US3654957A

US3654957A - Fluidic controlled refill system

Info

Publication number: US3654957A
Authority: US
Inventors: Barry Fichter
Original assignee: American Standard Inc
Current assignee: Trane US Inc
Priority date: 1969-09-16
Filing date: 1969-09-16
Publication date: 1972-04-11
Anticipated expiration: 1989-04-11

Abstract

A fluidically controlled refill system which automatically maintains the flow of the refill fluid until a predetermined liquid level or fluid pressure is achieved in the container to be filled. The system includes a diaphragm which interacts with the main valve to hold the valve in the open position during the filling operation, and a fluid switching device which causes the pressure on the diaphragm to decrease in response to predetermined conditions and thus close the main valve.

Description

United States Patent Fichter [is] 3,654,957 51 Apr. 11, 1972 [54] FLUIDIC CONTROLLED REFILL SYSTEM [72] Inventor: Barry Fichter, Dunellen, NJ.

[73] Assignee: American Standard Inc., New York, NY.

[22] Filed: Sept. 16, 1969 [21] Appl. No.: 858,326

[52] U.S. Cl ..137/596.l4, 137/815 [51] Int. Cl. ..F15c3/06,F16k31/145 [58] FieldoiSeai-ch ..137/596.14,596.15,8l.5

[56] References Cited UNITED STATES PATENTS 2,984,218 5/ 1 961 Christianson ..137/596.15 3,124,999 3/1964 Woodward ..137/81.5 X 3,232,316 2/1966 Carlisle ..137/596.l5 3,339,571 9/1967 Hatch, Jr. ..137/81.5

Wilkerson 1 37/8 1 .5

3,444,877 5/1969 Atchley 3,460,554 8/1969 Johnson 3,489,181 1/1970 Boothe ..137/8l.5

Primary Examiner-Samuel Scott Attorney-Sheldon H. Parker, Tennes 1. Erstad and Robert G. Crooks [57] ABSTRACT A fluidically controlled refill system which automatically 11 Claims, 9 Drawing Figures PATENTEDAPR 1 1 1972 3,654,957

sum 1- 0F 3 \M 1... 4 A 1 M: fill... m m 2 x f 'BY mvsu'rozz. I Barry Fic fer ATTORNEY PATENTEDAPR 11 I972 I SHEET 2 BF 3 --+TANK REFILL- QVENTILATION FLUIDIC CONTROLLED REFILL SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a fluid refill system, and, more particularly, to such a system which is controlled by a fluidic switching mechanism.

2. Description of the Prior Art The need for an efficient, reliable refill system for a variety of applications has long existed. For example, the various types of refill devices normally used in water closets are characteristically noisy, and are subjected to excessive wear. Also they do not normally stay in the full open position during the entire filling operation, but rather have to begin a slow close procedure well before the tank is completely full. Furthermore, these valves require the use of a large float and a lever arm mechanism, etc., which are relatively bulky in size and expensive to manufacture and assemble.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a refill system which is inexpensive, efficient and reliable, as well as being relatively quiet and durable.

It is a further object of the present invention to provide a refill system that may be maintained completely in the open position during the entire refill cycle, and then closed in a relatively short time to stop the refill cycle.

Briefly summarized, the system of the present invention comprises a first conduit connecting an inlet and outlet for the tank to be filled, valve means disposed in said first conduit and normally closed to prevent flow therethrough, a fluid chamber, means in said fluid chamber responsive to a predetermined fluid pressure in said fluid chamber for moving said valve means to an open position, a second conduit adapted to directly connect said inlet to said fluid chamber to establish said predetermined pressure in said fluid chamber, a flow switching chamber connected between said first conduit and said fluid chamber and normally permitting fluid flow therebetween to maintain said predetermined pressure in said fluid chamber, and switching means in said flow switching chamber responsive to a predetermined fluid flow from said outlet for switching fluid flow to and from said fluid chamber.

