GB2199770A - Shower head - Google Patents

Abstract

A shower head comprises three concentric spray rings (27, 38, 74) disposed one within the other, the outermost ring (74) being fixed to a casing of the shower head and defining a discharge outlet formed by flow grooves, and the innermost ring (27) being arranged to be angularly movable with the middle ring (38) relative to the outermost ring (74). Further discharge outlet are formed between inner and middle rings and the middle and outermost rings, though the discharge outlet between the middle and outermost rings can be closed by relative rotation between said rings, whereupon projections (50) middle ring move down respective cam surfaces (90, 91) on the outermost ring so that part of the middle ring seals onto part of the outermost ring to cut off flow to said discharge outlet. A four ring assembly is also disclosed, in which two discharge outlets can be closed. <IMAGE>

Description

SHOWER HEAD This invention relates to a shower head of the kind having a plurality of concentric spray members, usually rings.

An object of the invention is to provide such a shower head in a form which is convenient in use and improved over prior art shower heads of this kind.

According to the invention a shower head comprises at least two concentric spray rings disposed one within another, at least one discharge outlet, and means for axially displacing one of said rings by angular movement thereof so that in one axial position of said one of the rings flow can occur through the discharge outlet or one of said discharge outlets, and in another axial position of said one of the rings such flow is prevented.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figures 1A to 1C are a top, a part-sectional side view and an underneath view respectively of a first, inner spray ring of a shower head of the invention, Figures 2A to 2C are a top, a side view and an underneath view respectively of a second, middle spray ring, Figure 2D is a cross-sectional view on the line D-D of Figure 2A, Figures 3A to 3C show views equivalent to Figures 1A to '.C, for a third, outer spray ring, Figure 4 is a schematic fragmentary, longitudinal cross-sectional view of a shower head of the invention, with the view being split to show one position of the rings on the left hand side and a different position of the rings on the right hand side, Figures 5A to 5C and Figures 6A to 6C show views equivalent to Figures 1A to 1C of two spray rings which can be used together with the inner and outer spray rings of Figures 1A to 1C and 3A to 3C to replace the middle ring, and Figure 7 is a schematic view similar to Figure 4 but showing the middle ring replaced by these two rings.

The shower head of the invention comprises a stem 10 (Fig. 4) in the form of an elongate, hollow pipe 11 which has one end (not shown) externally threaded for connection to a water feed pipe. At its other end the pipe 11 is integrally formed with a generally cylindrical inner casing defining a chamber 12, which is hollow and is also open top and bottom. The pipe feeds into the chamber.

Just below its open top, the internal wall of the chamber is screw-threaded at 13 so that said open top can be closed by a cap 14. Any other suitable means of releasably engaging the cap with the casing, such as a bayonet fitting, can alternatively be employed. The cap has a circular domed outer surface 15 from the periphery of which an annular flange 16 depends. At the free extremity of the flange its external surface is screw threaded at 17 to match the thread 13. Just above the threaded portion the external flange surface has an annular groove to receive an O-ring or other section seal 18 so that when the cap 14 is screwed onto the top of the chamber 12 a watertight seal is formed.

The surface 15 has a central rectangular, elongate outwardly projected portion 19 which is so shaped as to provide ease of turning the cap, particularly when it is wished to release the cap after it may have been screwed tightly onto the top of the chamber 12. Inside the cap 14, is a depending, central, cylindrical flange 20 and a further depending, cylindrical flange 21. The flange 21 is concentric with the flange 20 and spaced outwardly of it.

The bottom of the chamber 12 has a cylindrical opening formed by an internal wall 22. Above this wall 22 is a frustoconical wall 23 sloping upwards and outwards.

The remainder of the chamber wall below the thread 13 is directed axially and is continuous except for an opening 24 whereby the pipe 11 feeds the chamber, and for three radially directed rectangular projections 25 (only one shown) which are equi-angularly spaced around the interior of the chamber. Each projection extends upwards from the wall 23 a short way along the main chamber wall above it. The pipe is received in a handset outer casing gila, in use.

As will be explained, a spray ring set is, in use, received in the chamber to close the bottom opening thereof and to produce an outlet spray pattern when water is fed to the chamber from the pipe 11. The projections 25 engage with the outermost ring of the set to hold it in position. One end of a compression spring 26 seats on the inside surface of the cap 14 between the flanges 20, 21, its other end engaging the innermost ring of the ring set as will be described.

The three rings of the spray ring set of a first embodiment of the invention will now be described.

Each ring is of plastics material, for example acetal.

