Patent GB-645861-A (GB)
Title: Improvements in fluid pressure operated shoe presses for stuck-on work and the like
IPC: A43D25/06
Filed: 1946-05-07
Abstract: 645,861. Shoe presses. RALPHS, G. C. May 7, 1946, No. 13771. [Class 17(i)] In a shoe press there are provided a fluid-pressure operated clamping ram for moving the clamping member to clamping position, a fluid-pressure operated locking ram for operating the locking means, and a distributing valve for distributing pressure fluid first to the clamping ram, then to the locking ram while maintaining the supply to the clamping ram and finally to the pad while maintaining the supply to both rams. A valve 8a, Fig. 1, supplies pressure fluid in turn to operate the clamping arm 2a, by means of a ram 3a, a locking device 4a for the clamping arm by a ram 5a, and to the pad la, by unions 11a, 12a, 13a respectively. The press may be of the twin type with corresponding members for operating the other half of the machine, not shown. The valve 8a consists of a fixed two-ended piston on which slides an openended cylinder. Pressure fluid is led into the piston by means of the inlet 14a. The unions 11a, 12a, 13a, are connected to the open-ended cylinder and as this moves on the piston in one direction the fluid pressure is connected to them in turn. Movement of the cylinder in the opposite direction opens the unions 11a &c. to exhaust. The valve is manually operated, and the two valves 8a and 8b may be connected together so that as one press is actuated the other is opened to exhaust. In a modification of the valve, Fig. 3, the cylinder 15 is fixed and the piston 17 slides in it between two stops 19. The pressure fluid inlets 14a and 14b lead into opposite ends of the cylinder 15 and are operated by a pedal 24 and change-over valve 20. In the position shown, pressure fluid passes from pipe 21 through the union 14a to the left of the piston 17 and is thereby connected to the clamping union 11a. When the pressure is sufficiently great, the piston is pushed to the right and brings in, successively, the locking union 12a and inflating union 13a. Meanwhile unions 11b, 12b, 13b have been connected to exhaust by pipe 14b and outlets 39b and 16. Operation of the changeover valve reverses the movement of the piston, and operates press 1b &c. and connects press 1a &c. to exhaust. In a modification, Fig. 5, a shoe press of the turret type is provided having a control valve 31 and a change-over valve 20 similar to that in Fig. 3. The pressure fluid for inflating the pad at the top position is led by union 13 to a central distributing valve 27. The other pads are kept inflated by pressure fluid led to valve 27 by union 21a. The rams 3 and 5, common to all the presses, for clamping and locking the arms 2 are mounted on a rocking lever 28 which pivots about the axis of the wheel 26 and is rocked by a ram 29 to turn the wheel and bring the pads in turn to the position at the top. As each pad reaches the top, union 13 is connected to exhaust, thus unclamping the work and allowing the press to be reloaded. Operation of the change-over valve 20 then allows the pad, clamping mechanism and rocking arm to be actuated. Specification 645,929 is referred to.