Patent EP-0100480-A1 (EP)
Inventor: COOPER ROYDON B
IPC: F16K31/524
Filed: 1983-07-19
Abstract: A duplex cam-operated pressure-balanced sleeve valve is provided for controlling fluid flow into either one or both of two fluid lines, such as to either one or both of two filter elements, comprising, in combination;
     (1) a valve housing; (1)   (2) first (8) and second (9) valve chambers in the housing in alignment with a cam chamber (10) therebetween;   (3) first (2), second (3), and third (4) fluid flow ports in the housing communicating with the first valve chamber (8), and fourth (5), fifth (6) and sixth (7) fluid flow ports in the housing communicating with the second valve chamber; (9);   (4) a first reciprocable sleeve valve member (30) in the first valve chamber (8), axially movable within the first valve chamber (8) between positions controlling flow from the first (2) fluid port to one or both of the second (3) and third (4) fluid flow ports;   (5) a second reciprocable sleeve valve member (31), preferably coaxial with the first sleeve valve member (30), in the second valve chamber (9) axially movable within the second valve chamber (9) with the first sleeve valve member (30) between positions controlling flow from one or both of the fourth (5) and fifth (6) fluid flow ports to the sixth fluid flow port (7);   (6) cam-following valve-actuating means (47) in the cam chamber (10) operatively connected to both the first (30) and second (31) sleeve valve members, for reciprocably moving both valve members together between their flow-controlling positions;   (7) a cam (50) in the cam chamber (10) movable between at least three selected positions and operatively connected with the cam-following valve-actuating means in a manner such that:
   (a) with the cam in a first position, the first sleeve valve member (30) is in a position communicating one of the second (3) and third (4) fluid flow ports with the first fluid flow port (2) and the second sleeve valve member (31) is in a position communicating one of the fourth (5) and fifth (6) fluid flow ports with the sixth fluid flow port (7);   (b) with the cam (50) in a second position, the first sleeve valve member (30) is in a position communicating the other of the second (3) and third (4) fluid flow ports with the first fluid flow port and the second sleeve valve member (31) is in a position communicating the other of the fourth 15) and fifth (6) fluid flow ports with the sixth fluid flow port (7);   (c) with the cam (50) in a third position, both the first (30) and second (31) sleeve valve members are in positions communicating the first (2) with the second (3) and third fluid flow ports and the fourth (5) with the fifth (6) and sixth (7) fluid flow ports;       (8) means for moving the cam (50) between each of the selected positions, thereby shifting the valves in unison;   (9) the first (30) and second (31) sleeve valve members each having an interior pressure-receiving surface exposed at all times to fluid pressure in the first (8) and second (9) valve chambers, respectively, and in the first (2) and sixth (7) fluid flow ports, respectively, and an exterior pressure-receiving surface exposed to fluid pressure in the second (3) and third (4), and fourth (5) and fifth (6) fluid flow ports, respectively, fluid flow through which is controlled by the respective sleeve valves (30-31), so that there is a zero component of force arising from any pressure differential across the valves tending either to move the sleeve valve members (30-31) or to resist cam-operated movement of the sleeve valve members (30-31) between their selected positions;   (10) the cam-following valve actuating means having opposed pressure-receiving surfaces, of which one is exposed to fluid pressure in the first valve chamber (8), and the other is exposed to fluid pressure in the second valve chamber (9);   (11) the opposed pressure-receiving surfaces of the cam-following valve-actuating means being of such small relative surface areas that any fluid pressure differential between first (8) and second (9) valve chambers on the opposed pressure-receiving surfaces thereof offers negligible resistance to cam-operated reciprocation of the sleeve valve members (30-31), so that such fluid pressure differential does not interfere with movement of the first (30) and second (31) sleeve valve members between their selected positions.