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Title:
WATER CONTROL FOR TOILET TANKS
United States Patent 3693649
Abstract:
Covers a water control valve for a water tank which is associated with a conventional toilet bowl. The water control valve includes a valve structure mounted on a vertical water inlet pipe and a float structure which moves vertically along the inlet pipe to control the valve structure. The float structure includes two cup-shaped elements, one positioned vertically above the other, both moving along the inlet pipe in response to any change in the water level within the water tank. The valve structure includes a flexible diaphragm which is normally positioned upon a seat at the upper opening of the inlet pipe and blocks the flow of water into the tank, and a pilot valve to control the movement of the flexible diaphragm. The pilot valve is mechanically coupled to the float structure so that, as the float structure descends toward the bottom of the tank, the pilot valve will be opened and, in turn, allow the diaphragm to be flexed upwardly to allow the entry of water into the tank. When the float structure reaches an upper predetermined position, the pilot valve will be closed and the diaphragm will be returned to its normal position to block the flow of water into the flush tank.


Inventors:
Gordon, Frederick Armstrong (Louisville, KY)
Griffin, James Richard (Louisville, KY)
Pezzarossi, John Joseph (Louisville, KY)
Application Number:
05/024247
Publication Date:
09/26/1972
Filing Date:
03/31/1970
Assignee:
American Standard Inc. (New York, NY)
Primary Class:
Other Classes:
73/322.5, 137/432, 251/45
International Classes:
F16K31/34; (IPC1-7): F16K31/18
Field of Search:
137/408,414,424,429,430,432,442 73
View Patent Images:
US Patent References:
3533437FLUSH TANK APPARATUSOctober 1970Young
3525354LIQUID LEVEL CONTROL DEVICEAugust 1970Parrish
3495803VALVE FOR CONTROLLING THE FLOW OF FLUID IN BALL COCK AND THE LIKEFebruary 1970Schoepe et al.
3386462Liquid level controlJune 1968Walters
3285277Toilet tank supply valve assemblyNovember 1966Goldtrap
3194258Float operated valveJuly 1965Grant
2911000Flush tank valveNovember 1959Doyle
2895707Valve constructionJuly 1959Bailey
2143204Float-operated valve mechanismJanuary 1939McCormack
Primary Examiner:
Nelson, Cary M.
Assistant Examiner:
Matthews, David R.
Claims:
What is claimed is

1. Water control mechanism for a tank comprising a substantially vertical water inlet pipe mounted within said tank, a substantially vertical movable float structure comprising a buoyant main body portion and an open ended top portion, the latter portion having a bleed hole therein, said float structure being mounted concentrically about said inlet pipe and being vertically movable to be substantially level with the water within said tank, a pilot valve having a piston which is substantially vertically movable and is coupled by a lever which is extended downwardly to the float structure, said mechanism also having a flexible diaphragm and a stationary retainer for peripherally holding said diaphragm, said diaphragm being relatively thin and substantially uniform in thickness and positioned on one side of said piston and fluidically coupled to the piston through a cavity in said retainer located on one side of the diaphragm and freely responsive to the movement of the piston to control the flow of water through said cavity, the diaphragm responding to the movement of the piston in one direction to reduce the water pressure on one side of said diaphragm and allow the diaphragm to be deflected in one direction to open said valve so that water may freely flow through said cavity into the open-ended float structure, the diaphragm also responding to the movement of the piston in the opposite direction to cause the diaphragm to be deflected in the opposite direction to close the valve by closing said cavity so that the flow of water through said cavity into said open-ended float structure may be reduced and then stopped, the diaphragm having a central aperture, and means fixedly mounted within said movable diaphragm aperture for cleaning said aperture during each deflection of said diaphragm, the discharge of water through the bleed hole as the float structure rises substantially increasing the buoyancy of the float structure.

2. Water control mechanism according to claim 1 in which the cleaning means comprises a stationary pin made of steel and exteriorly grooved and continually positioned immovably within the movable diaphragm aperture for removing foreign material as the diaphragm is deflected along the external surface of said pin.

3. Water control mechanism according to claim 2 in which the valve is normally seated upon the vertical inlet pipe above the normal water level within the tank, the flow of water through the inlet pipe being controlled by the deflection of the diaphragm of the valve.