BRIEF DESCRIPTION OF THE DRAWINGS Reference is now made to the accompanying drawings for a better understanding of the nature and objects of the refill system of the present invention, which drawings illustrate the best mode presently contemplated for carrying out the objects of the invention and its principles, and are not to be construed as restrictions or limitations on its scope. In the drawings:

FIG. 1 is a schematic illustration of the refill system of the present invention;

FIGS. 2-5 are schematic illustrations of modifications of the refill mechanism according to the present invention; and

FIGS. 6-9 are partial schematic illustrations depicting various arrangements of the main valve and its associated structure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The refill system of the present invention will be described in connection with the refilling of the main tank of a water closet by means of example, it being understood that it can be applied to any other related device. As shown in FIG. 1, a water inlet 10 is adapted to supply water to an outlet 12 by means of a conduit 14 and its branches 14a and 1412, it being understood that the inlet 10 is connected to the main water source and that the outlet '12 empties into the main tank of the closet. A secondary outlet 12a extends from the main outlet 12 and may be used in this environment to supply some water flow directly to the water closet bowl to wash down the latter during the tank refill operation.

I A slidably operated valve member 16 has a head portion 16a adapted to engage a reduced section in the conduit 14 to control the flow of fluid between the inlet 10 and the outlet 12. A shoulder portion 16b is formed on the valve member 16 and is connected to a diaphragm 20 disposed in a fluid chamber 22, the purpose of the latter being described in detail later.

A conduit 24 branches from the conduit 14 and connects the inlet 10 to the fluid chamber 22. A second valve member 26, having a head portion 26a adapted to cooperate with a reduced section of the conduit 24 controls the flow of fluid through the conduit 24. The valve member 26 is actuated by manually pressing its plunger portion 26b to start the refill operation, it being understood that it can be connected by linkage, etc., to also initiate the bowl flushing operation, in a known manner.

A branch of the conduit 14 extends into a fluidic switching mechanism comprising a nozzle 30 communicating with the branch 14c, a pair of

outlet conduits

32 and 34, and a vent tube 36 acting as a control for switching the flow in the nozzle 30 between the

outlets

32 and 34 in response to predetermined conditions. The design of the fluidic switching device is such that the flow normally passes from the nozzle 30 into the bypass conduit 34. However, when the vent tube 36 is open, air will enter the nozzle 30 and, due to an aspiration effect created, the flow is switched to the conduit 32. The free end of the vent tube 36 extends to a predetermined depth into the tank to be filled, which depth substantially corresponds to the level of water desired in the tank, and flow will continue through the conduit 32 until this end of the vent tube is blocked by the water in the tank. When this occurs, the aspiration effect is terminated, and water flow switches to its normal path through the outlet conduit 34. The outlet 32 communicates with the fluid chamber 22 and permits flow into the latter which will act on the diaphragm 20 and maintain the valve 16 in its open position despite the release of the plunger 26b. The outlet 34 is utilized as a bypass conduit and may empty directly into the water tank in the same manner as the main outlet 12.

In operation of the system of FIG. 1, the

valve members

16 and 26 are normally in their closed positions as shown by the solid lines in FIG. 1, and the system is actuated by manually depressing the plunger portion 26b of the valve 26 which, via the associated linkages, etc., empties the tank and causes its head portion 26a to move into the position shown by the dotted lines, and thus permit water to flow from the inlet 10 through the conduit 24 and into the water chamber 22. A predetermined pressure then builds up in the chamber which moves the valve 16 downwardly as viewed in FIG. 1, whereby its head portion 16a will move to the position shown by the dotted lines, to permit direct water flow from the inlet 10, through the conduit 14 and its branches 14a and 14b, and into the outlets l2 and 12a.

