GB2539512A

GB2539512A - Spray head

Info

Publication number: GB2539512A
Application number: GB1510881.4A
Authority: GB
Inventors: Paul Sansum Nigel; Westgate Simon
Original assignee: Kohler Mira Ltd
Current assignee: Kohler Mira Ltd
Priority date: 2015-06-19
Filing date: 2015-06-19
Publication date: 2016-12-21
Anticipated expiration: 2035-06-19
Also published as: WO2016203270A9; GB2539512B; EP3310489A1; WO2016203270A1; GB201510881D0

Abstract

A spray or shower head 100 comprising a spray plate 104 and a moveable element 102 behind the spray plate, wherein the moveable element is arranged to move to and from a position blocking fluid flow through the spray head in response to fluid pressure. The moveable element may be biased to block fluid flow through the spray head, and may move to unblock fluid flow when fluid pressure increases from a low to high value. The moveable element may be flexible e.g. a diaphragm 102, biased to block fluid flow, and having ribs, pins or protrusions (Fig. 6, 600) arranged to align with and block the spray holes 110 of the spray plate. The moveable element may also be a valve member (Fig. 10, 802), biased to engage a valve seat (Fig. 10, 818) to block fluid flow through the spray head. The spray plate 104 can have drain holes (Fig. 10, 810) to allow residual fluid to escape.

Description

SPRAY HEAD

This invention relates to a spray head for an ablutionary appliance or fitting. More particularly it concerns a spray head comprising a non-drip mechanism and to a shower system employing the spray head. The invention may have particular application to spray heads for shower systems but it need not be limited to this use.

For convenience, the invention is discussed primarily in relation to spray heads for showers. The skilled person will appreciate that other applications of the non-drip mechanism are possible, such as in taps or pressurised drink dispensers. Similarly, the invention is primarily discussed in terms of using water, but the skilled person will understand that the invention would equally apply to other fluids.

Prior art shower spray heads are prone to dripping after the shower system has been turned off due to residual water within the shower spray head and in the connecting hose and/or pipes. In addition to any irritation caused by the sight and sound of dripping water, this can lead to bathroom surfaces remaining wet and slippery for longer, so increasing the chance of accidents. Slowly dripping water may also lead to damp problems within the bathroom or shower room.

in addition, many prior art shower spray heads are sensitive to water pressure fluctuations. Variations in the pressure of water supplied to the shower spray head may cause uneven flow rates and result in a less comfortable user experience.

According to a first aspect, there is provided a spray head comprising a spray plate and a moveable element situated behind the spray plate. The moveable element is arranged to move to and from a position blocking fluid flow through the spray head in response to fluid pressure.

The moveable element may be arranged to move from the position blocking fluid flow through the spray head in response to an increase in fluid pressure for unblocking fluid flow through the spray head. The moveable element may return to the position blocking fluid flow through the spray head in response to a reduction in fluid pressure.

The moveable element may be arranged, in use to assume the position blocking fluid flow through the spray head when there is low, or substantially no, water pressure in the spray head and to move from the position blocking fluid flow as fluid pressure increases, unblocking fluid flow through the spray head.

"Low" may be defined as substantially zero, i.e. when the water supply is turned off or when there is no water supply to the spray head. Alternatively, "low" may be defined as less than a set threshold pressure below which the moveable clement assumes the position blocking fluid flow through the spray head, and above which the moveable element moves from the position blocking fluid flow to unblock fluid flow through the spray head.

In some embodiments, the moveable clement may be arranged to close outlets through the spray plate, blocking fluid flow through the spray head, and to move away from the spray plate as fluid pressure within the spray head increases to open the outlets through the spray plate, unblocking fluid flow through the spray head.

in such an embodiment, the moveable element may comprise a diaphragm or membrane that overlies and closes the outlets in the spray plate, blocking fluid flow through the spray head, and is moved away from the outlets by an increase in fluid pressure within the spray head, unblocking fluid flow through the spray head.

The diaphragm may be arranged such that, in use, the fluid flowing through the spray head passes between the spray plate and the diaphragm and is prevented from getting behind the diaphragm. The exclusion of fluid from this zone may ensure that the fluid pressure acts to move the diaphragm away from the spray plate, not towards it.

Advantageously, the diaphragm closes the outlets, which may comprise holes through the spray plate, when the fluid supply is turned off. This may reduce or prevent fluid dripping from the spray head when it is not in use.

The diaphragm may be made of a flexible elastic material such as rubber. The skilled person will understand that other materials may be used. Alternatively, the diaphragm may comprise one or more rigid, hinged sections and one or more extensible sections.