4. Water control mechanism according to claim 1 in which the float structure comprises two cylindrical cup-shaped members which are vertically arranged and vertically movable as a unit so that the upper cup member is open at the top and the lower cup member is open at the bottom and the upper cup member receives water discharged through the valve and has the bleed hole adjacent the bottom thereof to relay the received water to the tank.

5. Water control mechanism for a tank comprising a substantially vertical pipe positioned within the tank so that water may be supplied under pressure to the tank, a valve mechanism normally seated on the upper end of the vertical pipe and above the water level within the tank and having a thin, freely flexible diaphragm having an aperture, said diaphragm being of substantially uniform thickness so as to be flexible for the rapid control of the flow of water through the vertical pipe, a stationary retainer for peripherally holding said diaphragm while permitting the center of said diaphragm to be deflected, said valve mechanism incorporating a pilot valve positioned on one side of said diaphragm above the water level within the tank, said retainer having an opening therein for fluidically coupling the pilot valve to said diaphragm for controlling the movement of the diaphragm, a float structure having an open top cup with a bleed hole and an inverted bottom cup, both cups being concentrically arranged about the vertical pipe but below said valve mechanism and movable in response to changes in the level of the water within the tank, the diaphragm having a substantially central aperture, a substantially vertical pin fixedly mounted within a sleeve of said retainer so that the pin will be stationary and within said diaphragm aperture and remaining stationary as the diaphragm deflects in either direction about said pin, and means responsive to the movement of the float structure in one direction for operating the pilot valve for changing the pressure on the diaphragm and deflecting the diaphragm of the valve mechanism so as to allow water to enter the float structure, the pilot valve being opened and the diaphragm being elevated when the level of the water in the tank has dropped only a small distance to permit the flow of water through the vertical pipe into the tank, the pilot valve being closed and the diaphragm being deflected in the opposite direction to reduce the flow of water into the float structure and then stop the flow of water through the vertical pipe when the level of the water in the tank has reached a predetermined upper level, the discharge of water through the bleed hole of the open top cup increasing the buoyancy of the float structure as it rises so as to improve the closing action of the pilot valve.

6. Water control mechanism according to claim 5, in which the vertically arranged continuously stationary pin positioned within the aperture of the diaphragm is grooved, so that as the diaphragm moves in either direction, foreign matter deposited or to be deposited within said aperture will be displaced from said aperture.

7. Water control mechanism according to claim 5 in which the pilot valve includes a substantially vertically moving plunger which is coupled by a lever extending downwardly to the float structure.

8. Water control mechanism according to claim 5 in which the pilot valve has a piston positioned adjacent the opening in the retainer and movable to control the pressure applied to the diaphragm to thereby control its deflection.

9. A water control valve for a tank, including within said tank a substantially vertically arranged water inlet supply pipe, a valve normally seated adjacent the upper end of said inlet pipe and continuously positioned above the water level within said tank, an open-top float structure concentrically arranged about the inlet pipe for receiving some of the water discharged from said valve and for responding to the level of the water within the tank, said valve having a stationary retainer for a peripherally retained thin, easily flexible diaphragm of substantially uniform thickness and having a concentric aperture and including means to seal the upper end of the inlet pipe, a pilot piston mechanism to control the operation of the diaphragm, said retainer having an opening therein aligned with the pilot mechanism to control pressure on the diaphragm, means responsive to the downward movement of the float structure to operate the pilot mechanism and in turn relieve the pressure on the diaphragm so as to elevate the diaphragm and allow water to flow through the inlet pipe and through the valve into the open-top float structure and into the flush tank, and responsive to the movement of the float structure to a predetermined upper level to close the pilot mechanism and return the diaphragm to its normal position to cause the diaphragm to be re-seated adjacent to and atop of the inlet pipe, a pin fixedly held by said retainer and mounted so as to be spaced within the aperture of the diaphragm for preventing the clogging of the aperture as water flows therethrough with each movement of the diaphragm about said pin, and means to improve the buoyancy of the float structure, said means including a bleed hole in said float structure to release water therefrom as the float structure rises in said tank.

10. A water control valve according to claim 9, in which the float structure includes two cup-shaped members which are substantially vertically arranged, the upper cup-shaped member being open at the top for receiving water discharged from the valve and having a bleed hole for discharging the received water, the lower cup-shaped member being open at the bottom and substantially responsive to the level of the water within the flush tank to raise the float structure and cause the operation of the valve.

