AU2012203015A1 - Leveller Valve - Google Patents

Abstract

- 21 A valve comprising a valve body, a plunger assembly pivotally coupled to the body and having a reciprocally moveable plunger member, a lever member having a valve seat pivotally coupled to the valve body to open and close the valve, and an actuating arm pivotally coupled to the body 5 with the plunger assembly. The actuating arm is moveable between a first pivotal position and a second pivotal position, and movement of the arm causes the plunger to reciprocally move along the lever to pivot the lever and open and close the valve. AJ Park 23/05/2012 4:37:41 p.m. PAGE 26/031 Fax Server LIf COMS 0 No:ARCS-37027 RecoIv b'P AusI.Tro lmo(H m)1456 Dte -Md) 2012-O23

Description

Regulation 3.2 AUSTRALIA PATENTS ACT, 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT ORIGINAL Name of Applicant: HANSEN DEVELOPMENTS LIMITED Actual Inventors: COLLINS, Philip John Address for service AJ PARK, Level 11, 60 Marcus Clarke Street, Canberra ACT in Australia: 2601, Australia Invention Title: Leveller Valve The following statement is a full description of this invention, including the best method of performing it known to us. 4033438_1 -2 FIELD OF THE INVENTION The invention relates to a valve and in particular to a float valve for use in a reservoir for maintaining minimum and maximum fluid levels within the reservoir. 5 BACKGROUND OF THE INVENTION Float valves of various types are known and used in applications where water level needs to be maintained, such as in water troughs and water tanks. A typical float valve comprises a float element supported by the water within the trough/tank and coupled to an end of a pivoting pilot arm of the valve. As water level drops, the float and arm are no longer supported by the water 10 which causes the pilot arm to pivot down and open the valve. As water level rises the float causes the pilot arm to pivot in an opposite direction to close the valve. Some float valves operate to maintain the water level within a trough/tank above between a minimum and a maximum level. 15 It is an object of the present invention to provide an improved or at least alternative form of valve, or to at least provide the public with a useful choice. STATEMENTS OF THE INVENTION 20 In a first aspect the invention may broadly be said to consist of a valve comprising: a valve body having an aperture from an interior of the body to an exterior of the valve, a plunger assembly pivotally coupled to the body and having a reciprocally moveable plunger member configured to move in opposing directions in response to pivotal movement of the assembly relative to the body, 25 a lever member having a valve seat at one end adjacent the aperture and pivotably coupled to the valve body about a pivot such that pivotal movement of the lever member to a first state causes the seat to close the aperture thereby closing the valve and pivotal movement of the member to the second state causes the seat to pivot away and open the aperture thereby opening the valve, the plunger being arranged to move and act against either side of the pivot 30 point as it is moves reciprocally to pivot the lever into the first and second states respectively, and an actuating arm pivotally coupled to the body with the plunger assembly at one end, the actuating arm being moveable between a first pivotal position and a second pivotal position, and wherein movement of the actuating arm causes the plunger assembly to pivot such that movement of the actuating arm to the first pivotal position causes the plunger to move to a first 35 reciprocal position within the assembly to in turn pivot the lever to the first state and movement -3 of the actuating arm to the second pivotal position causes the plunger to move to a second reciprocal position to in turn pivot the lever to the second state. Preferably the plunger assembly further comprises a compression spring coupled to the plunger 5 and biasing the plunger out of the plunger assembly. Preferably the plunger assembly further comprises a rolling element at an end of the plunger for rolling the plunger over the lever member onto either side of the pivot point. 10 Preferably the plunger assembly comprises a plunger housing for reciprocally accommodating the plunger and the spring and having a formation at one end for pivotally coupling a pivot pin of the valve body. Preferably the first reciprocal position of the plunger is a retracted position where the plunger is 15 substantially retracted within the housing and the second reciprocal position of the plunger is an ejected position where the plunger is at least partially ejected from the housing. Preferably the lever comprises a sealing member for opening and closing the aperture. Preferably the lever comprises a recess for retaining the sealing member therein. Preferably the sealing 20 member is formed from a rubber material. Preferably the lever is pivotably coupled to the valve body adjacent a surface on which the plunger acts. 25 Preferably the surface comprises curved recesses at either end of the lever for accommodating the rolling element therein at either the first or second state. Preferably the valve is a float valve for maintaining a fluid level within a reservoir between a minimum level and a maximum level, the float valve further comprising: 30 a float element coupled to the actuating arm to cause the arm to pivot to the first pivotal position and close the valve when the maximum fluid level is reached, and a weight element of slightly negative buoyancy and coupled to the actuating arm to cause the arm to pivot to the second pivotal position and open the valve when the minimum fluid level is reached and the weight element is no longer fully supported by the fluid within the 35 reservoir.

