of a seam after a predetermined number of cycles. The mechanism (Fig. 23 not shown) which swings the control lever 464 after a predeter