GB2621041A

GB2621041A - Switch assembly

Info

Publication number: GB2621041A
Application number: GB2316492.4A
Authority: GB
Inventors: Dear Nathan
Original assignee: Longvale Ltd
Current assignee: Longvale Ltd
Priority date: 2023-10-27
Filing date: 2023-10-27
Publication date: 2024-01-31
Anticipated expiration: 2043-10-27
Also published as: GB202500812D0; GB202316492D0; GB2633727A; GB2621041B

Abstract

A flow switch assembly 100 comprises a housing 10 having a first chamber 11 separated from a second chamber 12 by a dividing wall 13. The first chamber comprises a recess 14 having a supporting ledge 15 and an overhang 16. A microswitch 20 is supported by the ledge and comprises a microswitch paddle 21 that is rotatable about a first pivot 22. Located in the recess are one or more seals 30,32, and a retainer 40. The retainer is located between the seals and the overhang and retains the microswitch and seals within the first chamber. Located in the second chamber is a piston 60 and spring 50 configured to bias the piston relative to the dividing wall. A fluid actuatable paddle 70 comprising a blade 71 is arranged to move the piston relative to the dividing wall in response to a rotation of the blade about a second pivot 72, which may be caused by a flow of fluid. Movement of the piston causes the microswitch paddle to rotate about the first pivot due to a magnetic interaction between the two, which actuates the microswitch. The microswitch paddle may be ferrous, and the piston may comprise a permanent magnet 62.

Description

TITLE

Switch assembly

TECHNOLOGICAL FIELD

Examples of the disclosure relate to a switch assembly, such as a flow switch assembly.

BACKGROUND

A flow switch assembly may comprise a fluid actuatable paddle. At least part of the fluid actuatable paddle may be located in a conduit, such as a pipe. Actuation of the paddle may, in turn, cause actuation of a microswitch, indicating the presence of an amount of fluid flow in the conduit.

BRIEF SUMMARY

According to various, but not necessarily all, examples there is provided a flow switch assembly, comprising: a housing comprising a first chamber separated from a second chamber by a dividing wall, wherein the first chamber comprises a recess, the recess having a supporting ledge and an overhang; a microswitch, supported by the supporting ledge, comprising a microswitch paddle that is rotatable about a first pivot; one or more seals, at least partially located in the recess; at least one retainer, at least partially located in the recess between the one or more seals and the overhang, configured to retain the microswitch and the one or more seals within the first chamber; a piston located at least partially in the second chamber; a spring, located at least partially in the second chamber, arranged to bias the piston relative to the dividing wall; and a fluid actuatable paddle comprising a blade that is arranged to cause the piston to move relative to the dividing wall in response to rotation of the blade about a second pivot, such that the movement of the piston causes the microswitch paddle to rotate about the first pivot in response to a magnetic interaction between the piston and the microswitch paddle, thereby actuating the microswitch.

The retainer may be a resilient retainer. The recess may be provided in a wall of the first chamber. The resilient retainer may be biased against the recess in the wall. The retainer may abut the overhang. The retainer may be a circlip.

The microswitch may abut the supporting ledge. The microswitch may comprise a platform that is supported by the supporting ledge. The one or more seals may be at least partially located in the recess, between the at least one retainer and the platform. The platform may comprise a plurality of electrical terminals of the microswitch.

The one or more seals may be one or more circumferential seals. The one or more seals may be one or more 0-rings.

The first chamber may comprise a volume for receiving potting compound and a formation for retaining the potting compound in the volume.

The spring may be arranged to bias the piston away from the dividing wall. The blade may be arranged to cause the piston to move towards the dividing wall. The fluid actuatable paddle may be arranged to push the piston towards the dividing wall in response to movement of the blade about the second pivot.

The magnetic interaction between the piston and the microswitch paddle may be a magnetic attraction or a magnetic repulsion. The microswitch paddle may be a ferrous paddle. The piston may comprise a permanent magnet that is arranged to magnetically influence the ferrous paddle in response to movement of the piston towards the dividing wall, and thereby cause actuation of the microswitch. The permanent magnet may be arranged to magnetically attract the ferrous paddle in response to movement of the piston towards the dividing wall, and thereby cause actuation of the microswitch.

According to various, but not necessarily all, examples there is provided a switch assembly, comprising: a housing comprising a first chamber separated from a second chamber by a dividing wall, wherein the first chamber comprises a recess, the recess having a supporting ledge and an overhang; a microswitch supported by the supporting ledge; one or more seals, at least partially located in the recess; and at least one retainer, at least partially located in the recess between the one or more seals and the overhang, configured to retain the microswitch and the one or more seals within the first chamber.

