WO2020150774A1

WO2020150774A1 - A thermostatic device

Info

Publication number: WO2020150774A1
Application number: PCT/AU2020/050034
Authority: WO
Inventors: Austin Carter; Gary Hay
Original assignee: Reliance Worldwide Corporation (Aust.) Pty. Ltd.
Priority date: 2019-01-23
Filing date: 2020-01-22
Publication date: 2020-07-30

Abstract

A thermostatic device including: a body having two inlets and an outlet; a piston in fluid communication with the two inlets and the outlet; a thermostatic element configured to assist in moving the piston such that movement of the piston assists in regulating fluid from the two inlets to the outlet; and a first spring configured to assist in biasing a member configured to move, where: the member assists in supporting a second spring that biases the thermostatic element; and the member is separate from the piston in order to allow the piston to move relative thereto.

Description

A THERMOSTATIC DEVICE

CROSS REFERENCE TO RELATED APPLICATION

[0001 ] This application claims priority to Australian Provisional Patent Application No 2019900209 filed on 23 January 2019, the contents of which are incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

[0002] The invention relates to a thermostatic device. In particular, the invention relates, but is not limited, to a thermostatic device in the form of a thermostatic cartridge. The invention also relates to a tap incorporating the thermostatic device as well as a method associated with the thermostatic device.

BACKGROUND TO THE INVENTION

[0003] Reference to background art herein is not to be construed as an admission that such art constitutes common general knowledge in Australia or elsewhere.

[0004] The fundamental purpose of thermostatic mixing device is to: i) receive cold water; ii) receive hot water; and iii) regulate the flow rates of cold and hot water to provide a relatively constant temperature output. There are various applications for thermostatic devices and the vast majority of the mixing devices on the market utilise subtle variations of a traditional design. By way of example, typically a cylindrical piston moves up and down in a body, via a separate thermostatic element, in order to achieve a set point temperature of output flow.

[0005] The assembly of thermostatic mixing devices based of the traditional design is currently complex. With complexity, the cost of thermostatic devices can be relatively high and an adherence to the traditional design has led to little economical improvements. That is, whilst adherence to the traditional design provides conventional comfort, this has resulted in few economical features being developed to offer a more commercially suitable product to clients. In addition, adherence to a traditional design has led to other improvements, such as homogenously mixing flows, being overlooked whilst reconciling the trade-offs between cost, performance and reliability remains an ongoing engineering challenge. SUMMARY OF INVENTION

[0006] In one form, the invention resides in a thermostatic device including:

a body having two inlets and an outlet;

a piston in fluid communication with the two inlets and the outlet;

a thermostatic element configured to assist in moving the piston such that movement of the piston assists in regulating fluid from the two inlets to the outlet; and a first spring configured to assist in biasing a member configured to move, wherein the member:

assists in supporting a second spring that biases the thermostatic element; and

the member is separate from the piston in order to allow the piston to move relative thereto.

[0007] In an embodiment, the member includes a seat portion that is configured to engage with the piston in order to limit fluid flow through at least one of the inlets.

[0008] In an embodiment, the member includes an inner bearing portion that is configured to support the second spring whilst an outer bearing portion is configured to engage with the first spring.

[0009] In an embodiment, the inner bearing portion and/or the outer bearing portion extends substantially perpendicular to an axial axis of the thermostatic device.

[0010] In an embodiment, the second spring overlaps at least part of the first spring in a projection that is substantially perpendicular to the axial axis of the thermostatic device.

[001 1 ] In an embodiment, the member is configured to be moved relative to the body from a force associated with the thermostatic element. In an embodiment, the member moves against the bias of the first spring.

[0012] In an embodiment, the thermostatic device is in the form of a thermostatic cartridge that is configured to be inserted into a tap.

[0013] In an embodiment, a sealing portion is configured to assist in providing a seal between the member and the body.

[0014] In an embodiment, the sealing portion is located between the outer bearing portion and the seat portion. [0015] In an embodiment, the sealing portion is configured to assist in providing a seal with the body whilst the member moves relative to the body.