The diaphragm may be biased towards the spray plate. In embodiments wherein the diaphragm is elastic, a natural resilience of the diaphragm may be sufficient to bias the diaphragm towards the spray plate and to maintain contact with the spray plate in the absence of opposing forces. Alternatively or additionally, biasing means may be provided to bias the diaphragm towards the spray plate and to maintain contact with the spray plate in the absence of opposing forces.

Biasing means may take any suitable form including, but not limited to, one or more springs.

The spray head may further comprise one or more formations such as protrusions behind the diaphragm. Advantageously, the protrusions limit the movement of the diaphragm away from the spray plate. The protrusions may define a set position adopted by the diaphragm at and above a particular water pressure within the spray head. The protrusions may locate and support the diaphragm in the set position.

The protrusions may extend from either or both of the diaphragm and a surface of the spray head. Advantageously, in embodiments wherein the protrusions extend from the surface of the spray head, the protrusions may be more rigid and hence may define the set position more reliably.

The spray head may further comprise a check valve across a water inlet to the spray plate region of the spray head. The check valve may be an umbrella valve, or any other suitable valve known to one skilled in the art. A spring and poppet arrangement may also be used.

The diaphragm may further comprise raised portions such as bumps aligned with at least some of the outlets. Advantageously, in use, the bumps block the outlets when the diaphragm is close to or touching the spray plate. The presence of these bumps advantageously means that full contact between the diaphragm and the spray plate does not need to be made in order for the outlets to be blocked.

The bumps may be made out of rubber or another elastomeric material. Advantageously, the deformability of the bumps ensures contact between the bumps and the outlet and provides a substantially watertight seal. The bumps may be made of the same material as the diaphragm or a different material. Where the diaphragm is made of rubber or elastomeric material, the bumps may be made of a material of different hardness, for example harder or softer, than the material of the diaphragm. The skilled person will understand that various shapes and configurations and materials may be used.

Alternatively or additionally, the diaphragm may comprise elongate formations such as pins aligned with at least some of the outlets. The pins may be arranged, in use, to restrict the flow of water through the outlets to an extent which depends on the water pressure. In this way a more even flow of water may be achieved so that the spray is substantially unaffected by fluctuations in the pressure of the supplied water.

The pins may have a stem and a head which is broader than the stem. In embodiments with bumps for blocking the outlets, the stem of the pins may broaden where it meets the diaphragm to provide such bumps. The head of each pin may be substantially teardrop-shaped, circular, ovoid, triangular or rhombic in cross-section.

The pins may be made of the same material as the diaphragm or a different material. Where the diaphragm is made of rubber or elastomeric material, the pins may be made of a material of different hardness, for example harder or softer, than the material of the diaphragm. The skilled person will understand that various shapes and configurations and materials may be used.

When pins are used, the outlets may be shaped so as to take advantage of the flow restriction capabilities of the pins. For example, the outlets may comprise a channel on the internal side of the spray plate and a curved widening portion on the external side of the spray plate. Advantageously, the channel may be narrower than the head portion of the pin, such that the pin cannot be pushed inside the shower head, obstructing its functioning.

Advantageously, the shape of the outlet is designed to complement the shape of the head portion of the pin. Movement of the head portion relative to the spray plate affects the cross-sectional area of the outlet which is open for water to flow through. As water pressure increases, the stem is drawn further into the spray head and the head portion of the pin approaches the channel, so reducing the available cross-sectional area for flow.

In embodiments with a curved widening portion of the outlets, the widening portion may extend from the spray plate outer surface by means of a raised lip protruding from the outer surface.

In alternative embodiments, the moveable clement may be arranged to close a flow path to the spray plate region of the spray head, blocking fluid flow through the spray head and to open the flow path as fluid pressure within the spray head increases, unblocking the flow of fluid to the spray plate.

In such an embodiment, the moveable clement may comprise a valve member that engages a valve seat to close the flow path, blocking fluid flow through the spray head, and is moved away from the valve seat opening the flow path by an increase in fluid pressure, unblocking fluid flow through the spray head.

The valve member may be biased towards the valve seat. Biasing means such as a spring may be provided to bias the valve member towards the valve seat and to maintain contact with the valve seat in the absence of opposing forces. The skilled person will understand that other biasing means may be used.

The valve member may be moveable away from the valve scat to open the flow path when the fluid pressure overcomes the biasing means. The valve member may adopt a set position at or above a pre-determined fluid pressure.

The spray plate may be configured to allow fluid to drain from the spray head when the valve member engages the valve seat to block fluid flow through the spray head. The spray plate may have one or more drain holes of larger area than the spray outlets. The drain hole or holes may be closed by the valve member in the set position so that fluid is discharged through the spray holes only and, when the valve member returns to the position engaging the valve seat blocking fluid flow through the spray head, the drain hole or holes are opened so that fluid remaining in the region of the spray plate is rapidly drained.

