GB2544430A

GB2544430A - A device for operating a switch

Info

Publication number: GB2544430A
Application number: GB1702707.9A
Authority: GB
Inventors: Hopkins Mark; Ross Watt David
Original assignee: Norcros Group Holdings Ltd
Current assignee: Norcros Group Holdings Ltd
Priority date: 2013-02-01
Filing date: 2013-02-01
Publication date: 2017-05-17
Anticipated expiration: 2033-02-01
Also published as: IE20140026A1; GB2511033A; IE86831B1; GB201301861D0; GB2511033B; GB201702707D0; GB2544430B

Abstract

In the presence of a predetermined pressure of fluid from an inlet 34 an actuator 40 moves from a retracted to an extended position against biasing spring 42. A member 45 is connected to or is movable by the actuator and extends transversely away from its axis, in a direction toward the retracted position and then transversely away from the actuator axis and then engages the switch when the actuator is extended. Member 45 can be extended in the actuated direction by sliding parts 43,46 between which is a biasing spring 72 housed in a recess, allowing operation of the switch to be blocked by movable blocking member 82. There can be two switch engaging members, each operating a respective switch, one of which can be blocked. The blocking member can selectively inhibit the use of one of two heating elements in a water heater for an electric shower where the switch is used to prevent overheating of a heating element due to insufficient water pressure.

Description

Title: A Device for operating a switch Description of Invention

The invention relates to a device for operating a switch. In particular, although not exclusively, the invention relates to a device for operating a switch for controlling an electrically operated heating element.

An electric shower is an example of an apparatus which has a water heater for heating water for use by a user during showering. The water heater has a chamber for receiving water from a water supply and one or more electrically operated heating elements positioned in the chamber for heating the water. A number of known prior art such showers have two heating elements within the chamber and three separate controls (usually on a front facing surface of the housing) to control the operation of the shower. The first is an on/off control for turning the electric shower on/off (i.e. providing a connection between the mains electricity supply and the internal workings of the shower). The second is a temperature control for adjusting the temperature of the water by varying the flow of water through the water heater. Finally, a power control is provided for controlling the amount of power supplied to heat the water to cater for the varying ambient temperature of the water supply. For example, during a hot, e.g. summer, period the ambient temperature of the water supply will be higher. In this case, using both heating elements would not suitable as it will overheat the water to an unsafe level for the user, so the user can operate the power control to ensure that only one heating element operates. During a cold, e.g. winter, period the ambient temperature will be lower and so both heating elements will be required to bring the final temperature to a suitable level (again, the user can select this by moving the power control).

It is well known that in order to safely operate the shower, a minimum water flow pressure is required before the heating elements are turned on. For example, if the heating elements are turned on when there is little or no water flow the water in the water chamber will be super-heated and could potentially boil causing the electric shower housing to fail. For this reason, the internal switches are linked to a water pressure actuator and arranged so that the internal switches cannot be operated unless a predetermined pressure / flow of water is present.

According to a first aspect of the invention, we provide a device for operating a switch including: a fluid pressure actuator including a chamber for receiving fluid from a fluid inlet and an actuator member positioned in the chamber, wherein the actuator member is moveable along its axis, in the presence of a predetermined pressure of fluid, from a retracted position to an extended position (Direction A); biasing means for biasing the actuator member towards its retracted position; and a switch engaging member moveable by the actuator member so as to operate the switch, wherein the switch engaging member includes: a first part which is moveable by or connected to the actuator member, and which first part extends transversely away from the axis of the actuator member; a second part connected to the first part, which second part extends away from the first part in a direction generally opposite to “Direction A”; and a third part connected to the second part, which third part extends transversely away from the axis of the actuator member, wherein a portion of the third part is engageable with the switch when the actuator member is moved to its extended position; and wherein the second part provides a connection for relative movement between the first and third parts.

This arrangement permits the switch, fluid pressure actuator and switch engaging member to be placed side by side, positioned substantially in the same plane. The arrangement thus takes up a correspondingly smaller amount of space than prior art designs. This permits a more compact design for the housing.

According to a second aspect of the invention we provide a combination of a switch and a device according to the first aspect of the invention.

According to a third aspect of the invention we provide a combination of two switches and a device according to the first aspect of the invention.

According to a fourth aspect of the invention, we provide a water heater connectable to a power supply including the combination according the second or third aspect of the invention and further including: an inlet for connection to a water supply; a chamber in fluid communication with the inlet for receiving water; an electrically operating heating element positioned in the chamber to heat the water; wherein the switch is operable to alter the power supplied to the electrically operating heating element.

