Apparatus for flushing a toilet, comprising an accumulator

Abstract

A flushing apparatus (1, 301) for being installed in the cistern of a toilet including a flushing device (2) for fluid connection with an outlet of a cistern and a hydraulically-driven control circuit (3, 303) for operating the flushing device. The control circuit (3, 303) includes a water inlet (P) for fluidly connecting the control circuit (3, 303) to a source of pressurised water and an accumulator (6) fluidly connected to the water inlet (P) and configured to supplement, in use, the flow of pressurised water supplied by the source trough the control circuit (3, 303) to activate the flushing device (2).

Claims

1. A toilet flushing apparatus comprising a flushing device for fluid connection with an outlet of a toilet cistern and a hydraulically-driven control circuit for operating the flushing device, the hydraulically-driven control circuit comprising a water inlet for fluidly connecting the control circuit to a source of pressurised water, a hydraulically-driven actuator comprising a cylinder and a piston disposed therein, an operating valve between the hydraulically-driven actuator and the water inlet for selectively opening fluid communication therebetween and an accumulator fluidly connected between the operating valve and the water inlet, wherein the accumulator is configured to supplement, in use, the flow of pressurised water supplied by the source to the actuator through the control circuit, the operating valve having an inlet fluidly connected to the accumulator and an outlet fluidly connected to a chamber in the cylinder, so that, when the operating valve is opened, pressurized fluid flows from the accumulator, through the operating valve, and into the cylinder chamber to drive the piston to operate the flushing device.

2. Apparatus according to claim 1 comprising an air inlet for introducing, in use, air into the accumulator.

3. Apparatus according to claim 2 comprising a venturi downstream of the water inlet, the venturi being in fluid communication with the air inlet for entraining air from the air inlet into the accumulator.

4. Apparatus according to claim 3 comprising an air inlet tube extending from the air inlet to or toward the venturi.

5. Apparatus according to claim 3 comprising a water inlet tube in fluid communication with the water inlet of the control circuit and with the accumulator, the water inlet tube comprising a restriction therein which provides, at least in part, the venturi.

6. Apparatus according to claim 5, wherein the water inlet tube extends into a base of the accumulator.

7. Apparatus according to claim 6 comprising a water outlet tube in fluid communication with a sump in the base of the accumulator.

8. Apparatus according to claim 2 comprising a non-return valve associated with the air inlet for allowing air to enter, in use, into the control circuit while inhibiting water egress therefrom.

9. A toilet cistern flushing apparatus comprising a flushing device for fluid connection with an outlet of a toilet cistern and a hydraulically-driven control circuit for operating the flushing device, the control circuit comprising a water inlet for fluidly connecting the control circuit to a source of pressurized water, a hydraulically-driven actuator, an operating valve between the actuator and the water inlet for selectively opening fluid communication therebetween and an accumulator fluidly connected between the operating valve and the water inlet, wherein the accumulator is configured to supplement, in use, the flow of pressurized water supplied by the source to the actuator through the control circuit, wherein the flushing device comprises a syphon having an inverted generally U shaped duct with an upleg and a downleg, an open-ended chamber fluidly connected to the upleg and a piston movable in the chamber, the actuator being operatively connected to the piston for moving the piston in the chamber to initiate a syphonic flushing action.

10. Apparatus according to claim 1, wherein the flushing device comprises a flush valve.

11. Apparatus according to claim 1 comprising a toilet cistern filling device in fluid communication with an outlet of the accumulator.

12. Apparatus according to claim 11, wherein the accumulator outlet in fluid communication with the toilet cistern filling device comprises a first outlet which bypasses the operating valve and the accumulator further comprises a second outlet in fluid communication with the hydraulically-driven actuator.

13. Apparatus according to claim 1 comprising a push button actuator operatively connected to the control circuit for operating the flushing device, the actuator comprising a surround with a recess, a body received within the recess of the surround and a push button mounted to the body, wherein the recess of the surround and the body comprise cooperating radial features such that the push button is in a first position in which it is flush or stands proud of the surround when the body and the surround are in a first relative radial orientation and is in a second position in which it is retracted relative to the first position when the body and the surround are in a second relative radial orientation.

