WO2008053207A1

WO2008053207A1 - Valve

Info

Publication number: WO2008053207A1
Application number: PCT/GB2007/004150
Authority: WO
Inventors: Nigel Paul Sansum; Austin Christopher Bumpsteed
Original assignee: Kohler Mira Limited
Priority date: 2006-10-31
Filing date: 2007-10-31
Publication date: 2008-05-08
Also published as: GB2456271A; GB0908164D0; GB2456271B; GB0621637D0

Abstract

A built-in mixer valve (100) has a valve body (101) which, in use is received in a recess in a wall and a concealing plate (102) for securing to the valve body (101) to cover the recess. A valve stem (104) projects from the valve body (101) for rotation about a first axis, and a control member (103) is mounted on the concealing plate (102) for rotation about a second axis. A coupling (105) for transmitting rotation of the control member (103) to the valve stem (104) for controlling fluid flow through the valve (100) is configured to provide linear adjustment in three mutually perpendicular directions of which one direction includes the first or second axis, and angular adjustment about either one of two mutually perpendicular directions normal to the first axis.

Description

VALVE

This invention relates to valves. The invention has particular, but not exclusive application to mixer valves for mixing hot and cold water to deliver water at an appropriate temperature for use in ablutionary installations" such as showers, baths, washbasins and the like. More especially, the invention is concerned with mixer valves of the type that are built into a recess in a wall with only the controls exposed to allow the user to operate the valve.

Built in mixer valves are typically installed in one of two ways. In one method, shown in Figure 36, the valve body 1 is screwed on to the surface at the rear of the recess 2. In the other method, shown in Figure 37, the valve body 1 is attached to mounting brackets 3 that are screwed onto the surface of the wall. Using either of these methods of installation, the wall is typically provided with a tiled surface 4 (known as the finished surface) .

The valve body 1 has a projecting valve stem or spindle that is rotatable by a control knob 6 to drive elements within the body for controlling fluid flow through the valve. In a common arrangement, the control knob 6 is mounted coaxially to the valve stem and the installation is completed by fixing a concealing plate 7 to the finished surface to hide the valve body 1 within the recess 2 as shown in Figure 38.

With this method, variation in the depth of the recess/thickness of the finished surface 4 (known at the building in depth variation) can be accommodated by making the valve body 1 long enough so that the controls protrude through the concealing plate 7 when the building in depth is a minimum as shown in Figure 38 and a maximum as shown in Figure 39. In addition, any angular misalignment between the finished surface 4 and the valve stem can be taken up by the clearance in the hole provided in the concealing plate 7 for the controls as shown in Figure 40.

The disadvantage of this method, however, is that the valve looks very different depending on the depth at which the valve is built in and the extent of the angular misalignment between the finished surface and the valve stem as can be seen from a comparison of Figures 38,39,40.

This is undesirable and it has been proposed to address this problem by fixing the controls to the concealing plate so that the valve always appears the same whatever the building in depth thereby allowing the industrial designer to design the aesthetics of the product without needing to compromise resulting in an appearance that is pleasing at all building in depths .

The disadvantage of this method, however, is that the controls will not be concentric to the valve stem if the concealing plate is not perpendicular to the axis of the valve stem. This can occur if the recess at the back of a stud wall is not parallel to the finished surface or if the tiles are not all at the same level so that, when the concealing plate 7 is tightened onto the tiles 8 it sits at an angle between the tiles 8 that protrude the most and least as shown in Figure 41.

This may not be an issue if there is sufficient clearance within the mechanism to allow for slight misalignment. However, where there is insufficient clearance, the misalignment can cause the controls to jam making it impossible to operate the valve while providing excessive clearance within the valve to avoid jamming can cause the controls to feel cheap and of poor quality. The present invention seeks to address the problems above-discussed. More especially, it is a preferred aim of the invention to provide an arrangement in which the controls can be fixed to the concealing plate in order to give the best aesthetic solution to the product but also allows for angular misalignment and variation in the building in depth of the shower valve.