According to a fifth aspect of the invention we provide an electric shower including the water heater according to the fourth aspect of the invention.

Further features of the various aspects of the invention are set out in claims 2 to 29 appended hereto.

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings, of which:

Fig.la is a front view of a water heater according to an embodiment of the present invention;

Fig. 1 b is a side view of the water heater of Figure 1;

Fig. 2 is a perspective view of the water heater of Figure 1;

Fig. 3a is a front view of the water heater according to Figure 1 with a front part of a housing of the water heater removed to show its internal components;

Fig. 3b is a side view of the water heater according to Figure 1 with a front part of a housing of the water heater removed to show its internal components;

Fig. 4a is a close-up perspective view of a device in accordance with the present invention position in the water heater of Fig. 3;

Fig. 4b is a close-up side view of the device shown in Fig. 4a;

Fig. 4c is a close-up perspective side view of a device shown in Fig. 4a from the another side;

Fig. 5 is close-up cross-sectional view of a lower part of the water heater of Fig. 1 showing the device Fig. 4a;

Fig. 6 is a close-up cross-sectional view of the device shown in Fig. 4a with a blocking member thereof in a non-blocking position;

Fig. 7a is a close-up perspective view of the device in the non-blocking position;

Fig. 7b is a close-up front view of the device shown in the non-blocking position;

Fig. 8 is a close-up cross-sectional view of the device shown in Fig. 4a with a blocking member thereof in a blocking position;

Fig. 9a is a close-up perspective view of the device in the blocking position shown in Fig. 8;

Fig. 9b is a close-up front view of the device in the blocking position shown in Fig. 8; and

Fig. 10 is a close-up perspective cross-sectional view of the device shown in Fig. 4a;

Referring to Figures 1a, 1b, 2, 3a and 3b, these show an instantaneous water heater apparatus 10 for a shower. The apparatus has a housing 12 including a front part 14 (which is removable to access the internal working components) and a rear part 16 which provides a support for the internal workings (to which they are connected). The front part 14 includes a side wall 18 which engages the rear part 16 to provide a sealed enclosure for the internal working components. The housing 12 is made of a suitable plastics material, e.g. by injection moulding.

The apparatus 10 is connectable to a water supply and power supply (not shown) as is well known in the art. Positioned on the front cover part 14 is a push button on/off switch 20 for providing a connection between the mains electricity supply and the internal workings of the shower and a water temperature control dial 22 to adjust the temperature of the water exiting the apparatus. The apparatus 10 includes an inlet 24 for connection to a water supply, an outlet 26 for connection to a shower hose and a heater can 28 positioned in between the inlet 24 and outlet 26. The heater can 28 is positioned on and connected to a central portion of the rear part 16. The apparatus 10 further includes two electrically operated heating elements (not shown) positioned within the chamber to heat the water flowing therethough. An electric circuit (not shown) is provided inside the housing 12 to deliver electricity from the mains power supply to the electrically operated heating elements.

The inlet 24 is provided by a tubular inlet member that extends sideways across a lower section of the rear part 16 from a right hand side of the side wall 18. The inlet 24 is in fluid communication with a variable flow control valve 29. The variable flow control valve 29 has a main outlet (not shown) in fluid communication with the heater can 28, and a side outlet 30. The temperature dial 22 permits adjustment of the variable flow control valve 29. The temperature dial 22 thus alters the flow of water into the heater can 28 and consequently alters the total amount of time over which the water is heated in the heater can 28 before use downstream to the shower rose. A device 31 is provided, also connected to the rear part 16, and two switches 32, 33 operable thereby (only one is visible in Fig. 3, but the other one can be seen in Figures 4a, 4c and 8). Each switch controls power to a respective heating element. The device 31 and two switches 32, 33 are positioned to the side of the heater can 28 and near the right hand side of the side wall 18. Switches 32, 33 lie substantially one behind the another when viewed from the front. The device 31 has an inlet 34 in fluid communication with the side outlet 30 of the variable flow control valve 29.

Referring to Figures 4a, 4b, 4c and 5, these show the device 31 and switches 32, 33 in more detail. The device 31 includes a fluid pressure actuator 36 including a chamber 38 for receiving fluid from the fluid inlet 34 and an actuator member 40, e.g. a piston, with a suitable diaphragm 35 positioned within the chamber 38 dividing the chamber 38 in to left 38a and right 38b hand portions. The actuator member 40 is moveable along its axis 41, when the pressure of the water in the left hand part 38a of the chamber 38 exceeds a predetermined level, from a retracted position to an extended position (Direction A as labelled in figure 5). In this embodiment, Direction A is generally horizontally towards the right hand wall 18 of the housing 12.

