HK1132019B - Flush valve - Google Patents

Description

Flushing valve

Cross reference to related applications

This application is a continuation-in-part of U.S. patent application No.11/481,220 filed on 5.7.2006, and claiming priority thereto, and is hereby incorporated by reference in its entirety.

Technical Field

The present invention relates to an improved flush valve for a plumbing fixture.

Background

Flushing systems for toilets used in, for example, commercial buildings normally include a flush valve that provides water to flush the individual plumbing fixtures. The flush valve is typically of the U.S. flushometer type which is actuated to provide a standard or metered volume of water for a flush operation. Examples of conventional flush valves are disclosed in US4,327,891 and US5,295,655. Another flush valve is disclosed in U.S. patent 4,662,602.

A typical flush valve includes a main valve to control the flow of water through the flush valve from the inlet to the outlet. Inlet pressure in the control chamber normally causes the main valve member to remain closed against the main valve seat. A seal, typically a diaphragm, isolates the control chamber from the inlet pressure, with a portion of the diaphragm or an element supported by the diaphragm acting as the primary valve member. A pilot valve member or a pressure relief valve member cooperates with the pilot valve seat. The pilot valve seat may be formed within the diaphragm or within an element supported by the diaphragm, for example may be part of the main valve member.

Pilot valve mechanisms typically have a valve stem adapted to be contacted by an actuator. In manually operated flush valves, the actuator may be a plunger or a push rod that is moved into contact with the valve stem by operation of a handle. When the valve stem is rotated or tilted by the actuator, the pilot valve opens, allowing the control chamber to exhaust toward the outlet of the flush valve. The inlet pressure moves the valve member from the closed position to the open position, and water flows through the flush valve to flush the plumbing fixture. Water gradually flows into the control chamber through the restrictive orifice, moving the diaphragm and the primary valve member back toward the closed position. After a standard amount of water flow, the main valve is closed, terminating the flush operation.

One problem with known flush valves is the unreliable and inconsistent initiation of a flush cycle under high inlet pressure conditions. The inlet pressure may clamp and tightly close the pilot valve, and the tilting of the pilot valve and valve stem may cause tilting of the main valve member rather than opening the pilot valve. If this occurs, the control chamber will not be completely drained and the desired flushing operation will not occur.

Another problem of known flush valves occurs when the actuator only slightly tilts the pilot valve stem. A short and rapid action of the actuator will not open the pilot valve and therefore vent the control chamber due to factors such as the inertia of the pilot valve.

A typical flush valve has a side inlet. Water passing through the valve flows in from the side and then flows upward and over the main valve seat at an uneven pressure and flow pattern caused by the side entry velocity (side entry velocity) effect. Side loading can cause friction, reduce the life of the valve, and result in inconsistent flush volumes. In addition, the uneven water pressure field in the control chamber causes the operation of the flush valve to be sensitive to the position of elements such as the restriction orifice.

Another problem with known flush valves is wear of the pilot valve. In a typical arrangement, in the pilot valve fully open position, the rigid plastic bracket is in contact with a fixed resilient base region. Repeated valve operation can cause wear on the pilot valve, which can be difficult to replace and maintain.

In known flush valves, the flow is greatest when the main valve is open and decreases as the main valve returns to the closed position. The main valve assembly is typically equipped with a flow regulating structure for regulating the water flow characteristics. However, known flow regulation includes a problem that the flow rate is continuously decreased as the valve is closed, which cannot be overcome.

Disclosure of Invention

It is a primary object of the present invention to provide an improved flush valve for providing a standard as well as regulated amount of water flow to flush a plumbing fixture. Other objects of the present invention are to provide a flush valve having a pilot valve structure which has a long service life and is easily replaced when worn; to provide a flush valve capable of achieving a consistent and reliable flush operation when actuated at high inlet pressures tending to pinch and close a pilot valve; to provide a flush valve with which reliable actuation can be achieved even if the operation of the actuating handle is short and rapid or tentative; to provide a flush valve in which difficulties caused by pressure non-uniformity caused by a side water inlet are overcome; providing a flush valve capable of maintaining a relatively uniform flow rate during an initial flush portion of a siphonic toilet flush cycle; and to provide an improved flush valve which is relatively inexpensive to manufacture and maintain and which overcomes the problems experienced with known flush valves.