Figures 1A to 1C show the smallest and thus innermost ring 27 of the rings making up the ring set. The ring 27 is in the form of a hollow cylinder having its lower end closed, the wall of the cylinder being denoted by the numeral 28 and the base by 29. The external periphery of the base 29 is formed with an annular step formed by an inward radial surface 30 and an inwardly, downwardly angled surface 31. Around the outside of the surface 28, immediately above the surface 31, are a multiplicity of regularly spaced, axially directed flow grooves 32. From the centre of the bottom of the base 29 an integral rectangular grip part 33 extends downwardly. The part 33 is for moving the ring 27 angularly, in use, as will be explained hereinafter.

The annular, flat, top surface of the cylinder is formed with three integral radial lugs 34, which are equi-angularly spaced therearound. The lugs extend away from the cylinder to an integral ring 35 which is concentric with the top cylinder surface but disposed outwardly of and above said surface, as best shown in Figure 1A, to provide slots 36. Each lug extends radially beyond the outer periphery of the ring 35 to form a location ear 37, which has a cylindrical projection 37a on its underside.

The next ring in the ring set is shown in Figures 2A to 2D and this second ring is denoted by numeral 38. Like the ring 27, it is of generally hollow cylindrical form, but unlike the ring 27, both its ends are open.

Moreover its wall is formed with a step to produce an upper cylindrical part 39 and a reduced diameter lower cylindrical part 40. The step forms an inner annular axially directed surface 41, and the equivalent outer annular axially directed surface is formed with a groove 42 containing a rubber O-ring seal 43, indicated in Figure 2D only.

The lower external surface of the lower part 40 is, like the ring 27, formed with an inward radial surface 44 and an inwardly, downwardly angled surface 45.

Around the outside of the part 40, immediately above the surface 45, are a multiplicity of regularly spaced, axially directed flow grooves 46. The surface 45 leads to a further inward radial surface 47, and a further inwardly, downwardly angled surface 48 which extends to the bottom annular surface 49 of the ring.

On the outside of the upper part 39 are three equiangularly spaced, rectangular projections 50, extending from the level of the base of the groove 42 to the top of the ring. At its lower end, each projection has a matching corner chamfered as at 51. The projections can be hollowed out, as shown, if required. The top of the ring is castellated and the inwardly facing surfaces thereof could be formed with undercuts at their tops.

Inside the ring, the bottom opening thereof is defined by a short inwardly sloping and upwardly directed surface 52 extending from the surface 49. Above this is an axially directed cylindrical wall 53 which extends to an outwardly, radially directed, annular surface 54. An axially directed, cylindrical surface 55 extends downwardly from the step surface 41 and is joined to the surface 54 by a short outwardly sloping surface 56. Extending from the surface 54 axially along the surface 55 to the surface 41 are six equi-angularly spaced ribs 57. The surface 41 carries 3 pairs of ribs 58, the pairs being at 1200 to one another and each extending along the inner wall of the part 39 for approximately half its height. The two ribs of each pair are spaced apart by an amount to receive snugly an ear 37 of the ring 27. The rib pairs are disposed in alignment with three of the ribs 57.

The external diameter of the wall 28 of ring 27 is such that the cylinder wall 28 is intended to be received as a sliding fit within the lower part 40, with the projections 37a engaging on the surface 41 between the pairs of ribs 58. This arrangement positions the bottom of the base of the ring 27 just above the surface 49 of the ring 38. When the ring 27 is received in the ring 38, with the three ears 37 received in the three rib pairs respectively, the rings 27 and 38 move together upon angular movement of the ring 27, as will be described.

When the rings 27, 38 are engaged together, an annular space 59 is defined between the outside of wall 28 and surface 55, this space being interrupted by the ribs 57. The top of the grooves 32 communicate with this space 59, with the lower parts of the grooves being closed in a radial direction by the wall 53. Flow to the space 59 is through the slots 36 and also around the side of the ring 27 and underneath it.

Alternatively the projections 37a can be omitted so that the ears 37 rest on surface 41, with flow being merely through the slots 36.

