Patent GB-103465-A (GB)
Title: Improvements in and relating to Sewing Machines.
Inventor: THOMPSON WILLIAM PHILLIPS
IPC: D05B29/06
Filed: 1915-09-28
Abstract: 103,465. Thompson, W. P., (Union Special Machine Co.). Sept. 28, 1915. Sewing-machines.-Relates to sewing-machines adapted to make a flat seam for covering or joining the edges of the fabrics as described in Specifications 6383/15 and 6442/15, and is distinguished from the invention described in Specification 13783/15. Multiple - needle machine ; loop - stitching; threads and the like, attaching. - The stitchforming devices comprise two pairs of needles arranged in staggered relation, or with the needles of one pair between the line of action of the other pair, and a threaded looper and a device for laying a surface thread for each pair of needles. The loopers 20, 21, Fig. 5, are independently mounted on the end of the looper shaft 23, which receives endlong and rocking movements from the shaft 31 by a connecting-rod 35, which has a ball connexion with the arm 36, Fig. 11, of the shaft 23 and has a pivoted arm 37 sliding in a sleeve 39 capable of rocking about the bearing 40. The thread-laying devices consist of two thread-guides 48, 49, Fig. 13, which are adapted to be reciprocated in the direction of the feed and are carried by a lever 76<1> connected by a link 78 to an arm 79 of a shaft which is rocked by connexion with the main shaft. Cooperating with the guides are hooks 50, 51 adapted to move across the line of feed and carry the thread from the guides into a position where they will be engaged by the needles. The hooks are carried by one arm 52 of a lever pivoted at 53, the other arm 55 being connected through the link 62 with an arm 61 of a sleeve which has a readily detachable connexion to a link driven by the needle-lever, so that, when necessary, the hooks may be swung out of position to give access to the needles for threading or renewing. Where the needles of a pair are close together, a loopretainer is provided to co-operate with the looper to hold the needlethread loops in the required position. The pairs of needles 12, 13 and 14, 15 are secured to the needle-bar as shown in Figs. 26 and 28. A needle-head 41 and a collar 45 are secured to the needle-bar 11. The needle 12 is secured to the head by a screw 42, and the needle 13 is secured in the needle-bar by a screw 43 and has its point raised above that of the needle 12. The needles 14, 15 are secured in the head by screws 44, 46 and are positioned correctly as regards height by abutments formed .by the base of the collar 45 and a lug 47 thereon. An alternative arrangement of the pairs of needles 12<a>, 13<a> and 14<a>, 15<a> is shown in Fig. 37. Frames.-The frame comprises a standard 2, Fig. 1, from which extends the overhanging arm 3 and a second upwardly and outwardly projecting arm 6, which is at right-angles to the arm 3 and supports a third arm " at right angles to the arm 6, this third arm supporting a fourth arm or work support 9 parallel to the arm 6 and extending under the end of the arm 3. The main shaft, which is mounted in the standard, has an eccentric operating the needle-lever 16, and drives, through a pair of connecting-rods 32, 33, a shaft 31 mounted in the arm 7 and having driving- connexions with the looper shaft and feedmechanism, which is mounted in the worksupporting arm 9. Feed by dogs.-The main feed-dog 119, Fig. 5, is carried by the bar 121, which is adjustable as regards its position in the work-arm by the link 124 and eccentric 126, and receives its feeding and up-and-down movements from an eccentric rod 133, which is driven by an eccentric on the shaft 31 and is connected to a lever 136, with adjustable fulcrum, oscillated by another eccentric on the same shaft. The auxiliary feed-dog 120 is carried by a bar mounted for up-and-down movement on the main feed-bar, and is connected thereto through the link 143, pivoted arm 146, and link 148. The position of the connexion between the link 148 and arm 146 is adjustable by a twoarmed lever 153, one arm of which is connected by a link 154 with the link 148. The feeding movement of the dog 120 is greater than that of the dog 119, to prevent stretching of the material, and the difference in the relative movements of the two dogs is adjustable by the connexions stated above. Trimming or cutting.-The material is trimmed between a stationary blade 82, Figs. 13 and 14, carried bv a presser-foot, and a movable blade 83 carried by an arm 84 secured to a yoke 86 carried by the presser-bar 102 and pressed down by a spring. The yoke has an arm connected by a pitman to one arm of a bellcrank lever pivoted to the frame, the other arm being connected by a link to the rear end of the needle-lever. The trimmed-off strip is guided away from the stitching - mechanism by a deflector consisting of a fixed part 96 which spans the slot in the presser-foot through which the edges of the material are guided, and a hinged part 97 which can be moved aside to give access to the needles and is held in either position by a spring. Presser-feet.-The presser - foot consists of a fixed part 108, Fig. 14, and a yielding part 109 normally held on the work by a spring.