Patent GB-190321198-A (GB)
Title: Improvements in Sewing Machines.
Inventor: SMITH WILLIS AUSTIN
Filed: 1903-10-02
Granted: 1904-02-25
Abstract: 21,198. Smith, W. A. Oct. 2. Lock-stitch shuttle sewing-machines ; embroidery-machines ; quilting- machines ; feed ; frames.-Relates to reversible feed mechanism particularly adapted for use on machines which lay the thread in parallel stitches or make stitches in which sharp angles are required, as in producing embroidery, quilting, or in sewing around pockets. The reversibility of the feed is obtained instantly and without stopping the machine or slackening its speed. Fig. 2 shows an underside plan of the machine, and Fig. 6 a perspective view of the feed mechanism. The feed-dog 26 is detachably connected to a bar 20 which is slidably fitted in a longitudinal slot 16 in a bridge 7 extending across the bed-plate and is capable of a combined reciprocatory and pivotal movement therein. The upper face of the feeddog 26 is provided with several pairs of teeth 27, 28, the members. of each pair being inclined in opposite directions, whereby the dog can feed the materials either backwards or forwards as required. The bar 20 is held at its rear end by a pin 34 on which it has a slidable and pivotal motion, and at the front end by a bar 35 which is bent at one place so that the two parts of the bar lie in different horizontal planes and, when the bar is reciprocated by its connection at 40 with the shuttle-bar 9, the bent part serves to impart a rising and falling motion to the bar 20. The free end of the bar 35 is supported in slots in adjustable plates 41, 45: and the slots limit the motion of the bar 35 to a rectilinear path. A backward and forward motion is imparted to the feed-bar 20 by a rod 81, operated by a rock-shaft 83, and having at its forward end a roller 82, which works in a straight groove 73 in a cam 72, on which is rigidly mounted a partially-toothed wheel 75 in gear with a segment 78 formed on a lever 76, pivoted at 77, and connected at 80 with a bar 50, which can be moved backwards or forwards to vary the position of the cam 72 in relation to the roller 82, and thereby cause the bar 81 to bear against one side or the other of a slot 23 in the feed-bar 20, and cause the latter to be moved accordingly either in a backward or forward direction. The bar 50 by which this reversing- operation is effected is normally held in place by a spring-pressed plunger 68 which forces teeth 62 on the bar into engagement with teeth 65 on a fixed piece 64, but the bar can be forced away from this engagement by manipulating a fingerplate 59 and can then be moved to alter the position of the cam 72. The disengagement of the bar 50 and its longitudinal motion may also be effected by a cam mounted upon it. The degree of lateral deflection of the bar 81 determines the length of the stitch, and, as this deflection varies with the position of the cam 72 operated by the bar 50, the length of the stitch will be regulated according to the extent of motion allowed to this bar by adjustable screws 58 which limit the motion of a slide 53 to which the bar 50 is pivoted. When a cam is employed to move the bar 50, a push-piece is also provided to move the bar inwardly without moving it longitudinally, so as to lower the feed-bar 20 without reversing it. A combined eccentric 101, Fig. 10, and cam 102 mounted on the same shaft serve respectively to operate the shuttle-bar 9 and the rock-shaft 83. Presser-feet.-The body 119, Figs. 27 and 28, of the presser-foot is formed with lugs 121 and holds the work flat irrespective of the direction in which it is being fed, while the slots 122, 123 allow of inspection of the stitches. To lift the presser-bar and regulate its stroke, a tumbler adjustable by a screw is pivoted in the machine head, and is engaged with a projection on the presser-bar.