AU728128B2 - Float valve - Google Patents

Description

j jW P100/0o11 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "FLOAT VALVE" The following statement is a full description of this invention, including the best method of performing it known to me:-

TITLE

"FLOAT VALVE" FIELD OF THE INVENTION THIS INVENTION relates to an improved float valve for use in controlling flow of liquid in or out of a storage tank which may include a toilet cistern, water trough, reservoir such as a barrel or cask, drinking fountains and the like.

SUMMARY OF THE INVENTION Conventional float valves include a valve body, an inlet, an outlet and a valve member which usually comprises a cylindrical piston having a circular plate like seal made of rubber or other resilient material on an inner end thereof. The end seal is in contact with water or exposed to water present in the valve body in use. The piston also includes on an outer end thereofa clevis which is provided with a pivot pin to which is 0. 015 attached a mating lug of a rocker member. The rocker member is also provided with a transverse pivot housing in which is inserted a 000. corresponding pivot pin which is passed through aligned openings in o o *opposed projections of a proximal end of the valve body.

There also may be provided a float arm which is attached to 20 the rocker member at an end thereof remote from the valve body. The float arm may also carry at an outer end thereof a hollow ball float which may rise and fall within the storage tank depending upon the level of liquid within the tank. When the float arm reaches its minimum level within the 3 storage tank, the float valve will open whereby liquid may pass from inlet to outlet to fill the storage tank. When the float arm reaches its maximum level within the storage tank, i.e. when the tank is substantially filled with water, the float valve will close thereby preventing ingress of liquid into the storage tank.

During operation of the conventional float valve as described above, considerable mechanical effort was required to close the float valve because it is often necessary to overcome large upstream pressure which often corresponded to mains pressure in or upstream of the inlet water pipe which communicates with the inlet of the float valve. In some cases, the pressure that had to be overcome was greater than 100 Ib pressure. This meant that the float arm was relatively long and the float was relatively large and, in the case of horse troughs, for example, the S"valve body and rocker member had to be extremely sturdy in structure. It 15 was also common in conventional float valves to have an outlet aperture which was relatively restricted in size often less than Y2 inch in diameter.

The requirement for a large float as well as a relatively long float arm also S meant that conventional float valves were relatively expensive and of complicated or cumbersome structure. Another problem of conventional 20 float valves was they were also subject to pressure variations that occurred upstream of the float valve such as water hammer which adversely affected satisfactory operation of the conventional float valve.

SUMMARY OF THE INVENTION 4 It is therefore an object of the invention to provide a float valve which may at least partially overcome the problems of conventional float valves referred to above.

The float valve of the invention includes a valve body, a valve chamber, a valve member, an inlet and an outlet. The valve chamber, however, is characterised by having a balance space which is in fluid communication with both the inlet and outlet. The valve member not only selectively controls flow of liquid through the outlet into the storage tank but is also provided with a balance seal which is connected to the valve member and which reduces pressure variations on the valve member. This means that the operating pressure on the valve member may be substantially reduced being independent of upstream pressures Sb so that operation of the float valve can take place without it being b.

necessary to provide a larger mechanical effort or overcome large .15 pressures present in a liquid supply conduit upstream of the float valve.

The valve body is elongate and may be provided with an inlet intermediate its length. The inlet may comprise an inlet port or oS. 'aperture or more suitably is provided with an inlet conduit which is in fluid communication with the valve chamber. The inlet conduit may be attached to a supply conduit which may be connected to a water main or other water source such as a rainfall collection tank which often will include a pump which therefore will increase upstream pressures.

The valve body is suitably cylindrical or more preferably is T- I, 1 shaped with the upright of the T forming the inlet conduit and the head of the T forming a cylindrical portion having an interior which forms the valve chamber. One end portion of the cylindrical valve chamber may comprise the aforementioned balance space and the other end portion of the cylindrical valve chamber may comprise an outlet portion of the valve chamber. The outlet portion may also be provided with an outlet which may also comprise an outlet conduit or more preferably an outlet aperture or outlet port which communicates with the interior of a liquid storage tank in use.

