Patent ES-353551-A1 (ES)
Title: Stitching machine
IPC: D05B1/02
Filed: 1968-05-04
Abstract: A sewing machine comprising a curved needle, two oscillatory holders for transferring the needle back and forth therebetween, and means for pulling the loose end of the thread through the work. Stitched seams, running-stitch and blind-stitching machine, needles,' needle guides and holders. The machine is adapted to secure the edge 274 of an upper fabric 272 to an overlapped under fabric 270 by overedge running stitches 264 each comprising a blind under portion 266 passing within the body of fabric 270, and a visible upper portion 268. Respective right and left hand holders 100, 168 for a curved needle 92, having an aperture 242 carrying a short thread, are pivoted about a common axis 24 and are adapted to be selectively oscillated by connections to respective cams on a rotary shaft 66. Holder 168 is initially raised, when a ball end (220) of a detent member carried thereby is spring- biased to engage a notch (260) near a blunt end of needle 92 to lock the latter to holder 168. Holder 100 is then in the lowered position, when a plate 160, rigid with a detent member carried by holder 100, engages an end 162 of a fixed bar 208 to withdraw the detent ball end (152) against spring bias to an inoperative position. Holder 168 then turns counter-clockwise to the lowered position, and needle 92, travelling along a curved path 250, is guided by aligned grooves 522, 524 in a block 496, and after passing within the body of fabric 270, raised by a ridge-former rod 694 having a chisel end formed with a needlepassing notch, passes through fabric 272 and enters holder 100. Near the end of the downward travel of holder 168, a plate 228 engages the end 230 of bar 208 to withdraw ball end (220) from notch (260). Holder 100 then swings counter-clockwise to the raised position, during the initial part of which movement plate 160, freed from end 162, allows ball end (152) to engage a notch (256) near the pointed end of needle 92 to lock the latter to holder 100. Holder 100 then moves slightly clockwise to form respective rear end for thread loops (246), 248 between the needle aperture 242 and the work 22, said loops being held apart by a finger 310 depending from bar 208 into groove 524. A pivoted bar 314 is then swung clockwise by connections to a cam on shaft 66 to carry a finger 312 thereon along a path 320. Finger 312 thereby engages and draws the near loop (246) into respective arms 466, 468. Arm 466 is thereby laid in a fixed guide hook 360. Arm 468 is clamped between a fixed anvil 368 and a pivoted arm 372 swung thereagainst by connections to a cam on shaft 66, and is also thereby directed into a groove 407 formed in a pin 404 rigid with and projecting laterally from a driven endless belt 416. Continued movement of the latter thereby serves to draw the loose end 245 of the thread through the work, thread arm 466 being laid in a groove 450 formed in a fixed horizontal bar 446, and thread arm 468 being laid in a channel 456 communicating with a passage 458 located under bar 446. After the end 245 passes into groove 450, a pivoted arm 474 is swung counter-clockwise by connections to a cam on shaft 66, whereby a finger 472 on arm 474 engages the thread arm 468 extending between clamp 368, 372 and channel 456 to push arm 468 into passage 458 to form the loose trailing end (470) in the formation of the next stitch. Ridge former 694 is then lowered, the work is advanced by a dog 606, and a verticallyslidable arm 94, mounting the needle holders is lifted by connections to a cam on shaft 66 to raise axis 24 by an amount 254. Holder 100 then turns clockwise to the lowered position, whereby needle 92 moves along a raised path 252 above the work 22, plate 160 engages end 162 tc release needle 92 from holder 100, and needle 92 enters holder 168. The latter then swings clockwise with needle 92 to its initial position in readiness to commence the next stitch. Work holding and feeding The upper surface of the work 22 is engaged by a plate 506 rigid with block 496 which is carried by a fixed arm 510. A fixed bracket 542, is rigid with a cylindrical casing 544 ports a vertical rod 586. biased upwardly by a spring 590 to engage a plate 538, rigid with the upper end of rod 586, with plate 506. A vertical rod 698, slidably mounted on bracket 542, is rigid with a cylindrical casing 544 biased upwardly by a spring 705. Ridgeforming rod 694 is slidable in the hollow upper end of rod 698 and can pass through a hole in plate 538. The latter can pass through an aperture 550 in the upper wall 548 of casing 544. A pin 630 on rod 586 journals a bar 716 having a forked end 722 engaging a pin 706 on rod 694. The other end of bar 716 is pivoted to a bolt in screwed engagement with a nut 714 carried by casing 544, for varying the height of rod 694. A wheel 608, rigid with a driven rotary shaft 64, is formed with a cam groove 66 engaged by a follower 626 on one end of a lever 618 pivoted intermediately at 624 on bracket 542 and formed at its other end with a slot 628. A bell crank lever 620, pivoted on pin 630, has a pin 632 on one arm engaged with slot 628. The other arm is connected by a pivoted link 622 to a pin 614 on the feed dog 606 which is passable through corresponding slots in plate 538. Groove 616 is also engaged by a roller 652 on one end of a lever 640 pivoted intermediately at 650 on bracket 542. The other end of lever 640 is pivoted to one end of a link 642, the other end of which carries a pin 660 which passes through a slot 684 formed in the lower end of a lever 682 and enters a groove 662 formed in a feed-regulating arm 644 pivoted at its upper end about a horizontal axis. Lever 682 is pivoted intermediately at 686 on bracket 542, and its upper end is connected by a pivotal link 648 to pin 614. A pin 588 at the lower end of rod 580 passes through the forked end of a knee padoperated lever 594, and is formed with an eye 592 slidably receiving a lower extension 708 of rod 698. Initial actuation of lever 594 thereby serves to lower rod 580 against the bias of spring 590 to lower plate 538, dog 606 and rod 694 for the insertion of work. Further actuation of lever 594 serves to engage eye 592 with a nut 710 on extension 708 for additionally lowering rod 698 and casing 544 against the bias of spring 705. On relation of cam wheel 608, lever 618 rocks bell crank lever '620 clockwise till dog 606 clamps the work against plate 506, whereafter pin 632 is forced downwardly in slot 628, and plate 538 and rod 694 are lowered. On continued rotation of wheel 608, bell crank lever 620 is rocked clockwise, where by dog 606 is lowered and plate 538 and rod 694 are raised. Lever 640 effects reciprocation of pen 660 in slot 684 and in groove 662 of feed-regulating arm 644. If the latter is vertical, lever 646 remains stationary and no feed motion is imparted to dog 606. Tilting of arm 644 in one or the other direction serves to oscillate lever 646 for imparting either forward or reverse feed motion to dog 606. Arm 644 is spring biased in the direction corresponding to forward feed, and its inclination is adjustable in accordance with the required stitch length. Arm 644 may be moved against said spring bias, by actuation of a treadle, to a separatelyadjustable position corresponding to a required rate of reverse feed. Frames, stands, driving, upper and lower shafts connecting. The machine is mounted on a stand comprising side plates (36), (38), a rear plate (40) and a top plate 42, and comprises a standard (52) supporting an upper arm 56 disposed at an acute angle to the direction of work feed. A motor, mounted on plate (40) is belt connected to a clutch-controlled shaft which is also mounted on plate (40) and is belt connected to shaft 64 in the machine base. Shaft 64 is connected to an upper shaft (78) which in turn is connected by level gearing to the arm shaft 66.