GB281478A - Improvements in sewing machines - Google Patents

Abstract

281,478. Armstrong, J. J. V., (Union Special Machine Co.). Dec. 10, 1926. Hat-sewing machines.-A sewing- machine having a laterally-vibrating needle 6, Figs. 1, 2, and 11, and a cooperating thread-carrying looper 26 oscillating about a fixed axis has a thread retainer 28 movable in a fixed path and co-operating with the looper to hold the needle thread back on the looper so that the needle will pass between the needle thread loop and the looper thread extending from the eye of the looper to the material. The feed of the material is suspended when the needle is shifted laterally so that the stitch produced, which is shown as fastening a sweat band H in a hat, is as shown in Fig. 10, the needle thread being as shown in perspective in Fig. 11 and the looper thread on the underside, as in Fig. 12. Needles, vibrating.-The needle-bar 5 is reciprocated in the usual manner by a needle-lever 7 and the pivotally mounted needle-bar gate 4 is vibrated laterally about an axis, centrally behind the axis of the needle-bar 5 by a bell-crank lever 15 connected at one end to a bracket 10 on the needle-bar gate, through a pivoted link 13, and at the other end by a cam-roll in a cam groove 20 on a drum 21 driven by gears 23, 24 from a main shaft 25. The cam groove is shaped so as to oscillate the needle bar gate 4 three times on the right hand side of the line of seam and once at the left hand side. The ends of the pivoted link connecting the bracket 10 with the bellcrank lever 15 may be adjustable in slots 46, 49, as in Fig. 6a to vary the throw of the needle. The needle may be vibrated at an acute angle to the line of feed to produce a stitch as shown in Fig. 8, by pivoting the needle bar gate 4 at 8<a> on one side of the axis of the needle-bar 5, as in Fig 8. Feed by dogs.-The material is fed by a dog carried by a feed-bar 30 Fig. 2 attached to a feedrocker 31 of known construction. The feedrocker is oscillated by an arm 32 operated by a crank on the end of the main shaft 25 and the feed-bar 30 is raised and lowered by a bell-crank lever connected to the feed-bar 30 by a link and oscillated about its pivot by a cam-roll running in a groove on the drum 21 so as to raise the feed dog twice during the rotation of the drum to feed the material for the two longitudinal steps in the stitch but to remain idle during the formation of the transverse part of the stitch. The needle threads may alternatively, be arranged at an acute angle to the line of feed to form a stitch of the form shown in Fig. 8 by arranging the feed-dog as shown in Fig. 7 to feed at an angle to the line of vibration of the needle. Specification 281,939 is referred to.