A portion of the flow through the conduit 14 will flow into the conduit 14c and into the nozzle 30 of the fluid switching mechanism. Since the tank is relatively empty at this point, air from the vent tube 36 will cause the flow from the nozzle 30 to pass into and through the conduit 32 and into the fluid chamber 22. Thus, the plunger 26b may be released and will move back to its closed position under the pressure of the water acting on its head portion 26a, while the above mentioned pressure will still be maintained in the fluid chamber 22. Flow continues in the above manner until the free end of the vent tube 26a is blocked as a result of the water attaining a predetermined height in the tank, in which case flow is switched from the conduit 32 to the bypass conduit 34, thus relieveing the pressure on the diaphragm 20. This causes the valve 16 to move to its closed position under the water pressure from the inlet 10, and thus cut off the supply of water from the inlet 10.

The embodiment of FIG. 2 is basically similar to that of FIG. 1 and therefore identical structure will be given the same reference numerals. In this embodiment a plunger portion extends upwardly from the shoulder 16b of the valve member 16 and is adapted to be manually actuated by pushing it downwardly as viewed in FIG. 2 in order to start the flushing operation as described above. As a result, the head portion 16a of the valve 16 moves to its open position, as shown by the dotted lines and permits a direct connection between the inlet and the outlets. 12 and 12a, via the conduit 14 and its branches 14a and 14b.

In operation of the embodiment of FIG. 2, the plunger is manually actuated as described above and held in that position while water flow flows from the inlet 10 to the outlets 12 and 12a, and via the branch 140 into the nozzle 30 of the fluid switching mechanism. The empty tank will permit air to pass through the vent tube 36 into the nozzle 30, and thus switch the flow to the outlet conduit 32 and into the fluid chamber 22 whereby it applies a pressure upon the diaphragm 22 to hold the valve 16 in its open position. At this point the operator can feel that the plunger 16a may be released and still permit the inlet 10 and the outlets 12 and 12a to be connected. As in the previous embodiment, the flow of water from the inlet 16 through the outlets 12 and 12a continues until the fluid level in the tank reaches the open end of the vent tube 36, whereby the fluid flow is switched from the conduit 32 to conduit 34. This relieves the pressure applied on the diaphragm 20 and causes the valve head 16a to move to a closed position as shown by the solid lines due to the water pressure exerted thereon from the inlet 10.

The embodiment of FIG. 3 is identical to the embodiment of FIG. 2 with the exception that the fluidic switching device has a flow reversal section 40 communicating with the nozzle 30, and a conduit 42 connecting the section 40 with the outlet conduit 32. In this embodiment, during the refill operation the water normally passes from the nozzle 30 into the conduit 32 by virtue of the air supplied into the nozzle 30 via the vent tube 36. However, when air flow through the vent tube 36 is blocked by the water reaching a predetermined level in the tank, the flow from the nozzle 30 is switched into the flow reversal section 40 which substantially blocks water flow. This relieves the pressure in the chamber 22 and thus causes the valve 16 to move to its closed position as shown by its solid lines, which terminates the refill operation. The conduit 42 permits a relatively small portion of water flow between the nozzle 30 and the chamber 22 to permit a gradual shutdown of the system and thus reduce or eliminate a water hammer which could otherwise occur as a result of a sudden shutting of the valve 26.

In the embodiment of FIG. 4, an inlet 50 is directly connected to the nozzle 70 of a flow switching device by means of a conduit 54. A valve member 56 is disposed in the conduit 54 and has a head portion 56a adapted to engage a reduced portion in the conduit 54 in its closed position as shown by the solid lines. A shoulder 56b is provided on the valve 56 which is connected to a diaphragm 60 disposed in a fiuid chamber 62, as in the previous embodiments.

A plunger 560 is provided on the valve 56 and is adapted to be manually pushed upwardly as viewed in FIG. 4 to the position shown by the dotted lines to initially start the refill system.

