Patent GB-574977-A (GB)
Title: Improvements in or relating to shoe upper conforming machines
IPC: A43D21/16
Filed: 1943-12-23
Abstract: 574,977. Lasting-machines. BRITISH UNITED SHOE MACHINERY CO., Ltd. (United Shoe Machinery Corporation). Dec. 23, 1943, No. 21566. [Class 17 (i)] Relates to various detailed improvements in machines for lasting the toe-end portions of shoes generally of the kind described in Specifications 553,881 and 574,397 which comprise a device for positioning a shoe heightwise thereof by engagement with the shoe bottom portion to clamp it against a forepart-supporting member, and fluid controlled means for controlling a sequence of operations, pulling-over grippers, power-operated wipers and a toe-former for lasting the marginal portion of the upper inwardly and for applying a pull to the upper before it is lasted, means arranged to trim away the margin of one or more , plies of upper material around the toe portion of 'the upper before it is lasted, and means to apply cement to aid in securing the upper in wiped condition. The toe former 292, Figs. 1, 2, upper trimming means 386, wipers 266, toe-end and side grippers 12, 14, resp., cementing means 388, retarder 420, as well as the positioning device 2, toe rest 6, instep-support 8 and heel rest are constructed generally as described in the Specifications' mentioned above. The means for maintaining the grip of the jaws of the pulling- over grippers 12, 14; 14, regardless of the thick ness of the material while permitting slip, in order to prevent damage to the upper, the means for supporting and moving the grippers, the wiper support, the action of the toe-former, the construction of trimming mechanism and the retarder mounting are; however, modified, and, in addition, means are provided for maintaining the pressure of the fluid by which the mechanism is'operated regardless of fluctuations of pressure of fluid at source. After the shoe has been presented in position in relation to the grippers, 12, 14, as determined by the position of the adjustable positioning plate 2 and pins 4, the grippers 12, 14 are closed, to grip the margin of the several layers of upper materials, by admitting pressure fluid to cylinders 36, 62 respectively in response to the operation of a treadle-operated rod 144 prior to starting the cycle of operations of the machine, which cycle corresponds to one revolution of a fluid-operated valve-controlling drum similar to that described in Specification 553,881. The force with which the jaws of the grippers engage the upper depends upon the adjustment of a pressure-relief valve 170, and a sleeve valve 140, located between a manifold 138, in which pressure oil is stored, and a supply pipe 48 leading via a pipe 46 to the cylinders 36, 62. Such pressure is independent of that in the manifold 138. A pressure controlling valve 146 between the valve 140 and pipe 48 reduces the pressure of fluid supplied to cylinders 36, 62 below that of the manifold 138. A spring 156 in a cylinder 148 in valve 146 together, if desired, with a spring in the relief valve, 170, accessibly mounted at the front of the machine, determines the point at which movement of the valve piston 152 in the cylinder 148 occurs to close a port 166 therein and thus to prevent further increase in pressure in the gripper-closing cylinders 36, 62, and to trap the fluid in those cylinders, so that any drop in pressure in the manifold 138, due to supply of oil to one of the other operating mechanisms of the machine while the grippers are in operation, will not effect a reduction of fluid pressure. On movement of valve 140 to exhaust position, a pipe 158 is opened, by uncovering ports 184, so that pressure in the pipe falls to zero, and spring 156 returns piston 152 of valve 146 to initial position to bring chamber 164 into register with port 166 and thus open cylinders 36, 62 to release the grippers. An accumulator comprising a cylinder 196 in communication with the pipe 46, and a piston 198 under the action of a spring 200, prevents the possibility of reduction of pressure of the gripper jaws if they should slip off one of the inner layers of material but retain grip on the other layers. The height of the gripper support 16 is controlled by adjusting the position of a slide 22 by a lug 20, on which the front of the support is engaged, the support being adjustable by operating a handwheel 204 through a crank pin 206 and links 208, and held in adjusted position by a pin 210 on a disc 212. Near the beginning of the cycle of operations, fluid-operated cylinders 74, 112 cause the grippers to pull the upper yieldingly in outward directions through springs 72, 100. At the same time, two pistons 218 movable vertically in cylinders 220 fast on the machine frame and each having a bar 221 at the upper end with a screw 222, engage and impart upward swinging movement to the gripper support 16 to pull the upper heightwise of the last. After the upper has been conformed for the first time its outturned margin is