-4 Preferably the float element is coupled intermediate the length of the actuating arm. Preferably the float element is positively buoyant. 5 Preferably the weight element is coupled to an end of the actuating arm opposite the end coupled to the valve body. Preferably the weight element is coupled to the end of the actuating arm via a non-rigid line. Preferably the valve body comprises a main hollow body component and an extension part at an 10 end of the body component, the plunger assembly and the actuating arm being pivotally coupled to the extension part and the aperture being formed from the interior to the exterior of the body component. Preferably the valve body further comprises a cap element for coupling over the extension to an 15 open end of the hollow body component, said aperture being formed in said cap element. In one embodiment the valve further comprises: an inlet port for fluid to flow to the interior of the body component of the valve, an outlet port for fluid to flow from the interior to the exterior of the body component 20 of the valve, and a diaphragm moveably mounted within the interior of the body component between a closed position where fluid pressure on either side of the diaphragm is equalised to close the outlet port and an open position where fluid pressure is reduced on one side of the diaphragm relative to the other side to open the outlet port, and wherein movement of the plunger assembly 25 to eject the plunger opens the aperture in the body of the valve to allow fluid to exit from the interior of the body component to reduce the pressure on the one side of the diaphragm and open the outlet port to the inlet port, and movement of the plunger assembly to retract the plunger closes the aperture in the body of the valve to cause fluid from the inlet port to build up within the interior of the body component to equalise the pressure on either side of the 30 diaphragm and close the outlet port from the inlet port. Preferably the diaphragm includes side walls and a thin flexible annular skirt extending from the periphery of the diaphragm and integrally formed with a major part of the body of the diaphragm, the distal edge of said skirt being sealingly retained around a cavity behind the 35 diaphragm, to movably mount the diaphragm within the interior of the body component of the -5 valve so that the diaphragm moves by flexing and/or folding of the skirt, the diaphragm further comprising a bleed aperture for fluid to flow through from said inlet port into the cavity behind the diaphragm, and wherein the aperture through the body is adjacent the cavity and sized to allow greater fluid flow from the cavity through to the exterior of the body component than 5 through the bleed aperture of the diaphragm when the aperture through the body is open. In a second aspect the invention may broadly be said to consist of a float valve for maintaining a fluid level within a reservoir between a minimum level and a maximum level, the float valve further comprising: 10 a valve body having an aperture from an interior of the body to an exterior of the valve, a plunger assembly pivotally coupled to the body and having a reciprocally moveable plunger member configured to move in opposing directions in response to pivotal movement of the assembly relative to the body, a lever member having a valve seat at one end adjacent the aperture and pivotably 15 coupled to the valve body about a pivot point such that pivotal movement of the lever member to a first state causes the seat to close the aperture thereby closing the valve and pivotal movement of the member to the second state causes the seat to pivot away and open the aperture thereby opening the valve, the plunger being arranged to move and act against either side of the pivot point as it reciprocates to pivot the lever into the first and second states 20 respectively, a float arm coupled at one end to the body with the plunger assembly, the float arm being moveable between a first pivotal position and a second pivotal position, a float element coupled to the float arm to cause the arm to pivot to the first pivotal position when the maximum fluid level is reached causing the plunger assembly to pivot to move 25 the plunger to a first reciprocal position and close the valve, and a weight element of slightly negative buoyancy and coupled to the float arm to cause the arm to pivot to the second pivotal position when the minimum fluid level is reached and the weight element is no longer fully supported by the fluid within the reservoir, to thereby cause the plunger assembly to pivot to move the plunger to a second reciprocal position and open the 30 valve. The term "reservoir" as used in this specification means a receptacle or chamber for holding a liquid, whether for supply to an external system or not, and is intended to include within its definition troughs, tanks, containers and other storage/supply receptacles or reserves. 35 -6 The term "comprising" as used in this specification means "consisting at least in part of". When interpreting each statement in this specification that includes the term "comprising", features other than that or those prefaced by the term may also be present. Related terms such as "comprise" and "comprises" are to be interpreted in the same manner. 5 BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the invention will be described by way of example only and with reference to the drawings, in which: 10 Figure 1 is a side elevation view of a float valve of the invention in the closed position, Figure 2 is a side elevation view of the valve of figure 1 shown in the open position, 15 Figure 3 is an enlarged cross-sectional view of the valve of figure 1 showing a first embodiment of the over-centre mechanism in the closed state, Figure 4 is an enlarged cross-sectional view of the valve of figure 1 showing the over-centre mechanism of figure 3 in the open state, 20 Figures 5 is an exploded view of some of the components of the valve of figure 3, Figure 6 is a cross-sectional view of the valve of figure 1 showing the diaphragm assembly and over-centre mechanism in the closed position, 25 Figure 7 is a cross-sectional view of the valve of figure 1 showing diaphragm assembly and over centre mechanism in the open position, Figure 8 is a cross-sectional view of a valve in the closed state in accordance with a second 30 embodiment of the invention, and Figure 9 is a cross-sectional view of the valve of figure 8 in the open state. DETAILED DESCRIPTION 35 -7 Float Valve Components and Operation Referring to figure 1 a preferred form valve 100 of the invention is shown. The valve 100 is a float type valve having a body 110 and an actuating or float arm 90 pivotally coupled at end 91 to the body 110 for pivoting between first and second pivotal positions to close and open the fluid 5 path between inlet and outlet ports 11 and 12 of the valve 100 respectively. A mechanism (not shown) at the end 91 of the float arm operates in response to movement of the float arm 90 to cause the valve 100 to open and close. The valve body 110 preferably comprises a main hollow body component 10 and a hollow extension 13 coupled to the hollow body 10 via cap element 16. 10 The float valve 100 will typically couple a reservoir for maintaining the fluid/water level within the reservoir between a minimum water level and a maximum water level. The reservoir may be used as a backup supply for an external system for instance. A float element 97 is coupled to the float arm 90 for ensuring the float valve 100 is closed when the maximum water level within the 15 reservoir is reached. The float element 97 is preferably positively buoyant. A weighted element 96 is also coupled to the float arm 90 for ensuring the float valve 100 is opened when water level within the reservoir drops below a minimum. The weighted element 96 is preferably coupled to an end 92 of the float arm 90 via a non-rigid line such as a string or braided cord 95. The line may be rigid in alternative embodiments but it is preferably flexible. Weighted element 96 is 20 slightly less than neutrally buoyant to remain submerged when the water level is above the minimum but not to an extent in which the element acts on the float arm 90 with enough force to pivot the arm 90. Referring now to figures 1 and 2, during operation, when the water level within the reservoir 25 drops to a minimum level 60 shown in figure 2, the weighted element 96 is no longer supported by the water and pulls on the end of the float arm 90 to thereby pivot the float arm 90 down to the second pivotal position shown in figure 2 to cause the mechanism at the end 91 of the arm 90 to open the valve 100. As water is released from outlet port 12 into the reservoir, the water level within the reservoir rises towards the maximum level 65. When the water level begins to 30 approach maximum 65, the float 97 becomes supported by the water once again and rises with the water. As the float 97 rises it pulls on the float arm 90 to pivot the float arm 90 back up towards the first pivotal position shown in figure 1 until the maximum level 65 is reached, at which point the valve 100 is closed by the mechanism at the end 91 of the float arm 90.