According to a second aspect, there is provided a spray head comprising a spray plate and a control member situated behind the spray plate, wherein the control member further comprises pins aligned with outlets in the spray plate. The control member is arranged, in use, to move towards and away from the spray plate in response to fluid pressure whereby the pins move relative to the outlets in the spray plate such that the flow through the outlets is controlled dependent on the fluid pressure.

The pins may have a varying cross-section, such that the proportion of the cross-sectional area defined by each outlet which is open for water to flow through varies as the pin moves.

The pins may have a stem and a head which is broader than the stem. The stem may have a constant cross-sectional area, and may be cylindrical. The head of each pin may substantially teardrop-shaped, circular, ovoid or rhombic in cross-section.

The stem is sufficiently narrow to pass through the outlets. The heads of the pins may be too wide to pass through the outlets. Advantageously, this may prevent the pins from being pushed inside the spray head and interfering with its operation. If a compressible material such as rubber is used for the pins, the width of the head may be such that the heads will fit through the outlets when sufficient force is applied for assembly of the spray head. Advantageously, this facilitates manufacture of the spray head and also reduces the chance of the pins being accidentally pushed back into the spray head.

In alternative embodiments, the pins may not comprise a separably identifiable head and stem. The pins may be frusto-conical in shape. The narrower end of the frusto-conical pin may be connected to the control member. The region of the pin nearer the control member is sufficiently narrow to pass through the outlet. Advantageously, the other end of the frusto-conical pin is too broad to pass through the outlets. Advantageously, this may prevent the pins from being pushed inside the spray head and interfering with its operation.

The outlets may comprise a narrow channel from the inner surface of the spray plate and a curved widening portion. The curved widening portion may extend from the spray plate outer surface by means of a lip.

Advantageously, the shape of the outlet is designed to complement the shape of the pin such that a wide variation of available outlet cross-sectional areas for water flow is provided as the pin moves relative to the spray plate.

The control member may be arranged, in use, to close the outlets in the spray plate when there is low, or substantially no, water pressure in the spray head.

The pins may further comprise a bump or widening in the region of the control member. Advantageously, in use, the bumps block the outlets when the control member is dose to or touching the spray plate. The presence of these bumps advantageously means that full contact between the control member and the spray plate does not need to be made in order for the outlets to be dosed.

According to a third aspect, there is provided a shower system comprising a spray head as described in the first aspect or the second aspect which is connected to a supply of water.

The spray head may comprise a handset and the shower system may further comprise a hose connecting the water supply to the handset. Alternatively the spray head may comprise a fixed spray head and the shower system may further comprise a substantially rigid pipe connecting the water supply to the fixed shower head. The water supply may provide a source of temperature controlled water. The source of temperature controlled water may comprise a mixer valve, an instantaneous water heater or other suitable source.

The skilled person will appreciate that features discussed in relation to any one aspect of the invention may be provided with any other aspect of the invention.

Embodiments of the invention will now be described in more detail by way of example only with reference to the accompanying drawings in which like reference numerals are used for like features: Figure 1 is a cross-sectional view of a spray head of an embodiment when the water pressure is on; Figure 2 is a cross-sectional view of the spray head shown in Figure I when the water pressure is off; Figure 3 is a cross-sectional view of a spray head of an alternative embodiment including a check valve when the water pressure is on; Figure 4 is a cross-sectional view of the spray head shown in Figure 3when the water pressure is off; Figure 5 show enlarged views of the areas labelled C and D in Figures 3 and 4; Figure 6 show enlarged views of the areas labelled A and B in Figures 3 and 4; Figure 7 is a cross-sectional view of a section of a spray head of an alternative embodiment; Figures 8A, 8B show an alternative outlet/pin arrangement; Figures 9A, 9B show an alternative outlet/pin arrangement; Figures 10A, 10B show an alternative outlet/pin arrangement; Figures 11A, 11B show an alternative outlet/pin arrangement; Figures 12A, 12B show an alternative outlet/pin arrangement; Figure 13 is a cross-sectional view of a spray head of an alternative embodiment including a check valve when the water pressure is on; and Figure 14 is a cross-sectional view of the spray head shown in Figure 13 when the water pressure is off.

Referring to Figures 1 and 2 of the drawings, a spray head 100 is shown. The spray head 100 comprises a flexible diaphragm 102 enclosed by a spray plate 104 and a body 106. The diaphragm 102 shown is made of rubber. The skilled person will appreciate that other materials or combinations of materials may be used.

The spray plate 104 comprises outlets 110. The outlets 110 are holes through the spray plate 104 through which, in use, water can pass. The spray plate 104 and body 106 shown are made of metal or plastics or a combination thereof and may be substantially rigid. The skilled person will appreciate that other materials or combinations of materials may be used.