Accordingly, in one aspect, the present invention provides a valve having a valve stem with an axis of rotation, a control member with an axis of rotation, and a coupling arranged to transmit rotation of the control member to the valve stem for rotating the valve stem to adjust the valve, the coupling being configured to accommodate misalignment between the rotational axis of the valve stem and the rotational axis of the control member.

Preferably, the valve is a built-in valve having a valve body that is located in a recess in a wall or the like with the valve stem projecting from the valve body, and the control member is mounted on a concealing plate that fits over the recess with the coupling connecting the control member to the valve stem.

With this arrangement, any misalignment between the rotational axis of the valve stem and the rotational axis of the control member such as may occur if the finished surface of the wall is not perpendicular to the rotational axis of the valve stem is taken up by the coupling so that the concealing plate may be located substantially flush against the finished surface of the wall. In this way, the size of any gaps between the concealing plate and the finished surface may be reduced. Preferably, the coupling is configured to accommodate variations in the building-in depth of the valve resulting from the depth of the recess in which the valve body is installed and/or the thickness of the finished surface on which the concealing plate is positioned.

Preferably, the coupling connects the valve stem to the control member via parts that provide linear adjustment along three mutually perpendicular axes and rotational adjustment about two of the axes with the third axis being the rotational axis of the valve stem.

In one preferred arrangement, the coupling comprises a drive part associated with the control member and a driven part associated with the valve stem, the drive part and driven part having co-operating formations providing relative movement between the parts and for transmitting rotation of the control member to the valve stem.

The driven part may comprise a split hub having a first part mounted on and rotatable with the valve stem and a second part mounted on the first part and linearly adjustable relative to the first part along a first axis normal to the rotational axis of the valve stem.

The drive part may comprise an annular retainer mounted on the second part of the hub with the retainer being linearly adjustable relative to the hub along the rotational axis of the valve stem and along a second axis normal to both the first axis and the rotational axis of the valve stem and being angularly adjustable relative to the hub about the first and second axes.

In another aspect, the present invention provides a built-in mixer valve comprising a valve body having a valve stem rotatable about a first axis, a concealing plate for securing to the valve body to cover a recess in a surface in which the valve body is mounted, a control member mounted on the concealing plate for rotation about a second axis, and a coupling for transmitting rotation of the control member to the valve stem for controlling fluid flow through the valve, the coupling providing linear adjustment in three mutually perpendicular directions of which one direction includes the first or second axis, and angular adjustment about either one of two mutually perpendicular directions normal to the first axis.

By this invention, the coupling compensates both for misalignment of the rotational axes of the valve stem and control member, and for changes in the build-in depth of the valve body relative to the surface in which the recess is provided for transmitting drive from the control member to the valve stem whatever the position of the valve stem relative to surface. In this way, the concealing plate can be mounted on the surface even if the valve stem is not perpendicular to the surface.

According to yet another aspect, the present invention provides an adjustable coupling for transmitting rotation of a control member to a valve stem of a valve, the coupling providing linear adjustment along two mutually perpendicular axes normal to a rotational axis of the valve stem and angular adjustment about said two mutually perpendicular axes.

Preferably, the valve is a built-in valve having a valve body received in a recess in a surface and the valve stem arranged to drive control means within the valve body for controlling fluid flow through the valve. In this arrangement, the linear and angular adjustment of the coupling compensates for misalignment of the rotational axis of the valve stem and a rotational axis of the control member. Preferably, the coupling provides linear adjustment along the rotational axis of the control member. In this arrangement, the linear adjustment of the coupling compensates for variations in a build-in depth of the valve body relative to the surface.

These and other features, benefits and advantages of the invention will be apparent from the description hereinafter of exemplary embodiments.