The nonle 70 is adapted to switch water flow between a pair of

outlet conduits

52 and 74 in response to a signal from a vent tube 76 which extends into the tank to be refilled and which operates as in the previous embodiments. Specifically, when the water level in the tank has not reached the end of the vent tube, water will flow through the conduit 52 and directly into the tank. A portion of this flow will be tapped by a conduit 78 and directed into the bottom portion of the fluid chamber 62 to cause the valve 56 to remain in its open position despite release of the plunger 560 by the operator. When the fluid in the tank reaches the end of the vent tube 76, the water flow is switched to the outlet conduit 74 thus relieveing the pressure in the chamber 62 and causing the valve 56 to move to its closed position as shown by the solid lines, which terminates the refill operation. It is noted that this arrangement is ideally suited for connecting the conduit 74 to a ventilating apparatus for the water closet, in a known manner.

The embodiment of FIG. 5 is designed so that it provides a single outlet for the fluid flow. Particularly, an inlet 80 registers with a conduit 84, with the head portion 86a of a valve 86 adapted to cooperate with a seat formed adjacent the conduit 84 to control the flow of fluid therethrough. A diaphragm 90 is disposed in a fluid chamber 92 and is attached to a shoulder portion 86b of the valve 86. A plunger 86c is formed on the valve and is adapted to be pulled upwardly as viewed in FIG. 5 to move the head portion 86a to an open position as shown by the dotted lines.

A nozzle of a fluid switching device is in communication with the conduit 84 and with two

outlet conduits

102 and 104, both of which register with a single outlet 106. A vent tube 108 is provided which operates as in the previous embodiments to switch flow between the

outlet conduits

102 and 104. During the refill operation, water flows from the nozzle 100 into the conduit 102 by virtue of the air'supplied by the vent tube 108. A large portion of the flow from conduit 102 is directed into the main outlet 106, and a small portion of the flow passes, via a conduit 110, into the bottom portion of the fluid chamber 90 to exert an upwardly extending pressure on the diaphragm 90 and provide the necessary force to maintain the valve member 86 in its open position despite a later release of the plunger 86c. When the fluid level in the tank reaches the height of the free end of the vent tube 108 and thereby blocks the flow of air, the flow of water from the nozzle 100 is diverted into the conduit 104 and flows directly into the outlet 106. The pressure exerted upwardly on the diaphragm 90 is thus relieved and the force of the water flowing from the inlet 80 downwardly onto the head portion 86a of the valve 86 will cause the latter to move into its closed position and thus ter minate the refill operation.

It can be appreciated that several modifications of the exact structure and particular arrangement of the valve members and their associated structure can be made within the scope of the above invention. For example, the embodiment of FIG. 6 is identical to the embodiment of FIG. 5, with the exception that the valve 86 has an enlarged portion 86d forming a shoulder which is engaged by a spring which applies a force in addition to the force applied by the water pressure from the inlet 80, to urge the valve 86 into its downward closed position. This, of course, will cause the valve to seat firmly and will eliminate any flow therethrough after the fluid level in the tank has reached its predetermined level.

In the embodiment of FIG. 7 a spring 122 is provided between the shoulder 86b and the upper wall of the chamber 92 to urge the valve head (not shown) against its seat, as in the previous embodiment.

The embodiment of FIG. 8 is similar to that of FIG. 5, but is designed to permit a slower closing of the valve 86. Specifically, the upper portion of the chamber 92 contains fluid and is in communication with a dash pot 124 via a restricted conduit 126. The arrangement is such that fluid in the upper chamber portion must flow through the conduit 126 into the dash pot 124 when the valve 86 moves upwardly to its open position as viewed in FIG. 8. Conversely, the fluid must flow from the dash pot through the conduit 126, and into the upper portion of the chamber 92 when the valve 86 moves downwardly into a closed portion. In this manner, a slower closing of the valve is achieved by virtue of the pressure of the dash pot 124 and the conduit 126, thus eliminating the water hammer problem described above which is normally associated with rapid closing valves.

