Patent GB-621710-A (GB)
Title: Improvements in or relating to shoe-upper conforming machines
IPC: A43D13/00
Filed: 1946-12-16
Abstract: 621,710. Lasting-machines. BRITISH UNITED SHOE MACHINERY CO., Ltd., and KESTELL, T. A. Dec. 16, 1946, No. 36962. [Class 17 (i)] Relates to shoe upper conforming machines of the kind described in Specifications 7005/00, 12304/03, [both in Class 17], and 431,867, and in Specifications 16398/15, 150424, [both in Class 17 (i)], 373,125, 373,183 and 396,086, which latter group are of " inverted " construction, and in all of which, after a first cycle, in which toe-end and side grippers tension the upper over a last, the machine comes automatically to rest, so that, by manipulation of hand levers, the position of the tensioned upper heightwise and lengthwise of the last may be adjusted as necessary before proceeding with a second cycle of operations, during which the upper is shaped to the last and secured to the insole in lasted position. The invention is concerned mainly with means to reduce the manual effort required by the operator in adjusting the position of the tensioned upper on the last by varying, by a single control member, the leverage of a member through which upper tensioning movement is imparted to the grippers, and is described as applied to a machine of " inverted " construction wherein the shoe to be lasted is supported bottom down on a work-supporting carrier 9, Figs. 1, 2. A toe-end gripper 11 and pair of side grippers 13 of usual construction are operated, through up-draw levers similar to those in existing machines of this type and which rock about fixed pivots, from a power shaft 5 supported in the machine frame and driven, on actuation of a treadle 6, through a clutch, from a continuously driven pulley. A vertical cam-shaft 7, geared to the shaft 5, carries the cams which operate the grippers, the toe gripper being operated as described in Specification 398,086, and the side grippers from a cam 15, which co-operates with a cam roll 17, mounted on a cam slide 19, to move it to and fro, under power, to actuate bell-crank up-draw levers 37, Fig. 3, through links 21 spaced widthwise of the machine, and which carry pivots 25 for the lower ends of links 27, the upper ends of which are pivoted on pins 29 to links 31. These in turn are pivoted on pins 33 to levers 37, arms 39 of which are coupled in known manner to the side gripper actuating members 40. Each link 27 is pivoted on a pin 26 to a friction locking device 41 by which it is pivotally connected to a curved lever 43. Each device 41 is formed in two parts an inner slide 151 and an outer slide 153, between which relative movement may take place during the early part of the movement of slide 19, but which become locked together during the end portion of the movement of the slide, to enable the effort required by the operator for a given adjustment of tension to be independent of the class of work being operated on. The slides 151, 153 are relatively adjustable by adjusting the spacing between stops 71, 73, between which is a leather washer 173. The inner slides 151 are moved positively and rapidly forwards out of locking position to permit the grippers 13 to be withdrawn fully from the work, and are restored to their initial positions, when the tacking devices associated with the wiping elements move inwardly, during the second of the two cycles of operation of the machine. Each lever 43 has an arcuate rear edge face 47 which is part of a cylinder and which bears against a roll 49 pivoted on the bifurcated forward end of an arm 53. The arrangement is such that the upper portions of the curved levers 43 are moved rearwardly an amount which is substantially independent of the yield of the uppers under pull and remains constant during the operation of the machine on successive shoes. One arm 53 is secured to the right-hand end of a shaft 55 and the other arm is formed integral with a sleeve 57 coaxial therewith, and also coaxial with the surfaces 47, before the commencement of the first cycle of operations, and causes the rolls 49 to be moved in the same or in opposite directions along the levers 43, according to the direction of rocking of shaft 55 and sleeve 57, to form independently adjustable fulcra. The lower ends of the levers 43 are pivoted to arms 61 which extend upwards from sleeves 63 freely rotatable on shafts 65 secured in the machine frame. Arms 67 secured to the sleeves 63, and approximately twice the length of the arms 61, are connected to strong tension springs 69 which constitute the updraw springs. These springs are anchored to a device 70 by which the tension of the springs may be adjusted and which is held in adjusted position by a latch 81 (not shown), release of which is controlled from a hand-lever 77. The pivot pins 26 are held at locations determined by the engagement of stops associated with the stops 73 which are adjustably secured in the machine frame. Rocking movement of the links 27 produced by movement of the slide 19 is transmitted through the links 31 and bellcrank up-draw levers 33 to the gripper-actuating members 40, to cause the grippers 13 to close on the upper and then to impart tension to it, in known manner. As tte resistance of the upper to tensioning increases to a limit determined by the resistance of the springs 69, and the position of the rolls 49 which form fulcra for the levers 43, further movement of the slide 19 will move the pivot pins 26 of the links rearwardly. The machine comes to rest with the upper tensioned by the grippers. The sleeve 57 and shaft 55 mentioned above have levers 95 (not shown), 97, Fig. 5, connected to one of their ends, and a lever 99 is freely pivoted on the sleeve 57. The hand lever 99 moves the side grippers in unison heightwise of the machine either jointly together or differentially in opposite directions. Sideways movement of a hand-lever 113 about its pivot 115 in one direction moves rods 105 (not shown), 107, connected at one end to a crossbar 109 and at the other end, through ball and socket joints 101 (not shown), 103, to the levers 95, 97. to move the shaft 55 and sleeve 57 in opposite directions to move the rolls 49 along the surfaces of levers 43 in opposite directions to adjust the grippers lengthwise of the shoe and to increase tension applied' by one gripper and simultaneously reduce that applied by the other. Movement of lever 113 in the opposite direction produces a reverse effect. Movement of lever 113 bodily up or down in a central position turns the shaft 55 and sleeve 57 through equal amounts to increase or decrease equally the tension applied lengthwise by the side grippers. The hand lever 113 and lever 99 are returned, under control of a dash pot 369, similar to that provided in machines of the type concerned, to their initial positions towards the end of the second cycle of operation of the machine. This dash pot slows down the first cycle of operations to cause lifting of the grippers 13 against the action of the up-draw springs. The grippers may be lifted immediately the lever 99 commences its upward swinging movement or after an interval depending inter alia on the distance through which the grippers have moved in imparting tension to the upper. A latching pawl 121, which engages an arcuate member 127, holds the lever 99 in desired position, the pawl being held out of engagement at the commencement of the first cycle, and also when desired in the pause between the two working cycles. Means comprising an arc-shaped plate with a central notch 139 engageable by a latch 141 on a hand grip 129 are provided for holding the hand lever 113 in central position on its stud 115. Means are also provided to effect bodily movement of the upper on the last, e.g. for throat-straightening without undesirable displacement of the last. After the lever 99 has been moved to a position to reduce appreciably the tension applied by the grippers, further movement of the lever by the operator in the same direction acts to lift the side grippers bodily against the action of their springs 69 to lift the upper relatively to the last. A cradle member 351, which partially surrounds each arm 39 of the levers 37, connects the arm to an equalising lever 353. A heel rest 397, similar to that described in Specification 12304/03 is yieldingly pressed by a cam slide 417, through action of a spring, lengthwise of the shoe into engagement with the heel, during the first cycle of operations, and means are provided to lock it against toe-ward movement after it has engaged the heel. An additional spring means 407 may be provided to hold the lever 99 firmly in its initial position during the initial stages of the first cycle against reactions set up in the machine. These means are rendered inactive towards the end of the first cycle.