IE60826B1

IE60826B1 - Improved spray head for ablutionary appliances

Info

Publication number: IE60826B1
Application number: IE303588A
Authority: IE
Original assignee: Caradon Mira Ltd
Priority date: 1987-10-06
Filing date: 1988-10-06
Publication date: 1994-08-24
Also published as: GB2210566A; IE883035L; GB8723417D0; GB2210566B

Abstract

A spray head assembly 4, such as for a hand shower 1, includes a construction for cleaning the apertured spray plate 10. The assembly 4 incorporates a fixed cleaner plate 9 and an axially movable spray plate 10 that are both retained by a mounting flange 11 engaging a collar 6. The cleaner plate 9 has a series of spike-like projections 19 arranged to engage in nozzle holes 5 of the spray plate 10. The cleaner plate 9 and spray plate 10 are supported together for relative axial movement by a splined hub 16. When there is no significant water flow, springs 31 and 35 hold the spray plate 10 in a drainage position in which the spray plate seal 15 is lifted from the seal face 14. By pushing inwardly on the spray plate 10, it is displaced so that the nozzle holes 5 are cleaned by the spikes 19. During use when water flows, the water pressure overcomes the spring force and maintains the spray plate 10 sealed against the face 14. Other embodiments with different spring and function arrangements are described.

Description

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

In the conventional and typical spray head there is a spray plate having an array of holes that provide orifices for the water which flows in the form of small jets according to the arrangement, size and relative disposition of the array of holes. A persistent problem with such spray heads is that limescale forms on the spray plate and causes the spray pattern to deteriorate and eventually the deterioration may be so great that the majority of the holes become blocked.

In domestic shower installations, the limescale formations can cause the spray pattern to deteriorate significantly in only a few weeks of normal domestic use. The rate of spray deterioration is very variable and is largely dependent on the type of the water supply. We have studied the mechanism of limescale formation and we have found that one of the causes arises from the water drying on the outer surface of the spray plate after the spray head has been used. We have also found that the limescale generally takes the form of a thin web closing across each spray orifice from an initial deposit around the peripheral edge of each hole.

In the traditional form of spray plate where the hole is a simple through hole in a single plate, the partly formed scale develops and grows like a lens iris until the hole is closed as the limescale builds up from the peripheral edge of the hole. In other types of spray heads where the spray plate may be an assembly of superimposed plates with slots that are brought into -3register to provide suitable holes, then the web of limescale builds up just the same at the edge of each slot. However, as the limescale builds up it quickly changes both the designed direction of the water jet .5 through the hole and the orifice size. In both of these cases as described, it is significant that the shape and direction of the overall spray pattern may be changed due to such deterioration even though the degree of limescale formation is hardly visible to the naked eye.

To the spray head user, this deterioration is most unsatisfactory and although the user may attempt to clean out the blocked holes in the spray plate, this is often not possible, or such attempt may damage the spray plate.

It is an object of this invention to provide a spray head which is of improved construction and design to obviate this deterioration due to limescale formation.

It is an object of this invention to provide an improved spray head in which the designed array of holes for the water jets may be cleaned in a simple and expedient manner to remove deposits of limescale or other detritus.

It is a further object of this invention to provide one particular construction of such improved spray head in which the array of holes may be automatically cleaned out on operation of the ablutionary appliance to which the spray head is fitted in use.

It is another object of this invention to provide a spray head having special features which reduce the main cause of such limescale formation as discussed -4above when the water dries on the outer face of the spray plate.

Other objects and advantages to be achieved by the invented improved spray head will be referred to later herein.

According to the broadest aspect of this invention, we provide a spray head for an ablutionary appliance having a hollow member defining a water passage terminating in an outlet end, the spray head comprising a mounting flange connected to the outlet end of the hollow member and defining a seating, a cleaner plate supported internally of the outlet end and retained by the mounting flange, and a spray plate retained within the mounting flange for movement relative to both the cleaner plate and the mounting flange, the spray plate having an array of nozzle holes for the discharge of water to a designed spray pattern and the cleaner plate having an array of cleaning projections arranged for register and engagement with the nozzle holes of the spray plate, the cleaner plate also having through passageways for the flow of water to and through the nozzle holes of the spray plate, the arrangement of the spray head being such that in one position of the spray plate (hereinafter called the spray position) the spray plate is disengaged from the cleaner plate for water to flow through the said passageways and through the nozzle holes of the spray plate with the spray plate engaging the seating of the mounting flange, and the spray plate being movable relative to the cleaner plate to another position (hereinafter called the cleaning position) wherein the cleaning projections of the cleaner plate extend into the respective aligned nozzle holes to clean same and remove any limescale and other detritus therein.