The invention will now be described in more detail by way of example only wherein:

Figure 1 is a perspective view, partly sectioned, of a mixer valve embodying the invention;

Figure 2 is a perspective view, to a reduced scale, of the mixer valve shown in Figure 1 with the concealing plate and controls detached from the valve body and showing the required freedom of movement for accommodating axial misalignment of the valve stem and controls and/or variations in the built-in depth of the valve body;

Figure 3 is an exploded perspective view of the component parts of the coupling shown in Figure 1;

Figure 4 is a plan view, partly sectioned, showing the allowable linear movement along the x-axis between top and bottom hub parts of the coupling shown in Figure 3;

Figures 5,6,7 are sectional views showing the range of allowable linear movement along the x-axis between the top and bottom hub parts; Figure 8 is a plan view, partly sectioned showing the allowable linear movement along the y-axis between the top hub part and control retainer of the coupling shown in Figure 3;

Figures 9,10,11 are sectional views showing the range of allowable linear movement along the y-axis between the top hub and control retainer;

Figures 12,13,14 are sectional views showing the range of angular movement about the x-axis between the top hub part and the control retainer;

Figures 15, 16, 17 are sectional views showing the range of angular movement about the y-axis between the top hub part and the control retainer;

Figures 18,19 are sectional views showing the range of allowable linear movement along the z-axis between the top hub part and the control retainer;

Figure 20 is a perspective view of an alternative coupling for a mixer valve according to the invention;

Figure 21 is an exploded perspective view of the coupling shown in Figure 20;

Figure 22 shows the assembly of the coupling of Figures 20 and 21;

Figures 23,24,25 are sectional views showing the range of angular movement about the x-axis of the coupling shown in Figures 20,21 ,22; Figures 26.27,28 are sectional views showing the range of angular movement about the y-axis of the coupling shown in Figures 20,21,22;

Figure 29 is a sectional view showing the effect of building-in depth on the position of the control knob relative to the concealing plate;

Figures 30,31 are sectional views showing a modification of the coupling shown in Figures 20 to 28;

Figures 32,33 are sectional views showing articulation in the x-plane of another alternative universal coupling for a mixer valve according to the invention;

Figures 34,35 are sectional views showing articulation in the y-plane of the universal coupling shown in Figures 32,33;

Figures 36,37 are side views showing two methods of installing a built-in mixer valve;

Figures 38,39,40 are sectional views showing one method of accommodating angular misalignment between the finished surface and the mixer valve and/or variations in the built-in depth of the mixer valve; and

Figure 41 is a plan view showing angular misalignment between the valve stem and controls of a mixer valve due to an uneven finished surface.

Referring first to Figures 1 to 3 of the drawings, a built-in mixer valve 100 for an ablutionary installation such as a shower is shown. The valve 100 includes a valve body 101 and a concealing plate assembly 102 including a control knob 103 operatively connected to a valve stem or spindle 104 by a coupling 105 described in more detail later.

As shown in Figure 1, the valve body 101 has mounting flanges 106,107 with holes 106a, 107a for screws or similar fasteners by means of which the valve body 101 is fixed in place within a recess (not shown) by either of the conventional methods described previously and shown in Figures 36 and 37.

The concealing plate assembly 102 is secured to the valve body 101 and has a larger diameter than the recess in the wall so that, when the assembly 102 is screwed to the valve body 101 it clamps against the finished surface, for example a tiled surface to hide the valve body 101 within the recess.

The valve body 101 has inlets 108a, 108b for connection to hot and cold water inlet pipes respectively (not shown) and an outlet 109 for connection to a water outlet pipe or hose (not shown) for supply to an ablutionary appliance such as a shower, bath or washbasin.

The valve body 101 houses a cartridge (not shown) including a proportioning valve for mixing the incoming supplies of hot and cold water. The coupling 105 transmits rotation of the control knob 103 to the valve stem 104 to adjust the proportioning valve according to user selection of the outlet water temperature. Rotation of the valve stem 104 may also control flow rate or a separate flow control may be provided.

