HK1134839B - Flush valve - Google Patents

Description

Flushing valve

Cross Reference to Related Applications

This application claims priority from U.S. patent application No.11/481,220, filed on 5.7.2006, the entire contents of which are incorporated herein by reference.

Technical Field

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

Background

Flushing systems for toilet fixtures in applications such as commercial structures typically include a flush valve that supplies water to flush each fixture. The flush valve is of the conventional flush valve type which operates to provide a metered or metered volume of water for a flushing 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 flow through the flush valve from the inlet to the outlet. Inlet pressure in the control chamber normally holds the main valve member 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 main valve member. A pilot or relief valve member is mated with the pilot valve seat. The pilot valve seat may be formed in the diaphragm or in an element supported by the diaphragm and may be part of the main valve member, for example.

The pilot valve member typically has a stem adapted to be contacted by an actuator. In manually operated flush valves, the actuator may be a plunger or push rod that is moved into contact with the stem by manual operation. When the stem is pivoted or tilted by the actuator, the pilot valve opens, draining the control chamber to 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 appliance. Water gradually flows into the control chamber via the restricted flow orifice, moving the diaphragm and the main valve member rearwardly toward the closed position. After a metered volume has passed, the main valve closes and the flush operation is stopped.

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

Another problem encountered with known flush valves occurs when the actuator tilts the pilot poppet post only slightly. A short, rapid movement of the actuator may not open the pilot valve and vent the control chamber due to factors such as the inertia of the pilot valve.

Typical flush valves have side inlets. Water flowing through the valve enters from the side and then flows up and over the main valve seat in a non-uniform pressure and flow pattern caused by the effect of the side entry velocity. Side loading can cause friction, reduce the life of the valve, and inconsistent flush volume. In addition, the non-uniform water pressure field in the control chamber results in flush valve operation being sensitive to the location of elements such as the choke orifice.

Another problem with known flush valves is pilot valve wear. In a typical arrangement, in the fully open position, the rigid plastic poppet contacts a fixed elastomeric seating portion. Repeated valve operation creates wear and is difficult to replace and repair.

In known flush valves, a maximum flow is generated when the main valve is open, and the flow decreases as the main valve returns to the closed position. Generally, a throttling structure is introduced into the main valve assembly to adjust the flow characteristics. However, known throttling arrangements do not overcome the problem of the flow decreasing as the valve closes.

Disclosure of Invention

It is a primary object of the present invention to provide an improved flush valve for supplying a metered and adjustable flow of water to a flush pipe appliance. Other objects are to provide a flush valve having a pilot valve structure that has a long service life and is easily replaced if worn; providing a flush valve that achieves a coordinated and reliable flush operation when actuated at high inlet pressures tending to pinch the pilot valve closed; to provide a flush valve with reliable actuation in the event that the operation of the actuating handle is short and rapid or indeterminate; to provide a flush valve capable of avoiding the difficulties caused by non-uniform pressure caused by a side water inlet; providing a flush valve capable of maintaining a relatively uniform flow rate during an initial flush phase of a flush cycle of a siphon type toilet fixture; and to provide an improved flush valve that is relatively inexpensive, easy to manufacture and repair, and overcomes the problems with known flush valves.

Briefly, in accordance with the present invention, there is provided a flush valve for a plumbing fixture. The flush valve includes 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. A control chamber on the first side of the main valve member communicates with the inlet for normally holding the main valve member against the main valve seat. The main valve assembly includes a conduit extending axially from the 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. A stem extends axially from the pilot valve member. An actuator located on a first side of the axis is engaged with the stem for tilting the pilot valve by laterally moving the stem. The housing includes a seat engaging the conduit at a second side of the shaft opposite the first side of the shaft for opposing the tilting force applied to the main valve assembly by the pilot valve assembly during lateral movement of the stem.