The device 31 further includes biasing means in the form of a spring 42 for biasing the actuator member 40 towards its retracted position. Two switch engaging members 43, 44 are provided, both moveable by the actuator member 40 so as to operate the switches 32, 33 (the member 43 operates the switch 32; the member 44 operates the switch 33). The switch engaging members 43, 44 lie substantially behind one another when viewed from the front and are connected together. The switch engaging members are made from a plastic suitable to withstand any heat generated from the housing.

Each member 43, 44 has first, second and third parts which are connected to each other in that order to provide a connection between the actuator member 40 and each switch 32, 33. The switch engaging member 43 includes a first part 45 which is connected to the actuator member 40 (in an alternative embodiment it may not be directly connected but may be moveable by the actuator 40). The first part 45 extends transversely away from the axis 41 of the actuator member 40 where it connects to a second part 46. The second part 46 extends away from the first part 45 in a direction generally opposite to the “Direction A” where it connects at its remote end to a third part 50. The third part 50 extends transversely away from the second part 46 and the axis 41. A remote, free, end portion 54 of the third part 50 is positioned near the switch 32 and is engageable with the switch 32 when the actuator member 40 is moved to its extended position. As discussed below, the second part 46 is configured to provide relative movement between the first part 45 and the third part 50.

The switch engaging member 44 is positioned in front of the member 43. This member 44 shares the first part 45, although a separate first part could be provided connected to or moveable by the actuator member. The remote end of the first part 45 also provides a connection to a respective second part 48 which itself extends away from the first part 45 in a direction generally opposite to the “Direction A” (parallel and directly in front of the part 46) where it connects at its remote end to a respective third part 52. The third part 52 extends transversely away from the second part 48 and the axis 41. A remote, free, end portion 55 of the third part 52 is positioned near the switch 33 and is engageable with the switch 33 when the actuator member 40 is moved to its extended position. The first part 45, second part 48 and third part 52 are rigidly connected to each other, to essentially provide a single component, which is collectively moveable by the actuator member 40.

As shown in Fig. 6, 7a, 7b and Fig. 8, 9a, 9b the apparatus 10 further includes a blocking member, shown generally at 56, which is slidably positioned on a right hand side wall 19. The right hand side wall 19 extends outwardly away from the rear part 16, towards the front part 14, and underneath the side wall 18. The blocking member 56 is for preventing switch engaging member 43 from operating switch 32 and thereby preventing operation of its respective electrically operated heating element. In other words, the blocking member 56 prevents the third part 50 of the switching engaging member 43 from engaging the switch 32. The blocking member 56 is slidably moveable between blocking 58 (only one heating element is ‘on’) and non-blocking 60 (both heating elements are ‘on’) positions.

The apparatus 10 can be operated with the blocking member 56 in either the blocking 58 or non-blocking 60 positions. When the blocking member 56 is in the blocking position 58, and the user depresses the power switch 20 to operate the apparatus 10, water flows from the inlet 24 to the variable flow control valve 29. Water leaves the variable flow control valve 29 with the majority flowing into the heater can 28 and the some flowing towards the inlet 34. If the water is above a pre-determined pressure the water causes the actuator member 40 to move, against the spring 42. Both switch engaging members 43, 44 move to the right under the action of the actuator member 40. The switch engaging members 43, 44 will continue to move until, eventually, the end portions 54, 55 of the switch engaging members 43, 44 engage their respective switches 32, 33. The third parts 50, 52 of the switch engaging members 43, 44 are therefore aligned one in front of the other. The switches 32, 33 then cause electricity to flow to the electrically operated heating elements. Water within the heater can 28 is thus heated by both of the electrically operated heating elements.

If the user sets the blocking member 56 to its blocking position 58, the blocking member 56 prevents the second part 46 of the switch engaging member 43 from moving. As will be described later, in this configuration, movement of the actuator member 40 to the right causes the first part 45 of the switch engaging member 43 to move relative to the second part 46 of the switch engaging member 43. The third part 50 of the switch engaging member 43 does not move at all since the second part 46 of the switch engaging member 43 is blocked from movement by blocking member 56. The switch 32 therefore stays in an in-operative position. The switch engaging member 44 is, however, free to move and so will operate its switch 33. Power is therefore only supplied to one of the electrically operated heating elements. The user can move the blocking member 56 between its blocking and unblocking positions whilst the shower is operational. If the blocking member 56 is moved from the blocking 58 to the non-blocking 60 position whilst the shower is operating, this will cause the third part 50 to be moved away from, and thus disengage, the switch 32.

