Patent GB-190714799-A (GB)
Title: Overseaming Sewing Machine.
Inventor: FAIRWEATHER WALLACE
Filed: 1907-06-27
Granted: 1908-01-16
Abstract: 14,799. Fairweather, W., [Singer Manufacturing Co.]. June 27. Overedge-stitching machines ; doubleloop stitching-machines ; needle driving frames.- Relates to overseaming sewing- machines provided with an inclined needle and t w o looping-implements co-operating therewith to form a double-loop stitch. The inclined needle-bar 12, Fig. 1, is carried in bearings 11 in the inclined head 10, and is provided with a collar 14, which is attached by means of a link to an arm 18 of a rock-lever mounted on an incline fulcrum-pin 20. The arm 22 carried by the pin 20 is connected by a ball joint to a pitman 24, which is connected to the actuating- crank 4 on the main shaft 2. The ball 23 carries a pin which is embraced by the forked end of the pitman. The primary looper 28 is secured to a vibrating carrier 30, Fig. 6, journaled upon a stud 31 fixed in a boss 32 on the base 1. The secondary looper 33 is held on the transverse shaft 38, and is reciprocated from the main shaft by a pitman 44, embracing the ball 43 on the shaft 42, and provided with a fork engaging with a pin 47. The carrier 36 of this looper is connected with the carrier 30 by a toggle connexion. As the needle rises, it throws out a loop which is entered by the looper 28. The secondary looper then rises and passes through the looper loop deflecting it by the shoulder 33<X>, and at the same time presenting its own loop for the passage of the needle at the next descent. The loopers then back out and the threads are drawn up, The secondary loopers may be replaced by a spreader 331, Fig. 16. The side of the base nearest the operator is enclosed by a removable plate 151 and a door 155 hinged to the plate 156. The looper-actuating mechanism is housed by a swinging work-plate section 160 having a depending apron 162 provided with an oil-receiving flange 163 at its lower edge, downwardly inclined from front to rear so that oil will run down into the drip-pan. Feed.-The feed-dog 74 is lifted by a link 76 embracing an eccentric on the main shaft, and is actuated by the feed-bar 75 pivotally connected at its rear end with the rocking-sleeve 79 provided with a lateral arm 84 which is connected to the upper end of a link 85. The link 85 is adjustably secured to the pivoted slotted arm 87, having an arm 89 connected to the eccentric rod 91 of the main shaft. The link 85 carries a pointer arm 93 which co-operates with a scale 94 on the work-plate. The length of stitch is adjusted by moving the pin 86 in the arm 87. Presser-feet.-The presser-bar 93 is pivoted to the plate 95 and has attached to its forward end the shank of a presser-foot 100, haviog an upturned portion 101, the sole-portion being pressed on to the throat-plate by means of the spring 102. Trimming and cutting; needle shields; cords, applying.-The trimming-mechanism comprises a stationary lower knife, and a reciprocating upper knife 108, carried by a vibrating bar 110, pivoted on the pin 111 in the plate 95 and reciprocated by an eccentric-rod 113, actuated from the main shaft 2. The forward end of the bar 110 is forked and carries the knife-carrying shaft on a gib, at one end of which is clamped the blade, which is pressed normally into contact with the fixed blade by the spring 126 interposed between the collar 122 and one of the members 115 of the fork. The lower knife blade is fitted in an inclined channel in the carrier block 127, and is clamped thereon by the laterally notched head 128 of a plug held by the nut 130. The carrier-block is mounted in guides in the frame, and has lugs 131 with adjustable stop-screws 132 to bear alternately upon the projecting portion 133 of the frame to limit the transverse movement. The adjustment of the carrier-block is effected by the screw 134, which has a swivel connexion with a slotted lug 135 and may be clamped by a screw to the frame. The carrier-block is provided with a needle-guiding plate 136, having an upper edge slightly inclined to the needle-path to ensure against the deflexion of the needle from the looper-path. The work-plate is also provided with a bracket piece 137 adjustably bolted thereto, to the forward end of which is attached an angular shield-plate having an upturned flange 142, Figs. 10 and 11, inclined at a similar angle to the portion 101 of the presser-foot, and having its end close to the trimmer blade whereby it is adapted to strip the trimmings from the fabric. To the forward end of the flange is fastened a cord-guiding member 145 having a cord-receiving groove 146, the member 145 with the lip 142<x> affording a threading slit for the channel. The delivery end of the guide has a transverse notch 147 to deliver the cord adjacent to the top of the throat-plate, while the member 145 has a notch 148 through which the cord is fed from the eye 149 beneath the tension device 68. Governing needle thread.-The upper thread takeup 63 has open guide-eyes 64, 65, and is secured to the actuating-arm 18 in such a position that the eye 64 moves into and out of alinement with the eye 67. The needle thread is led through the tension device 68, and guide-eyes 69, 64 to the eye 70 and down to the needle. When the needle carries two threads, less take-up is necessary and the eye 65 is used. Governing under thread.-The primary looperthread is led through the eye 59 to the eye 54 on the toggle connexion 50, and thence to the looper 28 and to the work. The secondary looper thread is led through the eyes in the plate 60 to the tension device 61, and thence to the hook 62, the hook 56 on the primary looper carrier, and on to the looper 33. As the loopers rise, the eyes 54, 59 and the hooks 56, 62 approach and thus allow the thread to slacken and the continued upward motion causes the straightening of the toggle and the consequent dwell of the looper 28. As the secondary looper approaches its extreme position, its thread is again tightened, the primary looper thread and the needle thread being simultaneously tightened by the engagement of the loops ; this completes the formation of the stitch simultaneously with the setting of the previous stitch.