According to various, but not necessarily all, examples there is provided examples as claimed in the appended claims.

The following portion of this 'Brief Summary' section, describes various features that may be features of any of the examples described in the foregoing portion of the 'Brief Summary' section. The description of a function should additionally be considered to also disclose any means suitable for performing that function While the above examples of the disclosure and optional features are described separately, it is to be understood that their provision in all possible combinations and permutations is contained within the disclosure. It is to be understood that various examples of the disclosure can comprise any or all of the features described in respect of other examples of the disclosure, and vice versa. Also, it is to be appreciated that any one or more or all of the features, in any combination, may be implemented by/comprised in/performable by an apparatus, a method, and/or computer program instructions as desired, and as appropriate.

BRIEF DESCRIPTION

Some examples will now be described with reference to the accompanying drawings in which: FIG. 1 illustrates a cross section of a housing of a flow switch assembly; FIG. 2 illustrates an exploded perspective view of the flow switch assembly; FIG. 3A illustrates a plan view of the flow switch assembly when a blade of a fluid actuatable paddle of the flow switch assembly is in a first position; FIG. 3B illustrates a cross section of the flow switch assembly when the blade of the fluid actuatable paddle of the flow switch assembly is in a first position; FIG. 4A illustrates a plan view of the flow switch assembly when the blade of the fluid actuatable paddle is in a second position, following actuation of the blade by a fluid; FIG. 4B illustrates a cross section of the flow switch assembly when the blade of the fluid actuatable paddle is in the second position.

The figures are not necessarily to scale. Certain features and views of the figures can be shown schematically or exaggerated in scale in the interest of clarity and conciseness. For example, the dimensions of some elements in the figures can be exaggerated relative to other elements to aid explication. Similar reference numerals are used in the figures to designate similar features. For clarity, all reference numerals are not necessarily displayed in all figures.

DETAILED DESCRIPTION

Embodiments of the invention relate to a switch assembly 100 and, in particular, to a flow switch assembly 100. Aspects of the switch assembly 100 advantageously allow for easy and precise manufacture of the switch assembly 100.

FIG. 1 illustrates a housing 10 of the switch assembly 100. The housing 10 comprises a first chamber 11 and a second chamber 12 separated by a dividing wall 13. The dividing wall 13 may be fluid-fight such that fluid (e.g., liquid or gas) cannot pass from the second chamber 12 to the first chamber 11 (or vice-versa). The housing 10 might be formed from one or more metals. The housing 10 may, for example, be formed of brass.

The first chamber 11 may be substantially cylindrical in shape, but this need not be the case in every example. The first chamber 11 comprises an opening 8 that provides access to the first chamber 11, for example for the purpose of manufacturing the switch assembly 100. The dividing wall 13 may provide a floor of the first chamber 11.

The first chamber 11 comprises a peripheral wall 6 which, if the first chamber 11 is substantially cylindrical in shape, may be a circumferential wall. The first chamber 11 comprises a recess 14 which is located in the peripheral wall 6. The recess 14 comprises a supporting ledge 15 and an overhang 16. The supporting ledge 15 may be located at the bottom of the recess 14 and the overhang 16 may be located at the top of the recess 14. The supporting ledge 15 can be considered to be a shoulder and/or a rim. The recess 14, the supporting ledge 15 and the overhang 16 may extend around the entirety of the peripheral wall 6 in some implementations, such as that illustrated.

The first chamber 11 may comprise a volume for receiving potting compound and a formation 17 for retaining the potting compound in the volume. The potting compound may be an electrical insulator. In this example, the formation 17 is provided by an internal thread 17 that is located on an inner surface of the peripheral wall 6. The volume for receiving the potting compound is located above the supporting ledge 15 of the recess 14.

The second chamber 12 may be substantially cylindrical in shape, but this need not be the case in every example. The second chamber 12 comprises an opening 9 that provides access to the second chamber 12, for example for the purpose of manufacturing the switch assembly 100. The dividing wall 13 may provide a ceiling of the first chamber 11. The second chamber 12 comprises a peripheral wall 7 which, if the second chamber 12 is substantially cylindrical in shape, may be a circumferential wall. Unlike the first chamber 11, the second chamber 12 may be formed as a blind bore having a uniform bore diameter.

