Patent GB-714960-A (GB)
Title: Improvements in and relating to automatically reversing valves
IPC: F16K11/12
Filed: 1952-04-21
Abstract: 714,960. Hydraulic machines; liquid-pressure engines. BAGHUIS, L. H. April 21, 1952 [April 25, 1951], No. 9985/52. Class 69 (2). [Also in Group XXIII] A valve device for automatically reversing the supply and discharge of pressure fluid respectively to and from the working spaces of a doubleacting cylinder containing a reciprocating piston and comprising a stationary housing, fluid inlet and outlet passages for the admission and the exhaust fluid to and from the housing, a valve body contained in the housing and co-operating with the passages, the valve body being arranged for reciprocation between two end positions by the action of the fluid in two separate chambers which are partly bounded by the valve body and vary their volumes oppositely during the movement of the body, ports opening into the chambers and alternately connecting them to the fluid inlet and the fluid outlet passages and a movable member adapted to be actuated by the piston and to control the movement of the valve body, is characterized in that the chambers are exclusively formed and the ports opening into the chambers are exclusively controlled by the valve body and the control member. In Fig. 1 a free valve body 12 is in its left-hand position and a control member 13 has just been placed in its left-hand position by contact of an arm 20 on the piston-rod 3 of a prime mover 1 with a lever 15, 16, pivoted at 14. Pressure fluid supplied at 9 accordingly enters a chamber 33 in the valve body 12 through ports 34 but is prevented from entering a chamber 32 by a piston 31 on the control member 13. The valve body 12 is consequently moved to the right, Fig. 2, fluid from chamber 32 being discharged through ports 43 and 24, while the control member 13 remains in the position of Fig. 1. Pressure fluid now entering at 9, Fig. 2, and filling an annular chamber 28 formed between the valve body 12 and casing 8, as before, leaves by port 23 and passes along conduit 7 to the cylinder space 5 of the prime mover 1, the cylinder space 4 meanwhile being vented by conduit 6, port 22, chamber 29 and port 24. The piston 2 of the prime mover 1 is thus forced to the left, and near the end of its travel the arm 20 on the piston rod 3, Fig. 1, makes contact with a lever 19 operatively connected to the lever 15, 16, thereby moving the control member 13 to the extereme right. The positions of valve body 12 and control member 13 with respect to the casing 8 in Fig. 3, not shown, are the reverse of those in Fig. 1. Pressure fluid now enters chamber 32 via ports 34, causing the valve body 12 to move to the left (fluid from chamber 33 being discharged through ports 44 and 25) and in that position causing pressure fluid to pass to the cylinder space 4 as shown in Fig. 1. The final movement occurs when the piston 2, nearly at the end of its travel to the right, brings about the movement of the control member 13 to the left. The parts 12, 13 are now in the position of Fig. 1 once more, whence the cycle is repeated. The ports 34 and the piston 31, on the one hand, and the ports 43, 44 and portions 35, 36 of the control member, on the other hand, serve for the alternate connection of the chambers 32, 33 to the supply line and to the discharge lines, respectively. In Fig. 5 a free valve body 12a and control member 13a are mounted for rotation relative to each other and to a stationary casing 8a. The member 13a is keyed to a shaft 38a rocked by the piston 2, Fig. 1, near the ends of its stroke. A single discharge chamber 41a takes the p!ace of spaces 29 and 30, Fig. 1, and ports 21a, 22a, 23a and 34a correspond respectively to ports 9, 22, 23 and 34 in Fig. 1. A wing 31a takes the place of the piston 31.