14. Apparatus according to claim 1 wherein the piston is operatively connected to the flushing device.

15. Apparatus according to claim 1 wherein the flushing device is either an outlet valve or a syphon.

Description

(1) Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:

(2) FIG. 1 is a perspective view of a flushing apparatus according to an embodiment of the invention;

(3) FIG. 2 is a partial section view of the apparatus of FIG. 1 illustrating the flow of pressurised water through the manifold;

(4) FIG. 3 is a partial section view of the apparatus of FIG. 1 illustrating the flow of pressurised water into and out of the accumulator;

(5) FIG. 4 is a partial section view of the apparatus of FIG. 1 illustrating the operating valve;

(6) FIG. 5 is a partial section view of the apparatus of FIG. 1 illustrating the flow of pressurised water into the actuator of the flushing device;

(7) FIG. 6 is a partial section view of the apparatus of FIG. 1 illustrating the operation of the fill device;

(8) FIG. 7 is a partial section view of apparatus of FIG. 1 illustrating the air valve for the prevention of backflow;

(9) FIG. 8 is a perspective view of the apparatus of FIG. 1 with the accumulator removed;

(10) FIG. 9 is a perspective view of the apparatus of FIG. 1 with part of the integrated hydraulic circuit removed;

(11) FIG. 10 is an exploded view of the inlet coupling of the apparatus of FIG. 1;

(12) FIG. 11 is a partially assembled view of the inlet coupling of FIG. 10;

(13) FIG. 12 is an assembled view of the inlet coupling of FIGS. 10 and 11;

(14) FIG. 13 is a section view of the assembled inlet coupling of FIG. 12;

(15) FIG. 14 is a perspective view of a push button actuator for connection with the operating valve of the apparatus of FIG. 1;

(16) FIG. 15 is an exploded perspective view of the body and surround of the push button actuator of FIG. 14;

(17) FIG. 16 is a partial section view of the push button actuator of FIG. 14 with the push button shown in a flush position;

(18) FIG. 17 is a partial section view similar to that of FIG. 16 in which the push button is shown in a proud position;

(19) FIG. 18 is a perspective section view of a flushing apparatus according to another embodiment of the invention; and

(20) FIG. 19 is a perspective section view of the accumulator of the flushing apparatus of FIG. 18.

(21) Referring now to FIGS. 1 to 9, there is shown a cistern flushing apparatus 1 including a flushing device 2 for fluid connection with an outlet of a cistern (not shown) and an integrated hydraulic circuit 3 for operating the flushing device 2 and for filling a cistern (not shown) following a flushing event.

(22) In this embodiment, the flushing device 2 is in the form of an adjustable syphon 2 similar to that which is disclosed in GB2486776, the entire contents of which are incorporated herein by reference. More specifically, the syphon 2 includes first, second and third parts 20, 21, 22 mounted in telescopic relation with one another to enable adjustment of the flush volume characteristics thereof. The first part 20 includes an evacuation tube 20a having a radial flange 20c and threaded portion 20b extending from the flange 20c for insertion through an outlet in the base of a cistern (not shown) to be secured thereto by a nut (not shown) in the normal way. The second part 21 includes a suction tube 21a and an open-ended chamber 21b. The third part 22 is in the form of an inverted generally U-shaped duct with an upleg portion 22a and a downleg portion 22b. The upleg portion 22a and downleg portion 22b of the U-shaped duct 22 are each mounted in telescopic relation with the suction tube 21a and evacuation tube 20a respectively.

(23) The first part 20 also includes a pair of lugs 20d projecting laterally from its upper end each with a hole 20e therethrough. The second part 21 includes a flat bracket 21d projecting laterally from the upper end of the suction tube 21a and having a plurality of spaced holes 21e through its thickness. The third part 22 includes a chain of lugs 22d extending downwardly from the front of the bight of the U between the downleg and upleg portions 22a, 22b and having a plurality of vertically spaced holes 22e through its thickness. A releasable fastener 23 (shown in FIG. 4) including a pair of spaced pins extends through a pair of adjacent holes 20e, 21e, 22e in each of the first, second and third parts 20, 21, 22 to secure simultaneously the parts 20, 21, 22 together.