The valve member may comprise a piston, preferably of cylindrical shape, which in one embodiment may be attached to a float o arm by the use of a rocker member as described above and as illustrated .o hereinafter. The valve member may also be provided with a plate seal formed by rubber or other elastomeric or resilient material which is attached to an inner end face of the piston. There also may be provided a balance seal which is located in the balance space and which may S. comprise a plate seal having a peripheral skirt or, in an alternative embodiment, may comprise an O ring, if desired. There also may be provided a connection rod which interconnects the piston with the balance seal so that upon movement of the piston, there is also provided corresponding movement of the balance seal.

In the above embodiment, the valve member in the form of piston and connection rod, may be located within the valve body. In another embodiment, the valve member may include a sealing member which contacts an adjacent outlet of the valve body in use in the closed position and is spaced from said adjacent end in the open position. The sealing member may be attached to a support frame or support member located externally of the valve body. In this embodiment, the valve body may have guide members attached thereto which undergo reciprocatable movement on the support member or support frame. Such reciprocatable movement may be initiated by the float arm being pivotally attached to one or more rocker arms wherein the rocker arm(s) are pivotally attached to the support frame and to inner ends of the float arm which, in this embodiment, may be U-shaped.

o In another embodiment of the invention, the float, such as a .:ball float, may be attached directly to the valve member thereby omitting the float arm, clevis and rocker member as described above to thereby provide a float valve of simplified construction in comparison to the embodiment described above. In this embodiment, the float is attached to outwardly extending portion of the valve member which projects through one end of the balance seal and this may comprise an outer end of the connection rod which extends through the balance seal. In this .o arrangement, the valve body may be oriented so that the outlet portion is oriented lowermost in the storage tank and the balance space is oriented in an uppermost position with the valve body submerged by liquid in the storage tank.

BRIEF DESCRIPTION OF THE DRAWINGS Reference may now be made to a preferred embodiment of the invention as shown in the accompanying drawings, wherein:- FIG. 1 is a sectional view of a conventional float valve; FIG. 2 is a sectional view of a first form of float valve constructed in accordance with the invention; FIG. 3 is a view similar to FIG. 2 showing the float valve in the closed position; FIG. 4 is a sectional view of the float valve of FIG. 2 in an open position; FIG. 5 is a sectional view of a second form of float valve constructed in accordance with the invention which is in the closed position; FIG. 6 is a similar view of the float valve of FIG. 5 in the open position; FIG. 7 is a perspective view of a third form of float valve constructed in accordance with the invention; FIG. 8 is a longitudinal sectional view of the float valve shown in FIG. 7 in the open position; and FIG. 9 is a similar view to FIG. 8 showing the float valve in the closed position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, the conventional float valve 10 comprises a valve body 11, inlet 12, outlet 13, valve chamber 14, inlet pipe 15, valve member in the form of a cylindrical piston 17 having a seal 18 attached to an inner face 19, outer face 20, clevis 21, rocker member 22, float arm 23 and hollow ball float 24. It will be noted that float arm 23 is of considerable length L 1 and is attached to rocker member 22 in rigid relationship such as a splined relationship or by overlapping ends in bearing relationship as at Clevis 21 is rigidly attached to outer face 20 of piston 17. Rocker member 22 is pivotally attached to clevis 21 by pivot pin 26 and is also provided with a pivot housing 27 enclosing pivot pin 28. There is also provided attachment aperture 30 for attachment of rocker arm 22 to float arm 23 by a suitable fastener (not shown).

In FIG. 2, similar reference numerals are utilised to describe similar parts as referred to above in FIG. 1. However, the float valve 31 of the invention is provided with a T-shaped valve body 32 having inlet conduit 33 which is attached in screw threaded relationship at 33A to inlet pipe 15 which is in fluid communication with a liquid supply source as described above. The valve body 32 has a valve chamber 33 which has a balance space 34 located in end portion 35 and outlet chamber 36 located in end portion 37. There is also provided outlet port 38 which may communicate with a liquid storage tank (not shown). In regard to valve body 32, such valve body may be of integral construction or alternatively, may comprise end portion 35 which is screw-threadedly attached to intermediate component 40 at 39 and end portion 37 is screw threadedly 9 attached to intermediate component 39 at 41.

The valve member 42 includes piston 17, connection rod 43 and balance seal 44 which is attached to connection rod 43 by opposed washers 45 and 46 and nuts 47 and 48 screw threadedly attached to connection rod 43.

The operation of float valve 31 is shown in FIGS. 3-4 whereby movement of float arm 49 in FIG. 2 moves piston 17 from the closed position shown in FIG. 3 to the open position shown in FIG. 4 and vice versa.