[0016] In an embodiment, the sealing portion is located in an outboard direction of the seat portion.

[0017] In an embodiment, the outboard direction is transverse to the axial axis of the thermostatic device.

[0018] In an embodiment, the second spring has an inner diameter that is similar to at least a portion of the thermostatic element to allow the second spring to be suitably moved over the portion of thermostatic element.

[0019] In an embodiment, the second spring is configured to engage with a spring engagement portion of the thermostatic element.

[0020] In an embodiment, the spring engagement portion extends transversely to a longitudinal axis of the second spring.

[0021 ] In an embodiment, the spring engagement portion is in the form of a shoulder. In an embodiment, the shoulder extends substantially perpendicular to the axial axis.

[0022] In an embodiment, the thermostatic device includes an adjustment assembly having a stop that assists in setting a predetermined outlet temperature by interacting with the thermostatic element.

[0023] In an embodiment, the second spring biases the thermostatic element towards the stop.

[0024] In an embodiment, the first spring biases the member towards the stop.

[0025] In an embodiment, in response to interacting with the stop, the thermostatic element is configured to provide a force that assists in compressing the second spring.

[0026] In an embodiment, movement of the piston assists in regulating fluid from the two inlets to the outlet to achieve a predetermined outlet temperature.

[0027] In an embodiment, the thermostatic element is connected to piston.

[0028] In an embodiment, in response to compressing the second spring to a predetermined limit, the first spring will begin to compress.

[0029] In an embodiment, a stiffness ratio of the first spring to the second spring is approximately 1 : 2. [0030] In an embodiment, the body includes a retainer that assists in retaining the first spring.

[0031 ] In an embodiment, the retainer is fixed to part of the body.

[0032] In a further embodiment, the retainer is releasably connected to the body.

[0033] In an embodiment, the body provides a ledge that acts as a stop for the member whilst it is being biased by the first spring.

[0034] In an embodiment, the body includes a seat portion that is configured to engage with the piston in order to limit fluid flow through at least one of the inlets.

[0035] In a further form, the invention resides in a thermostatic device including: a body having two inlets and an outlet;

a piston in fluid communication with the two inlets and the outlet;

a thermostatic element configured to assist in moving the piston such that movement of the piston assists in regulating fluid from the two inlets to the outlet; and a first spring configured to assist in biasing a member,

wherein:

a sealing portion provides a seal between the member and the body; and the member is separate from the piston in order to allow the piston to move relative thereto.

[0036] In an embodiment, the thermostatic device is as herein described.

[0037] In an embodiment, the sealing portion includes a sealing member formed from a plastic and/or a rubber.

[0038] In an embodiment, the sealing member is substantially circular.

[0039] In another form, the invention resides in a tap including:

a tap body; and

a thermostatic device as herein described.

[0040] In another form, the invention resides in a method associated with a thermostatic device, the method including the steps of:

biasing a member with a first spring towards a stop, the member being separate from a piston in order to allow the piston to move relative thereto; biasing a thermostatic element towards the stop with a second spring, the thermostatic element being supported by the member; and

allowing at least part of the thermostatic element to interact with the stop to move the piston in order to regulate fluid flow from one or more inlets to an outlet.

[0041 ] In an embodiment, the step of biasing the member with the first spring towards the stop includes allowing the first spring to bias the member from an outer bearing portion of the member.

[0042] In an embodiment, the step of biasing the thermostatic element towards the stop with the second spring includes allowing the second spring to bias the thermostatic element from an inner bearing portion of the member.

[0043] In an embodiment, the step of moving the piston in order to regulate fluid flow from the one or more inlets to the outlet includes engaging the piston with a seat portion of the member.

[0044] In an embodiment, the method further includes rotating an altering member to move the stop and set a predetermined fluid outlet temperature for the thermostatic device.

[0045] In an embodiment, the step of rotating the altering member includes moving an engagement member that in turn adjusts an adjusting member including the stop.