(24) The first part 20 includes a longitudinally extending rib 20f and the second part 21 includes a bracket 21f with a keyway that receives the rib 20f of the first part. These features 20f, 21f together with the telescopic connection between the parts 20, 21, 22 enables guided adjustment in their relative positions, as is known from GB2486776.

(25) Within the open-ended chamber 21b is a priming means in the form of a piston 23 including a frame 24 formed by a peripheral rim 24a with a series of ribs 24b extending between the sides of the rim 24a to provide a series of openings therebetween. The piston 23 also includes a flexible diaphragm 25 secured at the centre of piston 23 by a cylindrical rod mount 26 which receives and secures a piston rod 27. The piston rod 27 extends upwardly from the piston 23, through the top wall of the chamber 21b and is formed of a material having sufficient mass to urge, in use, the piston 23 back down toward its home position, as shown in FIG. 5. The top wall of the open ended chamber 21b also includes a series of openings 28 about the piston rod 27 and an inverted top-hat shaped sealing element 29 that surrounds the piston rod and is biased by a spring 29a against the top wall to cover and seal the openings 28. When the piston 23 is in a raised position, the rod mount 26 abuts the sealing element 29 and urges it against the spring bias to reveal the openings 28. Thus, a partial flush can be achieved by keeping the piston 23 in a raised condition, since the syphonic action is broken when the water level reaches the openings 28.

(26) The integrated hydraulic circuit 3 includes a manifold 4, a filling device 5, an accumulator 6, an operating valve 7, a hydraulic actuator 8 and a telescopic lock 9. The manifold 4 includes an inlet part 40, which defines a horizontal inlet passage 41 and a vertical outlet chamber 42, and an extension part 43 received telescopically within the outlet chamber 42 of the inlet part 40, which defines an adjustable extension of the vertical outlet chamber 42. The extension part 43 of the manifold 4 includes a pair of radial grooves 44 at its upper end that receive respective O-ring seals for sealingly engaging the outlet chamber 42. The extension part 43 also includes an accumulator port 45 extending laterally from a lower end thereof and having a pair of flanges 46 forming opposed facing locking channels on either side of the accumulator port 45. The inlet part 40 includes a coupling 10 at the inlet end of the inlet passage 41, more of which later.

(27) The filling device 5 includes a float-operated diaphragm-type equilibrium valve 50 in this embodiment. The valve 50 includes a two-part housing 51, a diaphragm 52 with a peripheral flange captivated between the two parts of the housing 51 and a flow restrictor pin extending through a hole through a central, enlarged valve member portion of the diaphragm 52. On a first side of the diaphragm 52, the housing 51 includes an inlet 53, a plurality of radial outlets 54 and a valve seat between the inlet 53 and outlets 54 against which the central portion of the diaphragm 52 seats when the valve 50 is in a closed condition. On a second side of the diaphragm 52, there is a control chamber defined between the diaphragm 52 and a facing portion of the housing 51 with a bleed port 55 extending from the control chamber through the housing 51. The valve 50 is mounted to the inlet part 40 of the manifold 4 such that the inlet 53 is coupled to and in fluid communication with the outlet chamber 42.

(28) The filling device 5 also includes a float chamber or reservoir 56, a float 57 and a float arm 58, all of which are mounted to the inlet part 40 of the manifold 4. The float chamber 56 is in the form of an open top container with a draining port (not shown) in its base and a mounting bracket 56a which surrounds the lower end of the inlet part 40 that defines the outlet chamber 42. The float 57 in this embodiment is an open bottom container with an upstand 57a extending upwardly from the top of the container and having a series of holes through its thickness adjacent its upper end. The float arm 58 includes a resilient stop 58a at a first of its ends and a hole at a second of its ends for receiving a fastener that extends therethrough and into one of the holes of the upstand 57a of the float 57. The float arm 58 is pivotally mounted relative to the inlet part 40 intermediate its ends such that when the float 57 is in a raised position the stop 58a of the arm 58 closes the bleed port 55 of the valve 50 and when the float 57 is in a lowered position the bleed port 55 is open.