Briefly, in accordance with another feature of the present 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 moves relative to the pilot valve seat. The control chamber is located at 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. A stem extends axially from the pilot valve member in a first axial direction away from the control chamber. The stem has an end portion and an intermediate portion between the end portion and the pilot valve assembly. An actuator is engaged with the intermediate portion of the stem for tilting the pilot valve assembly by laterally moving the stem to vent the control chamber and permit the main valve assembly to move axially in an opposite second axial direction. The enlarged portion at the end portion of the stem engages the actuator upon axial movement in the second direction for further lateral movement of the stem and further tilting of the pilot valve assembly.

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

Briefly, in accordance with another feature of the present invention, a flush valve for providing a flow of flush water to a plumbing fixture is provided. The flush valve includes: a housing having an inlet, an outlet, and a main valve seat; and a tubular wall defining an outlet passage extending from the first side of the main valve seat toward 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 the main valve seat to a closed position and away from the main valve seat to a fully open position. The normally pressurized control chamber is in the housing at a second side of the main valve seat. The main valve assembly includes a seal member between the main valve member and the housing for isolating the control chamber from the suction chamber. The pilot valve assembly is operable from a blocked position to a vent position for venting the control chamber to the outlet and moving the main valve member within the control chamber from the closed position to the fully open position. A stop in the control chamber engages the pilot valve assembly in the full open position of the main valve member for holding the pilot valve assembly in its blocked position. A restricted passage extends between the suction chamber and the control chamber for repressurizing the control chamber and returning the main valve member from the full open position to the closed position. First and second throttle assemblies are formed on the housing and on the main valve assembly. The first throttling assembly has minimal throttling effect at the full open position of the main valve assembly and provides enhanced throttling as the main valve member moves toward the closed position. The second throttling assembly has a maximum throttling effect at the full open position of the main valve assembly and provides a reduced throttling as the main valve member moves toward the closed position.

Briefly, in accordance with another feature of the present invention, a flush valve for providing a metered flow of flush water to a plumbing fixture is provided. 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 the main valve seat to a closed position and away from the main valve seat to a fully open position. A normally pressurized control chamber is in the housing on one side of the main valve seat. The main valve assembly includes a seal member between the main valve member and the housing for isolating the control chamber from the suction chamber. The pilot valve assembly is operable from a blocked position to a vent position for venting the control chamber to the outlet and moving 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 in the main valve assembly and a pilot valve member including a head portion in the control chamber that engages the pilot valve seat in the blocked position. A stop in the control chamber engages the pilot valve head portion in the full open position of the main valve member for holding the pilot valve assembly in its blocked position. A restricted passage extends between the suction chamber and the control chamber for repressurizing the control chamber and returning the main valve member from the full open position to the closed position. The head portion includes an inner body and a resilient seal member removably attached to the inner body. The sealing member has a cup shape with a base portion overlapping the inner body and a rim portion at the outer periphery of the inner body and is engageable between the inner body and the pilot valve seat in the blocked position of the pilot valve assembly. The stop includes a valve rotor structure that engages the base portion of the seal member in the full open position of the main valve member.

Drawings

The invention, together with the above and other objects and advantages, may best be understood from the following detailed description of the preferred embodiments of the invention illustrated in the accompanying drawings in which:

FIG. 1 is a perspective view of a plumbing installation including a control stop and 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, standby position;

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

FIG. 4 is a view similar to FIG. 3 showing the pilot valve assembly moved further open as the main valve assembly opens;

FIG. 5 is a view similar to FIGS. 2-4 showing the flush valve in a fully open position;

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

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

FIG. 8 is a cross-sectional view of the frame and conduit of the flush valve 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 perspective view of the inner cover; and

