Patent GB-743527-A (GB)
Title: Improvements in or relating to machines suitable for operating on shoes
IPC: D05B15/04
Filed: 1952-08-16
Abstract: 743,527. Sewing - machines. BRITISH UNITED SHOE MACHINERY CO., Ltd., (United Shoe Machinery Corporation). Aug. 17, 1953 [Aug. 16, 1952], No. 20643/52. Classes 89 (3) and 112. [Also in Group XXIX] A machine for operating along a shoe has a shoe support and power-operated means, comprising a plurality of fluidpressure-operated devices controlled by relay devices including displaceable nozzle arrangements, for imparting to the shoe translational and rotational movements so as to transfer the point of operation along the shoe while maintaining a predetermined operative relation between portions of the shoe successively operated on and the means which operates on the shoe. The mechanism acts automatically with shoes of different sizes and forms. In the machine described, for sewing an upper and welt to an insole rib of a shoe, three feelers in contact with the inside of the rib or the bottom of the insole, or both, control six fluid-pressure motors which respectively shift the shoe support along, or rotate it about, three mutually perpendicular axes to keep the shoe properly placed in relation to the needle and to feed it in concordance with the needle and awl, which are arranged to impart to it a substantially continuous feed movement. The shoe to be sewn is placed on a jack in a loading position, and is automatically moved to the operating position, sewn, and returned to the oading position. Separate supporting means1 are provided for locating and holding a second shoe on a holder, for replacement of the shoe being operated on. Operation is stopped automatically if the thread fails or if a feeler jumps over the insole rib. The means for translating a given displacement of each feeler into the required corrective displacement of the work includes a linear or rotary fluid-pressure engine connected by two pipes to a controlling device responsive to movements of the feeler to vary the distribution of pressure between the two pipes, the engine producing a translational or angular movement of the work in one or other direction, according to the difference of pressure in the pipes (see Group XXIX), to restore the feeler to its initial position, in which the controlling device is in a neutral position and movement of the engine is stopped. Provision is made to prevent response to oscillations of the feelers at frequencies above a certain value (due, for example, to roughness of the work or vibration of the machine), and to avoid any effect of change of temperature. Arrangement and operation of jack.-As shown diagrammatically in Fig. 10, the shoe S, secured in a holder 102, is fixed to a work-supporting member 100 of the jack, as described below, this member being supported for vertical movement by a fluid-pressure engine 106 controlled by a valve 210 and mounted on crossed slides 108, 110 on a table 112; the slides are moved along their respective mutually perpendicular axes by a double-cylinder engine 146 and a double-ended engine 154 acting through rack-and-pinion gearing. The slide 110 is always parallel to the length of the shoe and 108 perpendicular thereto, so that feed of the work past the needle and horizontal corrections of the position of the shoe relative to the needle in a direction perpendicular to the line of feed usually require a combination of movements of the slides; the two engines 146, 154 actuating the slides are therefore controlled by a combined valve 238 arranged in conjunction with a distributing member which is rotated in unison with the table 112 through gearing 266, 264 so that displacement of the valve member in a given direction affects only one or other of the engines, or both in varying proportion, according to the orientation of the table, in order to produce the required resultant movement. The table 112 is rotatable by a motor 168 controlled by a valve 324, and is mounted on crossed arcuate slides 116, 120 with their centres substantially at the point of operation of the needle on the shoe, these slides being actuated, to tilt the shoe laterally or longitudinally of the machine, by engines 178, 194 controlled by valves 344, 368 respectively. Three feelers engage the shoe to control the various valves, feeler 218 being in contact with the insole and the inside of the sewing rib R substantially at the operating point, 300 similarly engaging the sole and rib a short distance away, and 360 being in contact with the sole at a point inward from the operating point. The feeler 218 is universally pivoted at 222, 224, Fig. 11, and has a vertical arm 216 connected by a link 220 to the valve 210 and a horizontal arm 230 connected by a link 232 to the valve 238; vertical movement of 218 thus produces compensatory movement of the engine 106, and horizontal movement of 218 produces the necessary combination of movements of engines 146, 154. The feeler 300 is similarly universally pivoted at 306, 