(29) The accumulator 6 includes an inverted bottle 60 having a kidney shaped horizontal cross-section and a mouth 61 at its lower end that is threadedly engaged with a coupling adapter 62. The mouth 61 of the bottle 60 includes a radial recess about its outer surface within which is received an O-ring for providing a sealed connection between the bottle 60 and the coupling adapter 62. The coupling adaptor 62 defines a 90 degree elbow to provide a horizontal inlet to the accumulator 6 and includes a pair of flanges 63 on either side of the horizontal inlet to provide a bayonet fitting for receipt within the locking channels defined by the flanges 46 of the accumulator port 45.

(30) Referring to FIG. 9, the accumulator 6 is mounted to the accumulator port 45 by offering up the coupling adapter 62 with the bottle 60 oriented horizontally away from the syphon 2 such that the flanges 63 are oriented vertically, between the flanges 46 of the accumulator port 45. The accumulator 6 is then rotated upwardly to the orientation shown in FIG. 9 such that the flanges 63 are received within the locking channels defined by the flanges 46 of the accumulator port 45. In this orientation, the inlet of the accumulator 6 is lowermost such that pressurised fluid introduced therein from the source compresses air within the container to provide a pressurised store of water.

(31) The operating valve 7 is similar to the valve 50 of the filling device 5, but rather than being float-operated it is operated by a separate push button actuator 10 (shown in FIGS. 14 to 18). The valve 7 includes a two-part housing 71, a diaphragm 72 with a peripheral flange captivated between the two parts of the housing 71 and a flow restrictor pin extending through a hole through a central, enlarged valve member portion of the diaphragm 72. On a first side of the diaphragm 72, the housing 71 includes an inlet 73, a plurality of radial outlets 74 and a valve seat between the inlet 73 and outlets 74 against which the central portion of the diaphragm 72 seats when the valve 7 is in a closed condition. On a second side of the diaphragm 72, there is a control chamber defined between the diaphragm 72 and a facing portion of the housing 71 with a bleed port 75 extending from the control chamber through to a push fit fitting 76 in the housing 71. Attached to the push fit fitting 76 is a bleed pipe BP operatively connected to the push button actuator 10. The operating valve 7 is mounted to the extension part 43 of the manifold 4 such that the inlet 73 is coupled to and in fluid communication with the outlet chamber 42.

(32) The hydraulic actuator 8, shown more clearly in FIG. 5, includes an actuator cylinder 80 formed integrally with the extension part 43 of the manifold 4 and an actuator piston 81 reciprocable within the cylinder 80. The actuator piston 81 includes a hole within which the upper end of the piston rod 27 is received and secured by a screw 82. The bottom end of the actuator cylinder 80 is fed by the outlets 74 of the operating valve 7 and the top end of the actuator cylinder 80 is open. In this embodiment, the actuator piston 81 is sized and dimensioned such that a fluid flow entering the actuator cylinder 80 from below forces the actuator piston 81 upwardly within the actuator cylinder 80. The actuator piston 81 is also sized and dimensioned such that the clearance between the actuator piston 81 and the cylinder 80 permits some fluid to flow therebetween. Thus, in the absence of fluid flow entering the actuator cylinder 80 from the operating valve 7 the mass of the piston rod 27 urges fluid flow around the actuator piston 81 and lowering the syphon piston 23 back to its home position. In this embodiment, the actuator piston 81 is formed of a plastics material having a relatively low weight.