11. A water control valve according to claim 9, in which the pilot mechanism includes a piston which is positioned adjacent the opening in the retainer and is coupled by a lever extending downwardly to the float structure and moves substantially vertically.

12. A water control valve according to claim 11, in which the piston of the pilot mechanism is fluidically spaced from and coupled to the diaphragm.

13. Fluid control mechanism for a tank, comprising a substantially vertically moving float mechanism composed of two cup-like members one of which is open at the top with a bleed hole therein adjacent its bottom and the other is open at the bottom, a valve mechanism having an apertured retainer supporting a stationary vertical externally grooved pin and a substantially vertically moving piston-like element and a substantially uniformly thin flexible diaphragm peripherally held by said retainer and spaced from the fluidically coupled to said element by and through said aperture in said retainer which separates said element from said diaphragm, means for mechanically coupling said float mechanism to said element of said valve mechanism so that said float mechanism and said element move only in opposite directions, said diaphragm having a central opening within which said pin is spacedly positioned and remains stationary as the diaphragm moves in either direction about said pin, said aperture in said retainer and said opening in said diaphragm being spaced from each other by a substantially unobstructed path, and means responsive to the lowering of the float mechanism to operate the valve mechanism to permit fluid to enter the cup-like member which is open at the top and the tank through said unobstructed path and responsive to the return of said float mechanism to its original position to release the valve mechanism to interrupt the flow of fluid into the latter cup-like member and into the tank through said unobstructed path, the bleed hole exiting water into said tank to increase the buoyancy of the float mechanism as it is returned to its original position.

Description:
This invention relates to water control valves which are used in and in conjunction with a flush tank associated with a conventional toilet bowl for controlling the flow of water into the flush tank after the toilet bowl has been flushed.

Various arrangements have heretofore been proposed for controlling the flow of water into the flush tank associated with a toilet bowl. One of the most common types of control mechanisms includes a vertical water inlet pipe, which may be connected to the water supply system for receiving water whenever required to refill the tank, along with an inlet water valve and a conventional float coupled to the inlet valve by the usual long substantially horizontal rod. In such mechanisms, the float is usually ball-shaped and floats on the water surface within the tank. When the tank is in its substantially filled position, the inlet water valve will be closed to block the inflow of water through the inlet pipe and into the tank. After a flushing operation during which the water level has dropped almost to the bottom of the tank, the float, in its receded position near the bottom of the tank, will cause the inlet valve to be opened so that the tank may be refilled. After the water within the tank has reached its assigned upper level, the float mechanism will cause the inlet valve to become closed, thereby blocking any further inflow of water into the tank.

The ball float type of structure above referred to has several significant limitations. It requires considerable space for the operation of the lever mechanism interconnecting and coupling the ball float to the inlet valve. It is also slow in operation and, moreover, it is noisy, ofttimes producing a hissing sound which can be disturbing to those in the vicinity.

Other types of water control valves have also been proposed heretofore. One of these other types embodies a pair of flexible diaphragms which are intended to respond to the level of the water within the tank or to the water pressure in the vicinity of the diaphragms. When deflected, these diaphragms operate an input valve for conrolling the inflow of water to the water tank. Such structures are rather complex and therefore difficult to manufacture. They are expensive and subject to operating failures which introduce maintenance problems.

In accordance with this invention, a new form of water control valve is provided which includes a vertically arranged water inlet pipe or shank extension connected, for example, to the city water supply system, a main valve structure mounted fixedly at or near the top of the shank extension and a relatively small float structure which moves vertically and is closely spaced from but moves along the shank extension or sheath tube, if employed. The float structure includes two cup-shaped elements, one surmounted vertically above the other, the upper cup-shaped member being open at the top while the lower cup-shaped member is open at the bottom. The double-cupped float structure is mechanically coupled to the main valve mechanisms by means of a vertical rod which responds to and continually follows the vertical movement of the float structure. A lever is employed to couple the vertical rod to a pilot valve element in the main valve structure and in turn it controls the pilot valve. The pilot valve includes a piston-like element which moves vertically to initiate the inflow of water through the shank extension and into the main valve, together with a single flexible diaphragm which is normally seated on the inlet seat located generally at the upper end of the shank extension and is controlled by the pilot valve. When the water within the tank falls below its normal upper level immediately following a flushing operation, the lever-controlled pilot element will be raised and, in turn, actuate the diaphragm so as to elevate the diaphragm above the inlet seat. This will allow water to flow freely through the main valve and into the tank. When the water level is risen sufficiently within the tank, the lever-controlled pilot element will be returned to its former or lowered position, thereby causing the flexible diaphragm to be repositioned on the inlet seat to shut off the flow of water into the tank. The operational structures and features will be outlined hereinafter.