I -5By this improved spray head according to the broadest aspect of this invention, the nozzle holes of the spray plate are arranged to be cleaned by the projections of the cleaner plate when the spray plate is moved to the cleaning position. In the spray position of the spray plate, the spray head operates in the usual and conventional manner without any of the nozzle holes being obstructed, and when the spray plate is in the cleaning position, then the cleaner projections clean out the nozzle holes by entering same for cleaning purposes. This simple construction enables the spray head to be cleaned simply and effectively even though the limescale or detritus may be virtually invisible to the naked eye, and of course as explained, by keeping the nozzle holes clean, the build up of limescale is avoided.

It is also preferred that each of the nozzle holes is in the form of a frusto-conical hole tapering towards the outer face of the spray plate remote from the inside of the member.

The provision of such frusto-conical form of nozzle holes has been found to most effective in providing the maintenance of direction of the individual water jets through each hole in the designed spray pattern whilst enabling the cleaning projections to enter into each nozzle hole for the cleaning operation with the larger end of each nozzle hole providing a form of self-centring location for the cleaning projection when brought into engagement and entry therein.

Preferably, the spray plate and the cleaner plate are inter-engaged by complementary formations for the relative axial movement whilst maintaining the nozzle -6holes and the cleaning projections in the desired register.

This preferred arrangement may include interengaged complementary pin and hole formations on the spray and cleaner plates which act as guides during the relative axial movement of the two plates between the spray and cleaning positions of the spray plate.

In a preferred construction, the cleaner plate supports the spray plate which has a central hub engaged with the cleaner plate for the relative axial movement by means of complementary formations comprising splines on the central hub.

The arrangement of the central hub mounting the spray plate permits a neat and simple assembly of the spray and cleaner plates together, and this assembly is retained in situ by the mounting flange.

In one preferred arrangement of the improved spray head according to this invention, a spring is mounted on the hub to act between the cleaner plate and the spray plate whereby the spray plate is biased into the spray position by the spring for normal use when water is flowing through the spray head. By applying a force to the spray plate externally, the spring force may be overcome to push the spray plate towards the cleaner plate into the cleaning position for the cleaning engagement of the cleaning projections with the respective nozzle holes.

With such preferred construction, the user can operate the ablutionary appliance in the normal manner, and before or after use can actually clean the spray plate nozzle holes by simply pressing or pushing the spray plate to move it inwardly of the flange for the cleaning action. -7In another preferred arrangement of the improved spray plate according to this invention, another feature is provided to obviate the problem arising from the retention of water in the spray head after use and which causes the problem of drying out of the water on the outer face of the spray plate.

According to this preferred arrangement, the spray plate is retained within the mounting flange for sealing engagement with the flange seating when in the spray position spaced from the cleaner plate and when water is discharged through the spray head with the spray plate being maintained in the spray position by the pressure of water acting on the spray plate, the spray plate is movable relative to the cleaner plate to an intermediate position (hereinafter called the drain” position) in which the spray plate is moved out of sealing engagement with the flange seating leaving a gap through which any water in the spray head may drain when the flow of water ceases to act on the spray plate to maintain it in the spray position.

In the preferred arrangement as just mentioned, the water that might be retained in the spray head after use will automatically drain away from the spray head through the unsealed gap between the spray plate and the flange seating, and the risk of slow drying of water to form the limescale deposit is obviated. The operation of the spray head is normal for the user once water flows through the spray head to force the spray plate into the spray position in sealed engagement with the flange seating.

In such preferred arrangement with the selfdraining arrangement, the cleaner plate and the spray plate may be connected together for axial movement by a -8splined hub with spring means adapted and arranged to act between the cleaner plate and the spray plate to maintain the spray plate in the drain position with the drainage gap when there is no water pressure acting on the spray plate, and the spring means also acting between the cleaner plate and the spray plate so that the spray plate can be moved against the spring bias relative to the cleaner plate from the drain position to the cleaning position for the cleaning action as aforedescribed, and the spring means returning the spray plate to the drain position when the spray plate is released.