The spray plate 104 is attached to the body 106, for example by engagement of mating screw thread portions at the outer circumference of the spray pate 104 and body 106. Any other means of attaching the spray plate may be employed such as ultrasonic welding. The diaphragm 102 has an opening aligned with a water inlet 120 in the body 106 of the spray head 100. The diaphragm 102 is secured and scaled at the outer edge between the spray plate 104 and the body 106 and at the inner edge between the body 106 and a plug 118 secured in the inlet 120, for example by engagement of mating screw thread portions. Any other means of securing the diaphragm may be employed.

In the embodiment being described, the spray plate 104 is circular and the diaphragm 102 is substantially ring-shaped. In other embodiments (not shown), wherein the spray plate 104 is not substantially circular, the skilled person will understand that a different shape of diaphragm 102 may be more suitable. For example, if a square spray plate 104 is used, the diaphragm 102 may be substantially square with an opening aligned with the water inlet 120.

The diaphragm 102 is biased towards the spray plate 104 by one or more springs 108 such that the diaphragm 102 contacts the internal or rear surface of the spray plate 104 in the region of the outlets 110 and closes the outlets 110 in the spray plate 104 in a position Hocking fluid flow through the spray head 100 as shown in Figure 2. The diaphragm 102 and body 106 may define a chamber 126 in which the one or more springs 108 are arranged between the diaphragm 102 and a wall 128 of the body 106 so as to be isolated from the flow of water through the spray head 100.

In other embodiments (not shown), the springs 108 may be replaced by any other suitable biasing means providing an equivalent function, for example strips of elastic material. In other embodiments (not shown), the biasing means may be omitted and the diaphragm 102 may be configured so that the resilience of the diaphragm 102 biases the diaphragm 102 to the position shown in Figure 2.

it may be that the biasing of the diaphragm 102 is such that resistance to movement of the diaphragm 102 to open the outlets 110 is variable. For example a low resistance may be provided initially, so that the diaphragm 102 can move to open the outlets 110 easily and may increase to provide a high resistance as the diaphragm 102 moves away from the outlets 110 so that the diaphragm 102 can return quickly to close the outlets 110.

The body 106 of the spray head 100 may further comprise one or more protrusions 112 that extend from the wall 128 towards the diaphragm 102. The protrusions 128 may take the form of annular ribs. The protrusions 112 are spaced from the diaphragm 102 in the position shown in Figure 2 and provide stops to locate and support the diaphragm 102 in a set position in which the diaphragm 102 is spaced from the internal or rear surface of the spray plate 104 and opens the outlets 110 in the spray plate 104 unblocking fluid flow through the spray head 100 as shown in Figure I. In other embodiments (not shown), protrusions may be provided extending from the diaphragm 102 towards the wall 128 in addition to or in place of the protrusions 112. In other embodiments, protrusions 112 on the wall 128 and/or diaphragm 102 may not be provided.

The spray head 100 may further comprise a swivel connector 130 for attaching a fluid supply (not shown) to the spray head 100 and adjusting the position of the spray head 100 to direct the spray from the spray plate 104 in a required direction. The swivel connector 130 includes a swivel ball 114 and a coupling 116 for the fluid supply.

The swivel ball 114 is rotatable mounted in the water inlet 120 by bearings I22a, 1226. The position of the spray head 100 can be adjusted by rotating the spray head 100 about the swivel ball 114 and the bearings 122a, 122b are loaded by a spring 124 to generate friction between the bearings 122a, 122b and the swivel ball 114 for holding the spray head 100 in any adjusted position. The coupling 116 may be configured to attach to the fluid supply by any suitable means.

in alternative embodiments (not shown), the swivel ball may be omitted and the spray head 100 may be rigidly connected to the fluid supply. The skilled person will appreciate that other methods of connecting the spray head 100 to a fluid supply are possible.

The operation of the spray head 100 will now be described starting from the position shown in Figure 2 in which the outlets 110 in the spray plate 104 are closed by the diaphragm 102 under the biasing of the springs 108. This is the position of the diaphragm 102 when the water supply to the spray head 100 is turned off and/or the pressure of any water present in the spray head is insufficient to overcome the biasing of the springs 108.

The inlet 120 communicates with a central region of the spray plate 104 in which there are no outlets through the opening in the diaphragm 102. When the water supply to the spray head 100 is turned on, the force exerted on the diaphragm 102 by the springs 108 is counteracted by the pressure of the water in the spray head 100. As the pressure of the water increases, the spring force is overcome and the diaphragm 102 moves away from the spray plate 104 to adopt the position shown in Figure 1 in which the outlets 110 are open allowing water to flow through the spray head 100 and be discharged as a spray from the outlets 110. The protrusions 112 limit the movement of the diaphragm 102 and support the diaphragm 102 to control the deformation of the diaphragm 102 due to the water pressure and/or to control the compression of the springs 108.

