Patent GB-632578-A (GB)
Title: Improvements in and relating to driving arrangements for the nippers of shoe upper conforming machines
IPC: A43D21/18
Filed: 1946-09-03
Abstract: 632,578. Shoe-upper conforming machines. BATA, NARODNI PODNIK. Sept. 3, 1946, No. 26486. Convention date, Sept. 30, 1944. [Class 17 (i)] The grip with which a shoe upper is engaged and the pull applied to it by the grippers are both simultaneously hydraulically controlled through an arrangement of pistons between which is a spring- loaded by-pass valve. The grippers where single, are individually controlled, but those in groups, such as side grippers and ball grippers have common control valves. The jaws of each gripper are supported by a cylinder mounted so as to be fixed in the machine frame in any desired position, the fixed gripper jaw being supported on a piston movable in the cylinder and the movable jaw on a rod formed as a piston at one end and guided in the piston casing of the fixed jaw. An intermediate space in communication with the cylinder space of the cylinder through a spring- loaded by-pass valve is formed between these pistons. The gripper jaws are first closed by relative displacement of the pistons, caused by the inflow of pressure fluid, and finally pulling movement on the upper is produced by joint movement of the pistons in the cylinder, gradual increase in the pull and of the grip taking place. Control of the grippers is effected, through-the appropriate valves, by a knee-actuated lever, so that re-adjustment of the upper in the jaws may be made at any stage. After the upper has been stretched correctly, the control of these valves is changed over to automatic control from a cam shaft driven through a single-revolution clutch, and the work of lasting and tacking the forepart of the upper completed, the opened grippers being moved out of the way of upper wiping devices after pulling over has been completed. In the form shown, oil in a container 6, Fig. 1, in the base of the machine, is pumped continuously by a pump 4 driven by an electric motor 5, and conveyed by pipes 9 to an idle-running spring-loaded slide-valve 10, Figs. 1, 7, and, according to the position of a piston 21 therein, is either pumped back to the container 6 through a discharge pipe 18, or, through an outflow pipe 11, into a pressure line pipe 12, to which or to distributors connected to which all the slide valves which control the operation of the various grippers are connected. The oil pressure in line 12 is indicated on gauge 16 and is controlled by a safety pressure valve 13 set by a hand-wheel 14 to the desired maximum permissible pressure superfluous oil returning to the container 6. The piston 21 is moved, either by a knee lever 137 by the operator, or automatically from the cam shaft 147 of the machine to start, run, or stop the grippers. Emptying of the pipes of oil is prevented by a spring- loaded non-return valve 152. The grippers are all similar in construction, and each comprises a cylinder 27, Fig. 2, in communication with a tubular extension 28 clamped in an adjustable socket 29, by which the gripper is held so as to be movable away from the work by a system of hand levers. A sleeve 30 is guided in the extension 28 and carries a fixed jaw 31 and a pivot 32 on which the pivoted jaw 33 may turn. A piston 48 is fixed to the lower end of a rod 47 guided in a hollow rod 34 connected to the sleeve 30, the upper end of which rod carries a tubular extension 52 having forked ends 53, in grooves 54 in which a pin 55 is slidable, to coact with a slot 56 of gripper jaw 33, and thereby move it. The piston 48 slides in a piston 37. The inclined ends of a sleeve 57 on the rod 47 act against rounded ends 59 of two securing levers 60 pivoted on pins 61 in slots 62 of the sleeve 30. A pin 65 slides in a slot 64 in the tubular extension 28, the slot 64 being shaped to give the desired movement to the grippers when the sleeve 30 is moved in the extension 28. At the toe end and sides the grippers have an axial pulling movement only, but at the ball they have also a twisting movement imparted by curved shape given to the slot 64. The supply of pressure fluid to the cylinders 27 of the individual grippers is controlled by separate slide valves 70, Fig. 4, each having chambers 71, 72, 73. Control slide valves 122, 123, 124 are provided for each of the groups, 1; 2, 21 ; 3, 31 of grippers. The valves are controlled through a system of levers operated by the knee lever 137 and also automatically by cams. The levers act on pin on the control piston 21 of the idle running valve 10 and on the lower part of pins 100, 108 which engage recesses 101, 109 in levers 102, 110 respectively connected through springs 98 to pistons 74, 75 of the control valve 21 to hold the inflow and outflow openings of the control valve 21 closed and thus to block the entire working of the machine when knee lever 137 is moved to left. Automatic drive of the control valves is effected by cam discs on a cam shaft 47 driven through a gear-box and singlerevolution coupling from the motor 5. The valve 123 has control cams 149, 150 and the valve 10, cam 151. Cams 149, 150 move the opened grippers out of the way of wiping &c. devices which operate subsequently to the pulling over. The reduction of the oil pressure is effected by a reduction piston 76, which is loaded in an adjustable manner by a spring 114 regulated by a handwheel 115. The oil pressure is given on a,gauge 120.