In this preferred arrangement, the spring means comprises two springs each acting between the cleaner plate and the spray plate in opposition so that the combined spring forces maintain the spray plate in the drain position and one spring acts to return the spray plate from the spray position to the drain position.

Yet another arrangement of spray head according to this invention is preferred and in this the selfcleaning and drainage functions are achieved automatically relying on the pressure of the water flowing through the spray head.

In this further arrangement, the spray plate and cleaner plate are connected together by a splined hub for the axial movement of the spray plate relative to the cleaner plate and the flange seating, a spring acts between the cleaner plate and the spray plate to maintain the spray plate in the cleaning position wherein the cleaner projections engage in the aligned nozzle holes and to maintain the spray plate in the coincident drain position with the drainage gap between the spray plate and the flange seating, and the spring -9force being such that the pressure applied by water flowing through the spray head overcomes the spring force to displace the spray head away from the cleaner plate to open the nozzle holes and simultanously to bring the spray plate into the spray position with the spray plate being in sealing engagement with the flange seating, this arrangement being such that when the water pressure reduces on turning off the ablutionary appliance, then the spring acts automatically to return the spray plate towards the cleaner plate to the coincident cleaning and draining position for the selfcleaning function whilst any residual water in the spray head may drain away through the drainage gap.

Various detail design and novel features of the improved spray head according to this invention will be described hereinafter with reference to certain embodiments comprising the preferred arrangements just mentioned. However, it should be understood that the invented spray head may be applied to a wide range of ablutionary appliances where spray jets streams of water are required. Typical ablutionary appliances with spray heads are fixed shower heads or bidets, or hand held spray sets as in showers or over-sink sprays or in hairdressing or institutional installations.

In known manner, the specific size and shape of the spray head may be designed and variable for the spray pattern required, as well as the selection of the sizes of water flow passages and bores to accommodate differing water pressures and flow rates.

The invention will now be described with reference to three embodiments of the improved spray head as shown in the accompanying drawings wherein:-10FIGURE 1 is a sectional view of the first embodiment of a xspray head without the self-draining function and shown in the operating or normal mode for water discharge with the spray plate being in the spray position; and FIGURE 2 is a embodiment as head with the position. similar sectional view of the first shown in Figure 1 but showing the spray spray plate displaced to the cleaning FIGURE 3 is a sectional view of the second embodiment of a spray head including the self-draining function with the spray head being shown in the rest position when there is no water pressure acting thereon and the spray plate being retained in the drain position; FIGURE 4 is another sectional view of the second embodiment similar to that as shown in Figure 3 but showing the spray plate in the cleaning position; and FIGURE 5 is another sectional view of the second embodiment as shown in Figures 3 and 4 but showing the spray head in the operating mode with water being discharged and the spray plate being in the spray position.

FIGURE 6 is a sectional view of the third embodiment of a spray head designed to have a self-cleaning and selfdraining function, the spray head being shown in the operating mode with water being discharged and the spray plate being in the spray position; and FIGURE 7 is a similar sectional view of the third embodiment as shown in Figure 6, the spray head being shown in the rest position with the spray plate being in the coincident cleaning and drain position. -11With reference to the three embodiments as shown in the accompanying drawings, these are all based on the same application of the invented spray head to a shower hand set of an exemplary type which would be used and coupled to any suitable flexible hose connected to a supply of water, for instance to an instantaneous water heater or a thermostatically controlled faucet or mixing valve. These details for the supply of water are not considered to be relevant to the invention and are not described herein. Furthermore, for simplicity of describing the three embodiments of this invention, in this description and drawings, the same reference numerals are used, where appropriate, for the same component parts.

With reference to the first embodiment shown in Figures 1 and 2, there is shown a portion of a hand shower handle 1 having a hollow interior 2 providing a passageway therethrough for water and terminating in an outlet end 3. The invented spray head assembly 4 is mounted on the outlet 3 and, in known manner includes a plurality of nozzle holes 5 through which water jets are discharged when the water (shown by arrow W) flows through the internal passageway of the handle.

In this exemplary embodiment, the outlet end 3 of the handle 1 terminates in a external collar 6 having an internal thread 7. The collar 6 extends from a continuous internal shoulder 8 formed in the outlet end of the handle.