With reference to Figures 6 to 10, it can be seen that the second part 46 of the switch engaging member 43 is formed from separate component pieces and provides a moveable connection 62 between its first 45 and third parts 50. The moveable connection 62 is substantially parallel to the axis 41 of the actuator member 40 and offset therefrom.

The second part 46 has a first portion 64 connected to the first part 45 and a second portion 66 connected to the third part 50. The first and second portions 64, 66 are moveably connected to each other.

The first portion 64, the first part 45, the second part 48 and the third part 52 are formed as a single plastic moulding (although they could be formed as separate components connected to each other). The second portion 66 and the third part 50 are formed as a single plastic moulding (again, although they could be formed as separate components connected to each other).

The first portion 64 has a cylindrical passage 70 to receive an elongate projection 68 of the second portion 66 to connect the two plastic mouldings together. The switch engaging member 43 includes a further biasing means in the form of a spring 72 which is positioned in the recess 70 and extends around the projection 68. The spring biases the projection 68 out of the recess towards the right and therefore biases the first 45 and third 50 parts towards each other. The first and second portions of the second part 46 therefore provide a slidable connection between the first 45 and third 50 parts.

In more detail, the second portion 66 of the second part 46 includes first, second and third extension members 74, 76, 78, respectively, which together form a U-shape. The first extension member 74 is connected to the third part 50 and extends away therefrom generally in “Direction A”. The second extension member 76 is connected to the first extension member 74 and extends away therefrom generally towards the axis 41 of the actuator member 40. As discussed later, the member 76 has an outwardly facing (to the wall 19) surface which tapers outwardly as it extends towards the axis 41. The tapered surface provides a cam surface for engagement with a part of the blocking member 56. The third extension member 78 is connected to the second extension member 76 and extends away therefrom in a direction generally opposite to “Direction A”. The third extension member 78 has positioned at its remote end the projection 68.

The blocking member 56 includes a projection 80 for engagement by a user’s thumb / fingers. Connected to the projection 80 and extending downwardly inside the wall 19 is an abutment part 82. The abutment part 82 has a sloped / tapered inwardly facing surface for cooperation with the second extension member 76.

Whilst the blocking member 56 in the present embodiment is slidably moveable, it should be appreciated that a rotatable blocking member could be used to block movement of the second extension member 76 with an appropriate cam member or surface.

The design of the switch engaging members permits the switches to be positioned offset from the axis of the actuator member. This allows the fluid pressure actuator, switches, and switch engaging members to be positioned substantially side by side and substantially positioned in the same plane. This is advantageous since these components collectively extend only a relatively small amount along the length of the water heater thereby permitting a compact design.

The second and third parts of each switch engaging member form an L-shape in front view which permits the respective switch to be positioned within that space. This saves further space by bringing the switch engaging members and the switches closer together.

The arrangement of the blocking member on the side wall of the housing has advantages. It can be seen that the front part 14 of the housing extends over the right hand side wall 19 on the side where the blocking member 56 is positioned, such that, when viewed from the front of the housing 12, the blocking member 56 is concealed or substantially concealed from view.

In a variant of the embodiment described in the Figures, the water heater only has one electrically operated heating element and one switch engaging member for operating a power switch for that heating element. In such an embodiment, the switch engaging member 44 and its associated switch 33 are not required, but the blocking member is still provided so that the user can select whether or not to provide power to the heating element.

Further features of one or more aspects of the invention are set out in the numbered clauses provided below.

