Patent GB-190226459-A (GB)
Title: Improvements relating to Sewing Machines
Inventor: CHAUVET JOSEPH J M
Filed: 1902-12-01
Granted: 1903-11-12
Abstract: 26,459. Lake, H. H., [Chauvet, J. J. M., and Coulter, J. W.]. Dec. 1. Double-loop stitching- machines ; chain-stitching machines; multiple-needle machines.-Fig. 2 is a horizontal section in the plane of the work-plate of a two-needle sewing-machine. Two loopers d, d' are mounted in the ends of carriers e, e', secured upon a reciprocating rocking shaft 5. One of the loopers is shown in detail in Fig. 7. It contains a point-eye d<2> and a shank-eye d<3>, connected by a groove e<2>. The looper advances to take the needle thread on the right-hand side of the needle, and then, as the looper still advances, the needle rises and the loop of the needle thread is drawn back on to the throat of the looper behind the shoulders d<5>, d<6>. As the looper moves backwards, it retains the loop of the needle thread until the needle has entered the fabric. In its backward movement, the looper is moved to the left, so that the needle descends upon the right-hand of the looper and engages the looper thread, after which the looper is moved to the right again ready for its next advance. The looper shaft 5 is caused to reciprocate longitudinally in bearings 6, 7 by means of an eccentric 12 on the main shaft, which operates a pivoted rocking lever 10, one arm of which is connected to a plunger 8, coupled to the shaft 5 by a cross-piece 9. The forward and backward motions of the loopers are produced by an eccentric 14 mounted on the main shaft, and connected to the looper shaft by an eccentric-rod 15 and arm 16. Any required number of loopers may be arranged on the shaft 5 at any required distances apart, the needles being adjusted on a needle-clamp to correspond. In a modification, the under threads may be omitted, and a form of looper used which causes the needle to engage the loop of its own thread, in which case the machine described may be used for sewing a series of parallel single-thread seams. Feed ; work-supports.-The feed-bar is given an upward and a downward motion by means of an eccentric on the main shaft at 18, Fig. 2. Its forward and backward movements are produced by means of a disc 19 on the end of the main shaft, in the face of which is a groove in which a roller-pin 23, Fig. 12, engages. The pin 23 is connected to the feed-bar by a link 20, a pivoted rocker 21, and the link. The pin 23 can be adjusted by setscrews 24 to various positions in the groove, so as to vary the throw of the feed-bar. The work-plate slide is constructed of such a size, and so located that, by its removal, the whole length of each of the looper blades is exposed and made accessible for threading &c. Governing under thread.-Each successive looper in the series extending from left to right contains one additional eye in its shank, such as d<7>, Fig. 7. Each looper thread passes through a separate guide formed in a post f to the looper nearest thereto, which contains a number of eyes d<3>, d<7>, corresponding to the number of looper threads employed. The thread passing through the eye d<3> of the first looper is the thread for that looper. The thread passing through the eye d' of the first looper, passes to the eye d' of the second looper, and constitutes the thread for the second looper, and so on. By this arrangement, the length of throw of all the threads is the same between the loopers and the guide-post f<2>.