-8 The fully extended length of the cord 95 in conjunction with the length of the float arm 90 determines the level at which the weight element 96 will no longer be supported by the water (minimum level 60) for the valve 100 to open. The position of the float element 97 along the length of the float arm 90 determines the level at which the float 97 becomes supported by the 5 water (maximum level 65) for the valve 100 to close. Over-centre mechanism - components and operation Referring now to figures 3 and 4, a first embodiment of the over-centre mechanism is shown. The mechanism at the end 91 of the float arm 90 by which opening and closing of the valve 100 10 is achieved will now be described in detail with reference to this embodiment. The valve 100 comprises a hollow extension 13 at one end of the body 10 for retaining the mechanism that opens and closes the valve. The extension 13 is preferably a separate component that is coupled to the body 10 via a cap element 16 that threads onto the body 10 over a flanged end 1 3 a of the extension. The extension may alternatively be integrally formed or moulded with the cap 16 to fit 15 over the end of the body 10. In yet another alternative, the extension is an integrally formed with the body 10. The mechanism is an over-centre mechanism that is normally bi-stable in either a first state or a second state. Movement of the float arm 90 to the first or second pivotal position causes the 20 mechanism to switch or transition to the first or second state respectively. In the first state shown in figure 3, the mechanism closes the valve 100 and in the second state shown in figure 4, the mechanism opens the valve 100. Referring to figure 5, an exploded view of some of the valve components in a disassembled state 25 is shown. As shown, the hollow extension 13 is arranged to receive an end 91 of the float arm 90 and a pivot pin 98 is provided to pivotally couple the end 91 to the extension 13. The pin 98 may in the form of a pivot tube 98a receivable within the extension 13 and a split pin 98b configured to extend transversely through the corresponding apertures in the extension 13 to retain the pivot tube 98a in position. The extension 13 is configured to couple against a cover 2 9a of the valve 30 body 110 having the aperture 14 by action of a cap 16 (not shown in figure 5). The valve 100 and in particular the over-centre mechanism comprises a plunger assembly 70 and a lever member 75. The plunger assembly comprises a plunger housing 71, a plunger 72, a compression spring 73 and a roller element 74. In the assembled state, the plunger assembly 70 35 and lever member 75 reside within the extension 13. The plunger housing 71 comprises an -9 integral formation 71a at one end for pivotally/hingedly coupling about pivot pin 98. Furthermore, the housing 71 is hollow to accommodate the spring 73 and plunger 72. In the assembled state, the spring 73 couples about protrusion 72a at an end of the plunger 72 and is compressed between the plunger 72 and the housing 71. The plunger 72 comprises two hooked 5 extensions 72b/c which in the assembled form protrude through corresponding apertures 71b/c of the housing 71 to enable limited reciprocal movement of the plunger 72 within the housing 71. In the assembled form and during operation, as the compression spring 73 expands, the plunger 72 is ejected out of the housing 71 until an end 75b of the lever 75 engages an abutment 78 of the valve body 110. When the plunger 72 is retracted, the compression spring 73 is compressed 10 again. The roller element 74 is arranged to couple an end 72d of the plunger 72 for rollably engaging the lever 75 during operation. The roller 74 reduces friction as the plunger 72 moves along the upper surface of the lever 75 during operation. The lever member 75 comprises a pivot extension/fulcrum 76 about which the lever 75 pivots 15 during operation of the valve 100. The lever 75 further comprises lugs 79a for engaging corresponding recess portions 79b on cover 2 9 a. In the assembled form, the fulcrum 76 of the lever 75 engages a surface of the cover 29a and the lugs 79a rest within the corresponding recess portions 79b for enabling pivotal movement of the lever 75 relative to the covet 29a. It will be appreciated, in an alternative embodiment, the fulcrum 76 may be provided as a formation from 20 the lever 75 and on the cover 29a for example. One side 7 5a of the lever 75 comprises seal carrier or recess 75c for receiving a sealing member 77. During operation, as the lever 75 pivots, it moves the sealing member 77 in and out of engagement with aperture 14 in the cover 2 9a to close and open the valve respectively. An abutment 78 protrudes from cover 29a for engaging the end 75b of the lever 75 when the valve is in the open state during operation. 25 In the assembled form, the lever 75 and plunger assembly 70 are located adjacent one another within the extension 13 such that the roller 74 of the plunger assembly 70 abuts against the upper surface of the lever 75. During operation, as the plunger housing 71 is rotated with the float arm 90 about pivot pin 98, the plunger 71 is caused to roll over the surface of the lever 75 onto either 30 side (75a and 75b) of the fulcrum 76 to thereby pivot the lever 75 and close and open the valve respectively. In the preferred embodiment, the compression in the spring 73 is reduced as the plunger rotates and ejects onto side 75b and is compressed again as the plunger rotates onto side 75a and retracts.