Briefly stated, the present invention provides a flush valve for a plumbing fixture. The flush valve includes a housing with a longitudinal axis, an inlet, an outlet, and a main valve seat between the inlet and the outlet, the main valve seat being oriented transverse to the axis. The main valve assembly includes a main valve member movable in an axial direction relative to a main valve seat. A control chamber on a first side of the main valve member communicates with the inlet port to normally hold the main valve member against the main valve seat. The main valve assembly includes a conduit extending axially from a second side of the main valve member. The main valve assembly includes a pilot valve seat. The pilot valve member moves relative to the pilot valve seat. The valve stem extends axially from the pilot valve member. An actuator on a first side of the axis engages the valve stem to tilt the pilot valve by moving the valve stem laterally. The housing includes a seat that engages a conduit on a second side of the axis opposite the first side of the axis to resist tilting forces applied by the pilot valve to the main valve assembly during lateral movement of the valve stem.

Briefly, in accordance with another feature of the invention, there is provided a flush valve for a plumbing fixture, the flush valve including a housing having a longitudinal axis, an inlet, an outlet, and a main valve seat between the inlet and the outlet, the main valve seat being oriented transversely to the axis. The main valve assembly includes a main valve member movable in an axial direction relative to the main valve seat. The main valve assembly includes a pilot valve seat. The pilot valve member is movable relative to the pilot valve seat. The control chamber is located on a first side of the main valve member. A restricted passage between the inlet and the control chamber normally pressurizes the control chamber and holds the main valve member against the main valve seat and the pilot valve member against the pilot valve seat. The valve stem projects axially from the pilot valve member in a first axial direction away from the control chamber. The valve stem has an end portion and an intermediate portion between the end portion and the pilot valve. An actuator is engageable with an intermediate portion of the valve stem to tilt the pilot valve by moving the valve stem laterally to evacuate the control chamber and allow the main valve assembly to move in the opposite second axial direction. An enlarged member at the end portion of the valve stem may engage the actuator during axial movement in the second direction to enhance lateral movement of the valve stem and further tilt the pilot valve.

Briefly, in accordance with another feature of the invention, there is provided a flush valve for a plumbing fixture, the flush valve including a housing having a longitudinal axis and a main valve seat oriented transversely to the axis. The housing includes a tubular wall defining an outlet passage extending axially from a first side of the main valve seat. An annular inlet chamber surrounds the tubular wall. The housing includes an inlet passage extending radially into the inlet chamber. The main valve assembly includes a main valve member movable in an axial direction relative to a main valve seat. An annular passage extends from the inlet chamber to the main valve seat. A baffle is located within the annular passage. One of the annular passage and the baffle is symmetric about the axis and the other of the annular passage and the baffle is asymmetric about the axis.

Briefly, in accordance with another feature of the invention, there is provided a flush valve for providing a metered flow of flush water to a plumbing fixture. The flush valve includes a housing with an inlet, an outlet and a main valve seat, and a tubular wall defining an outlet passage extending from a first side of the main valve seat to the outlet. An annular inlet chamber surrounds the tubular wall and communicates with the inlet and the main valve seat. The main valve assembly includes a main valve member movable toward a main valve seat to a closed position and movable away from the main valve seat to a fully open position. A normally pressurized control chamber is located within the housing on a second side of the main valve seat. The main valve assembly includes a seal between the main valve member and the housing for separating the inlet chamber from the control chamber. The pilot valve assembly is operable from a blocking position to a venting position to vent the control chamber to the outlet and move the main valve member within the control chamber from a closed position to a fully open position. A restrictor within the control chamber engages the pilot valve assembly when the main valve member is in the fully open position to retain the pilot valve assembly in its blocking position. A restricted passage extends between the inlet chamber and the control chamber to repressurize the control chamber and return the main valve member from the fully open position to the closed position. First and second flow regulating assemblies are formed on the housing and the main valve assembly. The first flow adjustment assembly has minimal throttling effect at the fully open position of the main valve and provides gradually increasing flow adjustment as the main valve member moves toward the closed position. The second flow regulation assembly has a maximum throttling effect at the fully open position of the main valve and provides a progressively decreasing flow regulation as the main valve member moves toward the closed position.