(33) The telescopic lock 9 includes a rack 90 (shown more clearly in FIGS. 5 and 9) and a cooperating latch 91. The rack 90 is secured to the outside of the actuator cylinder 80 and includes a series of teeth 92 that extend substantially horizontally to define gaps therebetween. The latch 91 surrounds the inlet part 40 that defines the vertical outlet chamber 42 of the manifold and is rotatably captivated between the horizontal inlet passage 41 and the mounting bracket 56a of the float chamber 56. The latch 91 also includes a flat handle 93 to enable its manipulation and a series of teeth 94 that extend parallel to the teeth 92 of the rack 90 for engagement with the gaps between them. In this embodiment, the teeth 62, 63 lie at an angle relative to the horizontal so as to inhibit inadvertent disengagement between the latch 91 and the rack 90.

(34) As depicted in FIG. 1, the handle 93 of the latch 91 holds the accumulator 6 in place by inhibiting its rotation in the reverse direction to that described above. The handle 93 may be rotated in direction A to release the teeth 94 of the latch 91 from those of the rack 90, thereby enabling the inlet part 40 of the manifold 4 to be moved up or down with respect to the extension part 43. It will be appreciated that the entire filling device 5 is mounted to and moves with the inlet part 40, thereby enabling adjustment of the position of the filling device 5 relative to the bight of the U of the third part 22 of the syphon 2. It will also be appreciated that this position alters the fill volume of the cistern, since the float chamber 56 and float 57 are also moved.

(35) Thus, in order to increase the flush volume of the cistern, the third part 22 of the syphon 2 may be raised relative to the first and second parts 20, 21 and the inlet part 40 of the manifold may then be raised by a similar distance together with the filling device 5.

(36) Accordingly, the invention provides an integrated flushing and filling apparatus 1 that is adjustable to alter the flushing characteristics with minimal effort. In a conventional arrangement, such adjustment would require both an adjustable flushing device 2 and an adjustable filling device 5, which are not always present and, in any event, their independent adjustment would be more cumbersome.

(37) As shown more clearly in FIG. 7, the inlet part 40 of the manifold 4 also includes an anti back-syphonage valve 47 in the form of a non-return air valve 47. The non-return valve 47 includes a valve member 48 with a dome-shaped head carrying an O-ring that is biased by a spring 49 to seat against a valve seat. The force of the spring 49 is configured such that a back flow of pressure toward the supply pipe P from the manifold 4 causes the valve member 48 to unseat and allow air to be introduced into the manifold, thereby preventing a flow of water from the outlet chamber 42 and extension part 43 back into the supply pipe P.

(38) Referring now to FIGS. 10 to 13, the inlet coupling 10 is shown in greater detail. The inlet coupling 10 includes a first part 11 with a locking ring 12 having a series of inwardly extending radial teeth 13 and a triangular handle 14 for rotating the locking ring 12 between coupled and uncoupled orientations. The coupling 10 also includes a second part 15 with a series of outwardly extending radial teeth 16 each having a lead-in to facilitate insertion into the first part 11. The first part 11 includes a stepped recess 11a downstream of the locking ring 12. The second part 15 includes a filter recess 17 at its leading end, a push fit fitting 18 at its trailing end and an O-ring seal 19 received in a radial groove intermediate its ends which seals the second part 15 within the first part 11.

(39) The push fit fitting 18 includes an O-ring seal 18a for sealing against a supply pipe P received by the push fit fitting 18, a collapsible collar 18b and a retaining ring 18c surrounding the collapsible collar 18b. The collapsible collar 18b and retaining ring 18c have cooperating tapered surfaces such that the collapsible collar 18b is compressed on attempted removal, thereby retaining the supply pipe P within the push fit fitting 18.

(40) The coupling 10 also includes a conical filter 17a having a frame 17b with a circular inlet portion 17c corresponding to the mouth of the filter 17a and an O-ring seal 17d received within a radial groove in the circular inlet portion 17c which seals against a facing surface of the filter recess 17 of the second part 15 of the coupling 10. In the uncoupled orientation of the locking ring 12, the second part 15 is insertable into the first part 11 with its teeth 16 passing through the gaps between the teeth 13 of the first part 11. In the coupled orientation of the locking ring, the teeth 13, 16 of the first and second parts 11, 15 are aligned and removal of the second part 15 from the first part 11 is prevented.