- 10 Referring now to figures 6 and 7, operation of the over-centre mechanism will now be described in more detail with reference to this embodiment. The plunger member 72 is configured to be ejected out of the housing 71 and retracted back within the housing 71 in response to pivotal movement of the assembly 70. When the plunger 72 is ejected it causes the lever 75 to pivot to 5 the second open state shown in figure 7 and when the plunger 72 is retracted it causes the lever 75 to pivot to the first closed state shown in figure 6. The plunger 72 is ejected and retracted as it moves over either side of fulcrum 76 (over-centre). The distance between pivot 91 (where the plunger assembly 70 is coupled to the extension 13) and the lever side 75a/b which the plunger 72 engages is shortened/lengthened respectively to cause the plunger 72 to retract/eject in 10 response. The lever 75 is maintained in either the first or second state when the plunger 72 is retracted or ejected respectively. In the first state, the plunger 72 acts on one side 75a of the fulcrum 76 to pivot an end/sealing member 77 of the lever 75 to a closed position. In the second state, the 15 plunger 72 acts on another side 75b of the fulcrum 76 to pivot the end 77 of the lever 75 to an open position where side/end 75b rests on abutment 78 of the cover 29a. In the closed position, the seal 77 moves over and closes the aperture 14 of the valve body 110 to close the valve 100 and in the open position the seal 77 moves away and opens the aperture 14 to open the valve 100. 20 Referring to figures 1 and 2 also, when fluid level lowers it allows the weight 96 on the end of the cord 95 to exert a force on the float arm 90. The float arm 90 tries to rotate in a clockwise direction. The force of the spring 73 in the plunger assembly 70 resists this rotation until sufficient load is applied by the weight 96 (beyond level 60 shown in figure 1 for example). At 25 this point the float arm 90 rotates and pushes the plunger assembly over-centre where it then snaps to the open position. In other words, the plunger assembly 70 is caused to rotate and move relative to the lever 75 onto the side 75b of the fulcrum 76. The spring 73 then forces the plunger 72 out of the plunger housing 71 and causes the lever 75 to pivot thus opening the aperture 14. The plunger 72 acts against the lever side 75b to retain the lever 75 in the second open state. The 30 roller 74 in the assembly 70 reduces the friction so the assembly 70 can move freely. As the fluid level rises, it lifts the float 97 attached directly to the float arm 90. The float arm 90 tries to rotate in an anticlockvise direction but the force of the spring 73 in the plunger assembly 70 resists this rotation until sufficient load is applied by the float 97 (at level 65 as shown in figure 35 2 for example). At this point the float arm 90 rotates and pushes the plunger assembly 70 over- - 11 centre where it then snaps to the closed position. In other words, the plunger assembly 70 is caused to rotate and move relative to the lever 75 onto the side 75a of the fulcrum 76. The spring 73 biases the plunger 72 out of the plunger housing and causes it to act on the lever side 75a to pivot the lever 75 and retain it in the first closed state to close the aperture 14. 5 In the above described preferred embodiment, the terms "eject" and "retract" or similar terms are used to describe the two opposing reciprocal motions of the plunger 72. It will be appreciated that in alternative embodiments the plunger 72 may still be contained within the housing 71 in the open position or similarly still protruding from the housing 71 in the closed position 10 depending on the arrangement and relative dimensions of the plunger assembly components. Such alternatives are not intended to be excluded from the scope of the invention and the terms "eject" and "retract" and other similar terms are intended to broadly describe the two opposing directions of movement for a reciprocating member/plunger 72. 15 Referring now to figures 8 and 9 a second and more preferred embodiment of the invention is shown. The over-centre mechanism, and in particular the arrangement of the lever 75 is different in this embodiment to the one described above. All other features of the valve 100 and the operation of the valve 100 remain the same as described above and therefore will not be explained again in detail. Only the features of the lever 75 that are different to the above 20 embodiment will be described. In this second embodiment, the lever 75 is pivotally coupled to the housing above the rolling surface75d of the lever 75. The geometry of this pivotal coupling creates a more reliable over centre mechanism that is unlikely to stall in the mid-position between open and closed states. In 25 this particular embodiment, the lever 75 is pivotably coupled to an up-stand/protrusion 93 extending transversely from the cover 29a. The pivot point, X, is at an opposing side of the rolling surface 75d of the lever 75 to die aperture 14 to be sealed. In other words, the pivot point, X, is adjacent the rolling surface 75d of the lever 75and the plunger assembly 70 of the mechanism. This geometry helps prevent the lever 75 from stalling in between states. The 30 operation of the valve 100 otherwise remains the same as described thus far in relation to figures 1 7 It mill hn nnnrnnintnr1 fna thin nahnrlimannt amNi nA an in mai @*d if ii i..n iiih Ii ii i 1 i1 - 12 In addition, the lever 75 preferably comprises