When the water supply to the spray head 100 is turned off, the water pressure in the spray head 100 reduces and is overcome by the force exerted on the diaphragm 102 by the springs 108 and the diaphragm 102 moves towards the spray plate 104 and returns to the position shown in Figure 2 in which the diaphragm 102 makes contact with the spray plate 104 closing the outlets 110 and blocking the flow of water through the spray head 100. Any remaining water within the spray head 100 and the fluid line connecting the spray head to the water supply is therefore prevented from flowing out of the spray head 100. The arrangement of the diaphragm 102 to close the outlets 110 in the spray plate 104 provides an anti-drip mechanism so that the spray head 100 will not drip.

in alternative or additional embodiments (not shown), one or more tension springs may be located between the spray plate and the diaphragm. The springs are configured so that the springs still bias the diaphragm towards the spray plate. In such arrangement, the springs may be recessed into the diaphragm and/or into the spray plate so as to provide smooth contact between the diaphragm and the spray plate when the water supply is turned off. When the spray head is in use, the increase in water pressure overcomes the biasing of the springs causing the springs to extend/stretch as the diaphragm moves away from the spray plate. When the water is turned off, the reduction in water pressure allows the springs to return to the unextended configuration pulling the diaphragm back into contact with the spray plate. The skilled person will understand that springs could be replaced by any other biasing means providing an equivalent function, for example strips of elastic material.

Figures 3 and 4 show a spray head 300 according to an alternative embodiment in which like reference numerals are used to indicate the same or similar parts to the embodiment of Figures 1 and 2. Figure 5 shows enlarged views of the areas labelled C and D in Figures 3 and 4.

In this embodiment an additional check valve 310 is provided within the water inlet 120. The check valve 310 is an umbrella check valve comprising a flexible diaphragm. Any other check valve 310 known to one skilled in the art may be used. In alternative embodiments, a poppet valve and spring is used.

When the water supply to the spray head 300 is turned on, the increase in water pressure causes the check valve 310 to open as shown in Figure 3 so that water can flow from the water inlet 120 towards the spray plate 104. The increase in water pressure causes the diaphragm 102 to move away from the spray plate 104 opening the outlets 110 and allowing water to be discharged from the spray head 300 as described previously.

When the water supply is turned off, the water pressure decreases and the check valve closes as shown in Figure 4 to prevent fluid flowing from the central water inlet 120 towards the spray plate 104. The fall in water pressure allows the diaphragm 102 to move towards the spray plate 104 closing the outlets 110 and preventing water being discharged from the spray head as described previously.

In a modification (not shown) of the spray head 300, the diaphragm 102 may be omitted. In this modification, any water present within the spray head when the check valve 310 doses can drain through the outlets 110 in the spray plate 104 which remain open. However, water remaining in the fluid supply line from the water source to the spray head 300 when the water supply is turned off is isolated from the area behind the spray plate 104 by the check valve 310. As a result, the spray head 300 will not drip once any small volume of water has drained through the outlets 110.

Figure 6 shows an optional addition to the diaphragm 102 of the embodiment of Figures 3 and 4. Figure 6A corresponds to the area labelled A in Figure 3 and Figure 6B corresponds to the area labelled B in Figure 4.

In the embodiment shown in Figure 6, raised portions such as bumps 600 or protrusions are provided on the surface of the diaphragm 102 which faces the spray plate 104. The bumps 600 are aligned with the outlets 110 through the spray plate 104. When the water pressure is off (Figure 6B), the diaphragm 102 makes contact with the spray plate 104 and the bumps 600 scat in the outlets 110. When the water pressure is on (Figure 6A) the diaphragm 102 moves away from the spray plate 104 and the bumps 600 are displaced to open the outlets 110. In the embodiment being described, the bumps 600 are made of an elastomeric material. Advantageously, this provides good sealing contact with the outlets 110, preventing passage of water through the outlets 110 even if the diaphragm does not fully scat against the spray plate 104. In the embodiment being described, the bumps 600 arc made of the same material as the diaphragm 102. In alternative embodiments, the bumps 600 may be made of a different material.

The skilled person will understand that the bumps 600 shown in relation to the embodiment of Figure 3 and 4 can equally be used in the embodiment shown in Figures 1 and 2, or in any other embodiment.

Figure 7 shows a section of the diaphragm 102 of an additional or alternative embodiment of the invention. The embodiment shown in Figure 7 comprises elongate formations such as pins 700 which extend from the diaphragm 102. As with the bumps 600 shown in Figure 6, the pins 700 align with the outlets 110 and move relative to the outlets 110 when the diaphragm 102 moves.