[0046] In another form, the invention resides in a method associated with a thermostatic device, the method including the steps of:

placing a first spring in a body;

moving a member into a position such that it is biased by the first spring and sealed against at least part of the body; and

placing a thermostatic element into a position where it is supported by the member, the thermostatic element configured to assist in moving a piston such that movement of the piston assists in regulating fluid from the body, the member being separate from the piston in order to allow the piston to move relative thereto.

[0047] Further features and advantages of the present invention will become apparent from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] By way of example only, embodiments of the invention will be described more fully hereinafter with reference to the accompanying figures, wherein:

Figure 1 illustrates a thermostatic device, according to an embodiment of the invention;

Figure 2 illustrates a cross-sectional view of the thermostatic device, as shown in Figure 1 , according to an embodiment of the invention;

Figure 3 illustrates a further cross-sectional view of the thermostatic device, as shown in Figure 1 , according to an embodiment of the invention;

Figure 4 illustrates an upper perspective view of a member, as shown in Figure 1 , according to an embodiment of the invention;

Figure 5 illustrates a lower perspective view of a member, as shown in Figure 1 , according to an embodiment of the invention;

Figure 6 illustrates a perspective view of a tap including the thermostatic device, as shown in Figure 1 , according to an embodiment of the invention; and

Figure 7 illustrates a cross sectional view of the tap, as shown in Figure 6, according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0049] Figures 1 to 3 illustrate a thermostatic device 10 in the form of a thermostatic cartridge. As shown further in Figures 2 and 3, the thermostatic device 10 includes a body 100, an adjustment assembly 200, a thermostatic element 300, a piston 400, a member 500, a first spring 600 and a second spring 700.

[0050] The body 100 includes a first inlet, a second inlet and an outlet 130. The first inlet is in the form of a cold inlet 1 10 and the second inlet is in the form of a hot inlet 120. The cold inlet 1 10 and the hot inlet 120 are located at different locations along an axial axis 12 of the device 10. That is, the cold inlet 1 10 and hot inlet 120 are longitudinally offset along the axis 12. In certain configurations outlined below, the outlet 130 is in fluid communication with the inlets 1 10, 120. The outlet 130 is part of an aperture extending through the body 100. The outlet 130 is located in one end of the body 100. The body 100 also further includes a seat portion 140. As outlined further below, the seat portion 140 interacts with the piston 400 to regulate the flow of (cold) fluid to the outlet 130. In addition, the body 100 includes a retainer 150 to assist in retaining the first spring 600. In particular, the retainer 150 includes a connector 152 that fixes to a further part of the body 100.

[0051 ] The adjustment assembly 200 includes an altering member 210, an engagement member 220 and an adjusting member 230. The altering member 210 in this embodiment includes a pivot portion 212 and a handle 214. The handle 214 assists in rotating the pivot portion 212 about axis 12. The pivot portion 212 engages with a first engagement portion 222 of the engagement member 220. In particular, the first engagement portion 222 includes a plurality of splines that engage with corresponding keys of the altering member 210. In this regard, rotation of the altering member 210 causes the engagement member 220 to also rotate.

[0052] The engagement member 220 is also engaged with the adjusting member 230. That is, the engagement member 220 includes a second engagement portion 224 in the form of a thread that is releasably connected to the adjusting member 230. On this basis, rotating the engagement member 220, via the altering member 210, allows the position of the adjusting member 230 to be adjusted along the axis 12. The engagement member 220 will not move along the axis 12 as a circlip, inserted into the body 100, prevents axial movement of the engagement member 220. In this regard, rotating the altering member 210 adjusts the position of a stop 232, relative to the thermostatic element 300, along the axis 12. As outlined further below, the position of the stop 232, relative to the thermostatic element 300, assists in setting a predetermined fluid outlet temperature for the thermostatic device 10.