Briefly, in accordance with another feature of the invention, there is provided a flush valve for providing a metered flow of flush water to a plumbing fixture. The flush valve includes a housing having an inlet, an outlet, and a main valve seat. The main valve assembly includes a main valve member movable toward a main valve seat to a closed position and movable away from the main valve seat to a fully open position. The normally pressurized control chamber is located within the housing on one side of the main valve seat. The main valve assembly includes a seal between the main valve member and the housing for separating the control chamber from the inlet chamber. The water directing valve assembly operates from the blocking position to the drain position to drain the control chamber to the outlet and move the main valve member within the control chamber from the closed position to the fully open position. The pilot valve assembly includes a pilot valve seat within the main valve assembly and a pilot valve train including a head portion within the control chamber that engages the pilot valve seat in the blocking position. A restrictor within the control chamber engages the pilot valve head portion when the main valve member is in the fully open position to retain the pilot valve assembly in its blocking position. A restricted passage extends between the inlet chamber and the control chamber to repressurize the control chamber and return the main valve member from the fully open position to the closed position. The head portion includes an inner body and a resilient seal removably attached over the inner body. The seal is cup-shaped and includes a base portion overlying the inner body and a flange portion surrounding the periphery of the inner body and engaging between the inner body and the pilot valve seat when the pilot valve is in the blocking position. The restrictor includes a valve rotor structure that engages the base of the seal member when the primary valve member is in the fully open position.

Drawings

The present invention, together with the above and other objects and advantages, may best be understood by reference to the following detailed description of a preferred embodiment of the invention illustrated in the accompanying drawings, wherein:

FIG. 1 is an isometric view of a plumbing installation including a controllable restriction and a flush valve constructed in accordance with the present invention;

FIG. 2 is an enlarged vertical cross-sectional view of the flush valve taken along line 2-2 of FIG. 1 and showing the flush valve in a closed, armed position;

FIG. 3 is the same view as FIG. 2, showing the pilot valve being opened by the handle and push rod at the beginning of a flush cycle;

FIG. 4 is the same view as FIG. 3, showing the pilot valve moving with the main valve open to open further;

FIG. 5 is the same view as FIGS. 2-4, showing the flush valve in a fully open position;

FIG. 6 is an exploded isometric view of the pilot valve assembly of the flush valve;

FIG. 7 is an exploded isometric view of the main valve assembly of the flush valve;

FIG. 8 is a cross-sectional view of the flush valve frame and catheter taken along line 8-8 of FIG. 5;

FIG. 9 is a cross-sectional view of the frame and catheter taken along line 9-9 of FIG. 8;

FIG. 10 is an enlarged top plan view of the frame;

FIG. 11 is an enlarged isometric view of the inner cap; and

FIG. 12 is an enlarged cross-sectional view of the head assembly of the pilot valve assembly.

PREFERRED EMBODIMENTS FOR CARRYING OUT THE INVENTION

Referring now to the drawings and initially to FIG. 1, there is shown a plumbing fixture, generally designated 20, for flushing a toilet (not shown). The plumbing 20 has a water supply pipe 22 through which water is supplied from a pressurized water source, such as a municipal or local water supply system. Pipe 22 supplies water to a throttle controllable restriction 24, and water from throttle controllable restriction 24 is supplied through a transfer pipe 26 to a flush valve, generally designated 28, constructed in accordance with the principles of the present invention.

The flush valve 28 of the present invention is shown in detail in fig. 2-12. In general, the flush valve 28 includes a housing 30 having an inlet 32 connected to the transfer tube 26 and an outlet 34 for connection to an outlet tube 36 (FIG. 1). The main valve assembly 38 is movable between a closed position (fig. 2) and a fully open position (fig. 5) to control the flow of water from the inlet 32 to the outlet 34. The main valve assembly is normally held closed by pressure in the control chamber 40. The control chamber is normally pressurized by restricted communication with the inlet port 32 via the restricted passage 42. The pilot valve assembly 44 is movable from a closed or blocking position (fig. 2) to an open or venting position (fig. 3 and 4) to quickly evacuate the control chamber 40 to the outlet 34 to abruptly open the main valve assembly 30. The pilot valve assembly 44 is actuated to its open or discharge position by manipulation of the handle 46. The principles of the present invention are also applicable to flush valves having other drive systems, such as electrically operated flush valves.