The outer and largest ring 74 is shown in Figures 3A to 3C, and this ring is of generally hollow cylindrical form having an upper part 75 and a reduced diameter lower part 76. The top of the ring 74 may be castellated, and as with the ring 38 undercuts may be provided at the top of the inside surfaces thereof. At a position where the castellations finish, the ring is formed with an outwardly, radially directed annular flange which is interrupted to form 3 equi-angularly spaced flange portions 77. Below the flanges the outer cylindrical surface has three equi-angularly spaced dependent ribs 78. Below the ribs the outer surface has a frustoconical surface 79 forming a step between the parts 75 and 76. The surface 79 leads to a hollow cylindrical portion 80 having a multiplicity of regularly spaced, axially directed flow grooves 81 at its lower end.Extending through the surface 79 and also through the lower portion of the part 75 are three equi-angularly spaced generally semi-circular slots 82.

These are to engage with the projections 25 in chamber 12 to secure the ring 74 in position as will be described. The projections do not fully close the slots 82.

Connected to the top of the portion 80 but spaced inwardly thereof is a further hollow cylindrical portion 83, which extends downwardly beyond the end of the portion 80. The portion 83 has a lowermost interior surface 84 of cylindrical form leading to a short outwardly but generally axially directed frustoconical surface 85, above which is a flat axially directed annular surface 86. Six ribs 87 are provided on the surface 85 up to the level of surface 86.

Above and outwardly of the surface 86, substantially at the bottom of the upper part 75 is a further flat annular surface 88. Formed around this surface are three equi-angularly spaced cam-surfaces 89, each comprising a sloping part 90 and a raised flat part 91, terminated by a stop 92. The part 91 extends for approximately 300 around the interior cylindrical wall. Further stops 93 could be provided between adjacent cam surfaces 89.

In use, ring 38 is intended to be a sliding fit within ring 74, with ring 27 fitted in ring 38, so that the respective lower ends of the grooves 46 are just above the bottom of portion 83 when the projections 50 rest on the flat parts 91 and each engage a stop 92. In this state the sealing surface provided by the O-ring 43 is spaced slightly above the surfaces 85 and 86 so that as will be explained water can flow between the outer surface of ring 38 and the inner surface of ring 74 to the grooves 46 and then out of the spray head.

Angular movement of ring 38 by means of grip part 33 of ring 27, causes the projections 50 to move down the cam surfaces 89 onto the surfaces 88 to contact a stop.

Figure 4 (right hand side) shows the arrangement when the grip part has been angularly moved thereby angularly moving ring 38 and causing it to move axially downwards relative to ring 74.

The axially downward movement of ring 38 relative to ring 74, cuts off flow to the flow grooves 46 by the 0-ring 43 moving tightly to seal on surfaces 85 and 86 of ring 74. Thus the annular space above the flow grooves 46 is isolated from the flow grooves themselves. Thus the left hand side position in Figure 4 corresponds to full flow and the right hand side position to reduced flow.

It will be appreciated that by orientating the cam surfaces the other way up and by suitably similarly re-orientating the projections, it is possible to cause the rings to move axially inwardly on angular movement of an adjustment member, such as grip part 33.

Additionally by altering the relative lengths of various parts of the rings it would be possible for the position with the ends of the rings as shown in the left hand side of Figure 4 to correspond to a reduced flow position, with the axially displaced position of the rings, shown in the right hand side, corresponding to full flow. Of course the total number of rings used and the number which can be closed can be varied as required.

In use, the outer ring 74 is firstly fixed in the chamber 12 by means of the projections 25 and slots 82.

The other two rings are then received in place, as described, with their relative angular orientation being, for example as in the left hand side of Figure 4, with the projections 50 on their appropriate cam surfaces 91. The spring 26 is then arranged with one end in the hollow cylindrical part of ring 27 and its other end between the flanges 20, 21 as the cap 14 is lowered and tightly engaged with the chamber 12, with the O-ring seal 18 in place.

This represents a summer setting of the shower head, with maximum flow of water from the three sets of flow grooves 32, 46 and 81. Water flows from the pipe 11 into the chamber via slots 82, or between flange portions 77, and then to the flow grooves before leaving the shower head. The required spray angle is achieved by appropriate frusto-conical surfaces at the respective lowermost ends of the rings, below the flow grooves, which direct the individual annular spray arrangements downwardly and outwardly of the common central axis of the rings.

If it is desired to reduce the flow to a winter setting of the shower head the part 33 is angularly moved, as described, to shut off grooves 46. The pressure of the water aids the sealing off. In this winter setting, the projections 62 can be aligned with the slots 82 to serve to restrict the flow of water therethrough into the chamber 12, this control of flow thus varying as the ring 38 is rotated and the projections move around the interior of ring 74 once they move off the surfaces 91.