(41) Referring now to FIGS. 14 to 17, there is shown a push button actuator 100 for operating the syphon 2. The push button actuator 100 in this embodiment includes a manifold 101, a body 102, a surround 103, a push button 104 and a hexagonal securing nut 105 with an internal thread. The manifold 101 includes an internally threaded hollow cylinder 110 with an open end and a closed end, a radial inlet port 111 and a radial outlet port 112. Each of the inlet and outlet ports 111, 112 includes a push fit fitting for releasably securing and sealingly receiving a flexible tube (not shown). In this embodiment, the bleed pipe BP connected to the bleed port 75 of the operating valve 7 is configured to be connected to the inlet port 111 and a further pipe (not shown) is configured to connect to the outlet port 112 at one end and feed into the cistern (not shown) at the other end.

(42) The body 102 is in the form of a hollow cylinder with a central, threaded section 121, a tail section 122 of reduced diameter, also externally threaded, and a mounting flange 123 at the opposite end of the body 102 to the tail section 122. The tail section 122 includes radial inlet passageways 122a and radial outlet passageways 122b axially spaced from the inlet passageways 122a. The mounting flange 123 includes a series of radial spokes 123a separated by axial holes 123b about the mounting flange 123.

(43) The surround 103 is in the form of a hollow cylinder 130 with an outwardly extending radial flange 131 at one end and an inwardly extending radial flange 132 at the other end to form a base ring 132 of the surround. The base ring 132 includes a series of castellations 133 extending about its innermost edge. Each castellation 133 includes a pair of projections 134 at its outermost corners, which together define a recess 135.

(44) The push button 104 includes a dome-shaped head 140 and a stem 141 movably received within the body 102. The push button 104 is movable within the body 102 between a deployed position shown in FIGS. 14, 16 and 17 and an actuated or depressed position in which the stem 141 is pushed further into the body 102. In this embodiment, fluid communication between the inlet passageways 122a and the outlet passageways 122b is closed in the deployed position and open in the actuated or depressed position. The push button 104 is also biased by a spring 142 to the deployed position. Thus, water is prevented from flowing from the inlet passageways 122a to the outlet passageways 122b until the push button 104 is operated. On operation of the push button 104, water is able to bleed from the bleed port 75 through the push button actuator 100 and back into the cistern (not shown) through the aforementioned pipes.

(45) In an assembled condition, the body 102 is received within the surround 103 such that the mounting flange 123 of the body 102 engages the base ring 132 of the surround 103 and the securing nut 105 is threadedly engaged with the central section 121 of the body 102. In addition, the tail section 122 of the body 102 is received within and threadedly engaged with the cylinder 110 of the manifold 101 such that the inlet passageways 122a are aligned with the radial inlet port 111 and the outlet passageways 122b are aligned with the radial outlet port 102.

(46) As illustrated in FIG. 16, when the body 102 is in a first orientation the castellations 133 of the surround 103 are received within axial holes 123b between the radial spokes 123a of the body 102 and the push button 104 is substantially flush with the outwardly extending radial flange 131 of the surround 103. As illustrated in FIG. 17, when the body is in a second orientation, the radial spokes 123a of the body 102 rest on the castellations 133 within the recesses 135 between the projections 134 and the push button 104 stands proud with respect to the outwardly extending radial flange 131 of the surround 103.

(47) Thus, the push button actuator 100 may be adapted to suit the requirements of multiple different installations. For example, the arrangement of FIG. 16 may be desirable for aesthetic purposes, whilst the arrangement of FIG. 17 enables users with less dexterity to operate the push button actuator 100 with ease.

(48) In use and as shown in FIGS. 2 and 3, when the supply pipe P is connected to a source of pressurised water, such pressurised water flows through the supply pipe P, through the filter 17a, into the manifold 4, into the inlet 53 of the fill valve 50, into the inlet 73 of the operating valve 7 and into the accumulator 6. When the cistern (not shown) is full, the arm 58 of the filling device 5 is raised, thereby blocking the bleed port 55 of the fill valve 50, pressurising the control chamber defined between the diaphragm 52 and a facing portion of the housing 51 and forcing the diaphragm 52 against the valve seat to close the fill valve 50. With the push button actuator 100 in the deployed position, the bleed port 75 of the operating valve is also blocked, thereby pressurising the control chamber defined between the diaphragm 72 and a facing portion of the housing 71 and forcing the diaphragm 72 against the valve seat to close the operating valve 7. Pressurised water then charges the accumulator 6 ready for operation.

