GB2543570A

GB2543570A - Thermostatic mixing valve

Info

Publication number: GB2543570A
Application number: GB1518797.4A
Authority: GB
Inventors: Medina Carlo
Original assignee: Bome SRL
Current assignee: Bome SRL
Priority date: 2015-10-23
Filing date: 2015-10-23
Publication date: 2017-04-26
Anticipated expiration: 2035-10-23
Also published as: GB2543570B; GB201518797D0

Abstract

A thermostatic mixing valve comprises a body 2 having first and second connections 3, 4 for the entry of first and second fluid flows F1, F2, and a third connection 5 for the exit of a third flow F3 of mixed fluid. A plug element 6 slides inside a cavity 7 within the body 2 for defining first and second passage ports P1, P2 for the first and second flows F1, F2. Thermostatic actuating means 8 and counteracting spring 9 drive the plug element 6 to vary the passage ports P1, P2 to maintain the temperature of the third flow F3 at a desired value. A tamper proof cap 10 has an abutment portion 11 for presetting the actuating means 8 and plug element 6 to an operative position corresponding to the preset fixed temperature.

Description

THERMOSTATIC MIXING VALVE Background Of The Invention [0001] The present invention relates to a thermostatic mixing valve for a heating circuit of buildings of civil/residential or industrial type in general, more precisely a tamper-proof thermostatic mixing valve which is particularly intended to be used in public buildings such as hospitals, schools, public swimming pools, or wherever it is important to ensure a precise prefixed temperature of the mixed water and to prevent any attempt of temperature setting or change by any users or unauthorized people.

Prior Art [0002] Thermostatic mixing valves are known that are mounted along a heating circuit of a building to receive, through a first and second inlet respectively a flow of cold water and a flow of hot water that are mixed together within the body of the thermostatic mixing-valve in order to generate a third flow of mixed water exiting through an outlet of such a body. These valves include a thermo-sensitive element, coupled to a plug element, which can manually adjusted to a desired mixing temperature by rotating an adjustment-knob mounted on the valve-body.

[0003] In some areas of application, and/or in particular countries, such as in the United Kingdom where particular healthcare regulations are in force, it is required to provide these thermostatic mixing valve with tamperproof or safety devices which prevent any users or unauthorized people from intervening on the adjusting knob for changing the temperature setting of the valve. There are known thermostatic mixing valves provided with safety or tamper proof devices which are fastened through screw elements or equivalent fastening-means on the valve body in such a way as to enclose or to block the adjusting-knob thus avoiding a temperature adjusting.

[0004] Unfortunately, these safety or tamper proof devices often increase both the overall dimensions and the cost of said valves. Furthermore, disadvantageously, these safety or tamper proof devices can be circumvented by someone which is resolute and equipped with suitable tools; the unauthorized person can in this way dismantle the safety-device, change the mixing-temperature to a value different from the correct required value, and assemble again the tamper proof device on the valve with no problems at all.

[0005] Although the above mentioned safety or tamper proof devices associated to the valves perform in a sufficiently well, there is still room for further improvements and for further increasing the safety and tamper-proof features of said thermostatic mixing valves. It would also be desired to provide a technical solution with reduced overall dimensions, which is structurally simpler and cheaper with respect to the current prior art solutions, and which speeds up and simplifies the overall installation and adjustment procedures of the hydraulic circuits.

Short Description Of The Invention [0006] The above objects are achievable by means of a thermostatic mixing valve according to claim 1.

[0007] According to the invention, there is provided a thermostatic mixing valve for a hydraulic circuit, comprising: a valve body provided with a first connection for the entry of a first flow of fluid in a first direction, and with a second connection for the entry of a second flow of fluid in a second direction; a third connection for the exit of a third flow of mixed fluid in a third direction; a plug element, that is slidable inside a housing cavity within said valve body for defining a first passage port for said first flow of fluid and a second passage port for said second flow of fluid; thermostatic actuating means and counteracting elastic means arranged for driving said plug element and varying in a controlled manner said first passage port and said second passage port so as to maintain constant, at a desired value, the temperature of said third flow of fluid, characterised in that it further comprises a tamper-proof-cap-device provided with a pre-setting-abutment-portion for said thermostatic actuating means, said pre-setting-abutment-portion being configured for setting said thermostatic actuating means and said plug element to an operative position corresponding to only one pre-set fixed temperature, said tamper-proof-cap-device comprising a tamper-proof-coupling-portion though which said tamper-proof-cap-device is fastened to said valve-body for preventing external setting actions on said thermostatic actuating means and plug element.