The spray head assembly 4 includes a cleaner plate 9 and a spray plate 10 that are retained as an assembly within the external collar 6 by a mounting flange 11 in threaded engagement with the collar 6. -12The outlet end 3 of the handle 1 and the collar 6 and flange 11 are circular in plan shape and the outer side face of the mounting flange 11 has finger grip recesses 12 formed therein to enable the spray head assembly 4 to be fitted to or removed from the handle 1. The inner side face 13 of the flange 11 is substantially right-cylindrical and the outer end of the flange 11 is formed with an inwardly directed lip 14 providing a seating for engagement by an annular o-ring seal 15 carried around the periphery of the spray plate 10 in a suitable groove.

The spray plate 10 is circular in plan shape and is of convex shape as shown in the section view of Figures 1 and 2. The spray plate 10 is formed with a series of concentrically arranged nozzle holes 5 which are each of frusto-conical form tapering to the outer face of the spray plate. As shown, and as required for a desired spray pattern, the axes of the nozzle holes 5 are arranged to give a diverging spray pattern from the centre of the spray plate.

At the centre portion of the outer face of the spray plate 10, there is formed an embossment 10a for manual engagement for pushing the spray plate 10 inwards towards the cleaner plate 9 for the cleaning function as later described.

At the centre of the inner face of the spray plate 10 there is an inwardly extending hub 16 extending from a small pedestal 17, and a series of axially extending splines 18 are provided as a keyway on the hub 16.

The cleaner plate 9 is made of a tough and resilient plastics material and is also of circular shape in plan. The main annular portion of cleaner -13plate 9 has a series of cleaner projections 19 like spikes extending from the face opposed to the spray plate 10. The cleaner projections 19 are aligned with and for register with the nozzle holes 5 of the spray plate 10. Each cleaner projection 19 is designed to enter into a nozzle hole 5 for the cleaning action as later described, and it should be noted that as each cleaner projection 19 is arranged to enter into the larger end of each nozzle hole 5, then any slight misalignment of the projection with its associated nozzle hole will be accommodated by a self-centring action.

At arcuately spaced locations around the cleaner plate 9 there are provide a series of guidance holes 20 which receive complementary guide pins 21 projecting inwardly from the spray plate 10. The inter-engagement of the guide pins 21 with the guide holes 20 ensures that the cleaner and spray plates are located and guided in the correct position during relative axial movement.

At the centre of the cleaner plate 9 there is a hollow boss 22 with an internal sleeve extension 23 having rib or like formations seating in the splines 18 of the hub 16 of the spray plate 10. The inner end of the spray plate hub 16 may be provided with means for securing the boss 22 thereto by a circlip or the like (not shown). Interposed between the boss 22 and the internal sleeve 23 is an helical spring 24 which extends between the cleaner plate 9 and the spray plate 10 with one end of the spring 24 being engaged over the pedestal 17 at the base of the hub 16.

The cleaner plate 9 is mounted in the outlet end 3 by an annular flange portion 9a which seats against the -14internal shoulder 8 of the handle 1. There are circumferentially spaced radial webs 9b which extend between the main portion of the cleaner plate and the flange portion 9a with the spacing of the webs 9b being such as to be clear of the guide holes 20 and guide pins 21. The cleaner plate 9 is retained in the outlet end 3 by the threaded engagement of the mounting flange 11 within the collar 6. An O-ring 26 seal is disposed between the flange portion 9a and the inner end of the mounting flange 11.

In the cleaner plate 9 there are provided a series of through holes 27 providing passageways for the flow of water from the interior 2 of the handle 1 to the nozzle hole 5 of the spray plate 10 for spray discharge. Preferably these through holes 27 are of relatively large size and are radially spaced around the cleaner plate 9 intermediate those locations where there are the cleaner projections 19.

As shown in Figure 1, in the normal operating mode for the spray head when in use with water flowing therethrough, the spray plate 10 is maintained spaced from the cleaner plate 9 so that water can flow through the through holes 27 of the cleaner plate and be discharged in the desired pattern through the nozzle holes 5. The spray plate 10 is held in this spray position by the force of the spring 24 acting between the cleaner plate 9 and the spray plate 10, and the spray plate is sealed to the flange 11 by the engagement of the O-ring 15 with the lip seating 14.