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

Detailed Description

Referring now to the drawings and initially to FIG. 1, there is shown a plumbing fixture, generally designated 20, for flushing a toilet fixture (not shown). The pipe arrangement 20 has a water supply line 22 via which water is supplied from a pressurized source, such as a municipal or local water supply system. Line 22 supplies water to a throttle control stop 24, and water from control stop 24 is passed via a transfer line 26 to a flush valve, generally designated 28 and 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. The flush valve 28 generally includes a housing assembly 30 with an inlet 32 connected to the line 26 and an outlet 34 adapted to be connected to an outlet line 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 flow from the inlet 32 to the outlet 34. The main valve assembly is normally kept closed by the pressure in the control chamber 40. The control chamber is normally pressurized by restricting communication with the inlet 32 via the restriction passage 42. The pilot valve assembly 44 is movable from a closed or blocked position (fig. 2) to an open or venting position (fig. 3 and 4) to rapidly vent the control chamber 40 to the outlet 34 to abruptly open the main valve assembly 38. The pilot valve assembly 44 is actuated to its open or exhaust position by manipulation of the handle 46. The principles of the present invention are applicable to flush valves with other actuation systems, such as electrically operated flush valves.

The housing assembly 30 includes a body 48 and a frame 50 mounted inside the body 48. The conduit 26 is secured to the body 48 at the inlet 32. The outlet 34 is located at the lower end of the body 48. An inlet pressure region 52 is defined between the body 48 and the frame 50. The upper end of the housing assembly 30 is closed by a cover 54, the cover 54 being secured to the body 48. The inner cover 56 is grasped under the cover 54.

The main valve assembly 38 includes a diaphragm 58 having a peripheral sealing portion 60, the peripheral sealing portion 60 being captured between the inner cover 56, the frame 50 and the body 48 to seal the control chamber 40. The diaphragm plate 62 supports a central valve member portion 64 (fig. 7) of the diaphragm 58. A restricted passage 42 extends through diaphragm 58 and plate 62 for continuously restricting communication between inlet pressure region 52 and control chamber 40. The diaphragm 58 has a rolling diaphragm portion 66 that provides a long working stroke and a large control chamber volume, with very little friction and insignificant centering bias. A vent 67 (fig. 7) in the diaphragm plate 62 prevents a misaligned squeak or squeal condition from occurring by venting the upper portion of the diaphragm 58 to the control chamber and clamping the diaphragm 58 to 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 (fig. 2) that is engaged by the valve member portion 64 of the diaphragm 58 in the closed position. This prevents flow from the inlet 32 and the inlet pressure region 52 to the outlet passage 68 and the outlet 34 through the main valve seat 72. Frame 50 includes a flange portion 74 and ribs 76 (fig. 8 and 10) to support rolling diaphragm 66 of diaphragm 58.

The main valve assembly 38 includes a conduit 78, the conduit 78 being connected to the diaphragm plate 62 and extending downwardly inside the tubular wall 70 of the frame 50. Guide ribs 80 (fig. 7 and 9) on the conduit 78 slidably engage the tubular wall 70 and center the conduit 78 and the main valve assembly 38 in the housing assembly 30. The main valve assembly 38 also includes a supplemental flow control ring 82 (fig. 7 and 8) that cooperates 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 member 84, the orifice member 84 being captured in the opening of the diaphragm plate 62 by a retaining ring 86 (fig. 7). The orifice pin 88 extends through the orifice member 84 with a gap that forms a cross-sectional area of flow restriction. Movement of the pin is limited by contact with the frame 50 and the inner cover 56 and movement of the main valve assembly relative to the pin clears the restricted passage 42.

The pilot valve assembly 44 includes a head portion 90 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 sealingly retained on the valve seat surface 94 of the diaphragm plate 62 by the pressure of the control chamber 40 (fig. 7). Valve seat surface 94 surrounds an exhaust port 96 (fig. 7), exhaust port 96 extending through diaphragm plate 62 from control chamber 40 to the interior of conduit 78.

The head portion 90 of the pilot valve assembly 44 includes a head flange 98 of a pilot valve base 100. A generally cup-shaped pilot valve seal 102 (fig. 6 and 12) made of an elastomeric material such as rubber is mounted on top of the head flange 98. A reentrant edge 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 end of the head flange 98. The hub portion 108 is received in a 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 support portion 110 on the inner housing 56.

