Patent GB-114842-A (GB)
IPC: A43D117/00
Abstract: 114,84.2. United Shoe Machinery Corp oration, (Assignees of Topham, L. E.). April 9, 1917, [Convention date]. Lock-stitching by shuttles; lasts, mounting; feed by awls.-Machines for operating on boots and shoes or parts thereof in which the shoe and operating means are moved relatively by automatically acting mechanisms to transfer the point of operation about the shoe, and to correct the relative positions of the shoe and the operating means as the point of operation is transferred aoout the shoe, are arranged so that the relative times at which these mechanisms perform their function; are controlled from the shoe. The invention is described in connexion with a machine for stitching outsoles to welted shoes, the sewing-mechanism being substantially the same as that described in Specification 7793/92 and comprising a curved hook needle 2, Fig. 2, work-feeding awl 4, shuttle 6, work-support 18, and a presserfoot 20, all driven from a sewing cam-shaft 22, Fig. 1; in the present machine, the feed of the shoe is produced and controlled solely by the action of the awl. The shoe-supporting jack, Fig. 1, is mounted on a spindle 152 and comprises a spring- pressed last pin 154 carried by a slide 158, and a toe rest 164; the slide is adjusted, and afterwards clamped, so that the bulge, at the toe of the shoe is in line with the forward face of the toe rest, which adjustment brings the toe of a shoe to the same position with rlation to the spindle 152 regardless of the size of the shoe. The correcting movements imparted to the jack consist of lateral and longitudinal tipping movements to bring the shoe edge at the point of operation into the proper plane, lateral turning movements to bring the marginal edge into proper position with respect to the line of feed, and slight vertical movements to compnsate for the curvature of the surface of the shoe bottom. The jack spindle 152 is mounted to rotate in a frame 188, Figs. 2 and 10, which is pivotally secured by a shaft 194 to a yoke 196 on one end of a rod 198, the other end of which is adjustably connected by a shackle 202, yoke piece 208 and a pivoted link frame to supporting arms 220, 224, Fig. 1, pivoted, respectively, on shafts 270, 228. The rod 198 carries a slide block 228a, Fig. 2, which is connected by a link 230 to the yoke 208, and is pivotally connected to a supporting rcd 232 extending through a sleeve in trunnions 236 carried by an arm 238 on the yoke 208; a spring 240 surrounding the rod 232 permits the, jack to move vertically in accordance with variations in the vertical position of the. shoe. The lateral tipping movements of the jack, whether a right or left shoe is being sewed, are produced by forward and swinging movements of the lever 220, which carries a roll 244, Fig. 13, engaging a cam groove in a disk 246 on a correcting cam shaft 248; this shaft is driven in opposite directions for right and left shoes. The longitudinal tipping movements are produced by separate mechanisms for rights and lefts. For a right shoe, the jack spindle 152 carries a pivoted block 250, Fig. 10, which is pivotally connected by a rod 256, Fig. 3, and shackle members to a lever 268 pivoted on the shaft 270; this lever is formed with arms 272, Fig. 13, carrying a notched segment plate 274 adapted to be engaged by the upper end of a latch 276 on a lever 280, which is pivoted on the shaft 270 and is operated from the cam disk 246 on the correcting cam shaft 248. For a left shoe, a second block 360, Fig. 10, on the jack spindle is connected through a rcd 366, Fig. 3, and shackle members to a lever 376 and thence through a link 384 to an arm 388, Figs. 3 and 13, of a. lever 390; this lever is pivoted on the shaft 270 and carries a notched segment plate 394 adapted to be engaged by the lower end of the latch 276, when moved by the operator in changing from rights to lefts. Separate mechanisms also are employed for the correcting turning movements for rights and lefts. For a right shoe, a gear wheel 192, Fig. 10, on the jack spindle meshes with an internal gear segment 282, Figs. 3 and 10, carried by a hanger pivoted on the frame 188 and formed with an arm 292<a>, which is pivotally connected through a stud 294 and swivelled bracket 296 to a rod 302. This rod is connected through shackle members 304. 