In order to clean the nozzle holes 5 of the spray plate, either before or after use of the ablutionary appliance, all that is required is for the user to apply a manual pressure indicated by arrow M on the -15embossment 10a to push the spray plate 10 inwards of the flange 11 and towards the cleaner plate 9. As shown in Figure 2, when the spray plate 10 is so pressed, the spray plate is displaced relative to the cleaner plate 9 into a cleaning position in which the cleaner projections 19 engage and enter into the nozzle holes 5 to displace any limescale or other detritus in the nozzle holes. The force of the spring 24 is overcome by such manual pressure and the sealing engagement of the spray plate 10 with the lip seating 14 is disengaged to permit any trapped water to escape from the spray head 4.

Once the manual pressure is released from the embossment 10a, then the spring 24 acts between the cleaner plate 9 and the spray plate 10 to return the spray plate 10 to the spray position for normal operating use of the spray head 4. During such movement of the spray plate 10 relative to the cleaner plate 9, the guide pins 21 and the splines 18 ensure that any turning movement applied to the embossment 10a will not result in the spray plate 10 being moved arcuately relative to the cleaner plate 9 either damaging or misaligning the cleaner projections 19. Although a single cleaning action should be sufficient to clear and clean each nozzle hole 5, the user may repeat the action as desired without risk of damaging the spray head assembly.

Now turning to the second embodiment as shown in Figures 3, 4 and 5, the same references are used for the component parts which are the same as just described for the first embodiment.

In this second embodiment, the spray plate 10 has substantially the same form as just described with the -16central embossment 10a, the outer O-ring seal 15 and the array of nozzle holes 5. However, the spray plate has a recess 30 surrounding the base of the central splined hub 16 and one end of a helical spring 31 is seated in the recess 30.

The cleaner plate 9 is also substantially the same as just described with the outer flange 9a and webs 9b, the guide holes 20 and through holes 27. However, in this construction there is a central hollow boss 32 having internal axial ribs 33 engaging with the splined hub 16. The boss 32 provides an axial clearance in which the helical spring 31 is received with the other end of the spring abutting an inner shoulder 34.

On the outside of the cleaner plate boss 32 there is mounted a second helical spring 35 which is retained by an end plate 36 secured to the hub 16 of the spray plate 10 by a screw 37 received within a threaded entry 38 in the hub 16.

In this embodiment, the respective ratings of the springs 31 and 35 are selected and arranged so that the spray plate 10 is maintained in or returned to a drain position as shown in Figure 3 when there is no flow of water acting on the spray plate. In this drain position, when the spray head is at rest the spray plate 10 is displaced inwardly of the flange 11 so that the O-ring seal 15 is removed from the lip seating 14 and thereby provides a drainage gap 39 between the spray plate 10 and the flange 11. Any water trapped or retained in the spray head after use will then be able to drain away avoiding the risk of water drying on the outer surface of the spray plate to cause the formation of limescale. -17As shown in Figure 4, the spray plate 10 may be displaced into the cleaning position by manual pressure shown by arrow M applied to the embossment 10a to bring the cleaner projections 19 into engagement with the nozzles holes 5 for the cleaning action as previously described for the first embodiment. On such manual pressure, the combined force of the springs 31 and 35 are overcome, and on release of the manual pressure the spray plate 10 returns under the combined spring forces to the drain position as shown in Figure 3.

As shown in Figure 5, when the water flows through the spray head as indicated by arrow W, pressure is exerted on the back or inner face of the spray plate 10, and this force is sufficient to overcome the force of the second spring 35 to move the spray plate 10 outwardly away from the cleaner plate 9 into the spray position as shown. In the spray position, the cleaner plate 9 engages the O-ring seal 15 with the lip seating 14 on the flange 11 to thereby close the drainage gap 39 between the spray plate 10 and the flange 11.

As will be appreciated, when the pressure effect of the water ceases, then the spray plate 10 is returned to the drain position as shown in Figure 3 by the return force applied by the second spring 35.

Accordingly, in this second embodiment, the spray head is automatically self-draining when at rest and the cleaning function can be done when ever required or desired.

As will be understood, the relative ratings of the two springs is selected to suit the pressure differentials and water pressure. -18In the third embodiment as depicted in Figures 6 and 7, the spray plate 10 and cleaner plate 9 are substantially similar to those just described except that there is no separate return or second spring interposed between the cleaner plate 9 and the spray plate 10. The only spring force applied to the cleaner and spray plates is that of an inner spring 40 which is mounted over the central boss 41 of the cleaner plate 9 that has a splined connection to the inwardly extending hub 42 of the spray plate. As in the second embodiment, the spring 40 is retained on the hub 42 by an end plate 36 and screw 37.

