GB410463A - Improvements in or relating to sewing machines - Google Patents

Abstract

410,463. Sewing-machines. BRITISH UNITED SHOE MACHINERY CO., Ltd., GOULDBOURN, J., KEALL, F. B., and KESTELL, T. A., Belgrave Road, Leicester. Oct. 11, 1932, No. 28274. [Class 112.] The invention relates to improvements in lockstitch sewing-machines for boots, &c., of the general type described in Specification 23478/10, [Class 112]. Assuming the countershaft 525 of the machine to be driven but the main shaft 15 to be stationary, the operator places the margin of the shoe, sole uppermost, on the work-supporting table 161 so that the toe extends towards his right, the needle 67 being raised. The operator depresses the starting treadle 561 of the machine, keeping hold of the shuttle and needle threads for the first few stitches. The action of depressing the treadle 561 allows the presser foot 281 to descend upon and become locked against the work close to the needle and awl and allows the lower thread lock 63 to close upon the thread. The clutch upon the main shaft becomes engaged and the main shaft is rotated at low speed. Continued depression of the treadle causes the driving member 547 on the countershaft to move into driving engagement with the large pulley 541 to drive the machine at high speed. As the main shaft of the machine rotates the needle 67 first rises, descends through the work, receives the thread in its barb from the looper, and rises once more through the work. A guide 37 assists the needle in its work-penetrating movement, and prevents the thread from leaving the barb. The shuttle pulls the thread out of the barb and forms the stitch in usual manner, the needle guide being timed to permit this. The awl 69 pierces the work in readiness for needle penetration. When the stitching is completed the machine is stopped by allowing the treadle to rise. Feeding work. The presser foot 281 first becomes locked against the work close to the needle and awl. It is then gradually lifted from the work and, with the table 161, makes an idle return to the right, the work being held against backward movement by the awl. The presser is then locked against the work again by wedge mechanism, the needle and awl being clear of the work, and with the work table, moves the work to the left the length of a stitch. Pull off. The thread measuring lever 239 is swung by a cam to an extent depending on the thickness of the work, to pull off sufficient thread for successive stitches. A thread hook 39 and tension device co-operate to assist the looper 61 and needle in the formation of the stitch. Stitch setting. A rotary take-up roll 331 completes the setting of the stitch in the work. This device is similar to that described in Specification 390,842. The threads are cut after stitching, by mechanism as described in Specification 408,315. Waxing threads. The electrically-heated wax pot is of the general construction described in Specification 400,649 and has a thermostat for controlling the temperature of the wax. An edge gauge comprising a shank 467 and lip 469 may be provided. Channelling. A fudge knife comprising a stem 511 and rod 515 is provided for cutting a channel at the work for the stitches. Presser feet. The presser foot may be provided with a grooving knife to cut a shallow depression to make the stitches flush with the work. The high and low speed driving mechanism and the lubricating mechanism are described in Specification 410,496. The needle and awl driving mechanisms are described in Specification 410,497.