A still further variation of the arrangement of FIG. 5 is shown in the embodiment of FIG. 9 in which the conduit 110 has an enlarged portion 110a containing a ball valve 130. Two other portions 11% and 1100 of the conduit 110 connect the portion 110a to the chamber 92 and to the conduit 102, respectively. A plurality of flutes or grooves (not shown) are formed in the portion 11% of the conduit 110. In this manner, when water flows through the conduit 110 into the fluid chamber 92, the ball valve 130 is urged towards a seat defined by the conduit portion 110b, whereby water will flow rapidly through the flutes formed in the latter portion and into the chamber 92. When fluid is switched from the conduit 102 and therefore from the conduit 110, the fluid in the lower portion of the chamber 92 will begin to flow through the conduit 110 into the conduit 102. The ball valve 130 will thus be forced against a seat formed by the conduit portion 110C. The diameter of the ball valve 110 can be designed so that a small fluid flow will be permitted in the latter position of the ball valve so that the valve 86 will close gradually and thus prevent a water hammer.

It can be appreciated that several other variations of the above system may be made within the scope of the present invention. For example, other types of valve heads can be used other than those shown in the embodiments of FIGS. 1-5, such as ball valves connected to the stem portions. Also, the vent tubes disclosed above may be made adjustable to vary the desired water level in the tank and can be in the form of a vacuum line, or the like. Also, the variations of FIGS. 6-9 can be applied to the embodiments of FIGS. 1-4 as well as to the embodiment of FIG. 5.

Of course, other variations of the specific construction and arrangement of the refill system disclosed above can be made by those skilled in the art without departing from the invention as defined in the appended claims.

l claim:

1. Apparatus for controlling fluid flow between an inlet and at least one outlet, said apparatus comprising a first conduit connecting said inlet and outlet, valve means disposed in said first conduit and normally closed to prevent flow therethrough, a fluid chamber, means in said fluid chamber responsive to a predetermined fluid pressure in said fluid chamber for moving said valve means to an open position, a second conduit adapted to directly connect said inlet to said fluid chamber to establish said predetermined pressure in said fluid chamber, a fluidic flow switching chamber having at least one stable state and connected between said first conduit and said fluid chamber and normally permitting fluid flow therebetween to maintain said predetermined pressure in said fluid chamber, and switching means in said fluidic flow switching chamber responsive to a predetermined fluid flow from said outlet for switching fluid flow to and from said fluid chamber.

2. The apparatus of claim 1 further comprising a third conduit registering with said fluidic flow switching chamber, said switching means adapted to switch fluid flow from between said fluid chamber and said third conduit.

3. The apparatus of claim 1 further comprising an additional valve means disposed in said second conduit, said additional valve means adapted to be manually actuated to connect said inlet to said fluid chamber.

4. The apparatus of claim 1 wherein said flow switching chamber comprises,

a power nozzle,

a first switching chamber conduit,

a second switching chamber conduit and a control port conduit,

said first switching chamber conduit being connected between said flow switching chamber and said fluid chamber to permit fluid flow between said flow switching chamber and said fluid chamber to maintain said predetermined pressure in said fluid chamber,

said flow switching chamber power nozzle being arranged to receive flow from said first conduit,

said control port conduit being arranged to control flow in said flow switching chamber first conduit and said flow switching chamber second conduit by deflecting the fluid flow through said power nozzle from a first position in which said flow is directed toward said flow switching chamber first conduit to a second position in which said flow is directed towards said flow switching chamber second conduit, said control port conduit being said switching means in said flow switching chamber responsive to a predetermined fluid flow.

5. The apparatus of claim 1 wherein said switching means comprises vent means registering with said flow switching chamber, and adapted to supply air to said chamber to permit fluid flow between said first conduit and said fluid chamber.

