US3030981A

US3030981A - Diverting valve with independent pistons

Info

Publication number: US3030981A
Application number: US97776A
Authority: US
Inventors: George N Chatham; O O Shurtleff
Original assignee: Chatleff Controls Inc
Current assignee: Danfoss Chatleff Inc
Priority date: 1961-03-23
Filing date: 1961-03-23
Publication date: 1962-04-24
Anticipated expiration: 1979-04-24

Description

April 24, 1962 G, N. CHATHAM ETAL 3,030,981

DIVERTING VALVE WITH INDEPENDENT PISTONS Filed March 23, 1961 2 Sheets-Sheet 1 N Nu INVENTORS GEOAGE' IV. CHAT/944M 8Y0 0 S/YUQTLEFF United States Patent 3,030,981 DIVERTING VALVE WITH INDEPENDENT PISTONS George N. Chatham and 0 Shurtlelf, Austin, Tex., assignors to Chatleif Controls, Inc., Austin, Tex., a corporation of Texas Filed Mar. 23, 1961, Ser. No. 97,776 4 Claims. (Cl. 137-628) This invention relates to valves used for diverting fluid from one passage to another.

It is among the objects of this invention to provide a valve for directing fluid through either one of two circuits, in which the transfer from either circuit to the other is made gradually without any interruption of flow, in which the rate of movement of the valve during the transfer is controlled by the rate of fluid movement into and out of it, and which is quiet and positive in operation.

In accordance with this invention a valve housing contains a pair of spaced end chambers connected by a central passage of smaller diameter that is provided with a lateral outlet port. Each end of the passage has a valve seat in the surrounding chamber. Fluid pressure responsive means are mounted in the chambers for move ment toward and away from the valve seats to close and open the ends of the passage. The pressure responsive means, which are provided with central openings, separate the chambers into inner and outer sections. The valve is provided with by-passes permanently connecting each inner chamber section with the adjoining outer chamber section. The valve housing has two inlet ports, each of which opens into one of the inner chamber sections. In one outer chamber section there is a movable closure member for the central opening in the adjacent pressure responsive means, against which the closure means is pressed by a spring while that pressure responsive means engages the adjacent valve seat. A rigid tube in the central passage has one end joined to the other pressure responsive means around its central opening. The opposite end of the tube is smaller than the closed central opening and is located adjacent the closure member while the other pressure responsive means is spaced the maximum distance from the nearest valve seat. The tube has a central lateral outlet. A valve member in the other outer chamber section is operable to close the central opening in the adjacent pressure responsive means to cause the latter to engage the adjacent valve seat. The tube is long enough to push the closure member out of opening-closing position when said other pressure responsive means, is seated against its adjacent valve seat.

The invention is illustrated in the accompanying drawings, in which:

FIG. 1 is a plan view of our valve;

FIG. 2 is a side view;

FIG. 3 is an enlarged vertical section, taken on the line IIIIII of FIG. 1 showing the movable members in one position;

FIG. 4 is an enlarged fragmentary vertical section, taken on the line IV-IV of FIG. 1 at 90 to FIG. 3 showing the movable members in the other position;

FIG. 5 is a horizontal section, taken on the line V-V of FIG. 3; and

FIG. 6 is a horizontal section, taken on the line VIVI of FIG. 4.

Referring to FIGS. 1 to 6 of the drawings, in which the valve is shown vertical for convenience of description, a vertical cylinder 1 is closed at its lower end by a bottom cap 2, and is closed at its upper end by a top cap 3 and the lower part of a solenoid mechanism 4. The inside of the housing thus formed is separated into upper and lower end chambers by means of a central partition member 6 fitting tightly in the housing and through ice which extends a vertical passage 7 that connects the upper and lower chambers. The passage is considerably smaller in diameter than the chambers, and the side Wall of the passage projects a short distance above and below the partition to form circular valve seats 8 and 9 spaced from the side walls of the chambers. Midway between its ends the passage is provided with an outlet port 10 that extends outward through the partition and the cylinder. The port communicates with a hollow fitting 11.

Disposed in the upper and lower chambers of the valve housing are fluid pressure responsive means, each of which may include a flexible diaphragm or piston. Pistons 12 and 13 are illustrated, each of which preferably is cup-shaped. Each piston separates an end chamber into inner and

outer sections

14 and 15. The valve housing is provided with an inlet port 17 (FIG. 3) that opens into the upper inner chamber section 14, and with another inlet port 18 ('FIG. 4) that opens into the lower inner chamber section 14. A tubular fitting 119 is connected with port 17. Preferably, a T-fitting 20 is connected to the lower inlet port, although the same result could be obtained by providing the lower part of the valve housing with an outlet from lower inner chamber section 14. To permit the housing to be made as short as possible, parts of partition member 6 at the inner ends of the inlet ports are cut away so that the ports can overlap that member without being obstructed by it.

When a valve seat 8 or 9 is engaged by a piston, that end of passage 7 is closed. Piston 12 has a central opening 21 through it, and piston 13 is provided with a slightly larger central opening 22. Each piston also has a bypass hole 23 through it outside of the adjacent seat, for permanently connecting the adjoining inner and outer chamber sections '14 and 15 as will be explained presently. The same result could be obtained by substituting, for the by-pass hole, clearance between the piston and side of the housing.