The housing 30 includes a valve body 48 and a frame 50 secured within the valve body 48. The transfer tube 26 is secured to the valve body 48 at the inlet 32. The outlet 34 is located at the lower end of the valve body 48. An inlet pressure region 52 is defined between the valve body 48 and the frame 50. The upper end of the housing 30 is closed by a cap 54 fixed to the valve body 48. An inner cover 56 is provided beneath the cap 54.

The main valve assembly 38 includes a diaphragm 58, the diaphragm 58 having a peripheral sealing portion 60 disposed between the inner cover 56, the frame 50, and the valve body 48 to seal the control chamber 40. The diaphragm plate 62 supports a central valve train portion 64 (FIG. 7) of the diaphragm 58. The restricted passage 42 extends through the diaphragm 58 and the diaphragm plate 62 for continuous restricted communication between the inlet pressure region 52 and the control chamber 40. The diaphragm 58 has a rotatable diaphragm portion 66 that provides a long operating stroke and large control chamber volume with less friction and no perceptible center offset. A vent 67 (fig. 7) in the diaphragm plate 62 prevents a squeak or squeal noise condition when unseating by venting the upper portion of the diaphragm 58 to the control chamber and clamping the diaphragm 58 against the diaphragm plate 62.

Outlet passage 68 extends downwardly through a tubular wall portion 70 of frame 50 to outlet 34. The frame 50 includes an annular main valve seat 72, the annular main valve seat 72 being engaged by the valve train portion 64 of the diaphragm 58 when in the closed position (fig. 2). This prevents water flow from the inlet 32 and the inlet pressure region 52 through the main valve seat 72 to the outlet passage 68 and the outlet 34. The frame 50 includes a flange portion 74 and a rib portion 76 (fig. 8 and 10) to support the rotatable membrane 66 of the diaphragm 58.

The main valve assembly 38 includes a conduit 78 attached to the diaphragm plate 62, the conduit 78 extending downwardly within the tubular wall 70 of the frame 50. The guide ribs 80 (fig. 7 and 9) on the conduit 78 slidingly engage the tubular wall 70 and center the conduit 78 and the main valve assembly 38 within the housing 30. The main valve assembly 38 also includes a backfill water flow control ring 82 (fig. 7 and 8), the control ring 82 cooperating with the main valve seat portion 72 of the frame 50 during a flushing operation of the flush valve 28 as described below.

The restricted passage 42 is defined in an orifice section 84 (FIG. 7) secured in an opening in the diaphragm plate 62 by a retainer 86. The orifice pin 88 extends through the orifice member 84 with a gap that defines the cross-sectional area of the water flow restriction. Contact with the frame 50 and the inner cap 56 limits needle movement, while movement of the main valve assembly relative to the needle clears the restricted passage 42.

The pilot valve assembly 44 includes a head portion 90 located within the control chamber 40 and a stem portion 92 extending downwardly within the conduit 78 of the main valve assembly 38. The head portion is normally maintained in a drawn-against sealing relationship with a valve seat surface 94 (FIG. 7) located on the diaphragm plate 62 by pressure in the control chamber 40. The valve seat surface 94 surrounds a vent 96 (fig. 7), which vent 96 extends through the diaphragm plate 62 from the control chamber 40 to the interior of the conduit 78.

Head portion 90 of pilot valve assembly 44 includes a head flange 98 of a pilot valve base 100. Mounted on the head flange 98 is a generally cup-shaped pilot valve seal 102 (fig. 6 and 12), the seal 102 being made of a resilient material such as rubber. A reentrant rim portion 104 (fig. 12) of the seal 102 extends below the head flange 98 and engages the valve seat surface 94. The central upper portion 106 covers the top of the head flange 98. The hub portion 108 is received within the central opening of the pilot valve base 100. When the main valve assembly 38 is fully open (fig. 5), the central upper portion 106 engages a central seat 110 on the inner cap 56.

The support 110 is provided with a rotary valve arrangement, best shown in fig. 11. The service life of seal 102 is extended because as the resilient central portion 106 of pilot valve seal 102 engages the rotating seat 110 with each movement of the main valve assembly 38 toward the fully open position shown in FIG. 5, and the pilot valve assembly increases in rotation, valve contact wear is evenly distributed over the periphery of the reentrant edge portion 104 of pilot valve seal 102. In addition, since the seal 102 can be removed by pulling it off the head flange 98 by stretching the material, it can be easily replaced even if the pilot valve seal is worn. A new, replacement seal would then be installed on the head flange in the same manner. Drain passages 112 in head flange 98 prevent liquid from becoming trapped in pilot valve seal 102.

