Patent GB-308728-A (GB)
Title: Improvements in or relating to sewing machines
IPC: D05B15/04
Filed: 1929-03-26
Abstract: 308,728. United Shoe Machinery Corporation, (Assignees of Topham, L. E.). March 27, 1928, [Convention date]. Boot-sole sewing-machines; feed by awls; lock stitching by shuttles; perforating devices; worksupports.-In a sewing-machine primarily intended for use in sewing together outsoles, welts, lasted uppers and insoles, of the kind described in Specification 7793/92, devices such as the needle, presser foot, and work-support engage the work intermittently to operate upon it, and feed it; carriers to which these devices are secured reciprocate along the line of feed for this purpose and are mounted for simultaneous adjustment. Two carriers are provided, one on which the needle is mounted and one carrying the work support and presser foot. The needle carrier, Figs. 1 and 17, comprises a boss 70 in which is a stud 72 forming the pivotal support of the needle segment, a portion 74 extending downwards, a bar 76 extending rearwards in the direction of the feed and a block 78 with adjusting nuts 80. The carrier is supported by a link 82 pivoted at its upper end 84 to the machine frame, and by links 94 pivoted at their upper ends to the machine frame at 96 and at their lower end to the block 78 at 98. These links permit a backward and forward swing of the carrier in a straight line in the direction of feed. The carrier for the work support and presser foot is a slide 100 of the same type as described in Specification 7793/92. The carriers are reciprocated by two mechanisms which each comprise a cam and connections therefrom to the carrier. The slide 100 is moved by an arm 102, Fig. 22, pivoted at one end to the machine frame at 104 and at the other end at 110 to a link 108 which is pivoted in turn to a support 112 on the slide 100. Movement of the arm 102 about its pivot reciprocates the slide 100. The arm 102 is oscillated by a link 114 pivoted to the arm at 106 and pivoted at its upper end to a bell crank 116 which engages a cam groove in a disc 120 mounted on the shaft 122. The needle carrier 70 is reciprocated by similar mechanism, comprising a swing- ing arm 124 connected at 110 to the support 112 of the slide 100 and having its lower end connected by a link 126 to arms projecting rearwardly from the block 78 of the needle carrier. The arm 124 is connected by a link 128 to a bell crank 130 mounted on the same pivot as the bell crank 116, and it engages another cam groove in the disc 120, formed within the groove for the bell crank 116. The travel of the carriers 100, 70 can be varied simultaneously by adjusting the pivot 110. For this purpose, the support 112 is made adjustable on the slide 100. The needle segment is mounted directly on the pivot stud 72 and the needle guide on the hub of the needle segment. The needle guide has a friction shoe 140 forced by a spring 142 into contact with a surface 144 on the needle segment 62, Fig. 12. This causes the segment to move the guide backwards and forwards against the upper surface of the presser foot for any thickness of work. The work support 58 is of usual construction and is mounted on a standard 150, Fig. 6, rising from the forward end of the slide 100 so that the work support reciprocates with the slide. The shoe segment is also mounted on this standard. Presser bars, periodic control; lifting devices. -The presser foot 60 is secured to the front portion 152 of a lever mounted on the bush 154 secured to the machine frame. This lever reciprocates with the carriers in the line of feed. The rear part 158, Fig. 6, of the lever is held against movement on the bushing 154 and the front part 152 slides in grooves on the rear part to move with the feeding movement. A pin 160 secures the two parts together. The part 152 is moved by a flange which engages the standard 150 on the slide 100. The mechanism for locking the presser foot on the work and for actuating the presser foot lever 152 is the same as described in Specification 7793/92, and comprises pawls 168, 170 engaging respectively the lever 172 and rear part of the presser foot lever 158. Means are also provided for unlocking and lifting the presser foot manually and also for performing these operations automatically on stopping the machine. A hand lever 174, Fig. 16, on the machine frame, by downward movement, depresses the lever 158 to lift the presser foot from the work. To perform this operation automatically, a rod 200, extending through a perforation in the rear of the lever 174, is depressed on stopping the machine through connection with the stopping mechanism, to actuate the lever 174. A knife 204, Fig. 1, is provided for cutting a stitch-receiving slit in the work and is vertically adjustable in a holder 206. Starting and stopping gear.-The driving and stopping mechanism of the machine comprises a forwardly driving friction clutch, a reversely driving friction clutch which is thrown into operation on stopping the machine to reversely rotate the cam shaft at a low speed to final stopping position, and a timing cam for throwing the reversely driving friction clutch into and out of operation. The high speed forwardly driving friction clutch comprises a pulley 268, loose on the sleeve 272, and a hand wheel 270 secured to the sleeve 272 keyed to the cam shaft 122, Fig. 34. The pulley 268 is moved laterally into and out of engagement with the hand wheel 270 by a clutch shifting lever connected by a rod to the starting and stopping treadle. The reversely driving clutch comprises a driven clutch member 280 integral with the sleeve 282 mounted on the sleeve 272, and a driving clutch member 284, mounted to rotate loosely on the sleeve 272, and driven continuously at a comparatively low speed by a worm shaft 286 which is driven by a belt. The member 280 is connected to the hand wheel 270 so as to rotate at all times with it, but is mounted to slide on the sleeve 272 and is normally held out of engagement with the member 284 by springs 290. The timing cam 296 for moving the clutch member 280 into and out of engagement with the member 284 is mounted on the member 280 and is engaged by one end of a bell crank lever 298 which vibrates idly when the cam shaft 122 is driven forwardly. The bell crank is held against movement when the shaft 122 continues to move under its momentum, after the drive has stopped, and the cam 296 is forced to the left as shown in Fig. 34, to put the reverse driving clutch into action. Specification 115,032 also is referred to.