The pins 700 act to control flow. The pins 700 may compensate for pressure fluctuation and help to maintain an even flow rate of water. Each pin 700 comprises a stem 702 and a head 704. In the embodiment being described, the head has a teardrop shape. in alternative embodiments (not shown), the head may be substantially circular, ovoid or rhombic in cross-section.

in the embodiment shown, the outlet 110 comprises a narrow channel which widens towards the outer surface of the spray head 100. Each outlet 110 has a circular lip 706 extending from the outer surface of the spray head 100. In alternative embodiments (not shown), the lip 706 is not provided.

When there is no significant water pressure, i.e. when a spray head 100, 300 comprising pins 700 is not in use, the diaphragm 102 is near or in contact with the spray plate 104. In this case, the stem 702 of the pin 700 extends through the outlet 110 and the head 704 of the pin 700 is in the position shown by dotted line section 710. In this position, the head 704 is not within the outlet 110.

As pressure increases, i.e. when a spray head 100, 300 comprising pins 700 is in use, the rubber springs 108 are compressed by the force of the water and the diaphragm 102 is pushed away from the spray plate 104. The head 704 of the pin 700 nears or enters the outlet 110. The clearance between the pin head 704 and the outlet 110 is reduced. The pin head 704 causes restriction of the flow of water in the region indicated by label 720 by reducing the open cross-sectional area of the outlet 110.

If pressure fluctuates during use of a spray head 100, 300 comprising pins 700, the pins move and correspondingly increase or decrease the open outlet area 110. As a result the flow rate and spray may be substantially unaffected by variations in the water pressure. In other arrangements, the outlets and pins may be configured to produce other effects, for example a pulsing effect.

In the embodiment being described, the springs 108 are not located directly behind the pins 700. In alternative embodiments (not shown), a spring 108 is located directly behind one or more of the pins 700. The skilled person will understand that the location of the springs 108 relative to the pins 700 may affect the strength of the flex/compression at that point.

in the embodiment shown, the stem 702 of the pin 700 is of the same width between the head 704 and the diaphragm 102. In alternative embodiments (not shown), the stem 702 may be of varying width. In other embodiments (not shown) the stem 702 may be provided with features similar to the bumps shown in Figure 6 where the stem 702 meets the diaphragm 102. Advantageously, a wider portion of the stem 702 in the region of the diaphragm 102 may perform the same function as the bumps 600 described in relation to the embodiments discussed above.

Figures 8A,8B; 9A,9B, 10A,10B; 11A,11B and 12A,12B show alternative outlet and pin configurations that can be employed. For convenience the reference numerals used in Figure 7 are used to indicate the same or similar parts.

In Figures 8A, 8B the pin 700 has a teardrop shape. Figure 8A shows the position of the pin 700 with the flow off and Figure 8B shows the position of the pin 700 with the flow on. In use, as pressure increases, the pin 700 is drawn into the outlet 110 and the clearance between the pin 700 and outlet 110 is increased. Initially the flow area may be a minimum when the pin engages the outlet and increases to a maximum as the pin is drawn into the outlet.

In Figures 9A, 9B the pin 700 has a teardrop shape. The head 704 is provided with four channels 730 extending in the direction of the length of the pin 700.

The channels 730 may be uniformly or non-uniformly spaced apart in the circumferential direction. The channels 730 may be of uniform or non-uniform cross-section in the direction of the length of the pin 700. The number of channels 730 may vary. There may be more than or less than four channels 730. Figure 9A shows the position of the pin 700 with the flow off and Figure 9B shows the position of the pin 700 with the flow on. In use, as pressure increases, the pin 700 is drawn into the outlet 110 and the clearance between the pill 700 and outlet 110 is reduced. Initially the flow area may be a maximum and is reduced to a minimum when the pin engages the outlet and all or substantially all flow is through the channels 730.

In Figures 10A, 10B the pin 700 has a teardrop shape. One or both of the head 704 and stem 702 is provided with at least one channel 740, 750 extending in the circumferential direction. The number of channels 740, 750 may vary. There may be more than one channel 740 in the head and/or more than one channel 750 in the stem. Figure 1 OA shows the position of the pin 700 with the flow off and Figure 10B shows the position of the pin 700 with the flow on. In use, as pressure increases, the pin 700 is drawn into the outlet 110 and the clearance between the pin 700 and outlet 110 is reduced. Initially the flow area may be a maximum and is reduced to a minimum when the pin engages the outlet and all or substantially all flow is through the channel 740.