308, a bell-crank 312, and links 320, 324, 332, with an arm 336 of a lever 338, Fig. 13, which is pivoted on the shaft 270 and carries a notched segment plate 342 adapted to be engaged by the upper end of a latch 344 on a lever 348 operated from a cam disk 352 on the correcting cam shaft 248. For left shoes, the stud 294, Fig. 3, carries a pivoted bracket 396 pivoted to a rod 402, which is connected by shackle members 404, 408 and link connexions 412, 420, 424, 430, to an arm 434 of a lever 436, Fig. 13; this lever is pivoted on the shaft 270 and carries a notched segment plate 440 adapted to be engaged by the lower end of the latch 344. To keep the edge of the shoe between the presser-foot 20 and work-support 18, the jack spindle 152 carries a pulley 396a, Figs. 1 and 2, to which are fixed cables 398a, 400<a> passing in opposite directions round the pulley and respectively over guide-pulleys 402a, 404a and connected to tension springs 406<a>, 408a. The tension of these springs is automatically controlled during the sewing operation. The correcting cam-shaft 248 is driven in timed relation to the sewing cam shaft 22 for a predetermined rate of feed of the work. and automatically acting mechanism is provided for varying the speed of ,he correcting cam-shaft to maintain this timed relation in spite of variations which, for any cause, may occur in the rate of feed of the work from its predetermined rate. The correcting cam-shaft carries a worm wheel 682, Fig. 6, meshing with a worm 680, Figs. 4 and 6, on a shaft 684 slidably mounted in sleeves 686, 688, which carry bevel-wheels 694, 696 gearing with a wheel 698 on a shaft 700; the shaft 684 is movable by connexions with a hand-lever 726 to clutch the worm 680 to either wheel 694, 696 according to whether a right or a left shoe is to be sewed. The sleeve 688 has mounted on it a ratchet 746, Figs. 5 and 6, which is rotated by a pair of spring-pressed pawls 748, 750 carried by oscillating carrier 758; this carrier is formed with spaced arms 776 pivotally connected to a lever 762, which is actuated ihrough adjustable connexions 784, 790 from a cam disk 794 on the sewing cam-shaft 22. The lever 762 is pivotally mounted at 768 on a link 770 pivoted at 772 on a support 774, which comprises parallel side plates having trunnions engaging bearings in the machine frame. The speed of the sleeve 688 is determined by the angular adjustment of the support 774, which is provided with a gear segment 796, meshing with a segment 798 on a shaft carrying a disk 804, which is formed on part of its periphery with teeth and is adapted to be rotated in one or other direction by pawls 808, 810; it is held stationary except during the forward stroke of the pawls by a brake shoe 918. The pawls are pivoted, respectively, on carriers 814, 830, and are pivotally connected by links 818, 834 to arms 822. 838 of a rock shaft 824, which carries a gear wheel 842 meshing with a gear segment 844, Fig. 3, on one arm of a bell-crank 846 actuated from the cam disk 794 on the sewing cam-shaft 22. The pawls are normally held inoperative by a shield 856, Fig. 6, which, however, can be turned to release the pawl 808 or the pawl 810, and to bring a cut-away portion opposite its acting end according as to whether the speed of the correcting cam-shaft is to be increased or decreased. The shield 856 is shifted by a lever 864<a>, Fig. 6, pivoted intermediate of its ends to a longitudinally movable rod 870, and at its end to a rod 874 passing through and yieldingly connected to a sleeve 876, which is pivotally connected through bellcranks 880, 884 and a toggle 900, 902 with a lever 908; this lever is actuated from a cam groove 912 in a disk 914, which is journalled on the hub of a disk secured to the correcting cam-shaft 248 and is driven from, and at the same speed as, the worm wheel 682. The angular position of the bellcrank 880 is controlled by a. link 940 adjustably connected to an arm 942 of a segment 944, which meshes with a segment 946 secured to the upper side of the disk 804. The position of the central joint of the toggle 900, 902 is controlled through links 948, 950, 954 from an arm 956 of a lever 958, the angular position of which is determined before the machine is started by the placing of the shoe in the machine. To eliminate hard motions in the cam for actuating the jack, certain of their acting portions are extended beycnd their normal length, and to compensate for this the speed of the correcting cam-shaft is varied when these portions of the cams are operative. This is accomplished by the action of the cam groove 912 on the lever 908, which, since at the time the link 942 is held substantially stationary, causes a bodily movement of the bell-crank 880 to the left, Fig. 6, carrying with it the sleeve 876 and the rod 874; the rod 874 swings the lever 864<a> and turns the shield 856 so that the pawl 808 becomes operative to cause an increase in the speed of the correcting cam-shaft 248, as above described. The speed of this shaft also is varied by movement of either the lever 958 or the rod 870, the former of which has its angular position changed when a shoe of different size is placed in the machine, while the latter is moved when any variation takes place in the feed of the shoe from the predetermined rate for which the correcting cam-shaft is timed when the machine is started. The parts are so arranged that the actuation of the cam lever 908 to change the speed of the correcting cam-shaft occurs at least one stitch in advance of the point at which the change in the speed of the shaft is to be produced. In orde