(49) In order to initiate a flush, the head 140 of the push button actuator 100 is depressed, which opens fluid communication between the inlet 111 and the outlet 112, thereby allowing flow from the bleed port 75 of the operating valve 7 through the bleed pipe BP and through the push button actuator 100 into the cistern (not shown). This flow releases the pressure within the control chamber of the operating valve 7 and the pressure within the manifold 4 unseats the diaphragm 72. Water then flows as illustrated in FIG. 5 from both the supply pipe P and from the accumulator 6 through the outlets 74 of the operating valve 7 and into the actuator cylinder 80, thereby forcing the actuator piston 81 upwardly and forcing the syphon piston 23 upwardly within the syphon chamber 21b. This forces the diaphragm 25 against the frame 24 of the piston 23 and raises the volume of water within the chamber 21b up and over the bight of the U of the third part 22 of the syphon 2 and initiating a syphonic flushing action. Water then flows through the openings in the frame 24 of the piston 23, urging the diaphragm 25 upwardly, and continues to flow through the syphon 2.

(50) Thus, in situations where the pressure from the water supply is reduced or fluctuates, the accumulator 6 provides additional pressurised flow to ensure that the syphonic action is initiated effectively.

(51) If the head 140 of the push button actuator 100 continues to be depressed, water continues to flow through the actuator cylinder 80 and retains the piston in a raised position. As outlined above, this also keeps the sealing element 29 in a raised condition exposing the series of openings 28 such that when the water level within the cistern (not shown) drops to this point the syphonic action is broken, thereby resulting in a partial flush. If, however, the head 140 of the push button actuator 100 is released immediately or shortly after it is depressed initially, a full flush is effected.

(52) As the water level within the cistern (not shown) drops, the float chamber 56 empties through the draining port (not shown) and the float 57 drops within the float chamber 56. At this point, the arm 58 pivots and the resilient stop 58a unseats from the bleed port 55, thereby releases the pressure within the control chamber of the float valve 50 and unseating the diaphragm 52. Fluid flow is then opened between the inlet 53 and the outlets 54 and water drains out of the float valve 50 as illustrated in FIG. 6 to refill the cistern (not shown). As the water level rises above the top of the float chamber 56, it is refilled and the float 57 is once again raised to cause the resilient stop 58a to block the bleed port 55, thereby pressurising the control chamber of the float valve 50 and forcing the diaphragm 52 against the valve seat and closing the float valve 50.

(53) Turning now to FIGS. 18 and 19, there is shown a flushing apparatus 301 according to another embodiment of the invention. The flushing apparatus 301 according to this embodiment is similar to the flushing apparatus 1 described above, wherein like references depict like features that will not be described further herein. The flushing apparatus 301 according to this embodiment differs from the previous embodiment in that the hydraulic circuit 303 for operating the flushing device 2 is not integral with the flushing device 2 and it incorporates an air introduction assembly 310. In this embodiment, the hydraulic circuit 303 includes a supply pipe P incorporating a non-return valve 330, which feeds into an inlet manifold 331 via a push fit inlet fitting 331a. The hydraulic circuit 303 also includes an accumulator 306, an outlet manifold 332 and an outlet pipe O connecting an outlet push fit fitting 332a of the outlet manifold 332 to a push fit fitting 307 which feeds into the operating valve 7.

(54) The accumulator 306 is in the form of a bottle 360 with which the inlet and outlet manifolds 331, 332 are both formed integrally at its mouth. The accumulator 306 includes a water inlet tube 361 fluidly connected to and extending orthogonally from the supply pipe P and push fit fitting 331a into the accumulator 306 toward its base 362. The water inlet tube 361 includes a necked portion 363, which accelerates, or throttles, the flow of water therethrough. The accumulator 306 also includes a water outlet tube 364 fluidly connected to and extending from the outlet manifold 332 into the accumulator 306 toward its base 362.