The stem portion 92 of the pilot valve assembly 44 is shown in FIG. 7 and includes a stem shaft 114 secured within a stem groove portion 116 of the pilot valve base 100. A valve stem sleeve 118 is slidably mounted on the stem shaft 114 and is retained at the stem shaft 114 by a head portion 120.

One flush cycle of the illustrated flush valve 28 is initiated by actuating the handle 46 from the standby position shown in fig. 2 to the actuated position shown in fig. 3. A pusher member 122 partially contained within a bladder 124 moves radially inwardly toward the axis of the flush valve 28 and contacts the valve stem portion 92 of the pilot valve assembly 44. Thus, head portion 90 of pilot valve assembly 44 is tilted or pivoted away from pilot valve seating surface 94 as shown in FIG. 2. As water flows from control chamber 40 through drain 96 and down through conduit 78, control chamber 40 quickly drains toward outlet 34. The relief pressure in control chamber 40 allows inlet pressure to rapidly move main valve assembly 38 and pilot valve assembly 44 to the fully open position shown in FIG. 5.

In the normal, armed, closed position shown in fig. 2, the head portion 90 of the pilot valve assembly 44 is clamped closed by the main valve assembly 38 by the pressure differential between the relatively high inlet pressure in the control chamber 40 and the relatively low outlet pressure downstream of the main valve seat 72. When the inlet pressure is high, the clamping force may be large.

One problem with known flush valves is that the force clamping the pilot valve closed may be large enough to impede reliable valve actuation for initiating a flush cycle. A large side load force is required to open the pilot valve. However, the radial, eccentric thrust of the push rod against the pilot valve stem, and the resulting tilting action of the pilot valve stem (rather than tilting the pilot valve to the open or drain position), causes the main valve assembly and the clamped pilot valve assembly to tilt in unison. Uncontrolled and inconsistent leakage flow through the main valve seat may occur rather than rapid venting of the control chamber.

To solve the above problem, in the flush valve 28 of the present invention, the main valve assembly is firmly supported so that it cannot rotate when an eccentric radial driving force is applied to the pilot valve assembly 44. The conduit 78 includes an enlarged diameter skirt 126 at its lower end. The frame 44 of the housing 30 includes a strong, bulky support rib 128 disposed diametrically opposite the push rod 122. The support ribs 128 engage the skirt 126 (fig. 9) and positively prevent tilting of the main valve assembly 38 when the push rod 122 is acted upon by a radial driving force. Thus, even under elevated inlet pressure, actuation of handle 46 and the radially inward movement of push rod 122 cause pilot valve assembly 44 to pivot to a drain or open position relative to main valve assembly 38 in unison.

In accordance with the present invention, the lower end of pilot valve stem portion 92 is enlarged to provide a toggle open effect when pilot valve assembly 44 is actuated. In the illustrated arrangement, the pilot valve stem sleeve 118 includes a bell shaped enlarged member 130 at its lower end. In the closed position (fig. 2) and upon initial actuation (fig. 3), the enlarged member 130 is positioned below the contact end of the push rod 122. Immediately following the initial tilting contact of the push rod 122 against the valve stem portion 92, the pilot valve assembly 44 moves upward as the control chamber 40 rapidly empties. The enlarged member 130 engages the end of the push rod 122 (fig. 4) and without further movement of the handle 46 or push rod 122, the pilot valve stem portion tilts further away from center. This provides a toggle-like, snap-opening effect, which ensures consistent actuation even if the operation of the handle 46 is limited and rapid or attempted.

When the main valve assembly 38 and pilot valve assembly 44 reach the fully open position shown in FIG. 5, the rotor structure of the support 110 will impose a slight angle of wear distribution away from the pilot valve seal 102 and pilot valve assembly 44. The main valve assembly 38 including the valve train sealing portion 64 is displaced from the main valve seating surface 94 of the frame 50 and water flows from the inlet 32, under the main valve assembly 38, past the main valve seat 72 and the outlet passage 68 in the frame 50 to the outlet 34.

