Patent GB-190728685-A (GB)
Title: Hemstitch Sewing Machine.
Inventor: FAIRWEATHER WALLACE
Filed: 1907-12-31
Granted: 1908-07-30
Abstract: 28,685. Fairweather, W., [Singer Manufacturing Co.]. Dec. 31. Hem-stitching machines; lock-stitch hooks &c.-A high-speed hem-stitch machine is described in which the loop-taker has its face parallel to the needle reciprocations, has an axially fixed working position, and is not required to follow the lateral movements of the needle. The loop-taker 12, Figs. 3, 7, and 8, is driven from the main shaft 3 through pin-pulleys 6, 8 and a perforated belt 7, the smaller pulley 8 being fixed on the rearward end of a shaft 9, to the front end of which is fixed the hub 13 of the cupshaped hook 12 provided with a beak 14 and a loop-detaining horn 15. The hook has an annular seat in which rests the rib 16 of the thread-case 17, which has a lug 18 with a notch 19 for receiving the finger 20 of the holding-arm 21. The lug 18 has the usual clearance slot 22, which has a clearance cut 23 to accommodate the needle when moved laterally. Needle - holders ; needle - driving ; needle - bars, vibrating laterally; perforating-devices.-Theneedlebar 26, Fig. 5, journaled in the head of the arm 2, is connected at its upper end to a pitman 27, which is connected to the usual crank-pin on the disk 28, fixed upon the forward end of the main-shaft 3. The lower end of the needle-bar has a socket to receive the shank 35, Fig. 9, of the awl-clamp 36, which has a lug pivotally secured by a pin 42 to a laterally extending forked lug 40 of the needleclamp 41. To an extension of the lug 40 is secured an upwardly extending lever 48 having secured to its upper end a block 50, Fig. 3, which enters a slot 51 in an arm 52 having at its upper end a collar 53 secured to a reciprocating rod 55, journaled in the head and pivotally connected at its forked end 56 with a link 58, the opposite end of which is adjustably secured in a slot 60 in one arm of a bell-crank lever fulcrumed to the bracket arm. The other arm of the bell-crank lever carries a roller 64, Fig. 4, working in a peripheral groove 65 in the cam-cylinder 66, which has a bevel-gear 68 meshing with a pinion 69, of one-third its size, on the mainshaft. The rocking of the bell-crank lever serves to reciprocate the rod 58 and the arm 52, to cause the vibration of the lever 48 and the consequent lateral movement of the needle. The cam is shaped to cause the needle, in addition to its other lateral movements, to move laterally while in the work, so that, in commencing its ascent, the needle always assumes the full-line position shown in Fig. 4, and is thus in position to present its loop for seizure by the beak of the hook 12. If it is found desirable to provide a second awl in advance of the needle, a grooved plunger is provided to adapt the machine for curved seams. The needle-bar 26 is in this case provided with a plate 97, Fig. 14, which is secured to its lower end similarly to the clamp 36, and has a lug 39<x> attached by the pin 42 to the forked lug 40 of the needle-clamp 41. The additional awlclamp 100 carrying the awl 101, which is recessed at 102 to house the needle point, is pivotally attached to the plate 97, and is locked in operative position by a hook 106 on the end of a spring-held latch-lever pivoted to the plate 97. The awl may be turned up to facilitate the threading of the needle Feed; presser-feet.-The usual advancing and receding motions are given to the work by the feeddog 70, Figs. 3 and 5, which operates through the throat-plate 71 in opposition to the compound presser-foot 72, and is mounted on the forward end of a bar 73 pivotally connected to the arm 75 on the forward end of a shaft 76. This shaft 76 is driven through a crank-arm 77 and link 78 adjustably fixed to one arm 81 of a bell-crank lever, the other arm of which carries a roller stud, which works in a groove 85, Fig. 4, on the rearward face of the cam cylinder 66. The lever 73 is supported by a link 86 attached to the spring-held arm 87 of a feed-lifting rock-shaft 89, which is driven from the cam-cylinder 66 by a pin 95 working in a camgroove 96 therein. The pin 95 is attached to a swinging lever 93 fulcrumed on a pin 94 and connected to the shaft 89 through links 90, 91. The lateral movements of the needle, and the feeding and rising and falling motion of the feed-dog are thus all produced by the one cam-cylinder 66, as in Specification No. 17,095, A.D. 1899. Governing needle-thread.-The take-up is of the Singer type, and consists of two arms, one 29 attached to a pin 30 on the disk 28, the other 31 carrying the take-up eye 32, the take-up being pivotally connected at the junction of its arms to one end of a lever 33 pivoted at 34.