In Figures 11A, 11B the pin 700 has a linear shape. Figure 11A shows the position of the pin 700 with the flow off and Figure I iB shows the position of the pin 700 with the flow on. In use, as pressure increases, the pin 700 is drawn into the outlet 110 and the clearance between the pin 700 and outlet 110 is increased. Initially the flow area may be a minimum when the pin engages the outlet and increases to a maximum as the pin is drawn into the outlet.

In Figures 12A, 12B the pin 700 has a linear shape. The pin 70 is provided with four channels 760 extending in the direction of the length of the pin 700. The channels 760 may be uniformly or non-uniformly spaced apart in the circumferential direction. The channels 760 may be of uniform or non-uniform cross-section in the direction of the length of the pin 700. The number of channels 760 may vary. There may be more than or less than four channels 760.

In use, as pressure increases and the pin 700 is drawn into the outlet 110, the clearance between the pin and outlet is increased. Initially the flow area may be a minimum when the pin engages the outlet and all or substantially all flow is through the channels 760 and is increased to a maximum as the pin is drawn into the outlet.

Figures 13 and 14 show an alternative embodiment in which like reference numerals are used to indicate the same or similar parts to previous embodiments.

In this embodiment the diaphragm 102 and plug 118 are replaced by a valve assembly 812.

The valve assembly 812 includes a valve member 802 and a valve seat 818. The valve scat 818 is secured in the water inlet 120, for example by engagement of mating screw threads. Any other suitable means of securing the valve seat 818 may be employed. The valve member 802 is biased towards the valve seat 818 by a spring 808 acting between the valve scat 818 and a stem of the valve member 802 that extends through an opening in the valve seat 818. The skilled person will understand that any suitable biasing means can be used in the place of the spring 808 The valve member 802 scats against the valve scat 818 and a peripheral edge 802a of the valve member 802 makes contact with and seals against a seal member 809 provided on the inner surface of the wall 128 of the body 106 blocking flow of water from the water inlet 120 to the spray plate 104 in the closed position of the valve assembly 812 as shown in Figure 14. Any other sealing arrangement may be employed between the valve member 802 and the seal member 809. Any other arrangement of the moveable valve member 802 to block the flow of water from the inlet 120 to the spray plate 104 may be employed.

The spray plate 104 may further comprise a drain hole 810. The drain hole 810 may be positioned at or near the centre of the spray plate 104. When the peripheral edge 802a of the valve member 802 makes contact with and seals against the seal member 809, the drain hole 810 is open and water present in the region of the spray plate 104 can drain out of the spray head 800 through the drain hole 810, as marked by arrow F. The drain hole 810 is much wider than the outlets 110 and so permits more rapid draining of the spray head 800. In a modification a single drain hole may be replaced by a plurality of drain holes.

The operation of the spray head 800 will now be described starting from the position shown in Figure 9 in which the valve assembly 812 is closed, preventing flow of water from the water inlet 120 to the spray plate 104, by the valve member 802 engaging the seal member 809 under the biasing of the spring 808. This is the position of the valve member 802 when the water supply to the spray head 800 is turned off and/or the pressure of any water present in the water inlet 120 is insufficient to overcome the biasing of the spring 808.

When the water supply to the spray head 800 is turned on, the force exerted on the valve member 802 by the spring 808 is counteracted by the pressure of the water in the water inlet 120. As the pressure of the water increases, the spring force is overcome and the valve member 802 moves away from the valve seat 818 to the position shown in Figure 13 in which the valve member 802 seats against the spray plate 104 and seals around the peripheral edge of the drain hole 810 by means of a seal mcmbcr 819 to close the drain outlet 810. In this position the peripheral edge 802a of the valve member 802 is spaced from the seal member 809 opening the valve assembly 812 so that water can flow from the inlet 120 through the open valve assembly 812 to the area behind the spray plate 104 and be discharged as a spray from the outlets 110.

When the water supply to the spray head 800 is turned off, the water pressure in the inlet 120 acting on the valve member 802 reduces and is overcome by the force exerted on the valve member 802 by the spring 808. The valve member 802 moves towards the valve seat 818 under the force of the spring 808 and returns to the position shown in Figure 14 in which valve member 802 seats against the valve seat 818 and the peripheral edge 802a of the valve member 802 makes contact with the scaling member 809 closing the valve assembly 812 and blocking the flow of water through the spray head 800. At the same time the drain hole 810 in the spray plate 104 is opened and any remaining water behind the spray plate 104 within the spray head 800 can drain rapidly through the drain hole 810 while the fluid line connecting the spray head 800 to the water supply is isolated from the spray plate 104 by the valve assembly 812 so that any water remaining in the fluid line is prevented from flowing out of the spray head 800. As a result, the spray head 800 will not drip once any small volume of water has drained through the drain hole 810.