In the upper outer chamber section 15 there is a valve member, preferably a plunger 25, for closing the central opening 21 through the upper piston 12. The plunger is connected to a solenoid core 26 slidably mounted in a sealed tube 27 sealed in cap 3 and encircled by an electric coil 28. The core is urged toward the opposite end of the valve housing by

coil springs

29 and 30 encircling the lower end of the core.

Inside the lower outer chamber section 15 there is a check valve for central opening 22. The check valve includes a closure member 32 and a coil spring 33 for urging it toward piston 13. While the piston is engaging valve seat 9, opening 22 is closed by this check valve. Extending through central passage 7 directly above the check valve is a rigid tube 34, the upper end of which is secured to upper piston 12 around its central opening 21. The lower end of the tube is small enough to be projected through lower opening 22 and into engagement with the check valve. The tube is provided centrally with one or more lateral outlet holes 35 opening into the surrounding passage. The top of piston 13 may be provided with a sleeve 36 extending up into passage 7 to help guide the tube as it moves in the piston.

The normal position of the valve, in which solenoid coil 28 is not energized, is shown in FIGS. 3 and 5. In that position, plunger 25 closes the central opening 21 through the upper piston so the fluid pressure in upper chamber section 15 above the piston holds the piston on seat 8 because the fluid pressure is less in passage 7. At the same time, tube 34 holds closure member 32 down away from the central opening 22 in the lower piston 13, whereby lower chamber section .15 is in communication with the inside of the tube through holes or notches 37 in its lower end and, by means of holes 35, with the lower pressure in outlet port 10. If there is clearance between the side of the tube and sleeve 36, notches 37 are not necessary. Since the fluid pressure in lower chamber section now Will be less than in lower chamber section 14, the lower piston 13 will sink to the bottom of the valve housing and thereby open the lower end of passage 7. At this time the fluid therefore enters one end of the T -fitt-ing and is diverted through lower inlet port 18 into lower chamber 14, and then up into central passage 7 and out through outlet port 10. The circuit from the other end of the T-fitting through elements (not shown) outside of the valve and back to inlet port 17 is shut off by piston 12 at seat 8.

When the solenoid coil is energized, core 26 is drawn upward to remove plunger from central opening 21 in piston 12. With the opening of upper chamber section 15 in this manner, the pressure above the upper piston is reduced and the piston rises to the top of the housing. Simultaneously, the raising of tube 34 permits the check valve to close, so the fluid pressure below the lower piston is increased to move it upward to close the lower end of passage 7 as shown in FIG. 4. Fluid therefore can no longer enter the valve housing through lower inlet 18 to be short-circuited through the valve, so it flows straight through the T-fitting as shown in FIG. 6 and around to upper inlet port 17, and then down through the center passage to outlet port 10.

When the coil is de-energized again, gravity, or

springs

29 and 30, will cause plunger 25 to close the central opening through the upper piston and simultaneously open the check valve in the lower piston. The valve then will reverse itself to return to the position shown in FIG. 3.

The by-pass holes 23 through the pistons permit the fluid pressure in inner chamber sections 14 to be transmitted to outer chamber sections 15. The holes are large enough to permit the pistons to move at the desired speed, but not so large that either one would short-circuit the pressure imbalance created across a piston at the moment of opening its center hole, because in that case the piston would not move. The valve changes gradually from one position to the other without any flow interruption to cause water hammer, so quiet and positive operation are easily achieved. One circuit opens gradually at the same rate that the other is closed.

Although the valve has been described as if the solenoid mechanism were at the top, the valve will operate satisfactorily in any position. It is very compact, as all moving parts are concentric with one another.

According to the provisions of the patent statutes, we have explained the principle of our invention and have illustrated and described what we now consider to represent its best embodiment. However, we desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than ,as specifically illustrated and described.

We claim:

1. A diverting valve comprising a housing containing a pair of spaced end chambers connected by a central passage of smaller diameter provided with a lateral outlet port, each end of said passage having a valve seat in the surrounding chamber, fluid pressure responsive means mounted in said chambers for movement toward and away from said seats to close and open the ends of said passage, said means separating the chambers into inner and outer sections and being provided with central openings, the valve being provided with by-passes permanently connecting each inner chamber section with the adjoining outer chamber section, said housing having inlet ports opening into said inner chamber sections, a movable closure member in one of said outer chamber sections, a spring causing said closure member to close the central opening in the adjacent pressure responsive means while the latter engages the adjacent valve seat, a rigid tube in said passage having one end joined to the other pressure responsive means around its central opening, the opposite end of the tube being smaller than said closed central opening and being located adjacent said closure member while said other pressure responsive means is spaced the maximum distance from the nearest valve seat, the tube having a central lateral outlet, and a valve member in the other of said outer chamber sections operable to close the central opening in the adjacent pressure responsive means to cause the latter to engage the adjacent valve seat, said tube being long enough to push said closure member out of opening-closing position when said other pressure responsive means is seated against its adjacent valve seat.

2. A diverting valve according to claim 1, in which each of said pressure-responsive means includes a piston slidably mounted in the surrounding end chamber, said by-passes being openings through said pistons outside of said valve seats.

3. A diverting valve according to claim 1, in which the tube-carrying pressure-responsive means is movable through a greater distance than the other pressure responsive means.

4. A diverting valve according to claim 1, in which a stub tube projects into said central passage from around said closed central opening and receives the adjoining end of said rigid tube.

References Cited in the file of this patent UNITED STATES PATENTS