Patent GB-117951-A (GB)
Title: Ornamental Stitch Sewing Machine.
Inventor: FAIRWEATHER WALLACE
IPC: D05B57/02
Filed: 1917-08-10
Abstract: 117,951. Fairweather, W., (Singer Manujacturing Co.). Aug. 10, 1917. Multiple-needle machines; surface threads, attaching; chain stitching; starting and stopping gear; presser-feet.-Relates to ornamental-stitch sewing-machines comprising one or more needles and complemental loop-taking means and ornamental thread-looping devices mounted for universal movement laterally of the needle path. The invention consists in providing thread-loopers in front and in rear of the needles, and means for moving them towards and from the needle in the line of the seam and also laterally thereof, the nature of the seam being determined by the number of threaded needles and the number and arrangement of the thread-loopers employed. The loopers are mounted for universal movement on a bracket secured to the usual presser-bar and two methods of mounting and actuating them are described. In one arrangement, the bracket 50, Fig. 7, is fixed on the presser-bar and supports in the bearing 53 a pir 54, Fig. 4, to one end of which is secured an arm 56 provided with a sleeve 57 through which loose y passes a red 58 carrying at its lower end the rearwardly disposed looper 59. Endlong movement of the rod is prevented relatively to the sleeve by the boss of the looper and a collar 62. The forward looper 101, Fig. 1, is adjustably secured to a carrier 99 pivotally connected midway of its length to an angled arm 95 secured to a bearing pin 93 mounted in the bearing 90 of the bracket 50, Fig. 3. A rearward extension 96, Fig. 6, of the aim 95 is connected by a link 104 to an arm secured to the pin 54 at the opposite end to that supporting the arm 56. Simultaneously, movement of the loopers towards and from the needles is obtained by connecting a sleeve 64, Fig. 4, rotatably mounted without endlong movement on the rod 58 to a crank 11<b> on the needle-bar-actuating rock-shaft 10 by a link 67. Simultaneously, oscillating movements laterally of the line of the seam and of half the frequency of needle-bar reciprocation are obtained from a bell-crank lever 80 actuated by a link 78 from a countershaft driven at half the speed of the main shaft. The free end of the lever is connected by a link 85 to an arm secured rigidly to the bar 58, and by a link 120 to an arm of a rock shaft 13 at the other end of which is an arm 111 connected bv a link 108 to the upper end of the carrier 99. The presser-foot shank is arched tn allow a clear working space for the rearwardly disposed loopers, and the depending sides of the arch are grooved to receive the bars 40, Fig. 11, to which are pivoted the foot-plates 36, and a connecting bar 37 carrying the chaining foot. The parts are guided by headed pins and acted on by springs. In another arrangement, the loopercarriers 234, 235, Fig. 26, are pivotally mounted on studs 232, 233 on a frame 231 which is rocked on its bearing 230 across the line of seam. The carriers are also connected to opposite ends of a lever 244 pivoted on the frame 231 .so as to receive simultaneously oscillations in opposite directions in the line of seam. The actuating mechanism for the loopers comprises a bell-crank lever 249, Figs. 21 and 22, which is pivoted on a carrier 253 journaled on a sleeve 254 which is in turn journaled on a pin 255. The sleeve 254 and carrier 253 are actuated by crank and pitman connexions with two angularly displaced cranks on a countershaft driven from the needle-bar-actuating shaft at half the speed. The sleeve is connected to one end of the bell-crank lever 249 by the arm 265 and link 267. The other end of the bell-crank has a horizontal extension having an aperture 251 entered by a pin 250 on the carrier 234 and a guiding slot 251<1> entered by a pin 250<1> on the carrier 235. The toggle devices included in the train of actuating mechanism produce a dwell in the movements of the loopers during the first part of the downstroke of the needle. The shank 210, Figs. 19 and 27, of the presser-foot has rearwardly extending lugs 211 supporting a pivot pin 212 on which are fulcrumed the levers 213, 214 at the forward ends of which are pivotally mounted the main feet 215 and chaining foot 216. The levers are pressed down by springs 217 and guided and limited by headed pins 218. Acting in conjunction with the springs 217 are springs 219, the pressure of which is regulated: by nuts 220 on threaded rods 221 pivoted to the shank 210. The device for controlling and measuring the looper threads comprises a fixed plate 282 and an adjustable plate 287 having eyes for the passage of the threads. A curved arm 274 secured to the needle bar and provided with a thread engaging bar 286 pulls off thread during the downward movement of the needle-bar. The threads are held during this time between the plate 282 and spring fingers 280 carried by a lever 276, pivoted at 277, the upper end of which is cammed and adapted to be engaged by a projection 275 on the arm 274. The controlling mechanism for the needle threads comprises a spring- controlled rod 297, Fig. 18, actuated by a cam on the needle-bar-actuating shaft and provided at its upper end with a bar 295 which acts on the threads as they pass between guiding eyes on a bracket 299. To avoid the danger of setting the machine in motion until the parts are in working position and also of lifting the presser-foot and associated looper devices until the needles are in their highest position, a projection is provided on the presser-bar to act in conjunction with a notch on the crank-disk.