Clauses 1. A device for operating a switch including: a fluid pressure actuator including a chamber for receiving fluid from a fluid inlet and an actuator member positioned in the chamber, wherein the actuator member is moveable along its axis, in the presence of a predetermined pressure of fluid, from a retracted position to an extended position (Direction A); biasing means for biasing the actuator member towards its retracted position; and a switch engaging member moveable by the actuator member so as to operate the switch, wherein the switch engaging member includes: a first part which is moveable by or connected to the actuator member, and which first part extends transversely away from the axis of the actuator member; a second part connected to the first part, which second part extends away from the first part in a direction generally opposite to “Direction A”; and a third part connected to the second part, which third part extends transversely away from the axis of the actuator member, wherein a portion of the third part is engageable with the switch when the actuator member is moved to its extended position. 2. A device according to clause 1 wherein the second part provides a moveable connection between the first and third parts. 3. A device according to clause 2 wherein the moveable connection is substantially parallel to the axis of the actuator and offset therefrom. 3. A device according to clause 2 or 3 wherein the second part provides a slidable connection between the first and third parts. 4. A device according to clause 1,2 or 3 including a further biasing means for biasing the third part towards from the first part. 5. A device according to any preceding clause wherein the second part includes: a first portion connected to the first part; and a second portion connected to the third part, wherein the first and second portions are moveably connected to each other. 6. A device according to clause 5 wherein the first portion has a recess for receiving a projection of the second portion. 7. A device according to clause 6 where dependent directly or indirectly on clause 4 wherein the further biasing means is supported in the recess of the first portion. 8. A device according to clause 5, 6 or 7 wherein the second portion of the second part includes first, second and third extension members, wherein: the first extension member is connected to the third part of the switch engaging member and extends away therefrom generally in “Direction A”, the second extension member is connected to the first extension member and extends away therefrom generally towards the axis of the actuator, and the third extension member is connected to the second extension member and extends away therefrom in a direction generally opposite to “Direction A”. 9. A device according to clause 8 where dependent directly or indirectly on clause 6 wherein the third extension part provides the projection of the second portion. 10. A device according to any preceding clause wherein the device includes a blocking member for preventing the third part of the switching engaging member from engaging the switch. 11. A device according to clause 10 wherein the blocking member is moveable between blocking and non-blocking positions. 12. A device according to clause 11 wherein the blocking member includes an abutment part for engaging with the second part of the switch engaging member when the blocking member is moved to its blocking position 13. A device according to clause 12 where dependent directly or indirectly on clause 8 wherein the abutment part is engageable with the second extension member of the second portion of the second part. 14. A device according to clause 13 wherein the blocking member includes a cam mover formation which is engageable with a cam follower formation provided on the second extension member. 15. A device according to any one of clauses 10 to 14 wherein the blocking member is moveable linearly. 16. A device according to clause 15 wherein the blocking member is moveable towards and away from the axis of the actuator, substantially transversely to said axis. 17. A device according to any preceding clause including two of said switch engaging members each for operating a respective switch. 18. A device according to clause 17 where dependent directly or indirectly on clause 10 wherein the blocking member is only moveable to prevent one of the switching engaging members from engaging its respective switch. 19. A combination of a switch and a device according to any one of clauses 1 to 16. 20. A combination of two switches and a device according to any one of clauses 1 to 18. 21. A combination according to clause 19 or 20 wherein the switch(es) is(are) positioned offset from the axis of the actuator. 22. A combination according to any one of clauses 17 to 21 wherein the switch(es), switch engaging member(s) and actuator are positioned substantially side by side. 23. An apparatus according to clause 22 wherein the switch(es), switch engaging member(s) and actuator are positioned substantially in the same plane. 24. A water heater connectable to a power supply including the combination according to any one of clauses 17 to 21 and further including: an inlet for connection to a water supply; a chamber in fluid communication with the inlet for receiving water; an electrically operating heating element positioned in the chamber to heat the water; wherein the switch(es) is (are) operable to alter the power supplied to the electrically operating heating element(s). 25. A water heater according to clause 24 where dependent directly or indirectly dependent on claim 10 further including a housing having a rear part, a front part and a side wall extending therebetween, wherein the blocking member is positioned on a part of the side wall. 26. A water heater according to claim 25 wherein the front part of the housing extends over the part of the side wall on which the blocking member is positioned, such that, when viewed from the front of the housing, the blocking member is concealed or substantially concealed from view by the front part. 27. An electric shower including the water heater of any one of claims 24, 25 or 26. 28. A device or water heater substantially as hereinbefore described with reference to and/or as shown in the accompanying drawings. 29. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. A device for operating a switch including: a fluid pressure actuator including a chamber for receiving fluid from a fluid inlet and an actuator member positioned in the chamber, wherein the actuator member is moveable along its axis, in the presence of a predetermined pressure of fluid, from a retracted position to an extended position (Direction A); biasing means for biasing the actuator member towards its retracted position; and a switch engaging member moveable by the actuator member so as to operate the switch, wherein the switch engaging member includes: a first part which is moveable by or connected to the actuator member, and which first part extends transversely away from the axis of the actuator member; a second part connected to the first part, which second part extends away from the first part in a direction generally opposite to “Direction A”; and a third part connected to the second part, which third part extends transversely away from the axis of the actuator member, wherein a portion of the third part is engageable with the switch when the actuator member is moved to its extended position, wherein the second part provides a connection for relative movement between the first and third parts.