It will be appreciated, however, that because of the inclusion of balance seal 44 in balance space 34 that the pressure on either side of inlet conduit 33 is balanced and thus independent of pressure variations .i that occur upstream in inlet pipe 15. As a consequence, less mechanical effort is needed to operate valve 31 and hence float arm 49 only needs to have an effective length L 2 which is considerably less than the length L 1 of conventional float arm 23. This also means that float valve 31 is more efficient in operation and can be more compact than the conventional float valve In the embodiment shown in FIGS. 5-6, the float valve 31A is oriented vertically in the storage tank (not shown) wherein outlet end 37 is oriented lowermost and end portion 35 is oriented uppermost and inlet conduit 33 as well as attached inlet pipe 15 is oriented horizontally as shown. In this embodiment, float arm 23, rocker member 22 and clevis 21 2 and associated structure are now discarded and ball float 24 is attached directly to an adjacent end 49 of connection rod 43 as shown whereby end 49 may be screw threadedly engaged with internal lug 51 of float valve 24. Alternatively, end 49 may be welded to internal lug 51. Valve 31A, in this embodiment, is shown submerged by water 24A located in the storage tank.

FIG. 5 shows the closed position and FIG. 6 shows the open position where movement of float 24 caused by the level of water 24A in the storage tank results in the opening of the float valve 31A caused by corresponding movement of piston 17 to thereby open outlet port 38 to allow filling of the storage tank.

The embodiment of FIGS. 5-6 is simplified structurally compared to the embodiment of FIGS. 3-4 and is more effective in e operation because linear movement of connection rod 49 causes corresponding linear movement of float 24 without the need for any intermediate structure such as float arm 23, rocker member 22 and clevis 21.

In the embodiment shown in FIGS. 7-9, there is shown a third float valve 31B connected in accordance with the invention. Valve 31B includes valve body 60, valve chamber 60A, inlet arm 61 having a screw-threaded part 61A and inlet aperture 61B, outlet arm 62 having an outlet aperture 62A, support frame 64 for valve body 60 comprising parallel vertical posts 65, bottom cross member 66 rigidly attached to posts 65 at 67 and top cross

II

11 member 68 rigidly attached to posts 65 as shown. In this regard, each post 65 has a screw-threaded end (not shown) which engages with a mating nut 69 so as to attach each post 65 to top cross member 68.

There is also provided bolt 70 to which is attached a sealing assembly 71.

There is also provided tubular guide members 73 welded or otherwise rigidly attached to valve body 60 through which an adjacent post 65 may project in slidable relationship as best shown in FIG. 7.

There is also shown a U-shaped float arm 74 which has extensions 75 extending normally thereto which project through apertures 76 in opposed rocker arms 77 and which have washers 72 associated therewith. Each rocker arm 77 is pivotally attached to ends 78 of bottom cross member 66 as well as to extensions 75. To facilitate such pivotal attachment, each rocker arm 77, therefore, has enlarged ends 81 in the ~form of loops which each have the aforementioned pivot aperture 76 to retain an associated extension 75 and associated end 78 as illustrated.

S-The float arm 74 is also provided with offset ends 83 having pivot projections 84 which engage in mating sockets 85 which are integral with or rigidly attached to valve body 60. Float arm 74 has attached to its outer end 86 a float member 87 which may be of cuboidal shape in the form of a rectangular prism as indicated.

The valve body 60 is also provided with a top arm 88 which retains a sealing assembly 71 which is movable in a balance space 71A in top arm 88. Sealing assembly 71 has seal 90 interposed between 12 support plate or washer 91 which is rigidly attached to seal 90 and top washer 92. Seal 90 is also provided with a tapered side wall 90A to facilitate engagement with inner surface 89 of top arm 88. It is preferred that the seal 90 and washer 92 are loosely attached to bolt 70A so that they may be spaced from each other or that they can undergo independent movement from each other as indicated by spacing or gap 93. Bolt 70A also has nut 70B attached thereto. It is also preferred that sealing assembly 94 is also loosely mounted to bolt 99 and, in this respect, there may be provided washers 95 and 96 which may be spaced from each other or undergo independent movement of each other to provide a space or gap 98. Seal 97 may be attached to top washer 95 in this regard.