The shower head construction provides two other advantageous features. Firstly by pressing inwardly on the ring 27, and/or on ring 38, against the spring 26, one of both of the rings 27, 38 are released to the extent that the flow grooves open out for easy cleaning to remove scale and the like. After cleaning the centre ring is merely released and the spring returns it to its previous position along with the ring 38.

The rings can be constructed so that depression of the inner ring sequentially separates all the ring grooves for cleaning.

Secondly by unscrewing and removing the cap, the ring set can be easily removed from the shower head without the need for any special tools. The outermost ring could, if necessary, be released from the chamber 12 for removal. The other rings will merely slide out upon inversion of the chamber. Thus more thorough cleaning can easily be carried out if required. The provision of an elongate portion 19 allows even a very tightly screwed on cap to be removed for ring set removal.

In a second embodiment, the centre ring 38 is replaced by two spray rings fitted one within the other.

Figures 5A-5C and 6A-6C show the rings 138 and 154 and Figure 7 schematically shows a complete shower head with the rings replacing the single ring 38.

The smaller of the two rings replacing the ring 38 is shown in Figures 5A to 5B and this ring is denoted by numeral 138. Like the ring 38 it is of generally hollow cylindrical form with both its ends open. Its wall is formed with a step to produce an upper cylindrical part 139 and a reduced diameter lower cylindrical part 140.

The step forms an inner annular surface 141 and an outer annular axially directed surface 142.

The lowermost external surface of the lower part 140 is formed with an inward radial surface 143 and an inwardly, downwardly angled surface 144. Around the outside of the part 140, immediately above the surface 143, are a multiplicity of regularly spaced, axially directed flow grooves 145.

On the outside . of the -upper part 139 are three equi-angularly spaced, rectangular projections 146, extending from the surface 142 almost to the top of the ring. At the surface 142, each projection has a matching corner chamfered as at 147. The top of the ring is castellated and the inwardly facing surfaces thereof could be formed with undercuts at their tops respectively.

Inside the ring, the bottom opening thereof is defined by an axially directed cylindrical wall 148 above which is a short, outwardly directed, frustoconical surface 149. Another axially directed, cylindrical surface 150 then extends to the step surface 141. Extending from the surface 149 axially along the surface 150 to the surface 141 are six equi-angularly spaced ribs 151.

The external diameter of the wall 28 of ring 27 is such that the cylinder 28 is intended to be received as a sliding fit within the lower part 140, with the projections 37a on the ears 37 engaging on the surface 141. This arrangement positions the bottom of the ring 27 just inside the bottom of the ring 138. Where the projections 146 are provided on the outside of the upper part 139 of the ring 138, there is a corresponding rectangular recess 152 having its base as a continuation of the surface 141. With the ring 27 received in the ring 138, the three ears are received in the recesses 52 respectively, so that the rings 27 and 138 move together upon angular movement of the ring 27, as will be described.

When the rings are engaged together, an annular space is defined between the outside of wall 28 and surface 150, this space being interrupted by the ribs 151. The top of the grooves 32 communicate with this space 153, with the lower parts of the grooves 32 being closed in a radial direction by the wall 148. Flow to the space 153 is through the slots 36.

The larger of the two rings to replace ring 38 is a ring 154 of similar form to the ring 138 having an upper cylindrical part 155 and a lower, reduced diameter cylindrical part 156 separated by a step defining an inner annular axially directed surface 157 and an outer annular axially directed surface 158. The outside of the ring 154 is substantially the same as that of the ring 138 having at its lowest part an inward radial surface 159, an inwardly, downwardly angled surface 160, and a multiplicity of regularly spaced, axially directed flow grooves 161.

Like the ring 138, the outer surface of the upper part 155 has three equi-angularly spaced projections 162 thereon. However although the projections are rectangular, they each have their interiors removed.

Moreover they each extend downwardly from the castellated top of the ring to terminate short of the surface 158. Each projection has a matching corner chamfered as at 163. The inwardly facing surfaces of the castellations could be formed with undercuts.

The interior of the ring 154 is similar in form to the interior of ring 138 in respect of its lower portion, naving a cylindrical wail 164, a frustoconicai surface 165 and another cylindrical surface 166 extending up to the surface 157. Like the ring 138, six equi-angularly spaced ribs 167 extend from the surface 165 over the surface 166 to the surface 157.

On the flat, annular surface 157 at its junction with the inner surface of the part 155 are formed three equi-angularly spaced cam surfaces 168, each having a part 169 sloping up from the surface 157 and a flat raised part 170 extending for about 300 around the part 155 until it is terminated by a stop 171. Each stop 171 corresponds angularly with one side of a projection 162 while further stops 172 correspond angularly with the other sides of the projections 162 respectively, the sequence of cam surface 168 and stop 171, followed by stop 172 at the other side of a projection being followed around the surface 157.