This invention, together with its objects and features, will be better and more clearly understood from the following description and explanation, when read in connection with the accompanying drawing in which:

FIG. 1 illustrates a side elevational view, partly in section, of the principal mechanism of this invention;

FIG. 2 shows a top plan view of the arrangement of FIG. 1;

FIG. 3 shows a partial cross-sectional view taken along the lines 3--3 of FIG. 2, this figure showing the main valve mechanism in its closed position;

FIG. 4 is a view similar to that of FIG. 3, in which the main valve mechanism is shown in its open position;

FIG. 5 shows a cross-sectional view of the float structure per se;

FIGS. 6A and 6B show two views of the diaphragm retainer, which is one of the components of this invention, FIG. 6A showing a view from the underside of the retainer while FIG. 6B shows a side view of the retainer;

FIG. 7A shows a cross-sectional view of a portion of the diaphragm of the main valve mechanism of this invention, and FIG. 7B shows a plan view of the same diaphragm;

FIGS. 8A and 8B show two views of the diaphragm valve seat-body, FIG. 8A showing a cross-sectional view of the valve seat-body and FIG. 8B a plan view of the valve seat-body; and

FIG. 9 shows a cross-sectional view of a portion of the lower cap structure .

Referring to FIG. 1 of the drawing, there is shown part of a flush tank 2 which is normally mounted somewhat above pg,5 the toilet bowl (not shown) with which the flush tank 2 is to be associated. The float structure 5 includes two cup-shaped chambers 4 and 6 which are separated by a horizontal wall or barrier 8. The float structure 5, therefore, is vertically movable as a unitary structure about the vertical sheath tube 10 which is vertically supported on a cylindrical shoulder 12 of a sheath tube shank 14. A shank extension 15 is mounted concentrically within the sheath tube 10 and its lower end is threadedly connected to an opening in the shank 16. The sheath tube shank 14 is mounted on a circular peripheral washer 20 which is mounted on the inner bottom wall of tank 2. The lower end of the shank 16 extends through the bottom opening of tank 2 as shown and is held in place by a nut 13 which may have conventional bleed holes 13'. The function of the bleed hole 13' will be subsequently explained. The sheath tube shank 14 is threadedly connected to a flanged portion of shank 16 as shown.

The main valve mechanism 26 is fixedly mounted at or upon the upper end of shank extension 15. The main valve mechanism 26 includes two cap members, an upper cap 28 and a lower cap 30. A flexible diaphragm 32, as is more clearly shown in FIGS. 3 and 4, is peripherally held between the two cap members 28 and 30 and the diaphragm is so held by screws 34. Because the diaphragm 32 is held peripherally by the two cap members 28 and 30, the central part of the diaphragm 32 is therefore free to move upwardly or downwardly against a valve seat structure 31, as will be explained. The diaphragm 32 has a central opening 35 positioned about a pin 40 which is vertically disposed therein, as shown. A diaphragm retainer 42 has a central aperture 44 for receiving and permanently holding the upper end of the pin 40. The retainer 42 is maintained in a stationery position and hence the pin 40 is vertically positioned within the aperture of diaphragm 32 and is immovable. Thus, the diaphragm 32 can be moved alternately and repeatedly up and down in a vertical position about the stationary pin 40 throughout the repeated operations of the main valve 26.

As shown in FIGS. 1, 3 and 4, the chambers 4 and 6 of the float structure 5 are mechanically coupled to a vertical rod 50 so that, as the float structure moves upwardly or downwardly, the rod will likewise move upwardly or downwardly over the same vertical distance. The float rod 50 is shown mechanically coupled to a substantially horizontal lever 54 which is pivoted at 58 to a plunger element 60 which is retained and controlled by the lever 54. The plunger 60 is part of a pilot valve which is within the main valve 26 and is intended to move in a substantially vertical direction in response to the angular displacement of lever 54 about its pivot 58.