External threads 18, 19 may be located on an exterior of the peripheral walls 6, 7 respectively for mounting the switch assembly 100 in a system. The peripheral wall 6 of the first chamber 11 comprises a first external thread 18 for such mounting and a portion of the peripheral wall 7 defining the second chamber 12 comprises a second external thread 19 for such mounting.

FIG. 2 illustrates an exploded perspective view of an example of the switch assembly 100 in which the switch assembly 100 is a flow switch assembly 100. The flow switch assembly 100 may be used to monitor gas flow in a hydrogen reformation system, for instance. The flow switch assembly 100 comprises the housing 10 illustrated in FIG. 1 as described above. The flow switch assembly 100 may further comprise a microswitch 20, one or more seals 30, 32, at least one retainer 40, a spring 50, a piston 60 and a fluid actuatable paddle 70.

The microswitch 20 may comprise a platform 24. One or more electrical terminals 25 of the microswitch 20 may be located on the platform 24. A body 23 of the microswitch may be connected to the platform 24.

The microswitch 20 may comprise a microswitch paddle 21 that is rotatable about a (microswitch paddle) pivot 22. The microswitch paddle 21 may be formed from a ferrous material (i.e., be a ferrous paddle). The microswitch paddle 21 may be (permanently) magnetic.

The microswitch paddle 21 may be substantially L-shaped. The pivot 22 may be at least partially located in or on the body 23 of the microswitch 20. The pivot 22 may be located near a corner of the body 23. The pivot 22 may be provided by a pivot shaft that extends from the body 23, as shown in the FIGs. Rotation of the microswitch paddle 21 may cause actuation of the microswitch 20. In the illustrated example, the microswitch 20 comprises one or more plungers 26. The plunger(s) 26 may be located on the body 23. Rotation of the microswitch paddle 21 about the pivot 22 actuates the microswitch 20 by depressing the plunger(s) 26.

The seal(s) 30, 32 may be at least partially located in the recess 14 of the first chamber 11. This is described in further detail below. The seal(s) 30, 32 may be compressible. The seal(s) 30, 32 may be formed from one or more polymers, such as one or more rubber materials and/or one or more plastics materials. Each of the seal(s) 30, 32 may be a circumferential seal, such as one or more 0-rings. While two seals 30, 32 are shown in the illustrated example, more or fewer seals 30, 32 may be used in other implementations.

The retainer 40 is located at least partially in the recess 14 of the first chamber 11. This is described in further detail below. The retainer 40 may be a resilient retainer, such as a circlip. The retainer 40 may be formed from one or more electrically conductive materials, such as one or more metals, and may therefore be earthed to ground through its contact with the housing 10.

The piston 60 may comprise a piston housing 63. The piston 60 may comprise a magnet 62. The magnet 62 may be at least partially located in the piston housing 63. The magnet 62 may protrude beyond the piston housing 63, as shown in FIG. 2, such that the magnet 62 forms (at least part of) the extremity of the distal end of the piston 60. The piston 60 is located at least partially in the second chamber 12. The spring 50 is located at least partially in the second chamber 12 and is configured to bias the piston 60 relative to (e.g., away from) the dividing wall 13.

In the illustrated example, the fluid actuatable paddle 70 comprises a blade 71, a (blade) pivot 72 and a blade holder 74. The blade 71 is configured to rotate about the pivot 72, which in this example is provided by a pivot shaft. The blade 71 is hung from the blade holder 74, in which the pivot 72 is located. The blade 71 and the blade holder 74 are configured to rotate amount the pivot 72 in response to a force being applied to the blade 71 by a fluid (e.g., a gas or a liquid).

FIG. 3A illustrates a plan view of the flow switch assembly 100 when the blade 71 is in a first position. FIG. 3B illustrates a cross section of the flow switch assembly 100 when the blade 71 is in the first position. In use, the flow switch assembly 100 may be mounted in a system such that the blade 71 is located in a fluid path, such as a fluid path in a conduit (e.g., a pipe). When the blade 71 is in the first position, there is no force being applied to the blade 71 by a fluid.

It can be seen in FIG. 33 that the microswitch 20 is supported by the supporting ledge 15 of the recess 14, and that the seals 30, 32 and the retainer 40 are each at least partially located in the recess 14. The microswitch 20 abuts the supporting ledge 15. That is, the platform 24 of the microswitch 20 is seated on, and supported by, the supporting ledge 15. If the first chamber 11 and the recess 14 are substantially cylindrical in shape, the platform 24 may also be substantially cylindrical in shape, as shown in the FIGs.