[0053] The thermostatic element 300 is positioned along the axis 12 and includes a shaft 310. In response to the thermostatic element 300 being exposed to different environmental conditions, the shaft 310 is moved to assist in achieving the predetermined outlet temperature of the thermostatic device 10. That is, the shaft 310 is configured to move and engage / disengage with the stop 232 to adjust the position of the piston 400. The thermostatic element 300 also includes a spring engagement portion 320 that engages with the second spring 700. The spring engagement portion 320 is in the form of a shoulder on the thermostatic element 300. As outlined further below, the second spring 700 biases the thermostatic element 300 (and as such the piston 400) towards the stop 232.

[0054] The piston 400 is slightly smaller than a diameter associated with the first inlet and the second inlet. That is, the diameter of the piston 400, which may vary between portions thereof, is smaller than the body 100. The piston 400 extends substantially a height between the first inlet and the second inlet. The piston 400 includes a holding portion 410 that assists in holding the thermostatic element 300. The holding portion 410 is in the form of a thread in this embodiment and, as such, the thermostatic element 300 is fastened to the piston 400. The piston 400 is separate from the member 500 and, as such, the piston 400 can move relative to the member 500. In other words, the piston 400 can move towards and/or away from the member 500 as they are not connected together. The piston 400 further includes a plurality of apertures 420. The apertures 420 allow fluid to flow through an inner portion of the piston 400 after passing the seat portion 140.

[0055] The member 500 is located adjacent the piston 400. The member 500 is shown further in Figures 4 and 5. The member 500 is configured to move relative to the body 100. The member 500 moves within the body 100. The member 500 includes a seat portion 510. The seat portion 510 is substantially circular. In response to the piston 400 engaging / disengaging with the seat portion 510, the flow of hot fluid to the outlet 130 can be regulated (as further outlined below). In this regard, the member 500 is located by the outlet 130 whilst the piston 400 regulates the flow proceeding through the inlets 1 10, 120.

[0056] The member 500 includes an inner bearing portion 520. The inner bearing portion 520 is configured to support the second spring 700. To support the second spring 700, the inner bearing portion 520 includes a ledge 522. The ledge 522 provides a surface to allow the spring 700 to engage therewith and extend to engage with the spring engagement portion 320. In this regard, the spring 700 is typically compressed between the ledge 522 and the spring engagement portion 320. Moreover, the inner diameter of the second spring 700 is substantially similar to at least part of the outer diameter of the thermostatic element 300. This allows the spring 700 to engage with the spring

engagement portion 320 adjacent thereto. Furthermore, the second spring 700 also assists in providing turbulence to the flow thereover, assisting in the mixing of hot and cold fluids adjacent to the thermostatic element 300. As outlined further below, the second spring 700 acts as a return spring whilst the first spring 600 acts as an overtravel spring in this embodiment. This may be different in further embodiments. Overall, moving a spring away from the adjustment assembly 200, with the use of the member 500 and its associated structure, is counterintuitive to traditional designs and assists in reducing the size of the thermostatic device 10.

[0057] The member 500 also includes an aperture 530. The aperture 530 extends from one end of the support member 500 to its other end. The opening of the aperture 530, adjacent the seat portion 510, is substantially circular. The opening of the aperture 530, adjacent the ledge 522, includes a circular hole with a plurality of slots extending therefrom. This is shown further in Figure 5. The aperture 530 assists with the member 500 acting as a mixing tube for the fluids flowing therethrough.

[0058] The member 500 separately includes an outer bearing portion 540. The outer bearing portion 540 includes a ledge 542 to assist in bearing a force from the first spring 600. The first spring 600 assists in returning the member 500 to an initial position in the event that the thermostatic element 300 travels further than required and provides a force that moves the member 500 away from the stop 232. The first spring 600 therefore acts as an overtravel spring in this embodiment and, due to its arrangement with the member 500 and seat portion 510, the first spring 600 can be sized relatively large. Moreover, the use of the member 500 allows the first spring 600 to be positioned away from the adjustment assembly 200, which is different to the prior art. This assists with reducing the size of the thermostatic device 10 and its assemble.

[0059] The outer portion of the member 500 also includes a sealing portion 550.lt would also be appreciated that the sealing portion 550 may be located on the body 100 in further embodiments. The sealing portion 550 is located adjacent to the ledge 542 in this embodiment. The sealing portion 550 includes a channel 552 that is configured to receive a sealing member 560 in the form of an O-ring. The sealing member 560 is configured to maintain a seal with the body 100 as the member 500 moves therealong.