The valve 100 may be non-thermostatically controlled but is preferably thermostatically controlled to maintain a selected outlet water temperature substantially constant. The construction and operation of both non- thermostatic and thermostatic mixer valves will be familiar to those skilled in the art and is not described further herein as it forms no part of this invention.

In accordance with the present invention, the coupling 105 is configured to compensate for variations in the building in depth of the valve 100 as well as any misalignment of the rotational axis of the control knob 103 relative to the rotational axis of the valve stem 104 when the concealing plate assembly 102 is secured to the valve body 101.

As best shown in Figure 2, the coupling 105 is configured to allow for the following motion between the control knob 103 and valve stem 104:

• Freedom of rotational movement around the x and y plane (up to a specified maximum) to allow for the angular variation.

• Freedom of lateral movement in the x and y planes (up to a specified maximum) to allow for axial misalignment in the z plane as a result of the angular variation. • Freedom of lateral movement along the z-axis during installation to allow for the variation in building in depth.

• Fixed rotation between the control knob 103 and valve stem 104 around the z-axis to transfer rotational motion of the control knob 103 to the valve stem 104 for adjusting the proportioning valve.

The way in which the coupling 105 achieves the foregoing is now described with reference to Figures 4 to 19 in addition to Figures 1 to 3. Freedom along the x-axis is achieved using a split hub 111 comprising a hub base 112 and a hub top 113. The hub base 112 fits on top of the valve stem 104 and is provided with axial splines to engage axial splines 104a on the valve stem 104 so that rotation of the hub base 112 causes rotation of the valve stem 104.

The hub base 112 has a pair of opposed flats 112a, 112b engaged by a first pair of opposed downwardly extending lugs 113a, 113b on the hub top 113 such that the hub top 113 can move parallel to the x-axis relative to the hub base 112 as shown in Figure 4.

The hub base 112 also has a pair of opposed recessed portions 112c, 112d in which a second pair of opposed downwardly extending lugs 113c, 113d on the hub top 113 are received.

The lug 113c provides a stop to limit sliding movement of the hub top 113 to the right along the x-axis from a central position axially aligned with the hub base 112 and valve stem 104 shown in Figure 6 to the end position shown in Figure 5 in which the axis of the hub top 113 is offset to the right relative to the axis of the hub base 112.

Similarly, the lug 113d provides a stop to limit sliding movement of the hub top 113 to the left along the x-axis from the central position to the end position shown in Figure 7 in which the axis of the hub top 113 is offset to the left relative to the axis of the hub base 112.

The engagement of the flats 112a, b and recessed portions 112c, d of the hub base 112 by the lugs 113a,b,c,d of the hub top 113 is such that the two hub parts 112,113 are rotatably coupled together so that rotational motion is transferred from one to the other in all adjusted positions along the x-axis. The hub 111 is secured to the valve stem 104 by a screw 110.

Freedom along the y-axis is achieved using the hub top 113 and a control retainer 114. The hub top 113 has a pair of projecting ears 113e,113f that are received in a pair of opposed grooves 114a, 114b in the control retainer 114.

The grooves 114a, 114b extend parallel to the z-axis and are deeper than the radial dimension of the ears 113e, 113f providing limited radial clearance between the ears 113e,113f and the control retainer 114 in a central neutral position as shown in Figure 10. The clearance allows the control retainer 114 to move parallel to the y-axis relative to the hub top 113 as shown in Figure 8.

The ear 113e provides a stop to limit sliding movement of the control retainer 114 to the right along the y-axis from the central position shown in Figure 10 axially aligned with the hub top 113 to the end position shown in Figure 9 in which the axis of the control retainer 114 is offset to the right relative to the axis of the hub top 113.