a rolling surface 75d with curved/arced recesses 75e/f at either end of the lever 75 for accommodating the roller 74 as shown in figures 8 and 9. The arced recesses 75e/f add a level of pre-loading to the mechanism so that float 97 or weight element 96 must overcome some initial load before causing the valve 100 to switch states. It will 5 be appreciated that there may be only one recessed end for creating pre-loading either during closing or opening of the valve 100 as desired by the particular application. This feature may be incorporated on any one of the embodiments described in relation to this invention. The above preferred over-centre mechanism embodiments are described with reference to a float 10 valve; however other type valves may also make use of such a mechanism. External input is required to operate the mechanism which may be manual (e.g. through a handle) or automatic (e.g. electrical actuator) depending on the application. For instance, a simple tap with just an on and an off lever may also employ such a mechanism. These variations and embodiments are not intended to be excluded by the scope of this invention. 15 In the preferred embodiments described thus far, the over-centre mechanism in conjunction with the float arm (and float and weight elements) opens and closes aperture 14 to open and close the valve 100. Opening and closing of the valve 100 in response to opening and closing of the aperture 14 may be achieved through the use of an assembly within the body 10. In the preferred 20 embodiment, the float valve 100 is operable using a diaphragm assembly 80 shown in figures 6 and 7 (described in more detail below). However, any other suitable assembly for operating the valve in response to opening and closing of aperture 14 may be used and is intended to be covered by the scope of this invention. Furthermore, the valve may alternatively be constructed such that the aperture 14 is the outlet port of the valve, with the mechanism operating directly on 25 the outlet port to open and close the valve (such as in a simple on/off tap embodiment as described above). Diaphragm Assembly Referring to Figures 6 and 7, the preferred assembly within the main body and other components 30 of the valve will now be described in more detail. The main body component 10 has a hollow interior 15, an inlet port 11 by which the valve 100 may be connected to a pipe system from a fluid supply under pressure for example, and an outlet port 12 which may also connect to a pipe system or directly communicate with a reservoir. The inlet port 11 is formed by an aperture at end 10a of the body opposite end 10b. The aperture is internally threaded so that the valve 100 35 may be threaded onto the end of a pipe for example so that the end of the pipe communicates - 13 through the inlet port 11 and into the interior 15 of the valve 100. Outlet port 12 is provided for the exit stream of fluid from the interior 15 of the body 10 of the valve 100. Fluid will enter through inlet port 11 and flow through the interior 15 of the valve 100, exiting via outlet port 12 only when the valve 100 is open (as shown by stream C in figure 7). When the valve 100 is 5 closed, the fluid path is obstructed and the outlet port 12 is closed so no fluid exits the valve 100. A circular wall 30 extends from the inlet port 11 into the interior 15 of the valve as shown, and terminates at one end to form a valve seat 11a. A diaphragm 7 is mounted within the interior 15 of the valve. In the preferred form the diaphragm 7 is generally circular, and comprises a thin 10 annular skirt 7a which extends from the periphery of the side wall 7b of the preferred form diaphragm 7 as shown. The distal edge 7c of the skirt 7a and the inner surface of end 10b may both comprise complementary formations for retaining the distal edge 7c against/within the inner surface of end 10b. In the preferred embodiment shown, the valve body 110 further comprises a cap element 29 mounted at end 10b of the body 10. The cap element 29 having a 15 formation formed on the inside face for receiving and retaining the diaphragm 7. The cap element 29 in the preferred embodiment is shown as two separate components, a cover 29a engaging the main body component 10 at end 10b and a cap 16 threadably engaging the main body component 10 over the cover 2 9 a and extension 13 to retain the cover 29a and extension 13 at end 10b. Aperture 14 of the valve body 110 is provided in cover 29a and extends from the 20 interior to the exterior of the body 10. In an alternative embodiment the cap element 29 may be a single component. The cover 2 9 a and cap 16 will be referred to as cap or cap element 29 from here onwards. The skirt 7a is a thin, flexible skirt which can flex and fold to allow the diaphragm 7 to move 25 between the position shown in figure 7 where the diaphragm 7 seals against the seat 11a to close the outlet port 12, and the position shown in figure 8 where the diaphragm 7 has moved towards the cap 29 to open the port 12, to the interior 15 of the body 10. The diaphragm 7 is preferably a separately moulded plastic/rubber component which is simply 30 fitted to body 10 so that the edge 7c of the skirt 7a of the diaphragm 7 engages the annular formation in the body and the diaphragm 7 is not secured by screws or clamps or similar. This provides for easy assembly and a simple construction and moreover it has been found that the diaphragm 7 will effectively seal for both vacuum and pressure, up to relatively high pressures.

