Patent GB-527291-A (GB)
Title: Improvements in or relating to machines for use in the manufacture of boots or shoes
IPC: A43D11/00
Filed: 1939-03-04
Abstract: 527,291. Sewing-machines. BRITISH UNITED SHOE MACHINERY CO., Ltd. (United Shoe Machinery Corporation). March 4, 1939, No. 7120. [Class 112] Boot-sole stitching and lasting machines.-A machine for lasting a shoe upper and sewing the upper in lasted condition comprises a lasting device, sewing instrumentalities, a shoe-supporting jack, and means for causing relative movement between the jack and the lasting and sewing devices to transfer the point of operation automatically about the part of the shoe to be operated on, the machine operating progressively first at one side of the shoe and then at the other. According to the Provisional Specification certain features described below are also applicable to machines of other types. The general construction and mode of operation of the jack in the machine described are substantially as described in Specification 289,142, [Class 112]. Starting and stopping gear, At the end of the lasting and sewing operation, the head camshaft driving mechanism and the pattern cam shaft controlling the jack are thrown out of operation and an auxiliary mechanism is set into motion to complete the rotation of the pattern cam shaft, move the jack downwards and outwards and rotate it back to its initial position, and perform certain other operations described below, viz., causing mislooping of the needle after the last stitch, cutting the thread, and actuating the various elements operating on the welt. Feed by needle ; chain-stitching; thread-cutters and thread-end holders. - The curved hooked needle 60, Fig. 3, is carried by the usual segment pivoted at 104 on a frame 86 which is mounted on a shaft 88 for feed movement and is actuated by a cam 94, Fig. 8. It is actuated by a link from a cam lever mounted on an eccentric on a shaft 112 which is rotated by the stopping-gear to vary the needle throw so that the needle does not engage the thread on stopping. A thread finger 64 pivoted at a point above the needle segment is actuated by a cam and a thread gripper 66 pivoted at the same point is spring-biassed towards the finger 64 against a stop. These members are caused to grip the thread and tension it for cutting, by mechanism such as is described in U.S.A. Specification 1,952,770. A thread-cutting knife 157 is carried on a bar supported at the front by a depending arm and at the rear by a cam lever freely pivoted on a shaft 166 and provided with a retracting spring. The knife is actuated by a member on the shaft 112 engaging a roller on the cam lever. The lasting gripper is placed immediately in advance of the needle in line of feed, and has no movement in that line, the movement of the work while it is in action helping to locate the upper accurately for the next stitch; it comprises a smooth jaw 72, Fig. 8, formed on a vertical slide 180 and adapted to engage with the inner side of an insole rib and to slide off it in the upward movement of the gripper, and a corrugated jaw 74 pivoted at 184 on the slide to engage the upper. The slide is actuated by a cam lever 188, pivoted at 190, through an arm 192, on the same pivot, giving a positive lift of the gripper by abutments 202, 204 and a yielding downward movement through a spring 206. The jaw 74 is actuated by a cam lever 212, pivoted at 190, through a rod 220 giving positive opening and yielding closing movements. A detent 227 is spring-pressed to engage the abutment 202 to hold the gripper inoperative, this detent being withdrawn by a rod 230, Fig. 3, actuated from an arm controlled by the pattern cam to set the gripper in operation when the machine is working along the sides of the shoe but to put it out of action while working round the toe. Welt guiding, severing, and feeding.-The welt guide is spring-pressed forwards and is locked during part of each stitching cycle; it is retracted on stopping of the machine before the welt-severing knife is actuated. The welt end remaining in the machine is fed forward by a finger into position for a new operation, and is advanced by grippers as the work is fed during the initial stitch on a new shoe. The welt guide 70, Fig. 6, is fixed to a bar 634 pivotally supported at the front by an H-member 636 on pins 638 and at the rear by arms 642 on a shaft 166. The guide is pressed forwards by a spring acting on an extension of the member 636; another extension of this member has an arm 648 with rack teeth which are engaged by similar teeth on a cam-actuated lever to lock the weltguide in position during part of each cycle. The bar 634 with the welt - guide is retracted before the welt - severing knife is advanced, by a cam on the shaft 112, Fig. 3, connected to the stopping mechanism engaging a cam roller 688 on an extension of one of the arms 642. This cam is carried clear of the roller 688, to allow return of the welt-guide, by a slight movement of the shaft 112 on restarting of the machine. The