6. Apparatus of claim 5 further comprising a tank for said fluid, said vent means extending into said tank and adapted to be submerged upon the fluid reaching a predetermined level in said tank to restrict the supply of air to said chamber to effect said switching.

7. Apparatus for controlling fluid flow between an inlet and at least one outlet, said apparatus comprising a conduit connecting said inlet and outlet, valve means disposed in said conduit and normally closed to prevent flow therethrough, actuating means directly connected to said valve means for moving said valve means to an open position, a fluid chamber, means in said fluid chamber responsive to a predetermined fluid pressure in said chamber for maintaining said valve means in said open position, a fluidic flow switching chamber having at least one stable state and connected between said conduit and said fluid chamber and normally permitting fluid flow therebetween to maintain said predetermined pressure in said fluid chamber, and switching means in said fluidic flow switching chamber responsive to a predetermined fluid flow from said outlet for switching fluid flow to and from said fluid chamber, and an additional conduit registering with said fluidic flow switching chamber, said switching means adapted to switch fluid flow from between said fluid chamber and said additional conduit.

8. Apparatus for controlling fluid flow between an inlet and at least one outlet, said apparatus comprising a conduit connecting said inlet and outlet, valve means disposed in said conduit and normally closed to prevent flow therethrough, actuating means directly connected to said valve means for moving said valve means to an open position, a fluid chamber, means in said fluid chamber responsive to a predetermined fluid pressure in said chamber for maintaining said valve means in said open position, a fluidic flow switching chamber having at least one stable state and connected between said conduit and said fluid chamber and normally permitting fluid flow therebetween to maintain said predetermined pressure in said fluid chamber, and switching means in said fluidic flow switching chamber responsive to a predetermined fluid flow from said outlet for switching fluid flow to and from said fluid chamber, and a tank for said fluid, said actuating means comprising a plunger extending outwardly from said tank and adapted to be actuated manually.

9. Apparatus for controlling fluid flow between an inlet and at least one outlet, said apparatus comprising a conduit connecting said inlet and outlet, valve means disposed in said conduit and normally closed to prevent flow therethrough, actuating means directly connected to said valve means for moving said valve means to an open position, a fluid chamber, means in said fluid chamber responsive to a predetermined fluid pressure in said chamber for maintaining said valve means in said open position, a fluidic flow switching chamber having at least one stable state and connected between said conduit and said fluid chamber and normally permitting fluid flow therebetween to maintain said predetermined pressure in said fluid chamber, and switching means in said fluidic flow switching chamber responsive to a predetermined fluid flow said outlet for switching fluid flow to and from said fluid chamber, and said switching means comprising a vent means registering with said fluidic flow switching chamber, and adapted to supply air to said chamber to permit fluid flow between said first conduit and said fluid chamber, and a tank for said fluid, said vent means extending into said tank and adapted to be submerged upon the fluid reaching a predetermined level in said tank to restrict the supply of air to said chamber to effect said switching.

10. Apparatus for controlling fluid flow between an inlet and at least one outlet, said apparatus comprising a conduit connecting said inlet and outlet, valve means disposed in said conduit and normally closed to prevent flow therethrough, ac-

mating means directly connected to said valve means for moving said valve means to an open position, a fluid chamber, means in said fluid chamber responsive to a predetermined fluid pressure in said chamber for maintaining said valve means in said open position, a fluidic flow switching chamber having at least one stable state and connected between said conduit and said fluid chamber and normally permitting fluid flow therebetween to maintain said predetermined pressure in said fluid chamber, and switching means in said fluidic flow switching chamber responsive to a predetermined fluid flow from said outlet for switching fluid flow to and from said fluid chamber, and said means for maintaining said valve means in said open position comprising a diaphragm disposed in said fluid chamber and connected to said valve means, said diaphragm being movable in response to changes in fluid pressure in said chamber, and a dash pot connected to said fluid chamber for controlling the rate of fluid flow from said chamber.

