Patent GB-190619875-A (GB)
Title: Improvements in Sewing Machines for Sewing Straw Plait and other purposes.
Inventor: FISCHER GUILLAUME
Filed: 1906-09-06
Granted: 1907-07-18
Abstract: 19,875. Fischer, G. Sept. 6. Straw-plait-sewing machines.-A stitch, Fig. 17, for straw-plait, which is concealed between the plaits, is sewn by a two-needle machine. In forming the stitch, the needles f penetrate the material a short distance only so that their hooks f<1> are in line with a thread held centrally. The thread is pushed into the hooks, and the needles withdraw more laterally, penetrate the materials again, and carry the needle loops past each other. A flat hook p then passes between the needles, which are recessed at f<2> for this purpose, seizes the thread loops and carries them into'the position shown in Fig. 14. Here the hook is rotated to bring the barb uppermost and so release the upper loop which is retained by the lower loop, which has been passed through it and is retained by the hook. As the materials are fed, the loop held by the hook is lengthened, and when the needles descend to commence the next stitch they pass through the loop, and the new lower loop, Fig. 17, is pulled through it before being released by the hook as it moves to repeat its operation. During the time the needles are out of the work, the thread loops are retained in their barbs by special revoluble hooks or guides. Needle-driving; needle-bars, vibrating laterally. -The needle-bars c', c<2>, Fig. 1, are mounted to slide in frames k<3> which are pivoted at k<1>, k<2>. They are reciprocated by levers b<1>, b<2>, linked together by a rod a<1> operated by a cam a. The frames are vibrated laterally by a cam which actuates levers 15, pivoted at 14 and having spring clips i<1>, i<2>, which embrace them. Loop-stitching machines; work-supports.-The thread-guiding hooks 35, Fig. 22, which retain the loops in the needle barbs are carried by levers 34, pivoted to rotary sleeves 34<b>. The sleeves are toothed and gear with segmentally toothed levers 37, oscillated by racks 33, which are operated by levers on a shaft 31 which is connected by suitable link-work to a cam 25. The hooks are moved to and from the needles by fixed eccentric surfaces, on the needle-bars on to which they are pressed by springs 34<a>. The thread=pulling hookp is revolubly mounted in a plate n, Fig. 21, in the centre of the hollow work-support d. The plate is vibrated to move the hook longitudinally by a cam r, Fig. 1, through rods r<1>, r<2>. The hook is rotated to and fro through a quarter of a revolution by a rack-rod q, actuated from a cam-lever s<1>, Fig. 1. On the first short stroke of the needles, the thread is pushed into the needle barbs by a thread-striker, consisting of two-bent wires on the end of a rod t<2> which is suitably reciprocated. In the modification shown, the rod t<2> is actuated from a cam-lever t<1> through a lever 46 which is pivoted upon a pin 45. The lever is slotted to receive the pin, which is carried by a plate 44 and can be moved to and fro to vary the position of the fulcrum and the throw of the rod t<2> by a worm 40 and handle 42. A lever 52 presses the needles against the loop-puller and is actuated from the lever 46. Feed; presser-feet.-The feed-dog m is movable vertically in a slide suspended by levers m<2>, Fig. 4. The vertical motion is imparted to it by an eccentric 1 through linkages 20, 21. The horizontal motion is derived from a cam-groove x, Fig. 5, which actuates a lever x, slotted at z<17> to receive its adjustable pivot z<6>. The lever z is supported by and actuates a lever fixed to the feedshaft z<1>, and thereby through the lever z<3> moves the feed slide and dog. To vary the feed, the pivot z<6> is moved by a block z<15> linked to it by bars z<9>, z<17>. The block is toothed and is held in engagement with a fixed rack by a spring. The presser-feet: are of the usual type and are separated by a wedge rod 7. Governing needle thread.-The thread is tensioned by the usual form of spring-pressed disks and these are separated periodically by a cam-lever u<1>, Fig. 1. The supply of thread is measured off by a lever 11, Fig. 19, which is oscillated from the feed-shaft z<1> so that the supply varies with the length of stitch. Leaving the measurer, the thread passes through a self-acting thread clamp 12. A simple take-up, shown in two positions in Fig. 1 by dotted lines, is operated by a cam v.