Support 110 is configured with a valve rotor structure, as best shown in fig. 11. The service life of the seal 102 is extended because with each movement of the main valve assembly 38 to the full open position of fig. 5, the resilient central portion 106 of the pilot valve seal 102 engages the rotator abutment 110 and the pilot valve assembly is progressively rotated, evenly distributing valve contact wear over the circumference of the reentrant rim portion 104 of the pilot valve seal 102. Additionally, if the pilot valve seal is worn, it is easily replaced because it can be removed by stretching the material of the seal 102 to remove it from the head flange 98. A new, replacement seal is then installed on the head flange in the same manner. A vent passage 112 in the top flange 98 prevents liquid from becoming trapped in the pilot valve seal 102.

The stem portion 92 of the pilot valve assembly 44 is seen in fig. 7 and includes a stem shaft 114 secured within a stem socket portion 116 of the pilot valve base 100. A stem sleeve 118 is slidably received over the shaft 114, the stem sleeve 118 being retained by a head portion 120.

The illustrated flush cycle of the flush valve 28 is initiated by actuation of the handle 46 from the standby position of fig. 2 to the actuated position shown in fig. 3. A push rod member 122 partially contained within a bladder 124 moves radially inward toward the axis of the flush valve 28 and contacts the stem portion 92 of the pilot valve assembly 44. As a result, the head portion 90 of the pilot valve assembly 44 tilts or pivots away from the pilot valve seat 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 is quickly drained to outlet 34. The release of pressure in the control chamber 40 allows the inlet pressure to rapidly move the main and pilot valve assemblies 38 and 44 to the fully open position shown in figure 5.

In the normally closed standby position shown in FIG. 2, the head portion 90 of the pilot valve assembly 44 is clamped closed by the main valve assembly 38 under the differential pressure 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 becomes large.

A problem with known flush valves is that the force clamping the closed pilot valve assembly may be large enough to prevent reliable valve actuation for the initiation of a flush cycle. A large side load is required to open the pilot valve assembly. However, instead of tilting the pilot valve assembly to an open or vent position, the radial off-center thrust of the push rod against the pilot valve stem and the resulting tilting movement of the pilot valve stem may also cause the main valve assembly and the clamped pilot valve assembly to tilt in unison. Instead of a rapid discharge of the control chamber, an uncontrolled and inconsistent leakage flow across the main valve seat may occur.

To overcome this problem, in the flush valve 28 of the present invention, the main valve assembly is firmly supported such that it cannot pivot when an off-center radial actuation 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 assembly 30 includes a reinforced block-shaped support rib 128 diametrically opposed to the push rod 122. When a radial actuation force is applied by the push rod 122, the ribs 128 engage the skirt 126 (FIG. 9) and positively prevent tilting of the main valve assembly 38. As a result, even when the inlet pressure increases, actuation of the handle 46 and the radially inward movement of the push rod 122 consistently causes the pilot valve assembly 44 to pivot to a vent or open position relative to the main valve assembly 38.

In accordance with the present invention, the lower end of the pilot valve stem portion 92 is enlarged to provide a toggle opening action for actuation of the pilot valve assembly 44. In the illustrated arrangement, the pilot valve stem sleeve 118 includes a bell-shaped enlargement 130 at its lower end. In the closed position (fig. 2) and in the initial actuated condition (fig. 3), the enlarged portion 130 is below the contact end of the push rod 122. With the control chamber 40 rapidly exhausted, the pilot valve assembly 44 moves upward immediately after the push rod 122 initially tilts against the stem portion 92. The enlarged portion 130 engages the end of the push rod 122 (fig. 4) and the pilot valve stem portion tilts further away from center rather than moving the handle 46 or push rod 122 further. This provides a toggle-like quick opening action, ensuring consistent actuation even if the operation of the handle 46 is limited and rapid or indeterminate.