A hush tube designated 64 is provided, as shown in FIGS. 1 to 4, to release water via the main valve 26 into the flush tank 2. A convention refill tube designated 80 is provided to feed some of the water into the toilet bowl near the end of each flushing operation, as is well known. This fluid is employed as a seal in the toilet bowl.

We shall now consider the general operation and the features of the mechanism of the invention.

Upon the operation of the conventional external handle or lever (not shown) on the outside of the flush tank 2 to flush the toilet bowl, the water previously accumulated within the flush tank 2 will be released into the toilet bowl through a flush valve (not shown) which is positioned in the bottom of the tank 2. The float structure 5, continually occupying a position dependent upon, and responding to, the level of the water within the flush tank 2, will move downwardly to the limit of its fixed travel. This downward movement of the float structure 5 will cause a corresponding downward movement of the float rod 50, which is coupled to the float structure 5 as shown. Hence the lever 54 will be moved about its pivot 58 in a clockwise direction (when viewed in FIG. 1). This causes the plunger 60, which is mechanically coupled to the lever 54, to be raised so as to open the pilot hole or aperture 56. It will be noted in FIGS. 3 and 4 that a small drop in the water line W will cause full opening of the pilot hole 56, the advantage of which will be hereinafter described. This allows water within the cavity 62 above the diaphragm to travel through the pilot hole 56 provided in the diaphragm retainer 42 through passage 68 formed in the cap 28, and into the upper chamber 4 of the float structure 5. This discharge of water in cavity 62 to atmosphere reduces the pressure on the upper side of diaphragm 32, thereby allowing the incoming water from shank extension 15 to lift diaphragm 32 above the valve seats 33, 33'. Water will now flow through the shank extension 15 and over the main valve seats 33, 33', then along the underside of diaphragm 32, then through the discharge ports 72 and passageways 74 and through hush tube 64 into the flush tank 2. This is the main water supply to flush tank 2 for the refill operation.

Some of the water reaching the upper chamber 4 will be discharged through a bleed hole 70 at or near the bottom of the upper container 4 but the flow of water through the bleed hole 70 will be at a restricted rate due to the relatively small size of the bleed hole 70. Any recess or overflow of water above the volume retainable by the upper container 4 will always be released into the flush water tank 2 for filling the tank.

As pointed out hereinabove, a small drop in the water line W and a corresponding drop of float 5 will cause the full opening of the pilot hole 56. This has the advantage in that the pressure in chamber 62 is immediately reduced, causing virtually instantaneous full flow of refill water through the valve 26 to tank 2. This refill water, added to that already in the tank 2, generally causes a more complete and improved flushing action of the toilet bowl. Conventional ball-type valves do not allow full flow until the ball has dropped to its lowest level.

When the water within flush tank 2 rises to a sufficient level, the resulting elevated position of the float rod 50 will move the lever 54 about its pivot 58 in a counter clockwise direction, thereby moving the plunger 60 of the pilot valve downwardly to partially close the pilot hole 56. As soon as the flow of water through the pilot hole 56 becomes less than the flow of water through the generally annular opening formed between pin 40 and the central opening 35 of diaphragm 32, the diaphragm 32 will move downwardly to cover discharge ports 72 and also seats 33 and 33' and stop the flow of water through hush tube 64 and to refill tube 80. As water is released through the bleed hole 70, the weight of the float structure will be correspondingly reduced, thereby adding buoyancy to the float structure 5. After an interval determined by the inlet water pressure and the relative proportions of the different associated parts, the float rod 50 will be moved upward sufficiently so as to firmly close the plunger 60 against its seat 110 and thereby completely shut off the water flow through the pilot hole 56.

It is noted, therefore, that upon the upward flexure of the diaphragm 32, a sufficient volume of water will be received from the shank extension 15 and promptly released through the discharge ports 72, then through the passageway 74 and then through the hush tube 64 into the flush tank 2 as already explained. At the same time, some of the water entering from the shank extension 15 will be discharged through the refill tube 80 to provide a seal for the toilet bowl in the conventional manner.