Similarly, the ear 113f provides a stop to limit sliding movement of the control retainer 114 to the left along the y-axis from the central position to the end position shown in Figure 11 in which the axis of the control retainer 114 is offset to the left relative to the axis of the hub top 113.

The upper ends of the ears 113e,f are sized to be a close fit in the grooves 114a,b transverse to the y-axis such that the control retainer 114 and hub top 113 are rotatably coupled together in all adjusted positions along the y-axis so that rotational motion is transferred from one to the other .

Freedom of rotation around the x-axis and y-axis also takes place between the hub top 113 and control retainer 114.

Rotation about the x-axis is provided by the radial dimension of the ears 113e,f being less than the depth of the grooves 114a,b as described above to provide limited radial clearance between the ends of the ears 113e,f and the bottom of the grooves 114a,b as shown in the neutral (no rotation) position of Figure 13 in which the rotational axes of the hub top 113 and control retainer 114 are aligned.

The clearance allows limited rotation of the control retainer 114 in either a clockwise direction around the x-axis until the ears 113e,f engage the control retainer 114 as shown in Figure 12 or in an anticlockwise direction around the x-axis until the ears 113e,f engage the control retainer 114 as shown in Figure 14. In both cases, the rotational axis of the control retainer 114 extends at an angle to the rotational axis of the hub top 113.

Rotation about the y-axis is provided by the opposed sides of the ears 113e,f tapering inwards from the upper end to the lower end to provide limited clearance between the lower ends of the ears 113e,f and the side walls of the grooves 114a,b as shown in the neutral (no rotation) position of Figure 16 in which the rotational axes of the hub top 113 and control retainer 114 are aligned.

The clearance allows limited rotation of the control retainer 114 in either a clockwise direction around the y-axis until the ears 113e,f engage the control retainer 114 as shown in Figure 15 or in an anticlockwise direction around the y-axis until the ears 113e,f engage the control retainer 114 as shown in Figure 17. In both cases, the rotational axis of the control retainer 114 extends at an angle to the rotational axis of the hub top 113.

The location of the ears 113e,f in the grooves 114a,b is such that the control retainer 114 and hub top 113 are rotatably coupled together in all angularly adjusted positions about both the x-axis and the y-axis so that rotational motion is transferred from one to the other.

Freedom of linear motion in the z axis to allow for variations in the building in depth comes from the length of the grooves 114a,b in the control retainer 114.

The grooves 114a, b in the control retainer 114 are longer than the ears 113e,f on the hub top 113 in the z-direction. As a result, the ears 113e,f can sit at any position along the length of the grooves 114a,b from a specified maximum building in depth shown in Figure 18 to a specified minimum building in depth shown Figure 19.

In use, the control retainer 114 is received in and held in place by the concealing plate assembly 102 when it is clamped to the finished surface and the control knob 103 is located and coupled to the control retainer 114 to be coaxial therewith. Rotation of the control knob 103 is transmitted to the control retainer 114 and is transmitted in turn from the control retainer 114 to the valve stem 104 via the split hub 111. Rotation of the valve stem 104 may be employed to adjust mechanisms controlling selection of the outlet water temperature and/or flow rate. Variation in the building in depth between the specified maximum and minimum values is automatically compensated for by the ears 113e,f locating at the appropriate position along the length of the grooves 114a,b. Similarly, misalignment between the rotational axis of the control knob 103 and the rotational axis of the valve stem 104 is automatically compensated for by relative linear and/or angular movement between the control retainer 114 and the hub top 113 and/or between the hub top 113 and the hub base 112. As a result, the concealing plate assembly can be located on the finishing surface whether or not the surface is perpendicular to the rotational axis of the valve stem.

Referring now to Figures 20 to 28, an alternative coupling 205 for connecting the control knob 103 to the valve stem 104 is shown based on a universal joint. The coupling 205 consists of a part 240 incorporating a spherical end 240a in which there are three slots 240b, c,d and a part 241 incorporating a spherical recess 241a into which three integral pins 241b, c, d protrude.

