Patent GB-191513783-A (GB)
Title: Improvements in and relating to Sewing Machines.
Inventor: THOMPSON WILLIAM PHILLIPS
IPC: D05B29/06
Filed: 1915-09-28
Abstract: 13,783. Thompson, W. P., [Union Special Machine Co.]. Sept. 28. Sewing-machines. - Relates to sewing-machines adapted to make a flat seam for covering or joining the edges of the fabrics described in Specifications 6383/15 and 6442/15, and is distinguished from the invention described in Specification 103,465. Frames. - The frame is rectangular as distinguished from the triangular or oblique frame of Specification 6038/12, and comprises a standard 2, Fig. 1, from which extends the overhanging arm 3, and a second outwardly and upwardly projecting arm 6, which is at right-angles to the arm 3, and supports a third arm 7 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 on the standard, has an eccentric operating the needle lever 36 and drives, through a pair of connecting-rods 32, 33, a shaft 31 mounted on the arm 7 and having driving connections with the looper-shaft and feed-mechanism which is mounted on the work-supporting 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 fnlcrum, 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 two-armed 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 through the connections above stated. Multiple-needle machines; loop-stitching; threads and the like, attaching.-The stitch-forming devices comprise two pairs of needles arranged in staggered relation, or with the needles of one pair between the lines 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 end-long and rocking movements from the shaft 31 by the connecting- rod 35 which has a ball connection with the arm 36, Fig. 11, of the shaft 23, and has a pivoted arm 37 sliding in a sleeve 39 capable of oscillating 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 connection with the main shaft. Co-operating with the guides are hooks 50, 51 adapted to move across the line of feed to 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 connection 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 loop retainer is provided to co-operate with the lonper to hold the needle-thread loops in the required positions. 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 in 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 the point of the needle 12. The needles 14, 15 are secured in the needle head by the 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. Trimming or cutting.-The material is trimmed between a stationary blade 82, Figs. 13, 14, carried by the presser-foot, and a movable blade 83 carried by an arm 84 secured to a yoke 86, carried by the presser-bar 1(,2 and pressed down by a spring. The yoke has an arm connected by a pitman to one arm of a bell-crank lever pivoted on 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, wbich 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.