The diaphragm 32 will close the cylindrically arranged discharge ports 72 before the central section of the diaphragm 32 is brought to rest on the pitched circular seats 33 and 33' at the upper side of the valve seat body 31 and at the upwardly extending center portion of lower cap 30. The general contour of circular seat 33 of the valve seat body 31 is seen in FIG. 8A. The general contour of circular seat 33' is seen in FIG. 9. As seen in FIG. 4, the flexible diaphragm 32 will be deflected to the greatest extent at its central region adjacent to the pin 40. The diaphragm 32 will come to rest against the valve seats 33 and 33' and shut off the water supply. The closure of the peripherally arranged discharge ports 72 before diaphragm 32 is brought to rest against the valve seats 33 and 33' may cause oscillatory driving forces to act upon the diaphragm 32 to render it into vibratory motion thereby producing what is generally known as "water hammer". To reduce or eliminate the tendency toward the production of "water hammer", the radial passages 120 (see FIG. 8b) are especially provided in the valve seat body 31. These passages, which will preferably correspond in size and number to the discharge ports 72, effect a smoother closure of the diaphragm 32 against the main valve inlet seats 33 and 33'. It is a feature of this invention to secure the properly timed and smooth closure of the inlet seats 33 and 33' after the discharge ports 72 have been closed by diaphragm 32.

The plunger 60 of the pilot valve has a groove 90 so that it may receive and retain the fingers of the lever 54. A limited amount of lateral movement is provided by the spaces between the plunger 60 and the lever 54. Thus, the lever 54 may be rotated about its axis 58 in response to the vertical movement of float 5 as the water level rises and falls within the tank 2. This will cause the plunger 60 to be pushed down or pulled up substantially along a vertical path. In other words, the construction of the plunger 60 and lever 54 is arranged to enable the plunger 60 to be moved substantially vertically in response to the angular motion of lever 54 about its pivot 58. This facilitates a more precise opening and closing of the vertical pilot hole 56 by the plunger 60 of the pilot valve structure with a minimum of leakage.

The plunger 60 has a segment 92, preferably a flexible or rubber segment, affixed to its lower end so that the flexible or rubber segment will be firmly seated against the elevated seat 110 at the upper end of pilot hole 56 when the valve 26 is to be closed and leakage prevented. The rubber attachment 92 should be shaped so as to seal the upper cap 28 and thereby prevent any fluid within the main valve chambers from being released through the spaces provided around plunger 60. Thus, any spray or unintended discharge of water from the valve mechanism 26 is eliminated.

As already suggested, the upper cap 28 provides the main passageway through which water flowing through the pilot hole 56 may be discharged into the upper chamber 4 of the float structure 5. Water flowing upwardly through the pilot hole 56 and through the passage 68 formed in the upper cap 28 will be received in the upper chamber 4 of the float structure 5 only during the time when the flush tank 2 is to be refilled.

The diaphragm retainer 42 is positioned within the upper cap 28 which is so shaped internally as to provide a large contact area with the upper surface of the diaphragm retainer 42 to establish a good physical support for the diaphragm 32 in its upper position. In the absence of adequate support, the diaphragm retainer 42 might be flexed beyond its limit and possibly cracked due to the stresses applied.

The diaphragm retainer 42, as already noted, fixedly supports the central pin 40 in a continuously stationary position and remains inserted within the aperture 35 of the diaphragm 32 as it is flexed upwardly. Radial grooves 140 formed in the underside of diaphragm retainer 42 prevent the cohesion of the diaphragm 32 to the underside of the diaphragm retainer when the main valve is in its open position. Such cohesion would cause the malfunction of the main valve structure. The adherence of the diaphragm 32 to retainer 42 can cause an oversupply of water to the flush tank 2 and possibly also a flooding of the bathroom. Another function of radial grooves 140 is to provide adequate distribution of water above diaphragm 32 to assure sufficient driving force on the upper surface of the diaphragm when pilot hole 56 is closed.

As will be more clearly seen in FIGS. 3 and 4, the upper surface of the diaphragm retainer 42 is provided with a pitched seat 110 for receiving the resilient attachment 92 of the plunger 60, the edges of the seat being fairly sharp. The downward movement of the plunger 60 is physically limited by the projecting region of seat 110. The relatively sharp-edged configuration of pilot seat 110 allows for the smallest practical pilot hole area possible to assure the minimal pressure required to positively close off the pilot hole area.

The pin 40 may be any linear pin which can be conveniently press-fitted into the diaphragm retainer 42 and yet it should be of a size to be enterable into the aperture of the diaphragm 32 and interpose little or no friction as it moves up or down. The pin 40 may preferably be a grooved stainless steel pin, for example, a pin which is commercially known as "Driv-Lok". Although slots or grooves on pin 40 are not indispensible to the practice of the invention, they are preferable especially because they aid in establishing positive cleaning or wiping action to remove particles of dirt or other material from being deposited on the central opening 35 of the diaphragm 32 as it is flexed during each operation of the main valve. The grooves provide a scraping action and also maintain constant the size of the central aperture of the diaphragm 32 for the free movement of water upwardly through the spaces between the outer regions of the pin and the walls of the aperture into the upper chamber 62 of the valve.

