Patent GB-190322627-A (GB)
Title: Buttonhole Stitching Machine
Inventor: FAIRWEATHER WALLACE
Filed: 1903-10-20
Granted: 1904-08-25
Abstract: 22,627. Fairweather, W., [Singer Manufacturing Co.]. Oct. 20. Buttonhole - sewing machines; a lock-stitch shuttle sewing - machines ; buttonholes, cutting ; buttonholes, barring ; needle-bars s, vibrating laterally ; stopping-gear. -Relates to a machine containing means for automatically clamping the material, cutting the buttonhole, forming the barring-stitches in addition to the usual overedge stitching, releasing the finished material, and returning the various mechanisms to their initial positions. A shaft 71, Fig. 1, carries a driving-pulley 60, and through a friction clutch, described in Specification No. 16,460, A.D. 1894, and controlled by a lever 64, drives a main shaft which actuates the needlebar, by a crank and pitman, and the mechanism for vibrating the needlebar laterally through bevel gearing on a disc 32. This disc has a camgroove 34 in which gears a pin 35 on a swinging lever 36. The latter carries two studs 38, 39, each of which in turn engages with a slot in a link 40 and so, through a quadrant 48, produces a horizontal angular movement of a verticallypivoted box which carries the needle bar. During the formation of the barring-stitches, the link 40 is held in gear with the lower stud by a hook 45, having been depressed into that position by a lever 50 pivoted in the frame and connected to an eccentric on a shaft at the back. While in that position, a pawl 56, carried by the link 40, moves a slide 54 forwards until a pin 59 engages the hook 45 and releases the link 40, which is then lifted into gear with the upper pin 38 by a spring 43. In so doing, it disengages both the pawl 56 and a detent 55, and permits a spring 58 to return the slide 54 to its initial position. The length of the stitch is regulated by a pin 47 in the quadrant 48, but, for all sizes of buttonhole, the proportion of the barring to the overedge stitches is the same. The shuttle, which is of the usual Singer oscillating type, is driven by a crank attached to a rod 28 which is reciprocated by a crank on the end of a vertical shaft 26. An eccentric on the shaft 26 engages a lever 110 and so vibrates a lever 113, Fig. 4, mounted on the same spindle as a feed-wheel 98, to which it gives an intermittent rotary motion by a dog 114 which is caused to grip an annular ridge on the wheel by a spring 196. A cam-groove, composed of two spiral portions joined by a circular portion, on the upper face of the wheel, engages a pin 116 on a link 199 which also enters a slot in a lever 117, attached at its other end to a feed-plate 121, Fig. 8. The length of the feed is dependent upon the position of a fulcrum 118 which slides on the frame and is secured by a screw. Above the feed-plate is fixed a guide-plate 146, Fig. 8, having a slot, as usual, composed of two straight portions joined by a semicircular portion, and a pin 122 fixed to the cloth clamp passes through it and past the feed-plate into a radial slot in a disc 125 below, which is periodically rotated by means of a toothed plate 127, Fig. 4, by a segmental toothed rack on a disc, secured to the boss of the feedwheel. While the pin 116 is traversing the first spiral portion of its groove and one straight part of the buttonhole is being stitched, the feedpin 122 is held by a slot in the feed plate and traverses the first straight part of the slot in the guide-plate, and a lever catch 131 engages the plate 127 and prevents rotation. Directly this is completed, the straight feed ceases, a cam on the feed-wheel disengages the plate 127, and the rack engaging with it causes its other member 126 to rotate the disc 125, which rotates the cloth clamp, causing the pin to move out of the slot in the feed-plate and around the circular portion of the guide-slot. This done, the catch 131 re-engages the plate, and the pin 116 enters the second spiral portion of its groove and moves the feed-plate into a second slot, the rotary motion of which has carried the feed-pin 122 for the formation of the second straight portion of the buttonhole. On the underside of the above-mentioned disc, attached to the feed-wheel boss, is a cam-groove operating a bell-crank lever 141, attached to a slide, by which the cloth clamp is given a small lateral displacement during the formation of the circular end or eyelet portion of the buttonhole. To the base-plate of the cloth clamp, which is provided with a slot to embrace a needle throat button 148, Fig. 8, two standards are attached which support arms 156, carrying the clamp 158. The clamp is closed by bell-crank levers 161, also mounted on the standards, which bear against projections 160 when depressed on the first descent of the needle, as hereafter described The buttonhole cutter is carried by a spindle 164, mounted in a standard 165, secured to a plate 167, which serves as a cutting-board and, being free to move longitudinally only, is able to recede from the buttonhole but is carried round with the cloth clamp when rotated. The cutter is normally held up by a spring, but is depressed on the first descent of the needle-bar by a block carried by a bar mounted parallel to the needle bar. On this bar is pivoted a hooked lever, and, when this is released from a catch, which is raised at the end of the previous cycle, a spring pulls it into a position so that, on the next descent of the needle-bar, a pin on the needle bar will engage the hook and carry it down to actuate the clamp and cutter. During the next up-stroke, the pin bears against the curved edge of the hooked lever, and, forcing the lever outwards, causes its retention again by the catch. To return the various mechanisms to their initial positions, a shaft is mounted at the back and gears in a reverse direction through a clutch and worm and gear 73, 74, Fig. 4, with the shaft 71. At the end of the buttonholemaking operation, a cam on the feed-wheel engages a trip lever 65 and frees the starting-lever 64, but, to insure that the last stitch shall be through the material, the lever 64 is still retained by a hook 190, until, at the proper instant, a cam on the disc 32 lifts the hook and completely releases the lever, which is then forced towards the pulley 60 by a spring and so disengages the main shaft. Simultaneously, a lever, attached to the lever 64 by a shaft 63, couples the reversing- shaft to the shaft 71 and the feed-wheel to a vertical shaft 97, which gears with the reversing- shaft, and the whole is reversed until a cam on the reversing-shaft disengages the latter, leaving the machine in readiness for another cycle. The feed-wheel is coupled to the shaft 97 by a pin attached to a disc 101, Fig. 4, which, forming part of a short spindle inside the shaft 97, is coupled to the sleeve 103. When the sleeve is raised at reversal, the pin which passes through a hole in a flange on the shaft 97 enters a corresponding hole in the feed-wheel, and a cranked lever 197 moves the spring 196 outwards to release the dog 114 and permit the reverse rotation.