Short Description Of The Drawings [0008] Features and advantages of the thermostatic mixing valve will be clear from the claims and description that follow and from the attached drawings, which illustrate an embodiment thereof by way of non-limiting example, in which:

Figure 1 shows a tamper-proof-thermostatic mixing valve according to the invention;

Figure 2 is an exploded view of a the tamper-proof-thermostatic mixing in Figure 1;

Figure 3 is a partially sectioned view of the valve according to the invention;

Figure 4 is a perspective view of a plug-element included in the valve of the invention;

Figure 5 and 7 are side views of the plug-element;

Figures 6 and 8 are longitudinal section-views taken respectively along the planeVI-VI in Figure 5 and along the plane VIII-VIII in Figure 7;

Figure 9 is a side view of the valve;

Figure 10 is a section-view taken along the plane X-X in Figure 9;

Figure 11 is another section-view of the thermostatic-mixing valve but with the plug element in a different operative position with respect to Figure 10.

Detailed Description Of The Invention [0009] With reference to the attached Figures, a thermostatic mixing valve 1 is shown which is suitable for a heating circuit of buildings of civil/residential or industrial type. In particular, the thermostatic mixing valve 1 is of the tamper-proof type and is particularly suitable for being installed in any place where it is of crucial importance to ensure a prefixed temperature of the mixed water and to avoid any attempts of changing such a temperature by the users.

[0010] The thermostatic mixing valve 1 comprises a valve-body 2, provided with a first connection 3 for the entry of a first flow F1 of fluid, in particular hot fluid, in a first direction X1, and with a second connection 4 for the entry of a second flow F2 of fluid, in particular cold fluid, in a second direction X2. The thermostatic mixing valve 1 comprises a third connection 5 for the exit, in a third direction X3, of a third flow F3 of mixed fluid at the preset desired temperature. The first 3, second 4, third 5 connections are provided with nut-means 25 which ensure sealing-screwing connections to the respective pipes. In particular, the first X1 and second X2 directions are mutually aligned, and the third X3 direction is orthogonally arranged with respect to the first X1 and second X2 directions.

[0011] The valve-body 2 internally defines a housing cavity 7 inside which the two flows of water come and meet to mix and generate the mixed flow that abandons the valve 1 at the desired temperature.

[0012] The thermostatic mixing valve 1 includes a plug-element 6 which is slidable arranged within the housing cavity 7 and which acts for defining and controlling a first passage port P1 for the first flow F1 of hot fluid and for defining and controlling a second passage port P2 for the second flow F2 of cold fluid. In the valve-body 2 there is housed a thermostatic actuating element 8 which acts on the plug-element 6 and, according to any changes of temperature within the housing-cavity 7, undergoes a thermal dilatation or contraction thus displacing the plug-element 6 so as to adjust the first passage port P1 and second passage port P2 in order to ensure the correct pre-set temperature of the mixed fluid. Figures 10 and 11 show the valve 1 with the plug element 6 in two different transitory positions. With reference to Figure 10, the hot fluid runs along the path W1 through the passage port P1. Subsequently, a thermal dilatation of the thermostatic actuating element 8 reduces the section of the passage port P1 and increases the section of the passage port P2 for enabling the entry of cold fluid. Analogously, with reference to figure 11, the cold fluid runs along the path W2 through the passage port P2. Subsequently, a thermal contraction of the thermostatic actuating element 8 reduces the section of the passage port P2 and increases the section of the passage port P1 for enabling the entry of hot fluid.

[0013] The thermostatic mixing valve 1 therefore operates for maintaining constant, at the set desired value, the temperature of the mixed water as the water-supply-conditions may vary, i.e. as the temperature and pressure of the entering flows of hot and cold water vary.

[0014] The plug-element 6 is maintained abutted against the thermostatic actuating-element 8 by a counteracting spring element 9. The plug element 6 has a tubular shape and is configured for enclosing the thermostatic actuating element 8. In particular, the plug element 6 has a cylindrical wall 20 facing the cavities of the first 3 and second 4 connections and extending from a first end to an intermediate region of the plug element 6 itself. The plug element 6 comprises longitudinal band-walls 21 which are mutually spaced apart and extend from the above-mentioned intermediate region to a second end of the plug-element 6. The thermostatic actuating element 8 comprises an oblong body 22 having an enlarged flange portion 23 configured for abutting on a coupling-zone 24 of the plug-element 6 and intended to push the plug-element 6 upon a thermal dilatation of the thermostatic actuating element 8 against the action of the counteracting spring 9.

