IMPROVED SPRAY HEAD FOR ABLUTIONARY APPLIANCES

This invention concerns spray heads for ablutionary appliances and is particularly, but not exclusively, concerned with spray heads for showers.

Spray heads for showers typically comprise a spray plate with an array of holes for discharge of water to form a spray pattern according to the number, size and arrangement of the holes. In some spray heads, the user can alter the spray pattern by selecting different combinations of holes.

A problem arises, however, in areas where the water supply can lead to formation of limescale deposits in and around the holes that affects the discharge of water and causes the spray pattern to deteriorate and eventually cause blockage of the holes. To prevent or reduce the effects of limescale formation, various proposals have been made to manually remove limescale deposits without the use of household cleaners that may contain abrasive and chemical substances that could damage the spray head.

In one solution, the outer surface of hard spray plates can be rubbed with a finger or soft cloth to remove any deposits from around the holes. This, only removes limescale deposits formed on the outside of the spray head and, it may be necessary from time to time, to detach the spray plate to remove deposits on the inside of the spray plate.

In another solution, soft rubber nozzles can be provided that extend through the holes and project from the outer surface of a hard spray plate allowing the nozzles to deflect when rubbed with a finger or cloth causing limescale deposits to break off. This makes cleaning easier.

In another solution, suitable for multi mode handsets where an adjuster ring is rotatable to select alternative spray modes, a cleaning position can be provided in which an array of pins are mechanically driven through the holes thereby breaking off any limescale deposits.

Yet another solution, employs a spray plate that is sprung loaded to a spray position and, by pressing the spray plate, can be moved back against the spring loading onto an array of pins that extend through the holes thereby breaking off any limescale deposits.

The above solutions all rely on the user carrying out the cleaning operation manually.

It is an object of the present invention to provide an improved spray head in which limescale deposits can be removed automatically or manually.

Thus, according to one aspect of the present invention, there is provided a spray head for an ablutionary appliance having a spray plate provided with an array of holes for discharge of water and a cleaner plate located behind the spray plate and having an array of pins corresponding to the array of holes in the spray plate, wherein the spray plate is biased to a first position (hereinafter called the "self-cleaning" position) where the pins on the cleaner plate extend into the holes in the spray plate and is movable away from the cleaner plate to a second position (hereinafter called the "spray" position) providing clearance between the pins on the cleaner plate and the holes in the spray plate when pressure of water supplied to the spray head overcomes the biasing of the spray plate, and wherein the spray plate is manually movable towards the cleaner plate to a third position (hereinafter called the "manual cleaning" position) where

the pins on the cleaner plate extend further into the holes in the spray plate.

By this invention, the holes in the spray plate are automatically cleaned by movement of the spray plate from the spray position to the self- cleaning position when the spray head is not in use and/or there is insufficient water pressure acting on the spray plate to overcome the biasing of the spray plate to the self-cleaning position in which the pins on the cleaner plate extend into the holes in the spray plate to remove any deposits or detritus blocking the holes and inhibit formation of deposits in the holes. This self-cleaning occurs automatically during normal use of the spray head without requiring any manual intervention by the user. In addition, to this self-cleaning operation, the spray plate can be manually cleaned by pushing the spray plate towards the cleaner plate to force the pins on the cleaner plate further into and, more preferably through, the holes in the spray plate. Such manual cleaning involves greater force being applied to any deposits that may have started to form in or around the holes and thereby assist their removal before they can develop to cause a blockage. Manual cleaning may also be useful to remove any detritus carried by the water supply that causes a blockage in any of the holes and is not removed when the spray plate returns to the self-cleaning position.

Preferably, the spray head is self-draining in the self-cleaning position to prevent water being trapped and remaining in the spray head when the spray head is not in use which could then lead to formation of limescale deposits in the spray head. For example, the spray head may be sealed around the perimeter to a part of the spray head in the spray position so that water can only be discharged through the holes in the spray plate and, when the spray plate is in the self-cleaning position with the pins on

the cleaner plate received in the holes, the seal is broken to leave a clearance gap around the perimeter of the spray plate through which water can drain from within the spray head.

Preferably, the spray head is also self-draining in the manual cleaning position allowing the user to select this position not only when the spray head is not in use but also when the spray head is in use by allowing the water supplied to the spray head to escape through the clearance gap while the pins on the cleaner plate are blocking the holes in the spray plate.

Preferably, the spray plate is biased towards the self-cleaning position by a return spring that is overcome by the water pressure acting on the spray plate to compress the return spring when the spray head is in use to move the spray plate to the spray position. The return spring ensures the spray plate returns to the self-cleaning position when the spray head is not in use.

