Patent GB-191507400-A (GB)
Title: Improvements in Welt Sewing Machines and the like.
Inventor: SJOSTROM PETER
IPC: D05B67/00
Filed: 1915-05-17
Granted: 1915-10-28
Abstract: 7400. Sjostrom, P. May 17. Sewing-machines; driving.-In a welt - sewing machine or other machine for sewing heavy material such as leather, the mechauism is driven by a main shaft to which an oscillating motion is imparted by power, or hand ur treadle gearing. The main shaft 30, Fig. 4, has mounted on it a gear 29 meshing with a toothed sector 27 pivoted on an axis 21 and secured by a bolt 26 to a lever 20, which is connected by a link 19 with a rotary fly-wheel 18, Fig. 17, in such a way that the sector is oscillated by the rotation of the fly-wheel. The flywheel may be rotated by a power-driven belt running in its periphery, or by a treadle device 14, 15, 16. The sector 27 may be oscillated by a handlever, in which case the link 19 and lever 20 are removed, and a hand-lever 165, Fig. 15, is pivoted on the axis 21 and secured to the sector by the bolt 26. The lever 165 has notches 166, 167 adapted to contact with a stud 169 to limit the oscillations. Lock - stitching by shuttles; needles, driving; governing needle thread.-The barbed needle 47, Fig. 6, is mounted in a carrier 45 pivoted at 47, and oscillated by a lever 106<1> pivoted to a camdisk 105 on the main shaft 30. A needle guide 129 is provided on a hub 128, Fig. 8. It oscillates between limits under the action of a spring 131, The needle thread T passes through a variable thread. measuring pull-off 79, 83, Fig. 4, through a wax-pot 89, over rolls on a take-up lever 98, and through a thread-bending device 115. The threadmeasurer and thread-clamp comprise a pin 83 on a levet 81 pivoted at 82, and a number of thread-eyes in an extension 79 of the presserfoot lever 58. The position of the part 79 depends on the thickness of the material under the presser-foot. The lever 81 is rocked periodically to release the clamp and full off thread by an intermittent cam 162 on the rock-shaft 30 engaging an adjustable pin 151 mounted on the lever. The take-up lever 98 carrying the thread rolls 97, 99 is pivoted at 101 and actuated by a lever 103 pivoted to the cam-disk 105 at 104. The device 115 for placing the thread on the barb of the needle 47 is pivoted in the end of a lever 114, which is rocked about a pivot 110 by a cam-track 107 in the disk 105. A spring provided at the pivot 110 introduces friction to make the lever 114 stay where put by the cam. The part 115 carries two pins 116, Figs. 12 and 13, and is rocked periodically to bend the thread by a finger 125 on the needle-carrier 45. Fixed to the thread-guard 120 are fingers 122, Fig. 4, between which a spring 123, mounted on the hub of the' rocking lever 114, moves to clamp the thread. The shuttle-driver 144, Fig. 19, is osoillated at suitably varying speeds by a toothed sector 141, Fig. 5, meshing with a gear 142. The level 137 carrying the sector 141 has a cam-track 136 engaged by a roll on a lever 134 adjustably secured to the main rock-shaft 30. The shuttle race has a pivoted cap locked in position by a bolt. The shuttle-driver has a projection 172 adapted to engage the thread and force it out of the path of the awl to prevent entanglement. The shuttle thread is passed through poles 174, 175, 176 in the shuttle as shown in Fig. 21. Feed by awl ; perforating-devices.-The awl 41 is secured in a carrier 40, Figs. 6 and 8, pivoted on a pin 43 fixed in the needle-carrier 45, so that the awl oscillates with the needle. The sideways feeding movement is imparted to the awl by a lever 37, Fig. 4, pivoted at 31 and rocked by a cam 35. The cam 35 is formed on a disk 31 mounted loosely on the shaft 30, and actuated intermittently by a pin 34 on the oscillating gear 29 engaging stop-shoulders 33 on the disk. The lever 37 is held up to its cam by a spring, and the end which bears on the awl-carrier 40 has an adjustable bearing-member. The awl-carrier is returned after feeding the work by a spring 48, Fig. 8, this movement being limited hy an adjustable feed-controlling spring-pressed stop 49. Presser-bars, lifting ; presser-bars, locking; bootsole sewing-machines; fair-stitching.-The presserfoot 59, Fig. 7, is mounted on a lever 58 pivoted on the casing 50 of the stop 49, Fig. 8. The lever 58 is actuated in such a manner that the presser-foot adjusts itself for variations in thickness of the material after each feeding movement. Pivoted to the lever 58 at 64 is a lever 65 having pivotel to it at 66 a lever 68 and pawl 67. The pawl engages ratchet teeth 63 on the end of the lever 58. The lever 68 has a projection 74 adapted to be engaged by a cam 75 on the shaft 30 and the lever 65 has a roll 77 running on a cam 78. A spring 70 pulls the lever 68. In operation, when the feed is about to take place, the depression 160 in the cam 78 permits the roll 77 to fall, and the spring 70 raises the presser-foot. The cam 75 then disengages the pawl 67, and the spring 70 pulls the lever 65 about the roll 77 as a pivot and causes the presser-foot to contact lightly with the work in its fed position. The return movement of the cams engages the pawl 67 with the teeth 63 and then raises the roll 77 to cause the presser-foot to gr.p the work. A hand-lever 73 pivoted at 64 engages the end of the lever 68 as shown. On positioning the work at starting, the operator grasps the handles 60, 73 and moves them towards each other to disengage the pawl 67 and lift the presser-foot. Lubricating thread.-The wax-pot 89 is clamped to the frame and comprises a guide-roll 94x and a stripper 95.