[0015] The thermostatic mixing valve 1 comprises a tamper-proof-cap-device 10 which preserves the thermostatic actuating element 8 and the plug element 6 from external actions, thus making the thermostatic mixing valve 1 an inviolable and tamper proof thermostatic mixing valve 1. The tamper-proof-cap-device 10 is provided with a pre-setting-abutment-portion 11 for the thermostatic actuating element 8. The pre-setting-abutment-portion 11 is configured for setting the thermostatic actuating element 8 and the plug element 6 to an operative position corresponding to only one pre-set fixed temperature. This means that, even if the tamper-proof-cap-device 10 is unscrewed, there is no possibility to change the pre-set mixing temperature of the fluid. The tamper-proof-cap-device 10 comprises an abutment-surface 15 for abutting on a resting-surface 16 of the valve-body 2. The pre-setting-abutment-portion 11 comprises a positioning-surface 17 for receiving an end 18 of the thermostatic actuating element 8; such a positioning-surface 17 is spaced from the abutment-surface 15 by such a distance D1 as to define an operative position for the thermostatic actuating element 8 to which a prefixed set temperature corresponds for the third flow F3 of mixed fluid. Therefore, the height or thickness of the cap 10, more precisely the above mentioned distance D1 is suitably chosen and set during the manufacturing and assembling procedures in factory. In other words, the value of the mixing-temperature to be set depends on the degree of penetration of the pre-setting-abutment-portion 11 inside the housing-cavity 7 and thus it is settled in factory. Therefore, there will be different degrees of penetration of the cap 10 into the cavity of the valve-body according to the temperature-value which is desired to be set for the valve 1.

[0016] Once the cap 10 is obtained and assembled on the valve-body, there is no possibility to change, during the operative life of the valve 1, the temperature which is decided and permanently fixed in factory.

[0017] The tamper-proof-cap-device 10 comprising a tamper-proof-coupling-portion 12 though which it can be fastened to the valve-body 2 for preventing external setting actions on the thermostatic actuating element 8 and on the plug element 6.

[0018] The tamper-proof-coupling-portion 11 of the tamper-proof-cap-device 10 comprises a threading 13 for engaging with a further threading 14 provided on the valve-body 2. There is provided a sealing element 27 interposed between the tamper-proof-cap-device 10 and the valve-body 2.

[0019] The tamper-proof-cap-device 10 comprises fin-elements 19 projecting parallel to a longitudinal axis X, angularly distributed, and arranged for securing the end 18 of the thermostatic actuating element 8 in a correct position.

[0020] The tamper-proof-cap-device 10, in the mounted configuration, has an external portion 26 which slightly protrudes to the outside of the valve-body 2 only by a small amount. This configuration makes even more difficult any attempt to remove the tamper-proof-cap-device 10 and keeps the overall dimensions of the valve 1 highly reduced. The tamper-proof-cap-device 10 is obtained as a single-piece element. It can be made of a thermoplastic material such as Polysulfones (PSU) with reinforcing glass fibres, or of any other suitable material.

[0021] Advantageously, in this way, the thermostatic-mixing-valve 1, once assembled, is already in conditions to operate at the correct required temperature value even before being installed on the hydraulic circuit, without requiring any further expensive and time-consuming adjusting and setting procedures. In other words, there is no longer need to rely on an installer to set and adjust the thermostatic mixing valve to the required temperature.

[0022] Advantageously, the simplified geometrical configuration of the valve 1, with the structurally simple tamper-proof cap device 10, implies reduced costs as well.

[0023] From what has been disclosed and shown in the attached drawings, it is thus clear that the invention relates to a thermostatic mixing valve 1 having several advantageous improvements over the prior art systems and which fully achieves the previously mentioned objects and advantages of avoiding any undesired or unauthorised intervention or setting action on the thermostatic actuating means (8) and plug element (6) for changing the correct mixing temperature.

[0024] As can be seen from the description and the drawings, the valve 1 of the invention is simpler to make and easier and faster to assemble, and has very reduced overall dimensions.

[0025] The materials, as far as they are compatible with the specific use and with the respective single components for which they are intended, can be appropriately chosen according to the available prior art provided that they are suitable for the specific use for which they are intended.