It was explained above that potting compound may be placed into the volume in the first chamber 11 that is located above the platform 24. This is not shown in FIGs 3A to 4B for clarity reasons. The presence of the potting compound acts as a sealant, and in this regard may prevent or mitigate the ingress of fluids, such as explosive gases, towards the microswitch 20 where the ignition of such explosive gases could create a hazard. The seals 30, 32 may prevent or mitigate the ingress of fluids around the potting compound.

The platform 24 may be, or form part of, a printed circuit board. The electrical terminals 25 located on the platform 24 may face towards the opening 8 in the first chamber 11. The electrical terminals 25 may be connected to wiring that extends through the first chamber 11 and out of the opening 8. The wiring may be connected to the electrical terminals 25 before the introduction of the potting compound into the first chamber 11.

In some examples, such as that illustrated, a portion 28 of the printed circuit board may extend downwardly and the body 23 of the microswitch 20 may be located on the downwardly extending portion 28. The downwardly extending portion 28 of the printed circuit board may abut the dividing wall 13 in some examples.

The retainer 40 is located at least partially in the recess 14 between the seals 30, 32 and the overhang 16. The retainer 40 abuts the overhang 16 and is held in position by the overhang 16. The retainer 40 may be resiliently biased against the recess 14. The overhang 16 may apply a force to the retainer 40, causing the retainer 40 to compress the seals 30, 32 against the platform 24.

During manufacture, the microswitch 20 is inserted into the first chamber 11 through the opening 8, such that a portion of the platform 24 is located in the recess 14 and is supported by the supporting ledge 15. The seals 30, 32 are then inserted into the first chamber 11 and placed onto the platform 24, such that they are at least partially located in the recess 14. The retainer 40 is then placed at least partially in the recess 14 on top of the seals 30, 32, such that the retainer 40 is in contact with the overhang 16. The retainer 40 then acts to retain the microswitch 20 and the seals 30, 32 in position.

The piston 60 is located at least partially in the second chamber 12. In the illustrated example, the piston 60 is wholly located in the second chamber 12. The spring 50 is also located in the second chamber 12. In this example, the spring 50 is arranged to bias the piston 60 (downwardly) away from the dividing wall 13.

The spring 50 may be connected to (e.g., in contact with) the dividing wall 13. The piston 60 may be retained in the second chamber 12 by the spring 50. In the illustrated example, the piston 60 comprises a (permanent) magnet 62 that is located at a distal end of the piston housing 63. The magnet 62 may be fixed in place within the piston housing 63 using a fastener 64. A portion of the magnet 62 may face the dividing wall 13, such as a portion that protrudes beyond the piston housing 63. In FIGs 3A and 3B, when the blade 71 of the fluid actuatable paddle 70 is in a first position, there is a gap between the piston 60 and the dividing wall 13. That is, there is a gap between a distal end of the piston 60 and the dividing wall 13.

As explained above, the blade 71 is configured to rotate about the pivot 72. When the blade 71 is in the first position as shown in FIGs 3A and 3B, it is held in the first position under the influence of the biasing force from the spring 50. This is because the spring 50 biases the piston 60 towards the blade holder 74, which applies a force on both sides of the pivot 72.

The blade 71 is configured to move about the pivot 72 in response to the application of a force to the blade 71 by a fluid. If the magnitude of the force applied by the fluid is above a threshold level, the rotation of the blade 71 causes the piston 60 to move relative to the dividing wall 13 (for instance, towards the dividing wall 13). That is, the paddle 70 may provide a force that causes the piston 60 to move. The paddle 70 may push the piston 60 towards the dividing wall 13. The piston 60 may move in a linear manner. The paddle 70 may contact the piston 60 to cause the piston 60 to move towards the dividing wall 13. This is the case in the illustrated example, in which the blade holder 74 contacts the piston housing 63, applying a force to it and causing it to move towards the dividing wall 13.

In moving towards the dividing wall 13, the piston 60 is moving against the biasing force being applied to the piston 60 by the spring 50. Movement of the piston 60 towards the dividing wall 13 causes the magnet 62 to move towards the dividing wall 13. Movement of the piston 60 towards the dividing wall 13 reduces the gap between the piston 60 and the dividing wall 13, and may eliminate the gap.