It is intended that the ring 138 is a sliding fit in the ring 154. For this fit to occur with the respective lowermost portions of the grooves 145 substantially flush with the bottom of the ring 154, as in the left hand side of Figure 7, the ring 138 is angularly orientated relative to the ring 154 so that the bottom surfaces of the projections 146 rest on the parts 170 of the cam surfaces 168 respectively, with the side of each projection adjacent the chamfer 147 resting against a stop 171. In this arrangement the surface 142 is spaced upwardly from the surface 157 and thus, in use, flow can occur through an annular space between the outside of the part 140 and the surface 166 and then to the flow grooves 145, in a similar manner as for the grooves 132.

It is however possible to close the flow grooves 145 by changing the angular position of ring 138, and thus ring 27, inside ring 154. This can be carried out by manually grasping grip part 33 and rotating the ring 27, and thus also ring 138, clockwise as viewed in the drawings. This angular movement causes the projections 146 to move away from the stops 171 and along the parts 170, and then down the parts 169 onto the surface 157.

Rotation is stopped by the side of each projection spaced from the chamfered corner, engaging a stop 172.

Thus this angular movement causes displacement of rings 27 and 138 axially relative to the ring 154 so that the surface 142 is now engaged as a tight seal on the surface 157. Thus, in use, flow is now prevented to the flow grooves 145. Flow is, however, not prevented through grooves 32, as no relative axial displacement has occurred between the rings 27 and 138. Relative rotation of ring 138 to ring 154 will stop when projections 146 abut stops 172 of ring 154.

However if this angular movement is continued, the three inner rings move together relative to outer ring 74, thereby moving projections 162 down cam surfaces 89 onto surfaces 88 so that ring 154 is moved axially downwardly relative to fixed ring 74. Figure 7 (right hand side) shows the arrangement when the grip part has been fully angularly moved in one direction, thereby moving ring 154 axially downwardly from ring 74, and rings 27 and 138 downwards from ring 154.

As with the axially downward movement of ring 138 relative to ring 154, the axially downward movement of ring 154 cuts off flow to its flow grooves 161 by the surface 158 moving tightly to seal on surface 86 of ring 74, as in Figure 7. Thus as previously described with the rings 138 and 154, the annular space above the flow grooves is isolated from fluid flow to the spray head.

Thus with four spray rings, the summer setting or maximum flow is through grooves 32, 145, 161 and 181.

By rotating the grip part 33, flow through the flow grooves 145 can firstly be shut off and further rotation cuts off flow through the flow grooves 161 also, then giving a minimum flow or winter setting. As in the first embodiment the closing of the flow grooves adjacent the fixed outer ring can also involve restricting the flow through the slots 82. In this case the restriction would be by means of the.

projections 162 on ring 154.

The arrangement shown in the left hand side of Figure 7 is schematic, in that, the bottom surfaces of the rings may not be flush with the bottom of the chamber or with one another. The bottom surfaces of the rings could thus be arranged above or below the bottom of said chamber. This will vary the flow from the flow grooves, but not otherwise affect described operation of the device.

In a further embodiment of the invention, not illustrated, rotation of one or more of the rings can close the single discharge outlet or each discharge outlet, so that flow from the shower head is stopped, the shower head thus acting as a valve in its off position.

Claims (23)

1. A shower head comprising at least two concentric spray rings disposed one within another, at least one discharge outlet, and means for axially displacing one of said rings by angular movement thereof so that in one axial position of said one of the rings flow can occur through the discharge outlet or one of said discharge outlets, and in another axial position of said one of the rings such flow is prevented.

2. A shower head as claimed in claim 1, wherein the or each discharge outlet is formed by a set of flow grooves around an inner or an outer surface of a spray ring.

3. A shower head as claimed in claim 2, wherein one ring is of hollow, generally cylindrical form, having an axially or generally axially directed annular internal surface at one end, and another ring has larger and smaller diameter portions defining cylindrical outer surfaces separated by an axially or generally axially directed annular external surface, a set of flow grooves being in the outer surface of said smaller diameter portion, said another ring being received in said one ring so that in said one axial position said annular external surface is spaced from said annular internal surface so that, in use fluid flow is possible between the rings to said flow grooves, and in said another axial position, said annular external and internal surfaces are in fluid tight sealing engagement to prevent such flow.