The flow and pressure conditions through the flush valve 28 are not uniform about the central longitudinal axis. The main reason for this is to direct the water flow sideways to the radially oriented inlet 32 of the inlet pressure region 52. The side entry water flow causes a ram effect-the portion of the pressure in region 52 opposite inlet 32 increases, while the portion of the pressure in region 52 adjacent inlet 32 decreases. This uneven pressure field can cause difficulties such as side loading and increased operating friction of the main valve assembly 38. In addition, uneven pressure within the control chamber 40 may cause the operation of the flush valve to be undesirably sensitive to the position of the diaphragm 58 and the restrictive flow passage 42.

To avoid difficulties caused by uneven pressure in the area of the main valve assembly 38 and in the control chamber 40, the frame 50 includes a flow balancing baffle 132 upstream of the main valve assembly 38. In the illustrated embodiment of the invention, the baffle 132 is circular and lies in a radial plane within a circular inlet opening 134 formed in the valve body 48 below the main valve seat 72. The circular water inlet 134 is symmetrical about the vertical longitudinal axis of the flush valve 28, however the baffle 132 is offset and asymmetrical as shown in fig. 10. To compensate for flow regime differences in the inlet pressure region 52, the baffle 132 is offset in a radial direction away from the inlet port 32. The side 132A of the baffle opposite the inlet port 32 is relatively close to the circular aperture 134, while the side 132B closest to the inlet port 32 is spaced further from the edge of the circular aperture 134.

The baffle 132 partially restricts the incoming water flow but only produces a small pressure loss at maximum flow. The distribution of baffle flow restriction relative to the side inlet port 32 compensates for the flow rate effect of the port 32 to provide a uniform pressure field within the main valve assembly 38 and the control chamber 40. Side loading and the resulting valve operating friction are reduced or eliminated and the diaphragm 58 and restricted lower passageway 42 can be randomly placed with minimal impact on valve operation and flow delivery.

When the main valve assembly 38 and the pilot valve assembly 44 reach their uppermost, i.e., fully open, positions, delivery of metered and regulated flow of water for one flush cycle begins. In the fully open position (fig. 5), the control chamber 40 is at a minimum volume and is sealed because the pilot valve head portion 90 is forced by contact with the central seat 110 of the pilot valve sealing surface 94 that is in close abutment against the diaphragm plate 62.

The main valve assembly 38 then progressively recloses through a dashpot-like operation as the control chamber 40 is refilled from the inlet pressure region chamber 52 by water flowing through the restricted flow passage 42. The flow rate is dependent on the gap between the punch member 84 and the self-cleaning punch pin 88. There is a proportional relationship between the main valve flow area and the area of the restricted flow passage 42. The same inlet pressure region 52 acts on the main valve and the restricted passage 42, and there is a fixed ratio of water flow from the inlet 32 through the main valve to the outlet 34 to water flow through the restricted passage 42 into the control chamber 40. This proportional relationship ensures that a constant volume of flush water is maintained despite variations in supply pressure or differential pressure changes across the flush valve 28.

The illustrated flush valve 28 is designed to provide a configured flow to a siphonic toilet utilizing two-stage flow delivery. For this type of plumbing fixture, the initial stage of the flush cycle is a relatively large volume of flush water flow used to evacuate the fixture in a siphon action. The flushing water flow is followed by a relatively low flow to reseal the trapway of the plumbing fixture. The flushing performance of the syphon-type sanitary appliance will be improved if the initial high flow rate can be maintained at a sustained flow rate (even if the flow rate is less than the maximum possible) and also if the transition from high flush flow rate to low reseal flow rate is abrupt.

To optimize the flow characteristics during the flush cycle of a siphonic plumbing fixture, the flush valve 28 of the present invention utilizes two different flow regulating assemblies that operate sequentially during the high flow flush portion of the cycle. The second flow regulating assembly 136 functions to reduce flow at the beginning of the high flow portion and the main flow regulating assembly functions to reduce flow at the end of the high flow portion.

An outlet flow passage 68 (fig. 8) in the frame 50 extends from the main valve seat 72 to the outlet 34. The passageway 68 has an upstream section 68A, the diameter of the upstream section 68A being substantially the same as the diameter of the enlarged diameter skirt 126 of the conduit 78. The shoulder 142 separates the upstream segment 68A from the downstream segment 68B, which has a larger diameter and provides sufficient clearance for unimpeded water flow around the skirt 126 (fig. 9). Skirt 126 and shoulder 142 form second flow adjustment assembly 136.