The coupling is assembled in the following manner: • The part 241 is held so that its axis is perpendicular to the axis of the part 240 as shown in Figure 22.

• The part 241 is orientated so that the internal pins 241b, c are aligned with the two diametrically opposite slots 240b ,c in the part 240. • The part 241 is then lowered onto the part 240 so that the pins 241b, c locate in the slots 240b, c until the top of the ball 240a on the part 240 contacts the recess 241a in the part 241 and it can travel no further.

• The part 241 is then rotated 90° relative to the part 240 about the axis of the two diametrically opposite pins 241b, c thereby engaging the third pin 241c on the part 241 into the third slot 240c in the part 240.

In the assembled coupling (Figure 20) , rotation of the part 241 causes rotation of the part 240, the load being transferred via the pins 241b, c,d in the slots 240b, c,d. There is minimal clearance between the diameter of the pins 241b,c,d and the slots 240b, c,d in which they sit in order to minimise the rotational "backlash" .

The rotational axis of the part 241 can be angularly misaligned relative to the rotational axis of the part 240 up to the maximum allowed by the geometry and the part 241 is configured to prevent it being removed from the part 240 by an under cut portion 241e engaging against the spherical part 240a of the part 240.

In use, the coupling 205 is located at the top of the valve cartridge. The part 240 fits on the valve stem 104 and has splines 240e that engage the splines 104a on the valve stem 104 to transmit rotation of the part 240 to the valve stem 104. The control knob 103 is fixed via a grub screw or similar to the part 241 of the coupling 205. The grub screw can be fixed at any point along the length of the part 241. Rotation of the control knob 103 by the user is transferred through the coupling 205 to the valve stem 104. . Rotation of the valve stem 104 may be employed to adjust mechanisms controlling selection of the outlet water temperature and/or flow rate.

The part 241, and therefore the control knob 103, is free to swivel about the x-axis from a neutral (no rotation) position shown in Figure 27 in which it is coaxial with the part 240, and therefore the valve stem 104, to either of the positions shown in Figures 26 and 28 up to the maximum angle allowable with the geometry in which the axes of the parts 241,240 and therefore the rotational axes of the control knob 103 and valve stem 104 extend at an angle to each other.

Similarly, the part 241, and therefore the control knob 103, is free to swivel about the y-axis from a neutral (no rotation) position shown in Figure 24 in which it is coaxial with the part 240, and therefore the valve stem 104, to either of the positions shown in Figures 23 and 25 up to the maximum angle allowable with the geometry in which the axes of the parts 241 ,240 and therefore the rotational axes of the control knob 103 and valve stem 104 extend at an angle to each other

While this arrangement allows for angular misalignment between the valve and the finished surface when the pivot point of the finished surface coincides with the pivot point in the centre of the universal joint, it does not allow for the effect of building in depth variation.

More especially, as shown in Figure 29, if the finished surface 4 is not perpendicular to the rotational axis of the valve stem 104 and the pivot point of the coupling 205 is offset from the plane of the finished surface, the top part 241 is eccentric with respect to the concealing plate assembly 102.

One method of avoiding eccentricity of the control knob is to connect the top part 241 of the coupling 205 to the control knob 103 via the control retainer 114 of the first embodiment. Thus, as shown in Figures 30,31 the part 241 of the coupling 205 is provided with two pins 241f,g protruding from its outside diameter that locate in the grooves 114a,b in the control retainer 114. This arrangement additionally allows for lateral misalignment of the rotational axes of the control retainer 114 and part 240, and therefore the control knob and valve stem, and also the effect of building in depth variation so that the control knob 103 is still held concentric in the concealing plate assembly 102.

Another method of avoiding the eccentricity of the control knob is shown in Figures 32 to 35 where the part 241 of the coupling 205 is provided with two opposed spherical recesses 241a, 241a' to receive spherical ends 240a, 240a' of two parts 240,240' of which one part 240 is fixed to the valve stem 104 on the valve cartridge and the other part 240' is attached to the control knob 103.