4. A shower head as claimed in claim 3, wherein one of a cam surface and a projection is provided in the interior of said one ring and the other of the cam surface and the prcjection is provided on the outer surface of the larger diameter portion of said another ring, so that relative angular movement between said one ring and said another ring causes engagement or disengagement of the cam surface and the projection to provide said two axial positions respectively.

5. A shower head as claimed in claim 4, wherein the cam surface is provided on said annular internal surface of said one ring and the projection is provided on the outer surface of the larger diameter portion of said another ring.

6. A shower head as claimed in claim 5, wherein the cam surface comprises a ramp surface extending from said annular internal surface to a flat surface spaced axially from said annular internal surface, with a stop at its end remote from the ramp surface, the projection providing an axially directed undersurface for engagement with said annular internal surface and said cam surface.

7. A shower head as claimed in claim 6, wherein three such cam surfaces and three such projections are provided on the two rings respectively, being equi-angularly spaced therearound.

8. A shower head as- claimed in claim 7, wherein an inner ring is fitted in said another ring so as to rotate therewith, said inner ring having a cylindrical part closed at least at one end, with a set of flow grooves being in its outer surface at one of its ends, part of said outer surface of the inner ring being spaced from the interior surface of the smaller diameter portion of said another ring to provide an annular space in communication with said flow grooves, at least part of the lengths of which grooves are closed radially by an adjacent annular surface at an end of said smaller diameter portion of said another ring.

9. A shower head as claimed in claim 8, wherein at its end remote from the flow grooves, said inner ring has at least one ear projecting radially outwardly and engaging in at least one corresponding recess defined in or at the interior of said larger diameter portion of said another ring so that said another ring and said inner ring move angularly together.

10. A shower head as claimed in claim 8 or claim 9, wherein an axially extending grip portion is provided at said one end of the inner ring for angularly moving the inner two rings together.

11. A shower head as claimed in any one of the preceding claims, wherein the outermost ring of the spray rings has a set of flow grooves in an outer surface thereof disposed adjacent an inner surface of a casing of the shower head to provide a discharge outlet.

12. A shower head as claimed in any one of the preceding claims, wherein the outermost ring of the spray rings is engaged with a casing of the shower head by one or more projection and slot combinations.

13. A shower head as claimed in claim 12, wherein projections on the casing engage in respective slots in the outermost ring, the slots being larger than the projections to allow flow of water, in use, to the casing to pass through said slots and into the spray rings.

14. A shower head as claimed in any one of claims 3 to 10, wherein said annular external surface of said another ring is formed by an annular sealing ring disposed in an annular groove.

15. A shower head as claimed in any one of claims 3 to 10 and 14, comprising only said one ring, said another ring and said inner ring.

16. A shower head as claimed in any one of claims 8 to 10, comprising four spray rings only, namely said inner ring, said another ring, said ring, and an outermost ring, in which said ome ring is received, a set of flow grooves on an outer surface of said one ring being disposed adjacent an inner surface of the outermost ring to provide a discharge outlet.

17. A shower head as claimed in claim 16, wherein said outermost ring has three equi-angularly spaced cam surfaces around an annular internal surface thereof and three projections are correspondingly equi-angularly spaced around an outer surface of said one ring so that relative angular movement between said one ring and said outermost ring causes engagement or disengagement of each projection and associated cam surface to provide said two axial positions respectively.

18. A shower head as claimed in claim 17, wherein said outermost ring has a set of flow grooves in an outer surface thereof disposed adjacent an inner surface of a casing of the shower head to provide a discharge outlet.

19. A shower head as claimed in any one of claims 16 to 18, wherein said outermost ring is engaged with a casing of the shower head by one or more projection and slot combinations.

20. A shower head as claimed in claim 19, wherein projections on the casing engage in respective slots in the outermost ring, the slots being larger than the projections to allow flow of water, in use, to the casing to pass through said slots and into the spray rings.

21. A shower head as claimed in any one of the preceding claims, comprising a casing in the form of a generally cylindrical chamber having at one end an outlet, in which the spray rings are fitted, and at its other end a releasable closure cap, a compression spring being arranged between the closure cap and at least the innermost one of the spray rings to bias said ring to said outlet.

22. A shower head as claimed in claim 21, whereiin the closure cap is screw-threadedly engaged with the casing and has sealing means in engagement therewith.

23. A shower head substantially as hereinbefore described with reference to and as shown in Figures 1 to 4 or Figures 5 to 7 of the accompanying drawings.