The use of the rotatable diaphragm 58 provides an extended stroke to the main valve assembly 38, yet the main valve assembly can move a sufficient distance between the fully open and closed positions shown in fig. 5 and 2. In the fully open position at the beginning of the flush cycle, as shown in fig. 5 and 8, the skirt 126 is adjacent the shoulder 142 to regulate flow through the outlet flow passage 68. This reduces the flow rate below that which would be possible without the second flow regulating assembly 136, but promotes improved flushing performance by cooperating with the primary flow regulating assembly 138 to maintain a relatively uniform high flow rate flushing water flow.

The backfill flow control ring 82 cooperates with the main valve seat 72 to provide a main flow regulation assembly 138. As the main valve assembly moves downward from the fully open position, skirt 126 moves away from shoulder 142, reducing the throttling effect of second flow regulation assembly 136. Simultaneously, as the lower edge of ring 82 approaches main valve seat 72, main flow regulator assembly 138 begins to regulate flow. As the main valve assembly 38 is lowered, the throttling effect passes from the second trim assembly 136 to the main trim assembly 138 in order to maintain a more uniform high flush flow rate than would be achievable without the second assembly 136.

The backfill flow control ring 82 is provided with a flow adjustment groove 144 extending upwardly from its lower edge. When the lower edge of the ring 82 reaches the main valve seat 72, the flow is reduced from the high flow flush segment to a lower water seal reseal flow supplied through the groove 144. Due to the extended main valve stroke achieved with the rotatable diaphragm 58, a sharp and distinct transition from high flush flow to lower seal reseal flow is obtained.

Alternatively, the flush valve 28 may be configured for use in a urinal application, with a relatively constant, low flow of water being provided for flushing the fixture. For example, the flow control ring 82 may be modified to provide only a relatively constant fixture flush flow. Many of the principles of the present invention can be applied to both siphonic flush valves and urinal fixture flush valves.

The skirt 126 serves the additional function of directing the flow of water out of the downstream channel segment 68B and away from the valve stem sleeve 118 and the bell enlargement 130.

As the main valve assembly 38 is lowered toward the closed position shown in FIG. 2, the flared enlargement 130 of the sleeve 118 approaches the end of the pusher mechanism 122. If the handle is held in the actuated position, the flared section 130 is in the path of the descending sleeve 118. In this case, the sleeve 118 will slide upward on the valve stem shaft 114, allowing the main valve assembly 138 to close regardless of the position of the handle 46.

In an exemplary embodiment, the flush valve housing 30 discussed above has additional advantages over the prior art. Any connection of the flush valve requires penetration into the pressure chamber by various protrusions for the insertion/maintenance kit, the water outlet, the water inlet, and some activation means (e.g., manual handle or automatic actuator). In the prior art, these openings in the valve body typically utilize external bosses to attach the tabs to the valve body. For example, external threaded bosses in combination with seals and nuts have previously been utilized. In order to withstand the pressure of water from within the valve body acting on the external boss and protrusion, the prior art relies on high strength materials, such as metal and a number of similar materials, to achieve a mechanical connection and sealing arrangement between the valve body and protrusion.

The use of external bosses limits the materials that can be used as discussed above. This in turn limits the appearance of the flush valve manufacture. However, the use of an internal boss according to the present invention allows for a wider choice of design materials and more design shapes to be selected due to the elimination of a bulky external boss flush valve. The flexibility of material selection allowed by the internal boss of the present invention is very important to the manufacturer as it allows the manufacturer to reduce material and provide alternative material choices depending on the particular application. In addition, the use of an internal boss also allows the valve body to have a simple profile that is easier to clean and manufacture. In addition, each internal boss has a common axis in overall geometry.

The internal bosses 150, 148, particularly in the region of the water inlet 32 and handle 46, provide a number of advantages in accordance with one embodiment of the present invention, as shown in FIG. 2. First, the water pressure between the water inlet 32 and the outer diameter of the inner boss 148 cancel each other out so that no mechanical load is transferred from the water pressure to the mechanical connection. In contrast, the prior art outer bosses require support for the internal pressure that creates hoop tensile stress, which requires higher strength materials or the use of more material for supporting the hydraulic load.