This arrangement additionally allows for lateral misalignment of the rotational axes of the parts 240,240' , and therefore the control knob and valve stem, and also the effect of building in depth variation so that the control knob 103 remains concentric in the concealing plate assembly 102. In this way, infinite adjustment in the building in depth between the maximum and minimum allowable with the geometry can be made.

As will be apparent from the foregoing description of exemplary embodiments, the present invention provides a solution to the problems of angular and/or lateral misalignment of the rotational axes of the control knob and valve stem of a built-in mixer valve such as may occur if the finished surface is not perpendicular to the rotational axis of the valve stem as well as accommodating variations in the built-in depth in preferred embodiments.

Claims

1. A valve having a valve stem with an axis of rotation, a control member with an axis of rotation, and a coupling arranged to transmit rotation of the control member to the valve stem for rotating the valve stem to adjust the valve, the coupling being configured to accommodate misalignment between the rotational axis of the valve stem and the rotational axis of the control member.

2. A valve according to claim 1 wherein, the valve has a valve body that, in use, is located in a recess in a wall or the like with the valve stem projecting from the valve body, and the control member is mounted on a concealing plate that fits over the recess with the coupling connecting the control member to the valve stem.

3. A valve according to claim 2 wherein, the coupling is configured to accommodate any misalignment between the rotational axis of the valve stem and the rotational axis of the control member so that the concealing plate can be located substantially flush against a finished surface of the wall.

4. A valve according to claim 2 or claim 3 wherein, the coupling is configured to accommodate variations in the building-in depth of the valve resulting from the depth of the recess in which the valve body is installed and/or the thickness of a finished surface on which the concealing plate is positioned.

5. A valve according to any preceding claim wherein, the coupling connects the valve stem to the control member via parts that provide linear adjustment along three mutually perpendicular axes and rotational adjustment about two of the axes with the third axis being the rotational axis of the valve stem.

6. A valve according to claim 5 wherein, the coupling comprises a drive part associated with the control member and a driven part associated with the valve stem, the drive part and driven part having co-operating formations providing relative movement between the parts and for transmitting rotation of the control member to the valve stem.

7. A valve according to claim 6 wherein, the driven part comprises a split hub having a first part mounted on and rotatable with the valve stem and a second part mounted on the first part and linearly adjustable relative to the first part along a first axis normal to the rotational axis of the valve stem.

8. A valve according to claim 7 wherein, the drive part comprises an annular retainer mounted on the second part of the hub with the retainer being linearly adjustable relative to the hub along the rotational axis of the valve stem and along a second axis normal to both the first axis and the rotational axis of the valve stem and being angularly adjustable relative to the hub about the first and second axes .

9. A built-in mixer valve comprising a valve body having a valve stem rotatable about a first axis, a concealing plate for securing to the valve body to cover a recess in a surface in which the valve body is mounted, a control member mounted on the concealing plate for rotation about a second axis, and a coupling for transmitting rotation of the control member to the valve stem for controlling fluid flow through the valve, the coupling providing linear adjustment in three mutually perpendicular directions of which one direction includes the first or second axis, and angular adjustment about either one of two mutually perpendicular directions normal to the first axis.

10. An adjustable coupling for transmitting rotation of a control member to a valve stem of a valve, the coupling providing linear adjustment along two mutually perpendicular axes normal to a rotational axis of the valve stem and angular adjustment about said two mutually perpendicular axes.

11. An adjustable coupling according to claim 10 wherein, the linear and angular adjustment of the coupling compensates for misalignment of the rotational axis of the valve stem and a rotational axis of the control member.

12. An adjustable coupling according to claim 10 or claim 11 wherein, the coupling provides linear adjustment along the rotational axis of the control member.