Page:Federal Reporter, 1st Series, Volume 6.djvu/197

 8TEAW 8BWING MACHINE 00. V. BAMBS. 186 �thread shows on the upper surface, and aa it is desirable that it should show only at long intervais, further apart than can be conveniently fed or sewed in a sewing machine in the in- terval between one stitch and another, I have devised a con- trivance by the use of which some of the stitches will be made in the lower braid only. In order to do this the needle is set [so that it will net pierce the upper piece of braid at ail, unless the needle is bent or sprung over towards the roUer on its descent, and the needle-guide, /,] as before, and the guide is mounted upon a spring arm which tends to press it towards the roUer, e, whUe an adjustable stop, r, {seefig. 1), regulates the distance to which [the needle-guide] it shaU approach the roUer. Upon the presser-foot bar there is mounted, so th^t it can turn, an [irregular] irregularly polygonal plate, p, hav- ing secured to it a ratchet-wheel, n, provided with a detain^ ing pawl, if necessary, as at o, and with an actuating pawl, such as i, pivoted to a crooked bar, fe, which is pivoted on the presser-foot. A pin, «, is attached to the needle-bar, and the crooked bar and pin are so arrangea relatively to each other that each stroke of the bar shall reciproeate the pawl, and consequently turn the irregular plate which bears against the spring-support of the [needle] guide. By shaping this plate properly the needle can be caused to pierce the upper piece of braid at every other stitch, or every second, third, or fourth, or greater number of stitches, as desired, so that seams may be sewed like those in figs. 5 [and] or 6 ; or, by proper shape and adjustment of the parts, seams may be sewed where the upper thread shows at intervais on the upper surface of the Tipper braid, and at other times merely catches into the upper braid ; or seams may be sewed having some stitches showing in the upper surface of the upper braid, others oatching into it and not showing, and others still which do not catch the upper braid at ail. In sewing such seams the needle springs away from the roUer, and is drawn towards it at the time and to the extent desired by the spring guide, the latter being governed by the [irregular] irregularly-BhsbT^edi plate. The whole contrivance, therefore, is one for vibrating the needle to and fro in the direction of the Une of the seam, and any ��� �