-14 In one form, the diaphragm 7 including the integral skirt 7a are formed from a soft plastics/rubber material and the diaphragm 7 has a side wall 7b and an annular flange 7d extending inwardly from the side wall 7b for receiving an annular member/insert 17 of harder material. The annular flange 7d having an orthogonal base and wall structure for receiving an 5 end of member 17 therein. The member/insert 17 has a similar profile to the diaphragm 7 to allow the diaphragm 7 to lie against the member/insert 17 as shown and move up and down the body 10 with the member 17 to open and close the valve 100. Member/insert 17 aids the soft diaphragm 7 in keeping its structure as it moves up and down the body 10. However member/insert 17 is only a preferable feature and may not be employed in some embodiments. 10 Another annular member 18 fitted or otherwise integrally formed within the main body 10 of the valve 100 engages an upper surface of a flange 7e extending from the end 7c of the skirt 7a above the annular formation 8 to hold the flange 7e against the formation 8 and allow the thin skirt 7a to fold/flex to move the diaphragm 7 to open the valve 100 as shown in figure 7. 15 In the preferred embodiment, the diaphragm 7 is formed from a rubber material and over moulded onto the annular member/insert 17. A guide member 22 extends centrally from the cap 29 through an aperture or opening 21 in the centre of the diaphragm 7 and towards the port 11. The guide member 22 may be formed as a 20 separate component from the body 10 and received within a recess 23 of the cap 29 as shown. In the preferred form the guide member is a cylindrical pin 22. A guide bush 24 is accommodated within the bleed aperture or opening 21 at an end of the diaphragm and has a main body component 2 4a inside the diaphragm 7 and a flange 24b at an end of the body 24a engaging the end of the diaphragm at opening 21. The guide pin 22 extends through the centre of the bush 24 25 as shown. The bush 24 around the pin 22 is slightly larger than the diameter of the pin 22 and forms a channel 26 through the diaphragm from the port 11 to the cavity or space 25 behind the diaphragm (shown in Figures 6 and 7), between the rear side of the diaphragm and the cap 29 of the body. The guide bush 24 is formed from a harder material than the soft diaphragm 7 to thereby reduce friction as the diaphragm 22 moves up and down the pin 22. Preferably the guide 30 bush 24 is formed from a plastics material. The guide bush 24 may be formed separately or integrally moulded with the diaphragm and/or member/insert 17. Aperture 14 when opened enables fluid to flow from the cavity 25 to the exterior of the valve and is sized to allow greater flow than through the channel 26. The sealing member 77 at the end 35 of the lever 75 is situated adjacent the aperture 14 to open and close the aperture 14 with the aid - 15 of the over-centre mechanism described above. Seal 77 is preferably made of rubber to provide the necessary sealing against aperture 14 when the valve 100 is closed. In operation, when the float arm 90 pivots to the second pivotal position shown in figure 7, the 5 pilot arm will snap into the second stable state and open the aperture 14. There Vill be a reduction in pressure via the aperture 14 in the cavity 25 behind the diaphragm 7 and relative to the inlet port side of the diaphragm 7. This relative pressure imbalance will cause the diaphragm 7 to move towards the cap 29 from the position shown in figure 6 to that shown in figure 7, thus opening the outlet port 12 to the interior 15 of the body 10 to allow fluid to pass from the inlet 10 port 11 through to the outlet port 12 as indicated by arrow C. Fluid from the inlet port 11 will operate against the top surface of the diaphragm 7 to move the diaphragm towards cap 29 further thereby increasing fluid flow through the valve 100. When the float arm 90 pivots to the first pivotal position as shown in figure 6, fluid flow through 15 aperture 14 will be prevented/blocked off causing pressure within the cavity 25 to build up through channel 26 to thereby equalise with the inlet port side of the diaphragm 7. This equalisation of pressure alongside the natural resilience of the thin flexible skirt 7a of the diaphragm will cause the diaphragm 7 to move back up to its original position against seat 11a to close the outlet port 12 off from the inlet 11 as shown in figure 6. 20 The aperture 14 in the preferred embodiment is sized to allow greater fluid flow than through channel 26. Guide bush 24 aids with this requirement by providing an aperture at opening 21 that is only slightly larger than the diameter of the guide pin 22. However, in alternative embodiments the guide bush 24 and or guide pin 22 are not provided and the aperture at the top of the 25 diaphragm 7 forms the necessary sized channel 26. Channel 26 has a small width to restrict flow from the inlet side of the diaphragm to the cavity 25 to enable pressure reduction in the cavity 25 when the valve 100 (and aperture 14) is opened. For example the diameter of channel 26 may be approximately 1.9mm, the diameter of the guide pin may be approximately 1.6mm and the diameter of the aperture 14 may be approximately 1.9mm. These dimensions are only exemplary 30 and are not intended to be limiting. In the preferred embodiment, the valve 100 further comprises a spring element 40 or other biasing means fitted between the diaphragm 7 and the cap 29 in cavity 25 to assist in moving the diaphragm towards the closed position. Figure 6 shows the spring element 40 in a less 35 compressed/relaxed state and pushing the diaphragm 7 (and in particular acting on the relatively - 16 harder member 17) up against the valve seat 11a to close the valve 100. Figure 7 shows the valve 100 in the open position, with the member 17 acting against the top of the spring 40 to compress the spring 40 and thereby bias the diaphragm 7 towards the closed position. 5 The majority of components of the valve maybe formed by injection moulding of plastics material, or by metal casting for larger versions if desired. The foregoing description of the invention includes preferred forms thereof. Modifications may be made thereto without departing from the scope of the invention as defined by the 10 accompanying claim set.

