Patent GB-190619523-A (GB)
Title: Hemstitch Sewing Machine.
Inventor: FAIRWEATHER WALLACE
Filed: 1906-09-01
Granted: 1907-06-20
Abstract: 19,523. Fairweather, W., [Wheeler & Wilson Manufacturing Co.]. Sept. 1. Hem-stitching machines; needle-bars, vibrating laterally and in line of feed ; feed.-In a machine for hem-stitching, the work, is fed forward only,. and that twice for each group of three stitches, and the needle is vibrated both laterally and in the line of feed in order to produce the necessary relative motion of the work and needle. For this purpose, the needte bar slides in a frame 83 which is hung on a universal pivot 88, 90 on the head of the machine. It is vibrated laterally by a cam-actuated lever 70 through a pitman 81. The amplitude of this vibration can be varied by the sliding attachment 79. The needle is vibrated in the line of feed by a cam-actuated lever 99 through a rock-shaft 93 and a lever 95. The lever 95 is slotted and engages a tongue 96 on the needle-bar frame. The cam-slots, actuating the needle frame, are both in a disk 60 which is rotated once for: every three stitches. The lever 99 is held in engagement with the front wall of the cam-groove by a spring 107 acting on the needle-bar frame. The extent of the vibration in the line of feed is regulated by a screw stop 104 on a cranked arm of the lever 99. The needle-bar is reciprocated by a link 26, which is connected to the needle.-bar as described in Specification No. 18,732, A.D. 1904. The feed-dog is operated from cams 57 and 122, Fig. 2, on a shaft 118 which is rotated once for every three stitches. The cam 122 operates a lever 126 and a rock-shaft 127, having at its other end a second lever 131, Fig. 1, which carries a block, sliding in a slot in the feed-dog frame, to move the dog in avertical direction. Tne cam-groove 57 operates a lever 53, shown in dotted lines in Fig. 2, a rock-shaft 51, a lever 50, a link 46 slidingly connected at 49 to the lever 50, a lever 47, and a rock shaft 48. The rock-shaft 48 also carries a lever 115 by which it transmits its motion to the feed-dog. This horizontal motion can be regulated by a lever 44 which controls the position of the sliding connexion 49. The presser-foot and shuttle are of usual construction, the latter being rotated twice for each stitch. The stitch, shown in Fig. 8, is formed as follows:-As the needle is ascending from the stitch a, Fig. 7, it is moved laterally and the work is fed forward so that the needle is over the point d. The needle then descends and simultaneously is moved towards the operator so that it enters the work at b. While in the work, the needle is moved laterally to the edge of the fold so that the shuttle reaches the thread loop, and also so as to produce the openwork feature of the stitch. When the needle rises from the stitch b, it is moved away from the operator so that when it next descends it enters at c. Here again it is moved laterally towards the shuttle and produces the open - work feature of the stitch. This stitch completes the group of stitches; when the needle rises, it is moved towards the operator into its normal position and is moved laterally in to the line of the stitches a, so that when the work is fed forward a second time the needle enters at a<1>. When the needle is in the work at a<1>, it is moved laterally to bring the thread loop into the path of the shuttle.