Patent GB-170762-A (GB)
Title: Improvements in or relating to sewing machines for stitching shoe upper to sole lip
IPC: D05B15/00
Filed: 1920-10-22
Abstract: 170,762. Jackson, W. J. Mellersh-, (Reecc Shoe Machinery Co.). Oct. 22, 1920. Boot-sole sewing-machines; welting and turnshoe; chainstitching.-The main shaft 53 ,carries two cranks 56, 57, Figs. 1 and 2, and all the driven parts of the machine are actuated from these cranks by link-work. Lever arms 67, 75, F'igs. 1 and 19, are coupled together by a link 75a and to the crank 56 by a link 61 and drive a needle-threader D, a thread-finger E, and a channel-guide B, and impart feeding movement to a feeddog G. Lever arms 69, 73, Fig. 21, are coupled together by a link 70 and to the crank 57 by a link 62 and drive a curved needle U and a take-up F, control locks on a back-rest A and a welt guide H and impart a welt-feeding movement to the welt guide and up- and-down movement to the feed dog. The needlethreader D is given an oscillatory motion by bevel wheels d, d<1>, Fig. 2, pinion d<3>, Fig. 1, and a toothed segment 85 which is coupled to the rocker 67 by a link 84. The thread-finger E, which co-operates with the needle-threader D, is oscillated about a pivot e, Fig. 1, by means of a link 88 having a pin-and-slot connection with an arm 87 on the rocker 67. The channel-guide B, Figs. 2 and 19, is carried by a lever b pivoted at 101 and having a pin-and-slot connection with a sliding piece 79 connected by a link 78 to a slotted arm 77 of the rocker 75. The feed-dog carrier g is pivoted upon a shaft 101 and is adjustably connected by means of a bracket 130 and screw 133 with a lever g<2> also pivoted on the shaft 101 and connected by a link to the point 93a, Fig. 21, on the rocker 69. The carrier g and lever g<2> turn between collars on the shaft 101 which is reciprocated axially, for the feeding movements, by means of a lever 100, Fig. 18, a link 99, a sliding piece 98, a link 97 and an arm 96 secured upon the shaft 76a of the rocker 75. The welt guide H is urged toward the work by a spring h<1>, Fig. 21, and is moved positively backward in each cycle by means of a rocker 105 which is connected by a link 106 to the joint between two links 103, 63 connected, respectively, to the rocker 73 and the crank 57. A lever 107 is pivoted at 109, connected to the rocker 105 by a link 106, and has a screw stop 112 which contacts with a second lever 111 pivoted at 109, the lower arm of which is pivoted to the shank h of the welt-guide. The forward movement of the welt-guide is determined by the contact of a spring-stop 113 on the lever 111 with a buffer 114 on the machine frame. The welt-guide H and the back-rest A are intermittently locked by ratchet teeth h<4>, a<4>, Fig. 2, and pawls H', A', Fig. 1, which are actuated by cams on an arm 74 of the rocker 73. The curved needle C and the take-up F are operated from the crank 57 in the way described in Specification 107,475. The auxiliary take-up F<1> is pivoted at f<1> and moves between stops f<3>, f<4>. It is urged toward the stop f<3> by a spring f<8>, one end of which is -secured in a wheel which may be turned, to adjust the tension of the spring, by a screw f<10>. The stop f<4> is made resilient by being pivoted at f' and held in place by a spring-arm f<6> and an adjusting screw f<7>. In an alternative mechanism for actuating the welt-guide, the crank 57 is used as a cam to impinge upon a roller which is mounted for adjustment in two directions at right angles upon a lever connected to the shank h. Starting and stopping gear.-A sleeve 27, Fig. 4, feathered on the main-shaft has a cone-clutch surface 23 for engagement with a coned recess in the driving pulley 20, and a coned friction surface 24 for engagement with a brake block 26. When the control treadle is released a spring 33 urges the sleeve 27 to the right, but the movement is prevented, until a predetermined point in the revolution of the shaft, by a rod 41, which bears upon a disc 38 in which a segmental recess 39 is cut. The brake block is free to turn backward for about one quarter of a revolution against a spring, so that after the machine is stopped the operator may reverse it by hand in order to withdraw the needle from the work.