Patent GB-190717988-A (GB)
Title: Improvements in Sewing Machines.
Inventor: LARSEN CARL MAAG
Filed: 1907-08-07
Granted: 1908-08-07
Abstract: 17,988. Larsen, C. M. Aug. 7. Running-stitch machines; belting-sewing machines; frames; driving; multiple-needle machines.-In a machine for joining driving-belts by means of leather straps, a two-ended needle, which passes in both directions through the work, is used. The driving-shaft 1 carries a pinion 2 which gears with a bevel-pinion 3 formed in one with a pinion 5, and mounted on a pin 4, which, with a similar pin on the other side of the frame, forms the fulcrum on which the needle-carrier swings. A pinion 6 on the shaft 8 behind the needle-carrier gears with the pinion 5 and a pinion at the other end of this shaft gears with a pinion mounted on a shaft 7 which is carried by the pin 4 at the back of the frame. This shaft 7 drives the needle-carrier and perforator mechanisms. Needle-driving; needle-holders.--The needle carrier consists of a frame adapted to swing across from one side to the other, so that diagonal stitches are made in the work, and in order that the rows of stitches may be set at an angle to the belt axis, the carrier is also placed at an angle relatively to the frame. The frame is composed of two pairs of parallel bars 9, 10, mounted on the fulcrum pins 4, these levers forming bearings for the needle rollers I, K, the axles of which project on one side and carry pinions 14, 15 gearing with the travelling racks 16, 17 fixed together. The shaft 7 carries a pinion which gears with two pinions 20, 21, Fig. 8, mounted loose on the axles 12, 13, which pinions each form part of a clutch, the other members 22, 23 of which are actually movable by means of the forked piece 24 having arms 25, 26 entering grooves therein. The members 22, 23 are mounted to rotate with the axles 12, 13. In the position shown, the members 22, 25 are in engagement, and the axle 12 is thus driven from the pinion on shaft 7 in gear with the pinion 20. The rotation of the axle causes the movement of the two racks and the consequent movement of the axle 13. Both sets of rollers are therefore actuated, in opposite directions, and the needle which is held between the rollers will travel up or down, depending on which pinion 20, 21 is engaged. When the rack 16 approaches its highest position, a projection on it moves over a lever 27 which actuates a small rack by means of the rod 29. This rack engages a rack segment to which is attached by means of the rod 31, the bell-crank lever 32, which engages the sliding part of a fulcrum clutch 33 on the shaft 34, driven from the shaft 7. The engagement of the clutch causes the crank 35 to revolve and move the rod 36 to which is attached a bell-crank lever 41 which actuates another bell-crank lever 43 through the rod 42. This lever has an arm which actuates the member 24 to cause a reversal of the clutch and consequently of the direction of rotation of the rollers. The continued movement of the rod 36 moves the carrier over to its opposite inclined position and the rack in returning downwards, brings back the lever 27 and the attached train of rods and wheels, to its original position, and the crank 35 comes to rest after rotating through 180‹. Bars of wood or iron may be placed between the rollers to guide the needle, and the rollers are made of india-rubber or similar material, to hold the needle by friction. Needles.-The needle used is double pointed and has a plate H, Fig. 3, pivotally mounted at its centre by the pin F. As the needle is carried down by the upper rollers the plate H rests above the pivotal pin, but as the needle passes through the work and is gripped by the lower rollers the plate swings over to the reverse position. Perforating-devices.-The perforators are mounted on a frame coupled to swing with the needle-carrier. The frame is composed of two side pieces 51 joined by a yoke 52, the side pieces acting as guides for the slides 54 joined by a yoke piece 50 which carries the heads of the perforators in a T-shaped groove. The spindles are guided in pieces 57 secured to the yoke 52, and the perforators N are given the necessary small rocking motion by means of small rocking arms fitted to the guide and rocker by connexions to the shaft 61. The slides are moved up and down by the rods 69, 70 which are driven by cranks from the shaft 66. The rods 69, 70 have frame-shaped enlargements to provide room for two arms 71, Fig. 11, which have tapered lugs 72 adapted to engage the lug 76 of a lever 73 fulcrumed at 74 to a forked shape bracket 75 when the frame is swung. The lever 73 thereupon moves the clutch member 47 into engagement with the wheel 39 on the shaft 48. The shaft 66 is thus turned for one revolution, at the end of which the cam 79 moves the member 47 out of engagement by pressing down the sliding bolt 78 in the bracket 75. Instead of a swinging frame two sets of oppositely-inclined perforators, one above and one below the work, may be provided. Governing needle thread.-The sewing straps are kept stretched and released when necessary by hooked levers fulcrumed at 90 to small pieces on a cross-bar 92 secured to stretcher rods 96 on the frame. The springs 93 hold the cam-shaped rear ends of the levers in contact with pins 94 on a fixed bar 95 above the table so that as the stretchers move forwards the hooks release the straps. The stretcher rods are connected to pistons 97 in cylinders 98, 99 connected by lateral braces, and the cylinder 98 is secured to an endless rack 100 driven from a pinion 101 gearing with the teeth of one-half of the wheel 102 driven from the main shaft. The wheel 102 has two rows of teeth set off against each other laterally, each extending over half the periphery, the second row actuating another pinion 104 and rack 105 with connexions for moving the stretchers on the underside of the table. The hooks and cylinders will thus be taken forward and then brought back on either side of the table alternately. The backward position of the hooks is adjustable to the length of the strap by the yielding connexion between the pistons and cylinders, and the pistons are connected to counterweights 108, 109 to keep them against the air cushions. Feed; acork-supports.-The work-table is formed of two guides supported at either end and carrying slides between which the work is secured. The slides are fed by means of pawls 110 and rack 112 above and below the table, the pawls being operated by the swinging of the needle-carrier.