Claims (20)

1. A valve comprising: a valve body having an aperture from an interior of the body to an exterior of the valve, 5 a plunger assembly pivotally coupled to the body and having a reciprocally moveable plunger member configured to move in opposing directions in response to pivotal movement of the assembly relative to the body, a lever member having a valve seat at one end adjacent the aperture and pivotably coupled to the valve body about a pivot such that pivotal movement of the lever member to a 10 first state causes the seat to close the aperture thereby closing the valve and pivotal movement of the member to the second state causes the seat to pivot away and open the aperture thereby opening the valve, the plunger being arranged to move and act against either side of the pivot point as it is moves reciprocally to pivot the lever into the first and second states respectively, and an actuating arm pivotally coupled to the body with the plunger assembly at one end, 15 the actuating arm being moveable between a first pivotal position and a second pivotal position, and wherein movement of the actuating arm causes the plunger assembly to pivot such that movement of the actuating arm to the first pivotal position causes the plunger to move to a first reciprocal position within the assembly to in turn pivot the lever to the first state and movement of the actuating arm to the second pivotal position causes the plunger to move to a second 20 reciprocal position to in turn pivot the lever to the second state.

2. A valve as claimed in claim 1 wherein the plunger assembly further comprises a compression spring coupled to the plunger and biasing the plunger out of the plunger assembly. 25

3. A valve as claimed in either one of claim 1 or claim 2 wherein the plunger assembly further comprises a rolling element at an end of the plunger for rolling the plunger over the lever member onto either side of the pivot point.

4. A valve as claimed in any one of the preceding claims wherein the plunger assembly 30 further comprises a plunger housing for reciprocally accommodating the plunger and the spring and having a formation at one end for pivotally coupling a pivot pin of the valve body.

5. A valve as claimed in claim 4 wherein the first reciprocal position of the plunger is a retracted position where the plunger is substantially retracted within the housing and the second - 18 reciprocal position of the plunger is an ejected position where the plunger is at least partially ejected from the housing.

6. A valve as claimed in any one of the preceding claims wherein the lever comprises a 5 sealing member for opening and closing the aperture.