The loose mounting of sealing assemblies 71 and 94 as ~described above is advantageous in that such sealing assemblies are "floating" and thus are self-aligning in use in the event of any misalignment that may occur in operation of float valve 31A.

In operation of the float valve shown in FIGS. 7-9, movement of float arm 74 occurs from a closed position as shown in FIG.

8 to an open position as shown in FIG. 9 and vice versa. When the float 87 drops to the height in the storage tank corresponding to the position shown in FIG. 9, the valve is fully open and water may then enter the 94gl through the inlet arm 61 and out through the outlet arm 62 as shown by the arrows in full outline.

13 The action of float arm 74 and rocker arms 77 which is actuated by the water level in the storage tank is an "overcentre" action and this means that the initial part of the pivotal movement of rocker arms 77 has more mechanical effort applied thereto when compared to the later part which also means that the vertical distance moved by sealing assembly 94 is greater in the initial part of the pivotal movement rather than the later part. This has the advantage that the shut off applied to sealing member 94 has more bite or emphasis and thus, there is no real possibility that the valve can open accidentally or that sealing assembly 94 can become dislodged from the closed position. The use of the external guide members 73 facilitates this sequence of events.

:It is also preferred that the float arm 74 has offset ends 83 to ensure that the float arm is oriented normally to the longitudinal axis of valve body 60 as shown in FIG. 8. This is a preferred design feature but 15 is not essential to operation of the valve 31A.

o° In the embodiment of FIGS. 7-9, sealing assembly 71 corresponds to the balance seal of the embodiment of FIGS. 2-4 and the embodiment of FIGS. 5-6 and the balance space 71A corresponds to the balance space 34 of the above embodiments.

It will also be appreciated from the foregoing that the float arm 74 or float 87 may be directly attached to the valve member as in the FIGS. 5-6 embodiment or be indirectly attached to the valve member by virtue of an intermediate link rocker arm 22 or rocker arms 77).

Claims (14)

1. A float valve attachable to a float or float arm in a storage tank, said float valve having a valve body, a valve chamber, a valve member selectively controlling flow of liquid through the valve chamber, an inlet and an outlet wherein said valve chamber has a balance space which is in fluid communication with the inlet and the outlet and said valve member has a balance seal movable in the balance space which reduces pressure variations on the valve member.

2. A float valve as claimed in Claim 1 wherein the valve member is connected indirectly or directly to the float or float arm.

3. A float valve as claimed in Claim 1 or 2 wherein the valve body has the inlet in the form of an inlet conduit intermediate its length. 4*

4. A float valve as claimed in Claim 3 wherein the valve body is T-shaped with the upright of the T forming the inlet conduit and the head of the T forming a cylindrical portion having an interior which forms the S°valve chamber.

A float valve as claimed in Claim 4 wherein one end part of the cylindrical portion comprises the balance space and another end part of the cylindrical portion includes said outlet.

6. A float valve as claimed in any preceding claim wherein the valve member comprises a piston having a seal attached thereto which moves in and out of engagement with the outlet as well as said balance seal whereby said portion and said balance seal are interconnected by a connection rod.

7. A float valve as claimed in any preceding claim wherein the valve member includes a sealing member which contacts an adjacent outlet of the valve body in a closed position and is spaced from said outlet in the open position.

8. A float valve as claimed in Claim 7 wherein the valve member is attached to a support frame located externally of the valve body.

9. A float valve as claimed in Claim wherein the valve body has guide members attached thereto which undergo reciprocatable movement relative to the support frame.

A float valve as claimed in Claim 9 wherein the float arm is attached to one or more rocker arms wherein the rocker arm(s) are pivotally attached to the support frame and inner ends of the float arm.

11. A float valve as claimed in any preceding claim wherein the balance seal comprises a sealing member and washer loosely mounted to a support.

12. A float valve as claimed in Claim 11 wherein there is provided a sealing assembly in opposed relationship to the balance seal 20 which comprises a sealing member and a washer loosely mounted to a support.

13. A float valve as claimed in Claim 10, 11 or 12 wherein the inner ends of the float arm are offset to facilitate the float arm having an I 16 orientation which is substantially normal to a longitudinal axis of the valve body in the closed position.

14. A float valve substantially as herein described with reference to the accompanying drawings. DATED this twenty-fifth day of August 1997. MICHAEL DERMOTT MacMAHON, by his Patent Attorneys, FISHER ADAMS KELLY. S .o S oo