The rotator structure of the abutment 110 imparts a slight wear distribution angular offset to the pilot valve seal 102 and the pilot valve assembly 44 when the main and pilot valve assemblies 38 and 44 reach the fully open position shown in fig. 5. The main valve assembly 38 including the valve member sealing portion 64 exits 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 seating surface 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 around the central longitudinal axis. The primary reason for this is that the radially oriented inlet 32 introduces water into the lateral side into the inlet pressure region 52. The side inflow causes the impact effect as the pressure increases at the portion of the region 52 opposite the inlet 32 and decreases at the portion of the region 52 near the inlet 32. This uneven pressure field may cause difficulties such as side loading and increased operating friction of the main valve assembly 38. In addition, uneven pressure within control chamber 40 may undesirably cause flush valve operation to be sensitive to the position of diaphragm 58 and restricted flow passage 42.

To avoid the problem of uneven pressure in the area of the main valve assembly 38 and in the control chamber 40, the frame 50 includes a flow balance baffle 132 upstream of the main valve assembly 38. In the illustrated embodiment of the invention, the baffle 132 is annular and lies in a radial plane within an annular suction flow port 134 formed in the body 48 below the main valve seat 72. The annular flow opening 134 is symmetrical about the vertical longitudinal axis of the flush valve 28, while the flapper 132 is offset and asymmetrical, as shown in FIG. 10. To compensate for flow pattern differences in the inlet pressure region 52, the baffle 132 is offset from the suction inlet 32 in the radial direction. The side 132A of the baffle opposite the suction inlet 32 is relatively closer to the annular mouth 134, while the opposite side 132B closest to the suction inlet 32 is further from the edge of the annular mouth 134.

The baffle 132 partially restricts the inlet flow, but it causes only a small pressure loss at maximum flow. The distribution of the baffle throttling relative to the side-entry intake port 32 compensates for the flow rate effect of the port 32, providing 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 flow passage 42 may be arbitrarily positioned with minimal impact on valve operation and flow delivery.

When the main and pilot valve assemblies 38 and 44 reach their highest fully open positions, a metered and adjustable flow of water for the flush cycle begins to be supplied. In the fully open position (fig. 5), the control chamber 40 is at a minimum volume and is sealed as the pilot valve head portion 90 is forced into contact with the central abutment 110 against the pilot valve sealing surface 94 on the diaphragm plate 62.

The main valve assembly 38 then acts like a damper to progressively re-close as the control chamber 40 is refilled from the inlet pressure region chamber 52 through the restricted flow passage 42. The flow rate is determined by the clearance between the orifice member 84 and the self cleaning orifice pin 88. There is a proportional relationship between the main valve flow area and the area of the restricted flow passage 42. Likewise, the inlet pressure region 52 acts on both the main valve assembly and the restricted passage 42, and the flow of water from the inlet 32 through the main valve assembly to the outlet 34 is a fixed ratio to the flow through the restricted passage 42 into the control chamber 40. This proportional relationship ensures that a constant flush volume is maintained despite variations in the supply pressure or differential pressure across the flush valve 28.

The illustrated flush valve 28 is designed to provide a flow of water configured for a siphon-type toilet fixture configuration using a two-stage flow supply. With this type of plumbing fixture, the initial portion of the flush cycle has a relatively high volume flush flow for the siphoning action of the drain fixture. The flush is followed by a relatively low volume flow rate for resealing the trap (trap) of the appliance. The flushing performance of the siphon-type appliance is improved if a stable flow rate is maintained even at initially high flow rates, which are less than the maximum possible, and if the flow rate is abrupt from a high flush flow rate to a low reseal flow rate.

To optimize the flow characteristics during a siphon fixture flush cycle, the flush valve 28 of the present invention uses two different throttling assemblies that act in sequence during the high flow flush portion of the cycle. The secondary flow throttling assembly 136 attenuates flow at the beginning of the high flow portion and the primary flow throttling assembly attenuates 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 passage 68 has an upstream section 68A with a diameter substantially equal to the diameter of the enlarged diameter skirt portion 126 of the conduit 78. Shoulder 142 spaces section 68A from downstream section 68B, which has a larger diameter and provides a substantial gap for unobstructed flow around skirt portion 126 (fig. 9). The skirt 126 and shoulder 142 provide an auxiliary flow restriction assembly 136.