Preferably, the spray plate is manually movable from the self-cleaning position to the manual cleaning position against the biasing of an overload spring that returns the spray plate to the self-cleaning position on release of the spray plate. The ratings of the return spring and overload spring are selected so that the spray plate adopts and maintains the self-cleaning position in the absence of pressure applied to the spray plate either from within the spray head by water pressure or manually from externally of the spray head by finger pressure. Thus, the self-cleaning position is an intermediate position between the spray position and the manual cleaning position.

Preferably, the holes are tapered from an inlet end to an outlet end in the direction of flow with the inlet end being wider than the outlet end, and a distal or free end of the pins extends to the outlet end in the self-cleaning position and projects from the outlet end in the manual cleaning position. In this way, limescale or debris is ejected from the holes in both the self- cleaning and manual cleaning positions.

Preferably, the pins are partially withdrawn from the holes in the spray position providing clearance for water to flow past the pins through the holes for discharge from the outlet end of the holes. Alternatively, the pins may be completely withdrawn from the holes in the spray position.

Preferably, the pins restrict or even prevent flow of water through the holes in one or both of the self-cleaning and manual cleaning positions. For example, the pins may be a close fit in the outlet end of the holes in the self -cleaning position and/or the manual cleaning position.

According to another aspect of the present invention, there is provided a spray head for an ablutionary appliance having a spray plate provided with an array of holes for discharge of water and a cleaner plate located behind the spray plate and having an array of pins corresponding to the array of holes in the spray plate, wherein the spray plate is biased to a first position intermediate a second position and a third position, the pins extending to an outer end of the holes in the first position to clean same and remove any limescale or debris therein, wherein the spray plate is movable from the first position away from the cleaner plate to the second position when pressure of water supplied to the spray head overcomes the biasing of the spray plate for water to flow through the holes, and wherein the spray plate is manually movable from the first position towards the cleaner plate to the third position in which the pins project

from the outer end of the holes to clean same and remove any limescale or debris therein.

According to yet another aspect of the present invention, there is provided a spray head for an ablutionary appliance having a spray plate provided with an array of holes for discharge of water and a cleaner plate located behind the spray plate and having an array of pins corresponding to the array of holes in the spray plate, wherein the spray plate is biased to a first position (hereinafter called the "self-cleaning" position) where the pins on the cleaner plate extend into the holes in the spray plate and is movable from the first position away from the cleaner plate to a second position (hereinafter called the "spray" position) when pressure of water supplied to the spray head overcomes the biasing of the spray plate for water to flow through the holes, and wherein the spray plate is manually movable from the first position towards the cleaner plate to a third position (hereinafter called the "manual cleaning" position) closer to the cleaner plate than in the first position such that the pins on the cleaner plate extend further into the holes in the spray plate than in the first position.

The invention will now be described in more detail by way of example only with reference to the accompanying drawings wherein:

Figure 1 is a sectional view of one half of a spray head embodying the invention, the spray plate being shown in the "self-clean" position;

Figure 2 is a sectional view similar to Figure 1 with the spray plate being shown in the "spray" position; and

Figure 3 is a sectional view similar to Figures 1 and 2 with the spray plate being shown in the "manual clean" position.

Referring to the drawings, the spray head 1 has an inlet (not shown) for connection to a supply (not shown) of temperature controlled water from a mixing valve, instantaneous water heater or the like. The inlet opens to a chamber 3 and the spray head 1 is provided with an annular spray plate 5 having a series of holes 7 through which water is discharged to form a spray. The number and arrangement of holes 7 may be chosen to provide any desired spray pattern.

When the spray head 1 is not in use, the spray plate 5 is biased by a return spring 9 to a self-cleaning position shown in Figure 1 in which a cleaner plate 11 arranged behind the spray plate 5 has a plurality of pins 13 that are received in the holes 7 in the spray plate 5. The number and arrangement of the pins 13 correspond to the number and arrangement of holes 7 in the spray plate 5.

In this embodiment, the holes 7 are of circular cross-section and tapered in the direction of flow such that the inlet end 7a is wider than the outlet end 7b and the pins 13 are cylindrical or slightly tapered towards the distal or free end 13a such that, in the self-cleaning position, the distal or free end 13a extends to and is a close fit in the outlet end 7b of the corresponding hole 7. In this way, any build-up of lime scale or debris in the holes 7 is automatically pushed out by the pins 13 in the self-cleaning position by the distal or free end 13a of the pins 13 extending to the outlet end 7b of the holes 7. The flow of water through the holes 7 in the self-cleaning position is restricted or prevented by close fit of the distal end of the pins 13 at the outer end of the holes 7 to be substantially flush with the outer surface of the spray plate 5. As will be appreciated, the

holes 7 and pins 13 may have other configurations that serve to clean the holes 7 and remove limescale or debris from the holes 7 in the self- cleaning position.