11. Apparatus for controlling fluid flow between an inlet and at least one outlet, said apparatus comprising a conduit connecting said inlet and outlet, valve means disposed in said conduit and normally closed to prevent flow therethrough, actuating means directly connected to said valve means for moving said valve means to an open position, a fluid chamber, means in said fluid chamber responsive to a predetermined fluid pressure in said chamber for'maintaining said valve means in said open position, a fluidic flow switching chamber having at least one stable state and connected between said conduit and said fluid chamber and normally permitting fluid flow therebetween to maintain said predetermined pressure in said fluid chamber, and switching means in said fluidic flow switching chamber responsive to a predetermined fluid flow from said outlet for switching fluid flow to and from said fluid chamber, and said means for maintaining said valve means in said open position comprising a diaphragm disposed in said fluid chamber and connected to said valve means, said diaphragm being movable in response to changes in fluid pressure in said chamber, and an additional conduit connecting said fluidic flow switching chamber and said fluid chamber, and a ball valve disposed in said additional conduit for controlling the rate of fluid flow from said chamber.

Claims

4. The apparatus of claim 1 wherein said flow switching chamber comprises, a power nozzle, a first switching chamber conduit, a second switching chamber conduit and a control port conduit, said first switching chamber conduit being connected between said flow switching chamber and said fluid chamber to permit fluid flow between said flow switching chamber and said fluid chamber to maintain said predetermined pressure in said fluid chamber, said flow switching chamber power nozzle being arranged to receive flow from said first conduit, said control port conduit being arranged to control flow in said flow switching chamber first conduit and said flow switching chamber second conduit by deflecting the fluid flow through said power nozzle from a first position in which said flow is directed toward said flow switching chamber first conduit to a second position in which said flow is directed towards said flow switching chamber second conduit, said control port conduit being said switching means in said flow switching chamber responsive to a predetermined fluid flow.

10. Apparatus for controlling fluid flow between an inlet and at least one outlet, said apparatus comprising a conduit connecting said inlet and outlet, valve means disposed in said conduit and normally closed to prevent flow therethrough, actuating means directly connected to said valve means for moving said valve means to an open position, a fluid chamber, means in said fluid chamber responsive to a predetermined fluid pressure in said chamber for maintaining said valve means in said open position, a fluidic flow switching chamber having at least one stable state and connected between said conduit and said fluid chamber and normally permitting fluid flow therebetween to maintain said predetermined pressure in said fluid chamber, and switching means in said fluidic flow switching chamber responsive to a predetermined fluid flow from said outlet for switching fluid flow to and from said fluid chamber, and said means for maintaining said valve means in said open position comprising a diaphragm disposed in said fluid chamber and connected to said valve means, said diaphragm being movable in response to changes in fluid pressure in said chamber, and a dash pot connected to said fluid chamber for controlling the rate of fluid flow from said chamber.

11. Apparatus for controlling fluid flow between an inlet and at least one outlet, said apparatus comprising a conduit connecting said inlet and outlet, valve means disposed in said conduit and normally closed to prevent flow therethrough, actuating means directly connected to said valve means for moving said valve means to an open position, a fluid chamber, means in said fluid chamber responsive to a predetermined fluid pressure in said chamber for maintaining said valve means in said open position, a fluidic flow switching chamber having at least one stable state and connected between said conduit and said fluid chamber and normally permitting fluid flow therebetween to maintain said predetermined pressure in said fluiD chamber, and switching means in said fluidic flow switching chamber responsive to a predetermined fluid flow from said outlet for switching fluid flow to and from said fluid chamber, and said means for maintaining said valve means in said open position comprising a diaphragm disposed in said fluid chamber and connected to said valve means, said diaphragm being movable in response to changes in fluid pressure in said chamber, and an additional conduit connecting said fluidic flow switching chamber and said fluid chamber, and a ball valve disposed in said additional conduit for controlling the rate of fluid flow from said chamber.