[0026] Various elements can be replaced by further technically equivalent elements without thereby falling outside the scope of the invention.

[0027] What has been said and shown in the attached drawings has been provided by way of an illustrative example of the innovative features of the valve 1 and in particular of the tamper-proof cap device 10; thus further modifications can be made to the assembly or to parts thereof without thereby falling outside the scope of the invention.

Claims

1. A thermostatic mixing valve for a hydraulic circuit, comprising a valve body (2) provided with a first connection (3) for the entry of a first flow (F1) of fluid in a first direction (X1), and with a second connection (4) for the entry of a second flow (F2) of fluid in a second direction (X2); a third connection (5) for the exit of a third flow (F3) of mixed fluid in a third direction (X3); a plug element (6), that is slidable inside a housing cavity (7) within said valve body (2) for defining a first passage port (P1) for said first flow (F1) of fluid and a second passage port (P2) for said second flow (F2) of fluid; thermostatic actuating means (8) and counteracting elastic means (9) arranged for driving said plug element (6) and varying in a controlled manner said first passage port (P1) and said second passage port (P2) so as to maintain constant, at a desired value, the temperature of said third flow (F3) of fluid, characterised in that it further comprises a tamper-proof-cap-device (10) provided with a pre-setting-abutment-portion (11) for said thermostatic actuating means (8), said pre-setting-abutment-portion (11) being configured for setting said thermostatic actuating means (8) and said plug element (6) to an operative position corresponding to only one pre-set fixed temperature, said tamper-proof-cap-device (10) comprising a tamper-proof-coupling-portion (12) though which said tamper-proof-cap-device (10) is fastened to said valve-body (2) for preventing external setting actions on said thermostatic actuating means (8) and plug element (6).

2. Thermostatic mixing valve according to claim 1, wherein said tamperproof-coupling-portion (11) of said tamper-proof-cap-device (10) comprises a threading (13) for engaging with a further threading (14) provided on said valve-body (2), sealing means (27) being interposed between said tamper-proof-cap-device (10) and said valve-body (2).

3. Thermostatic mixing valve according to claim 1 or 2, wherein said tamper-proof-cap-device (10) comprises an abutment-surface (15) for abutting on a resting-surface (16) of said valve-body (2), and said presetting-abutment-portion (11) comprises a positioning-surface (17) for receiving an end (18) of said thermostatic actuating means (8), said positioning-surface (17) being spaced from said abutment-surface (15) by such a distance (D1) as to define an operative position for said thermostatic actuating means (8) corresponding to a pre-fixed set temperature for said third flow (F3) of mixed fluid.

4. Thermostatic mixing valve according to claim 3, wherein said tamper-proof-cap-device (10) comprises fin-elements (19) projecting parallel to a longitudinal axis (X) and arranged for securing said end (18) in a correct position.

5. Thermostatic mixing valve according to claim 4, wherein said fin-elements (19) are angularly distributed around said end (18).

6. Thermostatic mixing valve according to any one of the preceding claims, wherein said tamper-proof-cap-device (10), in the mounted configuration, has an external portion (26) which slightly protrudes to the outside of said valve-body (2) only by a small amount.

7. Thermostatic mixing valve according to any one of the preceding claims, wherein said first (3) and second (4) connections are arranged with said first (X1) and second (X2) directions being mutually aligned, and said third connection (5) is placed with said third direction (X3) being orthogonally arranged to said first (X1) and second (X2) directions.

8. Thermostatic mixing valve according to any one of the preceding claims, wherein said plug element (6) has a tubular shape and is configured for enclosing said thermostatic actuating means (8), said plug element (6) having a cylindrical wall (20) facing the cavities of said first (3) and second (4) connections and extending from a first end to an intermediate region of said plug element (6), said plug element (6) having longitudinal band-walls (21) which extend from said intermediate region to a second end of said plug-element (6).

9. Thermostatic mixing valve according to any one of the preceding claims, wherein said thermostatic actuating means (8) comprises an oblong body (22) having an enlarged flange portion (23) configured for abutting on a coupling-zone (24) of said plug-element (6) and for pushing said plug-element (6) upon a thermal dilatation of said thermostatic actuating means (8) against the action of said counteracting elastic means (9).

10. Thermostatic mixing valve according to any one of the preceding claims, wherein said first (3) second (4) and third (5) connections comprise nut means (25) for the sealingly connection to respective pipes.