Movement of the piston 60 (and therefore the magnet 62) towards the dividing wall 13 may cause the magnet 62 to magnetically interact with the microswitch paddle 21 through the dividing wall 13. That is, the magnet 62 may magnetically influence the microswitch paddle 21 through the dividing wall 13. In this example, the magnet 62 is configured to magnetically attract the microswitch paddle 21, but in other examples the magnet 62 might be configured to magnetically repel the microswitch paddle 21. In these examples, the microswitch paddle 21 might or might not be magnetised (i.e., might or might not comprise a permanent magnet).

In further examples, there might not be a magnet present in the piston 60. In such further examples, the microswitch paddle 21 may be magnetised (i.e., might comprise a permanent magnet) and at least a portion of the piston 60 may be formed from a ferrous material. That portion of the piston 60 may magnetically interact with the microswitch paddle 21 (e.g., may magnetically attract the microswitch paddle 21).

If the magnetic interaction between the piston 60 and the microswitch paddle 21 is strong enough (e.g., if the magnet 62 moves close enough to the microswitch paddle 21), the magnetic interaction between them causes the microswitch paddle 21 to rotate about the pivot 22, causing the microswitch paddle 21 to depress the plungers 26, thereby actuating the microswitch 20.

It will be appreciated by those skilled in the art that the microswitch 20 may be completely isolated from fluid that acts on the blade 71 due to the presence of the dividing wall 13. Advantageously, this may prevent the fluid from adversely affecting the performance of the microswitch 20 and/or may prevent or mitigate a hazard.

FIG. 4A illustrates a plan view of the flow switch assembly 100 when the blade 71 is in a second position, following actuation of the blade 71 by a fluid. FIG. 4B illustrates a cross section of the flow switch assembly 100 when the blade 71 is in the second position.

In the situation illustrated in FIGs 4A and 43, the force provided by the fluid flow is above a threshold level, which means that sufficient rotation of the blade 71 has been caused by the fluid flow to cause actuation of the microswitch 20. That is, rotation of the blade 71 has caused the piston 60 to move sufficiently far to cause a magnetic interaction between the piston 60 and the microswitch paddle 21 to occur which causes the microswitch paddle 21 to depress the plungers 26 and actuate the microswitch 20.

The threshold level of the fluid flow at which the microswitch 20 is actuated may depend upon the particular application. For example, the resistance of the blade 71, the amount of biasing by the spring 50 and the spacing of the components of the flow switch assembly 100 may be adjusted to calibrate the threshold level accordingly.

While a flow switch assembly 100 has been described above in detail, it will be appreciated that aspects of the above may be utilized with other forms of switch assemblies. For example, in other examples, the switch assembly may instead be for sensing proximity, position, temperature, fluid/liquid level, pressure or movement. In such examples, the components located in the first chamber 11 might be the same as those described above, and at least some of the components located in the second chamber 12 might be different.

Where a structural feature has been described, it may be replaced by means for performing one or more of the functions of the structural feature whether that function or those functions are explicitly or implicitly described.

The term 'comprise' is used in this document with an inclusive not an exclusive meaning. That is any reference to X comprising Y indicates that X may comprise only one Y or may comprise more than one Y. If it is intended to use 'comprise' with an exclusive meaning then it will be made clear in the context by referring to "comprising only one..." or by using "consisting".

In this description, the wording 'connect' and 'couple' and their derivatives mean operationally connected/coupled. It should be appreciated that any number or combination of intervening components can exist (including no intervening components), i.e., so as to provide direct or indirect connection/coupling/communication.

In this description, reference has been made to various examples. The description of features or functions in relation to an example indicates that those features or functions are present in that example. The use of the term 'example' or 'for example' or 'can' or may' in the text denotes, whether explicitly stated or not, that such features or functions are present in at least the described example, whether described as an example or not, and that they can be, but are not necessarily, present in some of or all other examples. Thus 'example', 'for example', 'can' or 'may' refers to a particular instance in a class of examples. A property of the instance can be a property of only that instance or a property of the class or a property of a sub-class of the class that includes some but not all of the instances in the class. It is therefore implicitly disclosed that a feature described with reference to one example but not with reference to another example, can where possible be used in that other example as part of a working combination but does not necessarily have to be used in that other example.

Although examples have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the claims.

Features described in the preceding description may be used in combinations other than the combinations explicitly described above.

Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not.

Although features have been described with reference to certain examples, those features may also be present in other examples whether described or not.

The term 'a', 'an' or 'the' is used in this document with an inclusive not an exclusive meaning. That is any reference to X comprising a/an/the Y indicates that X may comprise only one Y or may comprise more than one Y unless the context clearly indicates the contrary. If it is intended to use 'a', 'an' or 'the' with an exclusive meaning then it will be made clear in the context. In some circumstances the use of 'at least one' or 'one or more' may be used to emphasis an inclusive meaning but the absence of these terms should not be taken to infer any exclusive meaning.