In the non-operative or rest mode as depicted in Figure 7 when there is no water flowing through the spray head and no water pressure applied to the spray head, the spray plate 10 is biassed by the spring 40 into the cleaning position in engagement with the cleaner plate 9 with the cleaner projections 19 being received within the nozzle holes 5. In this cleaning position, the spray plate 10 is also displaced inwardly into the drain position so that there is the drainage gap 39 between the flange 11 and the spray plate 10 through which any retained water may drain.

In the operative or normal mode when water is flowing and as shown in Figure 6, the water pressure will act on the spray plate 10 and will cause the spray plate 10 to move outwardly and be maintained in the spray position as shown with the O-ring 15 sealed against the lip seating 14 of the flange 11. When the water pressure ceases or is reduced when the ablutionary appliance is turned off, then the spring 40 will act to bring the spray plate 10 inwardly to close onto the cleaner projections 19 and to be displaced -19away from the lip seating 14. The spray plate 10 is thus retained in the coincident cleaning and drain position as shown in Figure 7.

In this third embodiment arrangement, the user does not have to take any manual action to clean the nozzle holes 5 by pushing on the spray plate, and each time the spray head is used, the self-cleaning action is achieved relying on the water pressure. However, the spray head is designed so that it could be cleaned by the user when in use by merely pushing or pressing on the central embossment 10a of the spray plate 10 when the water is being discharged. This may be useful to certain users or under certain conditions where detritus becomes trapped in the nozzle holes 5 due to water impurities.

Although the emphasis given above for this improved spray head has been for the cleaning function and avoiding retention of water within the spray head to avoid limescale formation, there are other advantages achieved by providing the self-draining function as described with reference to the second and third embodiments. In particular, it has been found advantageous to drain off any entrapped or stagnant water in sanitary or ablutionary installations to avoid the risks of bacteria or germ or virus colonisation.

In addition, in some spray heads there is substantial water entrapment within the head after use, and this tends to weep or slowly escape from the fitting leaving unsightly marks or stains, and sometimes these cannot be removed.

The detail construction of the cleaner plate and the spray plate may be varied to suit the styling or deign of the spray head, and in this regard a non-20threaded coupling and connection may be used for the mounting of the spray head in the outlet end of the member though which the water is supplied. Such variations are envisaged to accomodate non-circular shapes of spray plates or spray rose fittings.

Another variation would be to use a splined or other connection between the flange and the outer peripheral walls of the cleaner and spray plates whereby the desired relative axial movement could be achieved whilst permitting a variation in the array of nozzle holes in the spray plate. This variation might be useful if the centre of the spray plate were required to be designed for a single jet stream nozzle as an optional feature in the spray pattern. In such an arrangement, there would be some special control for diverting the water flow from the outer array of small nozzle holes to a single central jet nozzle.

None of these variations are considered to detract from the essential nature of the improvements as described and are considered to be within the scope of any one skilled in this field and having an adequate knowledge of the design and construction of such ablutionary devices.