308, and has a vertical arm connected by a link 340 to the valve 344 and a horizontal arm 304 on which a crank 312 is swingably mounted by a leafspring 310, this crank being connected by a link 320 to the valve 324 and by a link 316 to the arm 230 of the feeler 218: vertical movement of 300 thus-produces tilting of the shoe in the line of feed, and horizontal movement produces rotation of the table 112 unless it is accompanied by similar movement of 218, which rocks the crank 312 to compensate, at the link 320, for the movement of its mounting 310. Vertical movement of the feeler 360 produces tilting of the shoe about the line of feed, by means of a link 364 to valve 368. Movement of the shoe in the line of feed is produced by displacement of the valve 238 by means of a link 408, Fig. 7, attached to a carrier 426 slidably mounted on the end of a shaft 414 and urged to the right by adjustable spring means (not shown); the carrier supports a roller 432 rigid with a worm wheel engaging a worm 416 on the end of the shaft 414. The welt W is pressed against the roller 432 by a roller 444 on spring-biased lever 442 connected to a second lever 450, 546 through which the roller 444 is retracted when the machine stops. The shaft 414 is driven in synchronism with the feed mechanism of the machine,-and any difference between the peripheral speed of the roller 432 produced by the rotation of the shaft and the speed of movement of the welt, which is pulled by the shoe, causes the roller to move along the welt, the wormwheel acting as a pinion and the worm 416 as a rack to shift the carrier 426 and thus displace the valve 238 to adjust the power feed accordingly. Shoe mounting.-At one side of the machine is a post 1090, Fig. 2, with a head 1092 formed with guides to receive a supporting plate 102 on which the shoe is mounted by a last pin 1006 on a lever 1004 spring-pressed into a notch in a plunger 1010, the toe of the shoe resting on an adjustable pad 1040 and between centring pads 1050; at the time of placing the shoe on the support the member 102 is clamped in its guides by a fluid-pressure cylinder 1098 and the centring pads 1050 are allowed to move apart by the withdrawal of wedges by levers 1114 actuated by a cylinder 1122, both these effects being produced by partial depression of a treadle 1192, Fig. 13, which also moves a catch 1174, by a link to lever 1114, to engage the heel part of the shoe-holder 102. The load of the shoe tilts the lever 1004 clear of the notch in the plunger 1010, which is thereupon spring-pressed to wedge the lever further up to press the toe of the shoe on the pad 1040; the treadle is then fully depressed to energize a cylinder 1154 to press the lever 1004 further by means of a rod 1162, to clamp the shoe more tightly against the toe-pad, the reaction on the holder 102 being taken by the catch 1174. Release of the treadle now allows the operating parts to return to their initial positions, the shoe remaining clamped by the lever 1004 being held by the wedge surface of the plunger 1010 and being further secured by release of the wedges which force the pads 1050 against the shoe under spring pressure; the holder 102 is freed in its guides, and is then moved by hand, compressing a spring which holds a stop 1072 against the head 1092, until the point at which it is desired to start sewing is opposite an indicating finger 1182 carried on a bracket on the post 1090. The stop 1072 is held by a pawl, and the holder may then be removed and placed in the head of the jack, being located in the required position by the stop. Operating cycle; starting and stopping.-The initial position of the jack, in which a shoe in its holder 102 is placed on it, is below and to the left of its initial operating position, and electrically-controlled valves are provided to control the various jack-positioning engines during the movements between the loading and operating positions, the operation of the sewing- mechanism also being electrically controlled in conjunction therewith. The jack rotates through successive half-revolutions during the sewing on successive shoes, and the shoe is carried on it with the heel well overhung, so that the jack is in one extreme position laterally of the machine at the start of sewing and in the opposite extreme position at the finish, being formed so as to operate limit switches at these two positions regardless of its orientation. The electromagnetic valves 562, 566, Fig. 13, controlling the jack-traversing engines 154, 146 have therefore to determine the direction of operation of these engines according to the orientation of the jack; for this purpose the valve 562 is moved from a normal central position by one of two solenoids 620, 622 selected by a switch 890, Fig. 14, which is operated by a cam on the rotary part of the valve 238 (Fig. 10), the valve 566 similarly having solenoids 660, 662 selected by a switch 892 actuated by the same cam. After the shoe is located on the jack a starting switch 900 is momentarily depres