When the spray head 1 is in use, water supplied to the spray head 1 passes through holes 15 (one only shown) in the cleaner plate 11 and the pressure of the water moves the spray plate 5 away from the cleaner plate 11 against the biasing of the spring 9 to a spray position shown in Figure 2 in which the outlet end 7b of the holes 7 in the spray plate 5 is clear-off of the distal or free end 13a of the corresponding pins 13 and a clearance gap 14 is provided between the pins 13 and holes 7 allowing water to be discharged from the spray head 1 through the holes 7.

In this embodiment, the pins 13 are partially withdrawn from the holes 7 in the spray position and the tapered configuration of the holes 7 provides sufficient clearance for water to flow past the pins 13 through the holes 7 to be discharged from the outlet end 7b forming a spray pattern. The tapered configuration of the holes 7 also allows some lateral movement of the pins 13 relative to the holes 7 in the spray position without adverse effect on the flow of water and acts as a guide for axial movement of the pins 13 relative to the holes 7 towards and away from the outlet end 7b. It will be understood that the pins 13 could be fully withdrawn from the holes 7 in the spray position.

The spray plate 5 is sealed relative to a retainer 17 in the spray position by an O-ring 19 located in a groove 21 extending around the perimeter of the spray plate 5. The spray plate 5 is held in this position by the water pressure and the water can only leave via the holes 7 in the spray plate 5 forming the spray pattern.

The spray plate 5 automatically returns to the self-cleaning position when not in use under the biasing of the return spring 9 and the O-ring 19 is carried by the spray plate 5 to a position in which it no longer seals the spray plate 5 relative to the retainer 17 as shown in Figure 1 allowing any water remaining in the spray head to drain past through a clearance gap 23 created around the perimeter of the spray plate 5.

If during operation the spray plate 5 fails to either retract fully onto the pins 13, for example due to debris causing a blockage in one of the holes 7 in the spray plate 5, or becomes stuck on the pins 13, for example due to formation of limescale causing the pins 13 to become temporarily attached to the spray plate 5, the user can manually push the spray plate 5 using a thumb or finger further onto the cleaner plate 11 against the biasing of an overload spring 25 to a manual cleaning position shown in Figure 3 in which the pins 13 extend through the holes 7 and the distal or free end 13a of the pins 13 projects outwardly from the outer end 7b of the holes 7 in the spray plate 5 thereby clearing any debris in the holes 7 and/or breaking any limescale attaching the pins 13 to the spray plate 5. Again the flow of water through the holes 7 is restricted or prevented in the manual cleaning position by close fit of the pins 13 at the outer end of the holes 7 with the distal or free end of the pins 13 projecting from the outer end of the holes 7 to be proud of the outer surface of the spray plate and thereby provide a visual and tactile indication of the manual cleaning position. The spray plate 5 is automatically pushed back into the self- cleaning position by the overload spring 25 when the manually applied thumb or finger pressure is released. The clearance gap 23 around the perimeter of the spray plate 5 is maintained in the manual cleaning position allowing the user to select this position both when the spray head is in use and when not in use.

The ratings of the return spring 9 and overload spring 25 are selected so that the spray plate 5 automatically assumes and maintains the self- cleaning position intermediate the spray position and the manual cleaning position in the absence of any pressure on the spray either from within the spray head 1 by water pressure or externally of the spray head by finger pressure. In the above-described embodiment, the springs 9,25 are helical springs of metal or other suitable material. It will be understood, however, that this is not essential and that one or both springs may be replaced by any means for biasing the spray plate to achieve the desired operation. For example, the spray head may include flexible moulded plastic features or other suitable biasing means.

In normal operation, movement of the spray plate 5 between the self -clean and spray positions shown in Figures 1 and 2 in response to water pressure should automatically keep the build-up of lime scale and debris to a minimum allowing the spray head 1 to keep functioning within its intended design parameters. If, however, this automatic self-cleaning operation is not sufficient to remove debris or the spray plate becomes stuck due to formation of limescale, manual cleaning can still be carried out to free the spray plate 5 for normal operation.

As will now be understood, the present invention provides a spray head that is self-cleaning in normal operation to remove deposits or detritus from the holes in the spray plate and which can be manually cleaned if required.

The above-described invention may be applied to spray plates in a variety of different types of spray heads. For example, the invention may be applied to fixed spray heads, handsets and the like.