welt-cutting knife 544, Fig. 6, is fixed to slide 658 on the bar 634 and slides across the end of the welt-guide 70. The knife 544 is operated by teeth on an arm 662 pivoted at 664 to a bracket on the bar 634, meshing with a rack on the slide 658. The arm 662 has a cam roller 670 engaging a cam groove in a lever 674 fixed to the shaft 166, which is actuated through a gear segment 680, Fig. 3, by a shaft 684 from the pattern cam and jack operating mechanism, the knife being advanced after the last stitch on depression of the jack but before the jack moves forward out of its operative position; both forward and backward movement are positive to prevent interference with the welt-feeding finger. The welt-feed finger 542, Fig. 6, is fixed in a part 696 pivoted to a slide 700 with a spring 704 to press the finger against the welt; the finger passes through a slot 710 in the welt-guide 70. The slide 700 is actuated from the shaft 166 through a rack 724 sliding in a bracket 714, Fig. 3, and engaging a pinion on a shaft 712 bearing in the bracket; a pinion at the upper end of the shaft engages rack teeth on the slide 700. During operation of the machine the slide 700 is retracted by a spring 740 on the shaft 712, but on the return of the shaft 166 after its clockwise movement which actuates the knife 544 an abutment 728 on a sleeve on the shaft engages a latch pivoted on the rack 724 to move the latter to cause the finger 542 to advance the welt into position for starting a new operation ; as the shaft 166 reaches its limit of movement, the latch engages a stop pin to release it from the abutment for return of the finger 542 to its rest position. The operations of the knife 544 and finger 542 overlap to allow relatively slow movement of the finger to prevent injury to a soft welt. The welt gripper which feeds the welt forward during the first stitch on a new shoe to place it a little ahead of its final position comprises a jaw 546, Fig. 8, integral with a slide 750 and a jaw 548 pivoted to it at 752 ; the slide is mounted in a support 754 rotatable on the spindle 88 which carries the needle-feed frame 86, the support being spring-biassed towards a pin 786 on the frame. The slide 750 is advanced by an arm, extending upwardly from the lever 662, Fig. 6, actuating the welt-severing knife, engaging the end of the slide. The jaw 548 is normally held open by a leaf spring 756 engaging a notch in the jaw, and is closed as the slide 750 is advanced to its operative position, by a lug 758 on the jaw engaging a stop 759 on the frame 86. The slide is held in operative position against a retracting spring 760 by a spring-pressed latch lever 768 pivoted on side of the support 754 and engaging a notch in the slide. During the stitching operation, the arm lies beside the slide 750, holding it clear of the .pin 786, which is being oscillated with the frame 86. Operation of the lever 662 to advance the knife 544 first causes the arm 780 to be retracted from the slide 750 to allow the latter to swing into the plane of the arm 780, the pin 786 riding over a low part of a leaf-spring 790 in a recess 788 in the slide as the needle comes to rest on stopping of the machine, with the needle at the limit of retraction in the line of feed. Return of the lever 662 to retract the knife advances the members 780 and 750, moving the raised part of the spring 790 to a position beneath the pin 786. On restarting of the machine for a new operation, the movement of the frame 86 to advance the needle with the work causes the pin 786 to engage the side of the recess 788 and swing the slide 750 to advance the gripper in the line of feed, carrying the slide 750 to one side of the arm 780 which is then moved forward, to hold the slide in its laterallydisplaced position, by the forward movement of the welt-guide. During the return of the needle along the line of feed the pin 786 moves off the spring 790, which rises to prevent the pin from returning into the recess 788. The second advance of the needle swings the slide 750 until a stop releases the latch 768 to allow the gripper 750 to retire from the work and release the welt. The pin 786 then oscillates idly over the low part of the spring 790. To feed the welt gripper in advance of and faster than the continuous feed of the shoe on the jack to place the end of the welt, for the formation of the first stitch, somewhat in advance of the position in which it is finally secured on the shoe, the needle support 86 is fed slightly faster than the shoe; this difference is not sufficient to interfere with operation, since the needle is in contact with the work during only about half of its feeding stroke, but the welt-gripper feed continues through the full needle-feed stroke (about 300 degrees of rotation of the main shaft). The welt slips back slightly relatively to the shoe during or just before backfeed of the needle, to position it exactly. The welt-slashing knife 330, which acts only around the toe of the shoe, slides in a bracket 334, Fig. 6, in which the welt