The presence of a feature (or combination of features) in a claim is a reference to that feature or (combination of features) itself and also to features that achieve substantially the same technical effect (equivalent features). The equivalent features include, for example, features that are variants and achieve substantially the same result in substantially the same way. The equivalent features include, for example, features that perform substantially the same function, in substantially the same way to achieve substantially the same result.

In this description, reference has been made to various examples using adjectives or adjectival phrases to describe characteristics of the examples. Such a description of a characteristic in relation to an example indicates that the characteristic is present in some examples exactly as described and is present in other examples substantially as described.

The above description describes some examples of the present disclosure however those of ordinary skill in the art will be aware of possible alternative structures and method features which offer equivalent functionality to the specific examples of such structures and features described herein above and which for the sake of brevity and clarity have been omitted from the above description. Nonetheless, the above description should be read as implicitly including reference to such alternative structures and method features which provide equivalent functionality unless such alternative structures or method features are explicitly excluded in the above description of the examples of the present disclosure.

Whilst endeavouring in the foregoing specification to draw attention to those features believed to be of importance it should be understood that the applicant may seek protection via the claims in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not emphasis has been placed thereon.

Claims

CLAIMS1 A flow switch assembly, comprising: a housing comprising a first chamber separated from a second chamber by a dividing wall, wherein the first chamber comprises a recess, the recess having a supporting ledge and an overhang; a microswitch, supported by the supporting ledge, comprising a microswitch paddle that is rotatable about a first pivot; one or more seals, at least partially located in the recess; at least one retainer, at least partially located in the recess between the one or more seals and the overhang, configured to retain the microswitch and the one or more seals within the first chamber; a piston located at least partially in the second chamber; a spring, located at least partially in the second chamber, arranged to bias the piston relative to the dividing wall; and a fluid actuatable paddle comprising a blade that is arranged to cause the piston to move relative to the dividing wall in response to rotation of the blade about a second pivot, such that the movement of the piston causes the microswitch paddle to rotate about the first pivot in response to a magnetic interaction between the piston and the microswitch paddle, thereby actuating the microswitch.
The flow switch assembly of claim 1, wherein the retainer is a resilient retainer.
The flow switch assembly of claim 2, wherein the recess is provided in a wall of the first chamber, and the resilient retainer is biased against the recess in the wall.
The flow switch assembly of claim 1, 2 or 3, wherein the retainer abuts the overhang.
The flow switch assembly of any of the preceding claims, wherein the retainer is a circlip.
The flow switch assembly of any of the preceding claims, wherein the microswitch abuts the supporting ledge. 2. 3. 4. 5. 6.
7. The flow switch assembly of any of the preceding claims, wherein the microswitch comprises a platform that is supported by the supporting ledge.
8. The flow switch assembly of claim 7, wherein the one or more seals are at least partially located in the recess, between the at least one retainer and the platform.
9. The flow switch assembly of claim 7 or 8, wherein the platform comprises a plurality of electrical terminals of the microswitch.
10. The flow switch assembly of any of the preceding claims, wherein the one or more seals are one or more circumferential seals.
11. The flow switch assembly of any of the preceding claims, wherein the one or more seals are one or more 0-rings.
12. The flow switch assembly of any of the preceding claims, wherein the first chamber comprises a volume for receiving potting compound and a formation for retaining the potting compound in the volume.
13. The flow switch assembly of any of the preceding claims, wherein the spring is arranged to bias the piston away from the dividing wall, and the blade is arranged to cause the piston to move towards the dividing wall.
14. The flow switch assembly of any of the preceding claims, wherein the fluid actuatable paddle is arranged to push the piston towards the dividing wall in response to movement of the blade about the second pivot.
15. The flow switch assembly of any of the preceding claims, wherein the magnetic interaction between the piston and the microswitch paddle is a magnetic attraction or a magnetic repulsion.
16. The flow switch assembly of any of the preceding claims, wherein the microswitch paddle is a ferrous paddle, and the piston comprises a permanent magnet that is arranged to magnetically influence the ferrous paddle in response to movement of the piston towards the dividing wall, and thereby cause actuation of the microswitch.
17. The flow switch assembly of claim 16, wherein the permanent magnet is arranged to magnetically attract the ferrous paddle in response to movement of the piston towards the dividing wall, and thereby cause actuation of the microswitch.