With respect to the handle 46 and the attached inner boss 150, exposure to water pressure only on the outer diameter results in the inner boss 150 being subjected to compressive hoop stress. This has advantages over prior art external bosses under tension type loading, as most materials are stronger under compression type loading than under tension type loading. This allows the inner bosses 148, 150 of the present invention to be manufactured from less material or alternatively a weaker material (plastic) than a comparable outer boss. The use of the internal boss 150 for the handle causes external loads to be transferred to the housing 30. As shown in fig. 2, the pushing force 156 is transmitted to one portion 152 of the housing 30 in a direction that is inherently strong with the housing 30, i.e., parallel to the housing vertical axis 154. When the same force 156 is applied to the outer boss, the outer boss will tend to twist and this mechanical load will tend to collapse the valve body.

While the present invention has been described with reference to the details of the illustrated embodiments of the invention, these details are not intended to limit the scope of the invention as claimed by the appended claims.

Claims (9)

1. A flush valve for a plumbing fixture, the flush valve comprising:

a housing having a longitudinal axis, an inlet, an outlet, an actuator opening, and a main valve seat between the inlet and the outlet, the main valve seat oriented transverse to the longitudinal axis;

the actuator opening includes an interior boss of the actuator opening located adjacent the actuator opening and within the housing;

the inlet includes an internal boss of the inlet located adjacent the inlet and inside the housing;

a main valve assembly including a main valve member movable in an axial direction relative to the main valve seat;

a control chamber located on a first side of the main valve member and communicating with the inlet port to normally hold the main valve member against the main valve seat;

the main valve assembly includes a conduit extending axially from a second side of the main valve member;

the main valve assembly includes a pilot valve seat;

a pilot valve member movable relative to the pilot valve seat;

a valve stem extending axially from the pilot valve member;

on a first side of the longitudinal axis, an actuator is engaged with the valve stem for tilting the pilot valve member by laterally moving the valve stem.

2. A flush valve as claimed in claim 1, wherein said housing includes a seat engaging said conduit on a second side of said longitudinal shaft opposite said first side of said longitudinal shaft to resist tilting forces applied to said main valve assembly by said pilot valve train during said lateral movement of said valve stem.

3. A flush valve as claimed in claim 2, said housing including a tubular wall defining an outlet passage extending between said main valve member and said outlet, said conduit extending within said tubular wall, and said seat including an axially extending support rib on said tubular wall.

4. A flush valve as claimed in claim 3, further comprising a plurality of guide ribs in sliding contact between said tubular wall and said conduit.

5. A flush valve as claimed in claim 3, said housing including an outer valve body and an inner frame, said inner frame including said tubular wall and said support rib.

6. A flush valve as claimed in claim 3, said guide tube including an enlarged skirt at its lower end, said support ribs being in sliding engagement with said skirt.

7. The flush valve of claim 1, wherein the main valve assembly includes a diaphragm coupled in sealing relation to the housing, the control chamber being defined in part by the diaphragm.

8. The flush valve of claim 7, further comprising a restricted passage in the diaphragm connecting the control chamber with the inlet.

9. A flush valve for a plumbing fixture, the flush valve comprising:

a housing having a longitudinal axis, an inlet, an outlet, an actuator opening, and a main valve seat between the inlet and the outlet, the main valve seat oriented transversely to the longitudinal axis;

the actuator opening having an interior boss located adjacent the actuator opening and within the housing;

the inlet having an internal boss of the inlet located adjacent the inlet and inside the housing;

a main valve assembly including a main valve member movable in an axial direction relative to the main valve seat;

a control chamber located on a first side of said main valve member and communicating with said inlet port to normally hold said main valve member against said main valve seat;

the main valve assembly includes a conduit extending axially from a second side of the main valve member;

the main valve assembly includes a pilot valve seat;

a pilot valve member movable relative to the pilot valve seat;

a valve stem extending axially from the pilot valve member;

on a first side of the longitudinal axis, an actuator engages the valve stem to tilt the pilot valve member by moving the valve stem laterally;

said housing including an abutment engaging said conduit on a second side of said longitudinal shaft opposite said first side of said longitudinal shaft to resist tilting forces applied to said main valve assembly by said pilot valve train during said lateral movement of said valve stem,

wherein the inner boss of the actuator opening inside the housing is exposed to water pressure only on the outer diameter.