In a modification (not shown), the drain hole 810 may be omitted and any water remaining behind the spray plate within the spray head can drain through the outlets 110.

It will be appreciated that the invention is not limited to the embodiments above described and the person skilled in the art will understand that various modifications can be made to the spray head without departing from the principles and concepts described herein.

Claims

CLAIMS1. A spray head comprising a spray plate and a moveable element behind the spray plate, wherein the moveable element is arranged to move to and from a position blocking fluid flow through the spray head in response to fluid pressure.
2. The spray head of claim 1 wherein the moveable element is arranged, in use, to block fluid flow through the spray head when there is substantially no fluid pressure within the spray head and to move as fluid pressure within the spray head increases, unblocking fluid flow through the spray head.
3. The spray head of any preceding claim wherein the moveable element is biased towards the position Hocking fluid flow through the spray head.
4. The spray head of claim 3 wherein the moveable element is biased by at least one resilient member.
The spray head of any preceding claim further comprising stop means arranged to limit movement of the moveable element away from the blocking position.
6 The spray head of any preceding claim wherein the moveable element is arranged to close outlets through the spray plate blocking fluid flow through the spray head and to move away from the spray plate to open the outlets unblocking the outlets through the spray plate.
7. The spray head of claim 6 wherein the moveable element is made of a flexible material.
R. The spray head of claim 6 or claim 7 wherein the moveable element comprises a diaphragm that closes the outlets in the spray plate in the position Hocking fluid flow through the spray head.
9. The spray head of claim 8 wherein the diaphragm is biased towards the spray plate.
10. The spray head of claim 9 wherein the diaphragm is moveable away from the spray plate to open the outlets when the fluid pressure overcomes the biasing means.
11. The spray head of any of claims 8 to 10 wherein the diaphragm further comprises raised formations aligned with at least some of the outlets.
12. The spray head of claim 11 wherein, in use, the raised formations seat in the outlets when the diaphragm is close to or touching the spray plate.
13. The spray head of any of claims 8 to 12 wherein the diaphragm further comprises elongate formations aligned with at least some of the outlets.
14. The spray head of claim 13 wherein the elongate formations are arranged, in use, to control the flow of fluid through the outlets.
15. The spray head of claim 13 or claim 14 wherein the elongate formations comprise pins received in the outlets.
16. The spray head of claim 15 wherein a distal end of the pins extends through and projects from the outlets when the moveable element blocks fluid flow through the spray head.
17. The spray head of claim 16 wherein the extent to which the distal end of the pins projects from the outlets is reduced when the moveable element moves to unblock fluid flow through the spray head.
18. The spray head of any of claims 15 to 17 wherein a clearance between the pins and the outlets is a maximum when the moveable element blocks fluid flow through the spray head.
19. The spray head of any of claims 15 to 17 wherein a clearance between the pins and the outlets is a minimum when the moveable element blocks fluid flow through the spray head.
20. The spray head of any preceding claim further comprising a check valve across a fluid inlet to the spray plate region of the spray head.
21. The spray head of any of claims 1 to 5 wherein the moveable element is arranged to close a flow path to the spray plate region of the spray head, blocking fluid flow through the spray head and to open the flow path as fluid pressure within the spray head increases, unblocking the flow of fluid to the spray plate.
22. The spray head of claim 21 wherein the moveable element comprises a valve member that engages a valve seat to close the flow path, blocking fluid flow through the spray head, and is moved away from the valve seat opening the flow path by an increase in fluid pressure, unblocking fluid flow through the spray head.
23. The spray head of claim 22 wherein the valve member s biased towards the valve seat.
24. The spray head of claim 23 wherein the valve member is moveable away from the valve scat to open the flow path when the fluid pressure overcomes the biasing means.
25. The spray head of any of claims 21 to 24 wherein the spray plate is configured to allow fluid to drain from the spray head when the valve member engages the valve seat to block fluid flow through the spray head.
26. The spray head of claim 25 wherein the spray plate has spray outlets and one or more drain holes of larger area than the spray outlets.
27. The spray head of claim 25 or claim 26 wherein the valve member is moveable away from the valve seat to close the drain hole or holes and, when the valve member returns to the position engaging the valve seat blocking fluid flow through the spray head, the drain hole or holes are opened so that fluid remaining in the region of the spray plate is rapidly drained
28. A spray head substantially as described herein with reference to the accompanying drawings.
29. A spray head comprising a spray plate and a control member situated behind the spray plate, wherein the control member further comprises pins aligned with outlets in the spray plate, and wherein the control member is arranged, in use, to move towards and away from the spray plate in response to fluid pressure whereby the pins move relative to the outlets in the spray plate.
30. A shower system comprising a spray head according to any of the preceding claims connected to a supply of water.