Patent GB-191506918-A (GB)
Title: Improvements in and relating to Sewing Machines.
Inventor: THOMPSON WILLIAM PHILLIPS
IPC: D05B15/04
Filed: 1915-05-08
Abstract: 6918. Thompson, W. P., [Union Special Machine Co.]. May 8. Multiple - needle sewing machines; chain-stitching and double-loop and other loop stitching; lubricating thread; presser-bars, lifting; presser-wheels; worksupports. - A threadmeasuring device and a thread take-up in a sewing-machine are both connected with the presserbar so that the thread control is influenced by the thickness of the material being sewn. In the machine shown, the needle-bar 13 carries three needles 14, 15, 16 cooperating with two loopers 9, but the improvements are applicable to other types of machines. The needle-bar 13 is driven by a lever 17 pivoted at 18 and operated by an eccentric 19. An arm 27 of this lever operates the loopers 9. The presser-bar 30 carries a presser-foot 29 and also an adjustably-mounted, pivoted, spring-pressed presser-wheel 53. The presser-bar 30 is guided by a parallel bar 41, Fig. 3, connected to it by a rod 45 and reciprocating in guides 43. The presserbar is held down by a leaf spring 35 acting on a pin 34, but may be raised by a band-lever 36, or by a foot-operated lever 47, which is normally held out of operation by a spring 50. The threads on their way to the needles pass under a bar in an oil-box 61, under a spring-pressed oil-stripper plate 67, through adjustable spring-pressed tension disks 71, through an automatically adjusted threadmeaiurer 79, 74, 86, through a thread clamp 105, and an automatically adjusted take-up device 106, 113, and then over a finger 120 and under a roll 121 to the needle-bar take-up 122, whence they pass down by the side of the need-bar to the needleeyes. The thread-measurer comprises a fixed roll 79, an adjustable roll 86, and an oscillating thread-pulling finger 74 working between them and mounted on the needle - operating lever 17. The roll 86 is mounted on a yoke 80 pivoted at 81 and is adjusted in position in accordance with the thickness of the material being sewn by a rod 87 attached by a lever 90 pivoted at 91, Figs. 2 and 3. One arm 94 of the lever 90 rests on the presser-bar 30. A link 95 connected with the lever 90 is guided by a head 100 on the pin 34, and has a pin 101 which is acted on by a plate spring 102. The plate springs 35, 102 bear on one another for part of their length and are adjusted by the same screw 103. The rod 87 is screwed at the ends so as to be adjustable in length. The thread clamp comprises a plate 105 and a spring plate 107, which is forced down to clamp the thread by an adjustable block 110 on the needle-operating lever 17. The adjustable taktup comprises thread-eyes 106 on the lever 17, and eyes 113 on the end of a lever 114 pivoted at 116. This lever is positioned, in accordance with the thickness of the material being sewn, by an arm 118 on the presser-bar 30. This arm has gear teeth meshing with gear teeth 117 in the end of the lever. The needle-bar take-up 122 co-operates with the finger 120 and the roll 121 for drawing off thread and setting the stitch. By this arrangement, sufficient thread is supplied to form the stitches, and the stitch is not set until the needle bas left the work, whatever the thickness of the material being sewn. The nose-piece 4 of the arm 2 is pivoted at 5, and the spring 6 keeps it in open or closed position as desired. The part 7 is readily detachable.