Patent GB-1049178-A (GB)
Title: Automatic looping machine and method of forming filament loops
IPC: D05B5/00
Filed: 1964-09-15
Abstract: 1,049,178. Sewing machines, knot tying. STITCH Inc. Sept. 15 1964 [Sept. 18 1963] No 37622/64. Headings D1C and D1G. A machine passes one end of a filament through a sheet of material at a first position and ties a knot in that end, then passes the filament through the sheet at a second position a predetermined distance from the first position, severs the thread thereat to form a loop, and finally ties a knot in the end of the loop at the second position. The machine comprises a base A, Fig. 1, having a bottom plate 3 and a top plate 1 carrying a pair of parallel vertical walls 2 connected at their ends by members 4, 6 and intermediately by members 8, 10, 64. A work-feeding clamp structure comprises a pair of parallel horizontal rods 20 slidable in members 4, 6, 8, 10 and fixed to a member 18 rigid with a plate 12 carrying a worksupporting plate 14 slidable on plate 1. A workengaging foot 40, which is formed with a longitudinal needle-passing slot 42 and carries a spring- biased work-engaging plunger 46, is rigid with a pair of rods 32, 47 vertically slidable in a member 22 rigid with rods 20. Rod 32 is separated by a compression spring 30 from a rod 28 slidable in member 22. A lever 50, pivoted at 52 to rods 20, is pivoted at one end to rod 28 and at the other end to a rod 54 slidable in member 18. A spring 56 biases rod 54 downwardly, whereby a roller 58 on rod 54 enters an aperture in plate 1 to raise foot 40 when the latter is in the forward position, roler 58 being supported by a member 270 carrying i roller 268 engaging a cam 266. A spring 60, interposed between members 18 and 64, biases the work-clamping structure in the rearward direction. A pin 310, carried by member 18 and passing through a slot 312 in plate 1, is pivoted to a lever 306. Thread T, Fig. 4, drawn from a source 200, passes on its way to the needle 94 between a pair of clamping discs 204. A lever 212, pivoted at 218 to the plates 2, carries at one end a thread-engaging eye 210 and is pivoted at the other end to a rod 222 which passes through plate 1 and carries a roller 228 engaging a cam 324 under the influence of a spring 226, the arrangement being such that normally an abutment 220 on lever 212 engages a pin 206 to separate the discs 204. A knotting bill D, Fig. 11, comprises a shaft 110 which is journalled in plate 3 ard carries a gear 114. A member 108, rigid with shaft 110, is formed with an upper jaw 116. A member 136, pivoted at 138 to member 108, carries a roller 144 and is biased by a spring 142 to close a lower jaw 140, formed thereon, with the upper jaw. A frame 122, trasversely slidable on member 108, carries a roller 132 and is biased to one end position by a spring 126. A stripping plate 124, rigid with frame 122, has a rounded portion 118 embracing the upper end of member 108. A motor G, Fig. 5, is adapted to drive a shaft 236 via a clutch 234. Shaft 236 is coupled via a shaft 238 to a cam shaft 240, and carries a gear 254 meshing with gear 114. The machine is started by depressing a treadle connected by a cable 244 to a lever 246, thereby engaging clutch 234 and disengaging a roller 250 on lever 246 from a notch in a cam on shaft 240. After one revolution of the latter, when the knotting bill has rotated eight times, roller 250 re-engages said notch to stop the machine. Upon commencement of operation, a rod 264, carrying cam 266, is moved axially by a cam on shaft 240, against the bias of a spring 274, to raise roller 58 to the level of plate 1 and to lower foot 40. A rod 278, carrying cam 280, is then moved axially by a cam on shaft 240, against the bias of a spring 282, to actuate the needle 94 which passes through the work and rises slightly to throw a loop adjacent a flattened end portion 95, Fig. 24, of the needle. A rod 150 is moved forwardly by a lever 286 actuated by a cam on shaft 240, whereby a sleeve 156 on rod 150 engages a fixed abutment 170 and is held stationary against the bias of a spring 164 to expose a hook 154, Fig. 24, on the end of rod 150. Rearward movement of the latter draws thread away from the needle at the flattened portion 95. The needle then rises, and release of sleeve 156 serves to grip and sever the thread end. The jaws 116, 140 during the second revolution of the knotting bill engage the thread between a pair of vertically-spaced fixed wire guides 104 (not shown) and 106, the thread being wrapped around the jaws during the second and third revolutions, and rod 150 moving forwards to yield the thread. A rod 296 is then moved forwardly against the bias of a spring 298, by a cam 294 on a rod 292 actuated, against the bias of a spring 293, by a cam on shaft 240. A cam 302 on rod 296 thereby engages roller 144 to depress jaw 140 below the level of the lower wire guide 106, whereby the thread is wrapped around the upper jaw during the fourth revolution, when the jaws close to grip the thread and a cam 300 on rod 296 engages roller 132 to operate the stripper 124 for completing the knot, the jaws finally opening at the end of the fourth revolution to release the thread end. Lever 306 is then influenced by its associated cam on shaft 240 to permit spring 60 to shift the working-clamping carriage to its rearward position determined by the engagement of member 18 with an adjustable stop member 66. Needle 94 then descends and the knot-tying operation follows the same sequence, except that the thread end is now held and severed by means provided on the end of a rod 150<SP>1</SP> actuated via a lever 316 by a cam on shaft 240. When the second knot has been tied, a rod 320, carrying cam 324, is actuated by a cam on shaft 240 against the bias of a spring 322 to turn lever 212 clockwise, whereby cam 220 releases pin 206 and the discs 240 close to clamp the thread, and eye 210 pulls the excess thread back through the needle eye. Lever 306 is also actuated to return the work-clamping carriage to its forward position. In a modification, Fig. 27 (not shown), the knotting bill comprises a shaft 330 driven by a gear 332. A frame 334, transversely slidable on shaft 330, is biased to an end position by a spring 336 and carries a roller 338. A member 340, rigid with frame 334, is formed with a lower jaw 342 and with a rounded upper end portion 356. A member 344, pivoted to member 340, is formed with an upper jaw 346 biased by a spring 348 against the lower jaw, and carries a roller 350. A stripper plate 352, rigid with shaft 330, is formed with a notch 354 through which the jaws 342, 346 project.