The plunger 60 to which the flexible or elastic attachment 92 is affixed is so arranged that, at the moment when the main valve is to be closed, there will be relatively light closing pressure applied by plunger 60 against the seat 110. Thus, as the flow of water through the pilot hole 56 is sufficiently reduced, the diaphragm 32 will begin moving in a downward direction to close discharge ports 72 and the main valve seats 33 and 33'. Under conditions of excessively high inlet pressure or when certain relationships exist between the effective areas of the pilot hole 56 and aperture 35 of diaphragm 32, some of the water will leak through the pilot hole 56 until the float structure 5 is buoyed up sufficiently to supply the additional force downwardly directed to more firmly close the plunger 60 against the seat 110. In order to keep the pilot hole closing time as short as possible, the float structure 5 has been arranged and proportioned so that all of the water in the upper chamber 4 of the float structure will drain through the bleed hole 70 into the flush tank 2. Thus, the loss of water from chamber 4 will add buoyancy to the float structure to raise the float structure sufficiently so as to fully shut off the pilot hole 56 and any further inflow of water. The quantity of water lost from chamber 4 will not appreciably raise the water line W after the main valve mechanism 26 has been closed off.

The pilot hole 56 is the first passage to be opened when the flush tank 2 is to be refilled and it is likewise the first passage to be closed when the refilling operation is to cease. The diaphragm 32 is raised as the pilot hole is opened to allow water to enter the tank 2 rapidly and it is likewise closed as the pilot hole 56 is closed to stop the water flow.

FIGS. 3 and 4 show the flexible backflow washer 98. When the main valve mechanism is in the shut-off state as shown in FIG. 3, the backflow washer 98 assumes a generally horizontal relaxed position just below the bottom surface of the valve seat body 31. When the main valve mechanism is in the "on" or open position, as shown in FIG. 4, the water being discharged through discharge ports 72 forces the backflow washer 98 downward against the sloping surface of lower cap 30 to allow the water to pass on to the hush tube 64 and to the refill tube 80.

If a sub-atmospheric pressure should develop in the shank extension 15 due, for example, to the connection of a pump to the city supply system on account of a fire or other contingency, the backflow washer 98 will be sucked upwardly against the underside of the discharge ports 72 to block the return flow of water from tank 2 to shank extension 15. Were it possible to return any of the tank water to the city supply system, contamination of the water supply might occur and possibly become a dangerous health factor. Thus, while water is traveling upwardly through the shank extension 15 through the valve mechanism 26 and then through the hush tube 64 into the tank 2, it will nevertheless be impossible for water to be returned from tank 2 to the shank extension 15 to contaminate the city water supply when suction is developed in shank extension 15 due to the interposition of the backflow washer 98.

Air holes or openings 130 are provided in the sloping surface of the lower cap 30 as shown in FIGS. 3 and 4. When the main valve mechanism 26 is in the open or "on" position, as shown in FIG. 4, the backflow washer 98 is forced downward as previously described. Thus, the air holes 130 may be sealed off by the backflow washer 98 whenever required, thereby preventing the discharge of water through the openings 130.

If foreign particles prevent the closure of the discharge ports 72 by the backflow washer 98 at a time when sub-atmospheric pressure conditions exist in the shank extension 15, actual backflow of water from tank 2 will be prevented because air would be pulled into the air holes 130 from the surrounding atmosphere. The total area of the air holes 130 is sufficient to supply enough air to the cavity below the backflow washer 98 to prevent the siphoning of water from tank 2 through the hush tube 64 or the refill tube 80.

All of the ports of the valve mechanism 26 of this invention, although shown as relatively small, have been made sufficiently large so as to enable free and easy passage of the kinds of foreign matter normally expected to be found in the usual water supply. Moreover, the central aperture 35 of the diaphragm 32 is maintained, by means of pin 40, in a relatively clean condition at all times so as to avoid or remove any scale deposits in or near the diaphragm opening 35. Such scale deposits on pin 40 or on the walls of aperture 35 would reduce the efficiency of the valve mechanism 26 and ultimately clog the central opening 35. This would reduce the efficiency of the main valve 26 and perhaps render it inoperative. The continuously maintained cleanliness of the central aperture 35 is an important feature in the operativeness and the minimal maintenance requirements of this structure.