positioned somewhat higher, and, in order to vary the height at which the grippers are supported so that they will' grip the upper for the second time, the lug 20 which initially supports the support 16 is moved upwardly through an adjustable screw 246, which secures a member 248 to one of the links 208. The member 248 has a downward extension 253 with which a detent 252 pivoted on the machine frame, and which may be arranged to be operated by admission of pressure fluid to a cylinder 256 on the machine frame when the heel-rest is operated at the beginning of the cycle of operations of the machine, may be swung into position to prevent subsequently the full downward movement of the gripper support. The grippers 12, 14 are movable as a unit with the support 16 lengthwise away from the heel to pull the upper, and also respectively in different directions. While the upper is held under tension by the grippers, a carrier 390 moves the upper-trimming mechanism 386 to operative position, and the wiper support 278 is raised by a pressure-fluid operated cylinder 286 to raise the wipers 266 and toe former 292, the wipers and toe former being held in a retracted position lengthwise of the shoe by a rod 330 on the wiper carrier 270. Upward movement of the toe former 292 causes the rod 330 to release the wiper support 278, by engagement of a frame 344 with a nut 352, and allows it to move forward under the action of a spring 354 to cause the toe former 392 to press the upper against the last. Continued upward movement of the support 278 causes the toe former 392 to wipe the upper heightwise of the last, the margin of the upper being free to slip more or less in the gripper jaws. During this movement the gripper support 16 is moved bodily rearwardly through links 378 to pull the upper lengthwise. The toe end gripper 12 is positively pulled through one or other of a pair of pawls 120 slightly staggered in relation to one another and pivoted on pins 122 on two jibs 124 which assist in guiding the gripper. One or other of the pawls engages teeth 126 to prevent reverse movement of the gripper 12 on its support, after it has been operated by springs' 72 and lever 68 pivoted on a stud 70 on the support 16. The pawls 120 are controlled by a plate 128 resting on a lug 130 on cylinder 36 and pivoted to pin 40 in upper jaw 26 of toe end gripper. The pawls prevent the gripper 12 from moving reversely forward by the pull of the margin of the upper during the upwiping operation produced by upward movement of the carrier 278: As the side trimming knives 392 begin their trimming action the grippers are opened and, during the outward movements of the side knives 392 substantially vertical knives 396 associated with each of the knives 392, against which they are pressed by springs 506, sever the opposite ends of the strip of waste material produced by the knives 392 and middle knife 394. The carrier 390 is then raised to inoperative position. Pressure of the U-shaped flexible toe former 292 on the upper at the toe end is increased by a piston 440. On a stud 474 of a block 294 which rests on the plane upper faces of the wiper holders 268 is mounted a plate 472 which underlies an intermediate part of a thin steel plate 470 which reinforces the outer face of the former 292. The block 294 has a rod 296 slidable in a bore 298 in a piston rod 276 to guide it longitudinally of the shoe. The former 292 is also pivoted on the stud 474 so as to be free to adjust itself angularly to the toe end of a shoe. Portions of the former 292 at the sides are adjustable, for dealing with shoes of different widths, by levers 328, by means accessible from the front of the machine. The toe former is also adjustable bodily lengthwise of the shoe, to enable the intermediate portion to apply adequate pressure to ,the toe end face, by turning a hand wheel 494, which shortens or lengthens a link to cause a cross-bar 490 to move the block 294. After the upper has been trimmed, fluid is admitted to the front of the cylinder 275 to retract the wiper carrier 270 and the wipers and the former. The wiper support is moved downwardly by releasing pressure from the cylinders 286. Release of pressure from the gripper operating cylinders 74, 112 causes the grippers to move inwardly towards the shoe by their return springs. Simultaneously, release of pressure, from the cylinder 220 permits the gripper support to swing downwardly until the detent 252 stops it in a position higher than when the grippers gripped the upper the first time. The carrier 390 with the cement-applying mechanism 388 is then swung into position over the toe end, and the grippers are closed on the trimmed margin of the upper with the same gripping pressure as was previously used, to pull the upper upwardly. Cement is applied to the shoe and a second upward movement is imparted to the wipers and toe former, and the wipers advanced to close the margin of the upper at the toe inwardly over the insole, the grippers releasing their hold as the wipers begin to