Patent GB-574462-A (GB)
Title: Improvements in or relating to machines adapted to apply levelling pressure to bottom portions of shoes
IPC: A43D25/06
Filed: 1944-01-08
Abstract: 574,462. Making boots. BRITISH UNITED SHOE MACHINERY CO., Ltd. (United Shoe Machinery Corporation). Jan. 8, 1944, Nos. 399 and 9049. [Class 17 (i)] Laying and levelling. A machine for applying levelling pressure to shoe bottoms, of the kind in which traversing movement of a shoe, mounted on a jack, relatively to a levelling roll is under constant control by the operator, is provided in one construction with hydraulic means for traversing the jack in accordance with movements of a hand lever, other hydraulic means for pressing the roll towards the shoe bottom, and further hydraulic means for reducing or removing the pressure of the roll on the shoe bottom in accordance with movements of a treadle. Still further hydraulic means effect tipping of the roll in accordance with movements of a second hand lever. The third-mentioned hydraulic means can move idly in response to variations of heightwise contour of the shoe bottom when full pressure is being applied by the roll, and are arranged to lift the roll above the shoe bottom when the jack is in loading position. The load on the hydraulic pump is relieved, when the machine is at rest, by a valve-controlled byepass. In a second construction, the roll is held away from the shoe bottom by springs and is pressed against it by hydraulic means. A single hand lever movable along two different paths controls these means and also further hydraulic means which effect tipping of the roll. According to the first construction, Fig. 1, the jack 22 is oscillated about a shaft 18 by a piston, not shown, to which pressure fluid is supplied by a pump 62 when a valve is operated by movements of a hand lever 84. Linkage between the hand lever, valve member and jack ensures that movements of the piston and jack are proportional to the rearward and forward movements of the hand lever. When the jack has been moved rearwardly, a latch 102 prevents its complete return to the forward, loading, position, i.e. complete disengagement from the levelling roll, until a treadle 122 is depressed. The pump 62 is constantly driven and draws fluid from a reservoir 16. The pressure-relieving byepass valve 128 is closed, when the jack begins to move rearwardly, by links 138, 140, 146. The levelling roll 24 is carried by a frame 154 adapted to be rotated about a pivot 158 to move the roll towards or from the shoe, and to be tipped about a shaft 162 to tip the roll relatively to the shoe bottom. When the machine is in operation, the roll 24 is pressed constantly towards the shoe by a piston 196 in a cylinder 184 acting through linkage 200, 206, 208 and a lever 214 which acts on a sleeve 182, sliding movement of which tilts the frame 154 about the axis 158. The thirdmentioned hydraulic means comprises a piston 222 connected to the lower end of the lever 214, so that it can operate in opposition to the piston 196 when it is desired to reduce the pressure of the roll on the shoe. Supply of pressure fluid to the piston by a valve, not shown, is so controlled by linkage from a treadle 250 that movements of the roll are proportional to those of the treadle. A surge tank connected to the valve chamber provides for idle movements of the piston 196 while levelling is in progress and the valve is not being controlled by the operator. Linkage from the valve to the jack-operating piston acts automatically to cause elevation of the roll when the jack moves to leading position. Tipping of the roll about the axis of the shaft 162 is effected by a piston 324 connected through links 326, 176 to the frame 154. Pressure fluid is admitted to the piston by a valve controlled by a hand lever 340. The valve is connected to the arm 176 by links 358, 350 so that it is moved back towards starting position as the roll tips. The hand lever is automatically moved back to a mid position, corresponding to the horizontal position of the roll, when the jack is moved to loading position. In the operation of the machine, the hand lever 84 is moved rearwardly, causing the byepass valve to be closed and causing pressure fluid to operate the jackoperating piston, to be shut off from the rollraising piston, and to operate the roll-lowering piston. Oscillation of the lever 84 then traverses the shoe beneath the roll, tipping of which can be effected by oscillation of the hand lever 340. If it is desired to relieve the pressure of the roll on the shoe, the treadle 250 is depressed to the desired extent. According to the second construction, Fig. 8, the jack 412 and the hydraulic mechanism for traversing it in response to rearward and forward movements of a hand lever 436 are similar to those described in Specification 543,547. The levelling roll 422 is mounted upon a holder 454 adapted to pivot about a horizontal pivot 450, the pivot being mounted in a carrier 452 adapted to tip about the axis of a shaft 453. The roll is held upwardly above the work by a spring 472 acting through a lever 476, sleeve 470 slidable on the shaft 453, and lever 458, and is lowered and pressed against the shoe bottom by fluid pressure acting below a piston which is connected by a link 714 to the lever 476. The piston 712 receives pressure fluid by way of a valve 708, Fig. 18, and a pressure-regulating valve 722. The valve 708 is opened through a cam plate 688, Fig. 8, and links 672, 666 and 662 when an arm 546 is moved rearwardly by a hand lever 542. The arm 546 is pivoted at 548 and is U-shaped, the hand lever being pivoted to the arm for sideways movement relatively thereto for effecting tipping of the levelling roll as described below. The regulating valve 722, Fig. 18, comprises elements 736, 738 connected to a piston 758. When the valve 708 is raised by movement of the arm 546, pressure fluid passes to the piston 712 to lower the roll 422, and by a passage 752 and needle valve 754 to the space 756 above the piston 758. Fluid also exerts pressure below the piston 758. The space 756 is connected by a pipe 766 to an exhaust valve 764, Fig. 8, wherein a valve element is urged to close an exhaust port by a spring, the compression of which is increased, as the arm 546 is moved rearwardly, by the engagement of an arm 788 connected to the arm 546 with a plunger 784 which abuts the spring. When the spring is not under compression, the fluid pressure through the pipe 766 can move the exhaust valve to open the exhaust. The pressure below the piston 758 then raises the elements 736, 738 so as to cut off supply of fluid to the piston 712, thereby controlling the pressure of the roll 422 against the shoe, exhaust of fluid through the exhaust valve being controlled by the position of the arm 546. When the members 736, 738 have moved sufficiently to shut off fluid from the piston 712, they open exhaust ports whereby the pressure fluid is exhausted rapidly, so that the roll 422 responds promptly to the operation of the exhaust valve 764. Means also are provided for exhausting fluid from beneath the piston 712 when the valve 708 has been closed. The tipping of the roll 422 about the axis 453 is effected by movements of a piston (not shown) which, through a rack and gear segment, actuates a lever 504 connected by a link 506, Fig. 8, to an arm 508 projecting from the carrier 452. Pressure fluid is admitted to either. side of the piston by a valve (not shown) comprising a sleeve member which is moved in response to sideways movements of the hand lever 542 through linkage 562, 566, 580. Connections between the link 580 and the lever 504 tend to return the valve sleeve member to neutral position, and the levelling roll is returned to horizontal position by springs acting on the link 566 when the hand lever 542 is released. In the operation of this second construction, the jack is traversed beneath the levelling roll in response to rearward and forward movements of the hand lever 436, and the roll is lowered against the work with controllable pressure by rearward movement of the hand lever 542 and tipped in either direction by sideways movements of the latter lever.