While a hush tube 64 is shown as a conventional pipe or conduit for simplicity of explanation and illustration, it may be any form of chamber, whether a swirl chamber or not, for supplying water to a water tank or reserve cistern or a toilet bowl. The hush tube 64 may, if desired, be filled with a foam material so as to improve the quietness of the water flow therethrough into main tank 2. The mechanism of this invention will operate at a relatively low noise factor.

It will be apparent that water fed from the city water supply upwardly through the shank extension 15 will be supplied both through the hush tube 64 to fill the tank 2 and through the refill tube 80 to the toilet bowl to provide the desired water seal in the toilet bowl. When the water within the tank 2 is at its normal or assigned upper level ready to be discharged to the toilet bowl by the conventional lever (not shown) wherever this is required, the diaphragm 32 will be, and will remain, in its lower position to block the influx of water through the main valve seats 33 and 33' and, at the same time, the plunger 60 and its flexible or elastic attachment 92 will be seated on and held against the pilot valve seat 110. No water will be traveling through either the hush tube 64 or the refill tube 80. In other words, no water will be traveling through the valve equipment 26.

However, after the control valve or hand lever on the outside of the tank 2 (not shown) is manipulated by the user to discharge the water accumulated in tank 2 into the toilet bowl, the float mechanism 5 will cause the pilot plunger 60 to open the pilot hole 56 which in turn relieves the pressure above diaphragm 32 so that water may enter the tank 2. Water can enter the tank 2 in volume only after the diaphragm 32 has been raised above the main valve seat 33 and 33. When this occurs, the upwardly flowing water will be directed over the valve seat 31 into the discharge ports 72 leading to the hush tube 64 and to the refill tube 80. Some water will also travel upward through the central aperture 35 of the diaphragm 32 into the chamber 62 below the retainer 42 through the pilot hole 56. While the float structure 5 remains below its uppermost position, the flow through the pilot hole 56 will be released through passage 68 formed in the upper cap 28 into the upper chamber 4 of the float structure 5. Water will continue to flow through the hush tube 64 and the refill tube 80 until the float structure 5 has risen substantially to its uppermost position. When the uppermost position is reached, both the pilot seat 110 and the main valve seats 33 and 33' will be sealed again, the diaphragm 32 will also be back to its normal or lower position and the plunger 60 will be back to its lower position.

There is a controllable, very small, timed relation, i.e., a predetermined small time interval, between the initial downward movement of the float mechanism 5 and the corresponding upward movement of plunger 60. The plunger 60 will be displaced from its seat 110 whenever the float mechanism 5 is spaced even by a small distance from its normal upper position. The flow of water into the flush tank 2 will be maximized almost from the initial displacement of plunger 60. But when the float mechanism 5 is returned substantially to its normal upper position, the plunger 60 will be returned promptly to its pilot valve seat 110, thereby locking the main valve 26. This correspondingly introduces a substantially sudden closure of the main valve mechanism 26.

Both the float structure 5 and the plunger 60 are assigned to, and travel over, substantially parallel paths. The mechanism which interconnects these two structures is arranged to maintain substantially linear vertical travel at all times.

In the vent that the shank extension 15 becomes fractured or broken even to a limited or small extent, the water within the shank extension 15 will then flow into the very narrow space between the shank extension 15 and the sheath tube 10. The water will then be drained through the space between the shank 16 and the sheath tube shank 14. The water will then travel through the opening in the bottom of the tank 2 at the periphery of the shank 16 and be discharged through the bleed holes 13' of the nut 13. The water will leak to the floor.

If back flow conditions exist in the water distribution system at the time a hole or crack is present in the wall of the shank extension 15, water cannot be sucked from tank 2 because of the barrier afforded by sheath tube 10. Thus, contamination of the city water system will not be possible.

Backflow prevention is shown and described herein because it is required in many localities. However, this feature may be omitted, if desired.

While the invention and its features have been shown and described in certain particular arrangements for illustration and explanation, it will be clearly understood that the general features and objectives of this invention may be organized in many different arrangements without departing from the spirit of the invention.