The use of the rolling diaphragm 58 provides an extended stroke for the main valve assembly 38 and the main valve assembly moves a substantial distance between the fully open and closed positions of fig. 5 and 2. In the fully open position at the beginning of a flush cycle, as shown in fig. 5 and 8, skirt portion 126 approaches shoulder 142 to throttle flow through outlet flow passage 68. This reduces flow below that which would be possible without the secondary flow throttling assembly 136, but helps to achieve improved flushing performance by maintaining a relatively uniform high volume flush flow in cooperation with the primary flow throttling assembly 138.

The refill flow control ring 82 cooperates with the main valve seat 72 to provide a main choke assembly 138. When the main valve assembly moves downward from the fully open position, the skirt portion 126 moves away from the shoulder 142, reducing the throttling effect of the secondary throttling assembly 136. At the same time, the primary throttling assembly 138 begins to throttle as the lower edge of the ring 82 approaches the valve seat 72. As the main valve assembly 38 descends, the throttling effect transitions from the secondary throttling assembly 136 to the primary throttling assembly 138, thereby maintaining a high flush flow that is more uniform than would be obtained without the secondary assembly 136.

The refill 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 provided through the groove 144 is reduced from the high flow flush segment to a low trap reseal flow. Since the extension of the main valve stroke is achieved by the rolling diaphragm 58, there is a sharp, well-defined transition from high flush flow to low trap fresh seal flow.

Alternatively, the flush valve 28 may be configured for use with urinals in which the fixture is provided with a relatively constant, low volume flow rate for downward flushing of the fixture. For example, the flow control ring 82 may be modified to provide only a relatively constant fixture flush down flow. Many of the principles of the present invention are applicable to flush valves configured for siphon flushing or urinal fixtures.

Skirt 126 has the additional function of directing the outward flow in downstream channel section 68B and directing the flow away from stem sleeve 118 and bell shaped enlargement 130.

As the main valve assembly 38 descends toward the closed position of FIG. 2, the enlarged bell portion 130 of the sleeve 118 approaches the end of the push rod member 122. If the handle is held in the activated position, the enlarged portion 130 may be in the path of the sleeve 118 being lowered. In this case, the sleeve 118 slides up the 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 described above provides additional benefits over the prior art. Any connection of the flush valve requires penetration into the pressure chamber by various protrusions for fitting insertion/maintenance, water outlet, water inlet, and some actuating mechanism (e.g., manual handle or automatic actuator). In the prior art, these openings in the valve body typically use external bosses to connect the projections to the valve body. For example, external thread bosses in combination with seals and nuts have been used previously. In order to withstand the pressure from within the valve body on the external boss and protrusion, the prior art relies on high strength materials such as metals and large amounts of such materials to create a mechanical connection and sealing method between the valve body and protrusion.

The use of external bosses limits the materials that can be used as described above. This in turn limits the visual display that can be constructed by the flush valve. However, the use of internal bosses in accordance with the present invention allows for a wider choice in material design, and also allows for a wider range of design shapes for the flush valve due to the absence of cumbersome external bosses. The flexibility allowed by the internal bosses of the present invention in material selection is important to manufacturers as it allows them to reduce material and provide varying material choices depending on the particular application. In addition, the use of an internal boss provides a valve body having a simpler profile that is both easier to clean and easier to assemble. In addition, each internal boss has a common axis for the entire geometry.

According to one embodiment of the invention shown in fig. 2, the internal bosses 150, 148 have several advantages, particularly in the area of the water inlet 32 and the handle 46. First, the hydraulic 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 transmitted from the hydraulic pressure to the mechanical joint. In contrast, the prior art external boss would have to support the internal pressure that generates the hoop stress in tension, which requires the use of high strength materials or more to support the hydraulic load.