Claims

Claims: 1. A spray head for an ablutionary appliance having a hollow member defining a water passage terminating in an outlet end, the spray head comprising a mounting flange connected to the outlet end of the hollow member and defining a seating, a cleaner plate supported internally of the outlet end and retained by the mounting flange, and a spray plate retained within the mounting flange for movement relative to both the cleaner plate and the mounting flange, the spray plate having an array of nozzle holes for the discharge of water to a designed spray pattern and the cleaner plate having an array of cleaning projections arranged for register and engagement with the nozzle holes of the spray plate, the cleaner plate also having through passageways for the flow of water to and through the nozzle holes of the spray plate, the arrangement of the spray head being such that in one position of the spray plate (the spray position) the spray plate is disengaged from the cleaner plate for water to flow through the said passageways and through the nozzle holes of the spray plate with the spray plate engaging the seating of the mounting flange, and the spray plate being movable relative to the cleaner plate to another position (the cleaning position) wherein the cleaning projections of the cleaner plate extend into the respective aligned nozzle holes to clean same and remove any limescale and other detritus therein.
2. A spray head according to Claim 1 wherein each of the nozzle holes is in the form of a frusto-conical hole tapering towards the outer face of the spray plate remote from the inside of the hollow member. -223. A spray head according to either Claim 1 or Claim 2 wherein the spray plate and the cleaner plate are inter-engaged by complementary formations for the relative axial movement whilst maintaining the nozzle holes and the cleaning projections in the desired register.
3.
4. A spray head according to Claim 3 wherein the formations comprise inter-engaged complementary pin and hole formations on the spray and cleaner plates which act as guides during the relative axial movement of the two plates between the spray and cleaning positions of the spray plate. 4.
5. A spray head according to any one of the preceding Claims wherein the cleaner plate supports the spray plate which has a central hub engaged with the cleaner plate for the relative axial movement. 5.
6. A spray head according to Claim 5 wherein the central hub of the spray plate and the cleaner plate are engaged for the relative axial movement by means of complementary formations comprising splines on the central hub. 6.
7. A spray head according to Claim 5 wherein a spring is mounted on the hub to act between the cleaner plate and the spray plate whereby the spray plate is biased into the spray position by the spring for normal use when water is flowing through the spray head, and by applying a force to the spray plate externally, the spring force may be overcome to push the spray plate towards the cleaner plate into the cleaning position for the cleaning engagement of the cleaning projections with the respective nozzle holes. -238.
A spray head according to Claim 5 wherein the spray plate is retained within the mounting flange for sealing engagement with the flange seating when in the spray position spaced from the cleaner plate and when water is discharged through the spray head with the spray plate being maintained in the spray position by the pressure of water acting on the spray plate, the spray plate is movable relative to the cleaner plate to an intermediate position (the drain position) in which the spray plate is moved out of sealing engagement with the flange seating leaving a gap through which any water in the spray head may drain when the flow of water ceases to act on the spray plate to maintain it in the spray position. 7.
9. A spray head according to Claim 8 wherein the cleaner plate and the spray plate are connected together for relative axial movement by complementary formations comprising splines on the central hub with spring means adapted and arranged to act between the cleaner plate and the spray plate to maintain the spray plate in the drain position with the drainage gap when there is no water pressure acting on the spray plate, and the spring means also acting between the cleaner plate and the spray plate so that by applying a force to the spray plate externally, the spray plate can be moved against the spring bias relative to the cleaner plate from the drain position to the cleaning position, and the spring means being arranged to return the spray plate to the drain position when the force applied to the spray plate is released. -2410.
A spray head according to Claim 9 wherein the spring means comprises two springs each acting between the cleaner plate and the spray plate in opposition so that the combined spring forces maintain the spray plate in the drain position and one spring acts to return the spray plate from the spray position to the drain position.
11. A spray head according to Claim 5 wherein the cleaner plate and the spray plate are connected together for relative axial movement by complementary formations comprising splines of the central hub, a spring acts between the cleaner plate and the spray plate to maintain the spray plate in the cleaning position wherein the cleaner projections engage in the aligned nozzle holes and to maintain the spray plate in the coincident drain position with the drainage gap between the spray plate and the flange seating, and the spring force being such that the pressure applied by water flowing through the spray head overcomes the spring force to displace the spray plate away from the cleaner plate to open the nozzle holes and simultaneously to bring the spray plate into the spray position with the spray plate being in sealing engagement with the flange seating, and the spring force being such that when the water pressure is reduced significantly then the spring acts automatically to return the spray plate towards the cleaner plate to the coincident cleaning and draining position for the self-cleaning function whilst any residual water in the spray head may drain away through the drainage gap.
12. A spray head according to any one of the preceding Claims wherein the hollow member is a hand shower handle. -2513.
A spray head according to any one of the preceding Claims wherein the spray plate is circular in plan shape and the nozzle holes are arranged as a concentric series. 5
14. A spray head according to any one of the preceding Claims wherein the spray plate is provided with a central embossment for use in applying a force externally to the spray plate as required in use of the spray head. 8. 10
15. A spray head according to Claim 1 substantially as shown in Figures 1 and 2 and substantially as described herein.
16. A spray head according to Claim 1 substantially as shown in Figures 3,4 and 5 and substantially as described 15 herein.
17. A spray head according to Claim 1 substantially as shown in Figures 6 and 7 and substantially as described herein.