(55) The inlet manifold 331 includes a third branch 333 receiving the air introduction assembly 310. The third branch 333 includes a flange at its upper end and receives an insert 311. The insert 311 includes a part-spherical shoulder for redirecting the inlet water flowing from the supply pipe P into the water inlet tube 361 and an air inlet tube 312 open at its upper end and extending into the necked portion 363 of the water inlet tube 361 to provide fluid communication between the third branch 333 and the necked portion 363.

(56) The air introduction assembly 310 also includes a non-return valve 313, which includes an air inlet 313a, a valve member 314 reciprocable within a retainer 315. The valve member 314 includes a piston with an O-ring seal about its periphery and a longitudinal guide pin received within a guide ring in the base of the retainer 315 to ensure smooth reciprocating motion therein. The valve member 314 is retained within the retainer 315 by a shoulder at its upper end against which the piston seals when forced in its uppermost position. The retainer 315 is retained within the third branch 333 by a cap ring 316 which engages the flange of the third branch 333. The insert 311 is captivated between the retainer 315 and a shoulder of the inlet manifold 331.

(57) The outlet manifold 332 includes a second outlet fitting 332b, which is in the form of a threaded tail in this embodiment. The apparatus 301 includes a filling device 305 having a threaded collar 350 for threadedly engaging the second outlet fitting 332b to provide a fluid connection therebetween. The filling device 305 is in the form of a substantially conventional fill valve 351 operated by a float 352, similar to that which is disclosed in EP0961892 and offered commercially by the present applicants, but for the means by which it connects to the outlet manifold 332 of the present invention.

(58) In use and when the operating valve 7 and the fill valve 351 are both closed, the pressure within the accumulator 306 urges the valve member 314 against the shoulder of the retainer 315, thereby sealing off the non-return valve 313. When a user initiates a flushing action as described above in relation to the first embodiment, the operating valve 7 opens and pressurised water flows from the accumulator 306 through the outlet pipe O and through the operating valve 7 to initiate the symphonic action. This occurs even in the absence of fluid pressure from the source. Following operation, the operating valve 7 closes.

(59) As the water level drops, the float 352 of the filing device 305 lowers and opens the fill valve 351 and water flows from the accumulator, out of the second outlet fitting 332b and out through the filling device 305. The flow of water from the supply pipe P through the water inlet tube 361 creates a venturi effect within the necked portion 363, thereby reducing the pressure within the third branch 333 of the inlet manifold 331. This reduction in pressure causes the valve member 314 to unseat from the shoulder of the retainer 315 and air is entrained from the air inlet 313a and into the accumulator 306. As outlined above, the applicants have observed that air in the accumulator may become depleted over time, but the air introduction assembly 310 regularly reintroduces air into the accumulator, thereby mitigating this phenomenon. The provision of an air inlet which introduces air through a venturi means enables this reintroduction of air to occur automatically.

(60) As the water level rises, the float 352 rises and closes the fill valve 351. As a result, the circuit 303 pressurises and the accumulator refills, ready for the next flushing action.

(61) It will be appreciated by those skilled in the art that several variations to the aforementioned embodiments are envisaged without departing from the scope of the invention. For example, although the invention has been illustrated with reference to a cistern flushing apparatus, it will be appreciated that it may be incorporated into any suitable fluid supply system, such as a drain cleaning apparatus, for example one which uses a jetting device. Whilst the accumulator in the specific embodiments is in the form of a bottle 60, 360, it will be appreciated that the accumulator may be provided by any enclosed volume, provided by, for example, multiple components assembled together to form a reservoir that is configured to function as described. It will also be appreciated by those skilled in the art that any number of combinations of the aforementioned features and/or those shown in the appended drawings provide clear advantages over the prior art and are therefore within the scope of the invention described herein.