7. A valve as claimed in claim 6 wherein the lever comprises a recess for retaining the sealing member therein. 10

8. A valve as claimed in claim 7 wherein the sealing member is formed from a rubber material.

9. A valve as claimed in any one of the preceding claims wherein the lever is pivotably coupled to the valve body adjacent a surface on which the plunger acts. 15

10. A valve as claimed in claim 3 wherein the lever comprises recesses at either end for accommodating the rolling element therein at either the first or second state.

11. A valve as claimed in any one of the preceding claims wherein the valve is a float valve 20 for maintaining a fluid level within a reservoir between a minimum level and a maximum level, the float valve further comprising: a float element coupled to the actuating arm to cause the arm to pivot to the first pivotal position and close the valve when the maximum fluid level is reached, and a weight element of slightly negative buoyancy and coupled to the actuating arm to 25 cause the arm to pivot to the second pivotal position and open the valve when the minimum fluid level is reached and the weight element is no longer fully supported by the fluid within the reservoir.

12. A float valve as claimed in claim 11 wherein the float element is coupled intermediate 30 the length of the actuating arm.

13. A float valve as claimed in either one of claim 12 or claim 13 wherein the float element is positively buoyant. - 19

14. A float valve as claimed in any one of claim 11 to claim 13 wherein the weight element is coupled to an end of the actuating arm opposite the end coupled to the valve body.

15. A float valve as claimed in claim 14 wherein the weight element is coupled to the end of 5 the actuating arm via a non-rigid line.

16. A valve as claimed in any one of the preceding claims wherein the valve body comprises a main hollow body component and an extension part at an end of the body component, the plunger assembly and the actuating arm being pivotally coupled to the extension part and the 10 aperture being formed from the interior to the exterior of the body component.

17. A valve as claimed in claim 16 wherein the valve body further comprises a cap element for coupling over the extension to an open end of the hollow body component, said aperture being formed in said cap element. 15

18 A valve as claimed in any one of the preceding claims further comprising: an inlet port for fluid to flow to the interior of the body component of the valve, an outlet port for fluid to flow from the interior to the exterior of the body component of the valve, and 20 a diaphragm moveably mounted within the interior of the body component between a closed position where fluid pressure on either side of the diaphragm is equalised to close the outlet port and an open position where fluid pressure is reduced on one side of the diaphragm relative to the other side to open the outlet port, and wherein movement of the plunger assembly to eject the plunger opens the aperture in the body of the valve to allow fluid to exit from the 25 interior of the body component to reduce the pressure on the one side of the diaphragm and open the outlet port to the inlet port, and movement of the plunger assembly to retract the plunger closes the aperture in the body of the valve to cause fluid from the inlet port to build up within the interior of the body component to equalise the pressure on either side of the diaphragm and close the outlet port from the inlet port. 30

19. A valve as claimed in claim 18 wherein the diaphragm includes side walls and a thin flexible annular skirt extending from the periphery of the diaphragm and integrally formed With a major part of the body of the diaphragm, the distal edge of said skirt being sealingly retained around a cavity behind the diaphragm, to movably mount the diaphragm within the interior of 35 the body component of the valve so that the diaphragm moves by flexing and/or folding of the - 20 skirt, the diaphragm further comprising a bleed aperture for fluid to flow through from said inlet port into the cavity behind the diaphragm, and wherein the aperture through the body is adjacent the cavity and sized to allow greater fluid flow from the cavity through to the exterior of the body component than through the bleed aperture of the diaphragm when the aperture through the 5 body is open.

20. A float valve for maintaining a fluid level within a reservoir between a minimum level and a maximum level, the float valve further comprising: a valve body having an aperture from an interior of the body to an exterior of the valve, 10 a plunger assembly pivotally coupled to the body and having a reciprocally moveable plunger member configured to move in opposing directions in response to pivotal movement of the assembly relative to the body, a lever member having a valve seat at one end adjacent the aperture and pivotably coupled to the valve body about a pivot point such that pivotal movement of the lever member 15 to a first state causes the seat to close the aperture thereby closing the valve and pivotal movement of the member to the second state causes the seat to pivot away and open the aperture thereby opening the valve, the plunger being arranged to move and act against either side of the pivot point as it reciprocates to pivot the lever into the first and second states respectively, 20 a float arm coupled at one end to the body with the plunger assembly, the float an-n being moveable between a first pivotal position and a second pivotal position, a float element coupled to the float arm to cause the arm to pivot to the first pivotal position when the maximum fluid level is reached causing the plunger assembly to pivot to move the plunger to a first reciprocal position and close the valve, and 25 a weight element of slightly negative buoyancy and coupled to the float arm to cause the arm to pivot to the second pivotal position when the minimum fluid level is reached and the weight element is no longer fully supported by the fluid within the reservoir, to thereby cause the plunger assembly to pivot to move the plunger to a second reciprocal position and open the valve. 30