[0060] Figures 6 and 7 illustrate a tap 1000 including the thermostatic device 10. As shown further in Figure 7, the inlets 1 10, 120 of the thermostatic device 10 align with openings in a tap body 1010 that communicate either with a hot or cold fluid source. In order to regulate the temperature of the fluid leaving the tap 1000, the temperature of the mixed water leaving the outlet 130 needs to be set. Furthermore, it will be appreciated by a person skilled in the art that activation of fluid flow through the tap 1000 in this embodiment may be carried out with, for example, a movement sensor connected to a separate valve.

[0061 ] In order to set the temperature of the mixed water leaving the outlet 130 (and as such the outlet of the tap 1000), the altering member 210 is moved. That is, moving the altering member 210 with the handle 214 adjusts the position of the stop 232 along the axis 12. In response to moving the stop 232 towards the thermostatic element 300, the predetermined outlet temperature of the thermostatic device 10 is lowered. In contrast, if the stop 232 is moved away from the thermostatic element 300, the predetermined outlet temperature of the thermostatic device 10 is increased. [0062] With the above in mind, to set the thermostatic element 300 in place, the second spring 700 is located in the member 500 and the thermostatic element 300 is rested on the second spring 700. The piston 400 may also be attached to the thermostatic element 300 at this stage. Following this, the combination of the thermostatic element 300, piston 400 and the member 500 are positioned in the body 100 such that part of the member 500 bears against the body 100. As a next step, the first spring 600 is positioned over the member 500 to engage with the ledge 542. The retainer 150 is then connected to another part of the body 100 to retain the first spring 600.

[0063] Accordingly, with the stop 232 set at a predetermined position, and the thermostatic element 300 in place, the thermostatic element 300 will react to the mixed fluid flowing thereover to control the temperature of fluid leaving the tap 1000. In response to the thermostatic element 300 reaching a temperature above the predetermined temperature, the shaft 310 will move to apply further pressure on the stop 232. As a result, the thermostatic element 300 will move the piston 400 towards the seat portion 510, potentially to engage therewith, limiting the flow of hot fluid through the thermostatic device 10. In the event that the piston 400 engages with the seat portion 510, the pressure thereon is suitably resisted via the second spring 700.

[0064] In contrast, as a result of the thermostatic element 300 reaching a temperature below the predetermined temperature, the shaft 310 will shift to remove its pressure from the stop 232. Accordingly, the second spring 700 will urge the piston 400 towards the seat portion 140, via its engagement with the thermostatic element 300, to limit the flow of cold fluid past the end of the piston and therethrough. In this regard, the temperature of the mixed outlet fluid will rise.

[0065] On this basis, it is noted that as fluid flows over the thermostatic element 300, the second spring 700 assists in mixing the fluid, via promoting turbulence, to further ensure that the thermostatic element 300 is exposed to a substantially uniform

temperature from the mixed flow. This assists in avoiding the thermostatic element 300 being exposed to hot or cold spots that may not be representative of the mixed fluid temperature.

[0066] In addition, as outlined above, the second spring 700 assembled with the thermostatic element 300, the piston 400 and the member 500 makes it easier to assemble the thermostatic device 10 due to reduced complexity. Furthermore, the member 500, in combination with spring 600 and/or spring 700, reduces the size and cost of the thermostatic device 10, whilst also improving the ease of manufacturing and assembly. These non-obvious features are of both commercial and technical importance. [0067] In this specification, adjectives such as left and right, top and bottom, hot and cold, first and second, and the like may be used to distinguish one element or action from another element or action without necessarily requiring or implying any actual such relationship or order. Where context permits, reference to a component, an integer or step (or the alike) is not to be construed as being limited to only one of that component, integer, or step, but rather could be one or more of that component, integer or step.