2. A device according to claim 1 for operating a further switch including; a further switch engaging member moveable by the actuator member so as to operate the further switch, wherein the further switch engaging member includes: a first part which is moveable by or connected to the actuator member, and which first part extends transversely away from the axis of the actuator member; a second part connected to the first part, which second part extends away from the first part in a direction generally opposite to “Direction A”; a third part connected to the second part, which third part extends transversely away from the axis of the actuator member, wherein a portion of the third part is engageable with the further switch when the actuator member is moved to its extended position.

3. A device according to claim 1 wherein the second part provides a slideable connection for relative movement between the first and third parts.

4. A device according to claim 3 wherein the slideable connection is substantially parallel to the axis of the actuator and offset therefrom.

5. A device according to claim 1, 3 or 4 including a further biasing means for biasing the third part towards the first part.

6. A device according to any one of claim 1,3, 4 or 5 wherein the second part includes: a first portion connected to the first part; and a second portion connected to the third part, wherein the first and second portions are moveably connected to each other.

7. A device according to claim 6 wherein the first portion has a recess for receiving a projection of the second portion.

8. A device according to claim 7 where dependent directly or indirectly on claim 5 wherein the further biasing means is supported in the recess of the first portion.

9. A device according to claim 6, 7 or 8 wherein the second portion of the second part includes first, second and third extension members, wherein: the first extension member is connected to the third part of the switch engaging member and extends away therefrom generally in “Direction A”, the second extension member is connected to the first extension member and extends away therefrom generally towards the axis of the actuator, and the third extension member is connected to the second extension member and extends away therefrom in a direction generally opposite to “Direction A”.

10. A device according to claim 9 where dependent directly or indirectly on claim 6 wherein the third extension part provides the projection of the second portion.

11. A device according to claim 1, or any one of claims 3 to 10 wherein the device includes a blocking member for preventing the third part of the switching engaging member from engaging the switch.

12. A device according to claim 11 wherein the blocking member is moveable between blocking and non-blocking positions.

13. A device according to claim 12 wherein the blocking member includes an abutment part for engaging with the second part of the switch engaging member when the blocking member is moved to its blocking position

14. A device according to claim 13 where dependent directly or indirectly on claim 9 wherein the abutment part is engageable with the second extension member of the second portion of the second part.

15. A device according to claim 14 wherein the blocking member includes a cam mover formation which is engageable with a cam follower formation provided on the second extension member.

16. A device according to any one of claims 11 to 15 wherein the blocking member is moveable linearly.

17. A device according to claim 16 wherein the blocking member is moveable towards and away from the axis of the actuator, substantially transversely to said axis.

18. A combination of a switch, and a device according to any preceding claim.

19. A combination of two switches, and a device according to claim 1 wherein the switch engaging member is for operating one of the switches.

20. A combination of a switch and a further switch and a device according to claim 2.

21. A combination according to claim 18, 19 or 20 wherein the switch(es) is(are) positioned offset from the axis of the actuator.

22. A combination according to any one of claims 18 to 21 wherein the switch(es), switch engaging member(s) and actuator are positioned substantially side by side.

23. An apparatus according to claim 22 wherein the switch(es), switch engaging member(s) and actuator are positioned substantially in the same plane.

24. A water heater connectable to a power supply including the combination according to any one of claims 18 to 21 and further including: an inlet for connection to a water supply; a chamber in fluid communication with the inlet for receiving water; an electrically operating heating element positioned in the chamber to heat the water; wherein the switch(es) is (are) operable to alter the power supplied to the electrically operating heating element(s).

25. A water heater according to claim 24 where dependent directly or indirectly on claim 11 further including a housing having a rear part, a front part and a side wall extending therebetween, wherein the blocking member is positioned on a part of the side wall.

26. A water heater according to claim 25 wherein the front part of the housing extends over the part of the side wall on which the blocking member is positioned, such that, when viewed from the front of the housing, the blocking member is concealed or substantially concealed from view by the front part.

27. An electric shower including the water heater of any one of claims 24, 25 or 26.

28. A device or water heater substantially as hereinbefore described with reference to and/or as shown in the accompanying drawings.

29. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.