Patent GB-107603-A (GB)
Title: Improvements in and relating to Sewing Machines.
Inventor: THOMPSON WILLIAM PHILLIPS
IPC: D05B3/02
Filed: 1916-04-03
Abstract: 107,603. Thompson, W. P., (Union Special Machine Co.). April 3, 1916. Sewing-machines ; frames.-The frame of a sewing-machine comprises a standard 1, Figs. I and 2, from which projects an overhanging arm 3, and a lateral arm 5 at rightangles thereto and supporting an arm 6 which is parallel to the arm 3 and to the free end of which is secured, by lugs 72 and bolts 73, the L- shaped work-supporting arm 8, the end of which lies under the head of the arm 3. The main shaft 9 is mounted in the arm 6 and rocks the needle-bar-actuating shaft 4 in the arm 3 by a crank 14 and link 15 which extends through the lateral arm 5. The other end of the shaft 9 actuates two eccentric rods which drive the looper and feed mechanisms contained in the work-supporting arm 8. Multiple-needle machines; extra threads, attaching.-The invention is described as applied to a sewing- machine for stitching two pieces of fabric edge to edge by means of two pairs of needles 22, 23, Fig. 8, each pair co-operating with a single looper and with a surface-thread-laying device consisting of a fixed thread-guide 28 and a thread-laying finger 31. The fingers 31 are carried bv a bracket 33 secured to the lower end of a sleeve 38, Fig. 6, surrounding the presser-bar 25 and retained in bearings in the head of the machine. The sleeve 38 is rocked by a link 44 attached to one end of a bell-crank lever 41, the other end of which is connected by a link 50 to an arm 51 secured to the needle-bar-actuating shaft 4. The loopers 74, 75, Fig. 17, are carried by a shaft 77 which is rocked by an arm 80 connected by a link 84 to one arm 83 of a rock-lever pivoted at 82. The other arm of the rock-lever is actuated bv an eccentric-rod 86 from the main-shaft 9. A second eccentric-rod 98, actuated by the main shaft, drives a three-armed rock-lever 96. Endlong movement of the looper-shaft is obtained by a sliding block 88 loosely retained on the shaft and connected adjustably by a link to a slotted arm 94 of the rock-lever 96. Feed by dogs.-The feeding mechanism comprises a main feed-dog 99, Fig. 17, and an auxiliary feed-dog 111 to which differential movements can be given. The main feed-dog is carried by a bar 100 to which rising and falling movements are given by a strap 101 embracing an eccentric on the looper shaft, and feeding movements bv a link 106 adustably connected to a slotted arm 109 of the rock-lever 96. The bar 112 of the auxiliary feed-dog is connected for rising and falling movements directly with the main feed-bar, and for its feeding movements is connected by a link 117 to an arm 116 of a rockshaft 115, which is provided also with a slotted arm in which a link connexion with the main feedbar can be adjusted. This adjustment is effected by a lever 123 having a finger-piece projecting through the side of the arm and connected by a link to the adjustable-link connexion between the main feed-bar and rock-shaft 115. Trimming or cutting.-The fabric edges to be joined are trimmed by a fixed blade 52, Figs. 6 and 8, and a movable blade 53 which is carried by a bracket 54 secured-to the lower end of a bar 55 which passes loosely through bearings 61, 64 in the head of the machine and is acted on bv a spring 62 to keep the blades in operative position. The bar 55 is rocked by an arm on a collar 65 secured thereto which is connected to an eccentricrod 67 embracing an eccentric on the sleeve 38. Presser-bars.-The presser-bar 25, Fig. 6, has secured to it an arm 56 through which passes freely a guide-bar 55 and is acted on by a spring 59 bearing on a washer 58 and adjustable sleeve 60. The washer 58 is cup-shaped and its flange engages an annular recess in the arm 56.