[0068] The above description relating to embodiments of the present invention is provided for purposes of description to one of ordinary skill in the related art. It is not intended to be exhaustive or to limit the invention to a single disclosed embodiment. As mentioned above, numerous alternatives and variations to the present invention will be apparent to those skilled in the art from the above teaching. Accordingly, while some alternative embodiments have been discussed specifically, other embodiments will be apparent or relatively easily developed by those of ordinary skill in the art. The invention is intended to embrace all modifications, alternatives, and variations of the present invention that have been discussed herein, and other embodiments that fall within the spirit and scope of the above described invention.

[0069] In this specification, the terms‘comprises’,‘comprising’,‘includes’,‘including’, or similar terms are intended to mean a non-exclusive inclusion, such that a method, system or apparatus that comprises a list of elements does not include those elements solely, but may well include other elements not listed.

Item List:

Claims

Claims:

1 . A thermostatic device including:

a body having two inlets and an outlet;

a piston in fluid communication with the two inlets and the outlet;

a thermostatic element configured to assist in moving the piston such that movement of the piston assists in regulating fluid from the two inlets to the outlet; and a first spring configured to assist in biasing a member configured to move, wherein:

the member assists in supporting a second spring that biases the thermostatic element; and

2. The thermostatic device of claim 1 , wherein the member includes a seat portion that is configured to engage with the piston in order to limit fluid flow through at least one of the inlets.

3. The thermostatic device of claim 1 or 2, wherein the member includes an inner bearing portion that is configured to support the second spring whilst an outer bearing portion is configured to engage with the first spring.

4. The thermostatic device of any one of claims 1 to 3, wherein the second spring overlaps at least part of the first spring in a projection that is substantially perpendicular to the axial axis of the thermostatic device.

5. The thermostatic device of any one of claims 1 to 4, wherein a sealing portion is configured to assist in providing a seal between the member and the body.

6. The thermostatic device of any one of claims 1 to 5 wherein the second spring has an inner diameter that is similar to at least a portion of the thermostatic element to allow the second spring to be suitably moved over the portion of thermostatic element.

7. The thermostatic device of any one of claims 1 to 6, wherein an adjustment assembly having a stop assists in setting a predetermined outlet temperature by interacting with the thermostatic element.

8. The thermostatic device of claim 7, wherein the second spring biases the thermostatic element towards the stop.

9. The thermostatic device of any one of claims 1 to 8, wherein in response to compressing the second spring to a predetermined limit, the first spring will begin to compress.

10. The thermostatic device of any one of the claims 1 to 9 wherein the body includes a retainer that assists in retaining the first spring.

1 1. A thermostatic device including:

a body having two inlets and an outlet;

a piston in fluid communication with the two inlets and the outlet;

wherein:

12. The thermostatic device of claim 1 1 , wherein the sealing portion includes a sealing member formed from a plastic and/or a rubber.

13. A tap including:

a tap body; and

a thermostatic device of any one of claims 1 to 12.

14. A method associated with a thermostatic device, the method including the steps of: biasing a member with a first spring towards a stop, the member being separate from a piston in order to allow the piston to move relative thereto;

biasing a thermostatic element towards the stop with a second spring, the thermostatic element being supported by the member; and

15. The method of claim 14, wherein the step of biasing the member with the first spring towards the stop includes allowing the first spring to bias the member from an outer bearing portion of the member.

16. The method of claim 14 or 15, wherein the step of biasing the thermostatic element towards the stop with the second spring includes allowing the second spring to bias the thermostatic element from an inner bearing portion of the member.

17. The method of any one of claims 14 to 16, wherein the step of moving the piston in order to regulate fluid flow from the one or more inlets to the outlet includes engaging the piston with a seat portion of the member.

18. The method of any one of claims 14 to 17, wherein the method further includes rotating an altering member to move the stop and set a predetermined fluid outlet temperature for the thermostatic device.

19. The method of any one of claims 14 to 18, wherein the step of rotating the altering member includes moving an engagement member that in turn adjusts an adjusting member including the stop.

20. A method associated with a thermostatic device, the method including the steps of: placing a first spring in a body;