With respect to the handle 46 and the attached internal boss 150, it is only hydraulically acted upon on the outer diameter, causing the boss 150 to be under compressive hoop stress. This has advantages over prior art external bosses under a tensile type load, as most materials are stronger under a compressive type load than under a tensile type load. This allows the inner bosses 148, 150 of the present invention to be manufactured with less material or to be replaced with a weaker material (plastic) than the outer bosses. The use of the internal boss 150 on the handle results in the transmission of external loads to the housing 30. As shown in fig. 2, a thrust force 156 is transmitted to a portion 152 of the lift shell 30 in a solid orientation within the shell 30, i.e., parallel to the shell vertical axis 154. When subjected to the same force 156, the outer boss will tend to twist and this mechanical load will tend to damage the valve body.

Although the present invention has been described with reference to the details of the embodiments of the invention shown in the accompanying drawings, these details are not intended to limit the scope of the invention as claimed in the appended claims.

Claims (17)

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

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 oriented transverse to the axis;

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

a control chamber at a first side of the main valve assembly above the main valve seat and in communication with the inlet for holding the main valve assembly against the main valve seat;

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

the main valve assembly includes a pilot valve seat;

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

a stem extending axially from the pilot valve assembly;

an actuator engageable with said stem on a first side of said axis opposite said inlet for tilting said pilot valve assembly by laterally moving said stem; the flush valve is characterized in that:

the pilot valve assembly having a central upper portion;

a central support configured with a rotor structure for engaging a central upper portion of the pilot valve assembly;

the housing including a seat engaging the conduit at a second side of the axis adjacent the inlet for opposing an oblique force applied by the pilot valve assembly to the main valve assembly during lateral movement of the stem; and wherein the pilot valve assembly is progressively turned when a central upper portion of the pilot valve assembly engages the central abutment with the main valve assembly open,

the main valve assembly further includes a diaphragm sealingly connected with respect to the housing, the control chamber being partially defined by the diaphragm, the flush valve further including a restricted passage in the diaphragm connecting the control chamber to the inlet.

2. The flush valve of claim 1, wherein the diaphragm comprises a rolling diaphragm.

3. The flush valve of claim 1, the housing including a tubular wall defining an outlet passage extending between the main valve assembly and the outlet, the conduit extending within the tubular wall, and the seat including an axially extending support rib on the 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. The flush valve of claim 3, said housing comprising an outer body and an inner frame, said inner frame comprising said tubular wall and said support ribs.

6. A flush valve as claimed in claim 3, said guide tube having an enlarged skirt portion at its lower end, said support rib being slidingly engaged with said skirt portion.

7. The flush valve of claim 1, further comprising:

a tubular wall defining an outlet passage extending axially from a first side above the main valve seat;

an annular suction chamber surrounding said tubular wall;

the housing includes an inlet passage extending radially into the suction chamber;

an annular passage extending from the suction chamber to the main valve seat; and

a baffle in the annular channel;

one of the annular channel and the baffle is symmetric about the axis and the other of the annular channel and the baffle is asymmetric about the axis.

8. The flush valve of claim 7, wherein:

the main valve assembly including a sealing member between the main valve assembly and the housing for isolating the control chamber from the annular inlet chamber;

said conduit extending within said outlet passage in said tubular wall, said conduit having an enlarged portion, said tubular wall including an upstream portion having a first cross-sectional area and a downstream portion having a second cross-sectional area greater than said first cross-sectional area, said tubular wall including a shoulder between said upstream and downstream portions;

said pilot valve assembly being operable from a blocked position to a vented position for communicating said control chamber to said outlet and moving said main valve assembly from a closed position to a fully open position within said control chamber;

a stop engageable with said pilot valve assembly in said control chamber in said full open position of said main valve assembly for holding said pilot valve assembly in its blocked position;

a restricted passage extending between said suction chamber and said control chamber for pressurizing said control chamber and returning said main valve assembly from said fully open position to said closed position;

first and second throttling assemblies formed on said housing and said main valve assembly, said first throttling assembly including a refill flow control ring that cooperates with said main valve seat, said second throttling assembly including said shoulder and said enlarged portion of said conduit;

the first flow restriction assembly having a minimal flow restriction effect in the fully open position of the main valve assembly and providing an enhanced flow restriction when the main valve assembly moves toward the closed position; and

the second flow restriction assembly has a maximum flow restriction effect in the fully open position of the main valve assembly and provides a reduced flow restriction when the main valve assembly moves toward the closed position.

9. The flush valve of claim 8, wherein:

said pilot valve assembly including a head portion in said control chamber engageable with said pilot valve seat in said blocked position;

the head portion includes an inner body and a resilient sealing member removably attached to the inner body, the sealing member being cup-shaped having a base portion covering the inner body and a rim portion surrounding the outer periphery of the inner body and engageable between the inner body and the pilot valve seat in the blocked position of the pilot valve assembly.

10. A flush valve for a plumbing fixture, said flush valve comprising:

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 oriented transverse to the axis;

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

the main valve assembly includes a pilot valve seat;

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

a control chamber on a first side of the main valve assembly above the main valve seat;

a stem extending axially from the pilot valve assembly in a first axial direction away from the control chamber;

an actuator engageable with an intermediate portion of said stem for tilting said pilot valve assembly to evacuate said control chamber by moving said stem laterally and permitting said main valve assembly to move axially in a second opposite axial direction; and

said stem having an end portion and an intermediate portion between said end portion and said pilot valve assembly;

the pilot valve assembly having a central upper portion;

a central support configured with a rotor structure for engaging a central upper portion of the pilot valve assembly;

a restricted passage between said inlet and said control chamber for pressurizing said control chamber and holding said main valve assembly against said main valve seat and said pilot valve assembly against said pilot valve seat;

an enlarged portion at said end portion of said stem engageable with said actuator during said axial movement in said second axial direction for further lateral movement of said stem and further tilting of said pilot valve assembly;

wherein the pilot valve assembly is progressively rotated when a central upper portion of the pilot valve assembly engages the central abutment with the main valve assembly open, and the main valve assembly further comprises a diaphragm sealingly connected with respect to the housing, the control chamber being defined in part by the diaphragm.

11. The flush valve of claim 10, said diaphragm comprising a rolling diaphragm.

12. A flush valve for a plumbing fixture, said flush valve comprising:

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

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

a control chamber at a first side of the main valve assembly above the main valve seat and in communication with the inlet for holding the main valve assembly against the main valve seat;

the main valve assembly includes a conduit extending axially from a second side of the main valve assembly below the main valve seat; the flush valve is characterized in that:

the actuator opening has an actuator boss adjacent thereto and located inside the housing;

the inlet having an actuator boss adjacent thereto and located inside the housing;

the main valve assembly includes a pilot valve seat;

a pilot valve assembly having a central upper portion, the pilot valve assembly being movable relative to the pilot valve seat;

a stem extending axially from the pilot valve assembly;

an actuator engageable with said stem on a first side of said axis opposite said inlet for tilting said pilot valve assembly by laterally moving said stem; and

a central support configured with a rotor structure for engaging a central upper portion of the pilot valve assembly;

wherein the pilot valve assembly is progressively rotated when a central upper portion of the pilot valve assembly engages the central abutment with the main valve assembly open, and the main valve assembly further comprises a diaphragm sealingly connected with respect to the housing, the control chamber being defined in part by the diaphragm, the flush valve further comprising a restricted passage in the diaphragm connecting the control chamber to the inlet.

13. The flush valve of claim 12, wherein said housing includes a seat engaging said conduit at a second side of said axis adjacent said inlet for opposing an inclination force applied to said main valve assembly by said pilot valve assembly during said lateral movement of said stem.

14. The flush valve of claim 13, the housing including a tubular wall defining an outlet passage extending between the main valve assembly and the outlet, the conduit extending within the tubular wall, and the seat including axially extending support ribs on the tubular wall.

15. The flush valve of claim 14, further comprising a plurality of guide ribs in sliding contact between the tubular wall and the conduit.

16. The flush valve of claim 14, said housing comprising an outer body and an inner frame, said inner frame comprising said tubular wall and said support ribs.

17. The flush valve of claim 14, said guide tube having an enlarged skirt portion at a lower end thereof, said support rib slidingly engaging said skirt portion.