AU2005297588B2

AU2005297588B2 - Sanitary thermostatic mixing valve

Info

Publication number: AU2005297588B2
Application number: AU2005297588A
Authority: AU
Inventors: Lars Schmid
Original assignee: Hansa Metallwerke AG
Current assignee: Hansa Metallwerke AG
Priority date: 2004-10-20
Filing date: 2005-10-08
Publication date: 2010-05-27
Anticipated expiration: 2025-10-08
Also published as: WO2006042656A1; EP3407155A1; DK1803044T3; AU2005297588A1; DE102004050996B4; EP1803044A1; EP1803044B1; ES2689285T3; DE102004050996A1

Description

WO 2006/042656 1 18.04.2007 Sanitary thermostatic mixing valve The invention relates to a sanitary thermostatic mixing valve with a) a housing, which has a cold water inlet, a hot water inlet and a mixed water outlet; 5 b) a temperature-sensitive thermostatic element disposed in the housing, against which element the mixed water flows and which element normally rests unilaterally on a stop; c) a control element controlled by the thermostatic 10 element; and d) an adjusting member for the setpoint temperature of the mixed water, with which member the position of the control element can be varied in the housing. A thermostatic mixing valve of the type specified at the 15 beginning is known for example from EP 0 973 083 Bl. It is used in the sanitary field as a thermostatic premixer with which the maximum flow temperature for a sanitary fitting can be preset. For reasons of hygiene, in particular to avoid 20 colonization by legionella, sanitary fittings must be thermally disinfected from time to time. To do this, the flow temperature at the premixer known from EP a 973 083 B1 must be increased by an expert to approx. 609 to 700 C and reset again once the flushing process 5 is complete. This is laborious and harbours the risk that resetting of the flow temperature will be forgotten, so that users may scald themselves with excessively hot water. 10 According to the present invention, there is provided a sanitary thermostatic mixing valve with a) a housing, which has a cold water inlet, a hot water inlet and a mixed water outlet; b) a temperature-sensitive thermostatic element disposed in the housing, against 15 which element the mixed water flows and which element normally rests unilaterally on a stop; c) a control element controlled by the thermostatic element; and d) an adjusting member for the setpoint temperature of the mixed water, with which member the position of the control 20 element can be varied in the housing, wherein e) a flushing member which is independent from the adjusting member and with which the stop for the thermostatic element can be raised at least to the extent that this completely opens the hot water inlet without affecting the 25 setpoint temperature as determined by the adjusting member. Preferred embodiments of the present invention may provide a thermostatic mixing valve in which thermal disinfection 30 can be undertaken easily without the setpoint temperature setting of the thermostatic mixing valve having to be changed.

-2A Also described herein is a thermostatic mixing valve including a flushing member, with which the stop for the thermostatic element can be raised at least to the extent that this completely opens the hot water inlet. 5 The flushing member advantageously may have an opening lever. This facilitates simple operation.

WO 2006/042656 3 18.04.2007 In an advantageous embodiment, the thermostatic element is held against the stop by a pretensioning spring. The stop is supported on the adjusting member via a safety 5 spring and the opening lever is formed so that when operated it bends the safety spring together and the thermostatic element is moved by the pretensioning spring into a position in which the mixing valve opens the hot water inlet. 10 This facilitates a simple and compact design of the thermostatic mixing valve. In an alternative embodiment, in which the thermostatic element is likewise held by a pretensioning spring against the stop and the stop is supported via a safety 15 spring on the adjusting member, the flushing member is formed so that when operated it unbends the safety spring and the control element is moved in this way by the pretensioning spring into a position in which it opens the hot water inlet. 20 A removable covering cap is preferably provided, which when fitted conceals the adjusting member and is dimensioned such that it can only be fitted in the unactuated position of the adjusting member.

WO 2006/042656 4 18.04.2007 Due to the covering cap the function of the adjusting member is concealed and is only accessible to the specialist personnel, so that users are not misled into moving the thermostatic mixing valve round. Due to the 5 design of the covering cap, forgetting to reset the adjusting member again once flushing is complete is also prevented. A set screw is advantageously provided for locking the adjusting member. This effectively prevents accidental 10 adjustment of the setting of the thermostatic mixing valve in the case of a flushing process. In a further preferred embodiment the flushing member comprises a removable key. Due to this, setting of the thermostatic mixing valve can only be undertaken by 15 specialist personnel in possession of such a key. The thermostatic mixing valve according to the invention can both be formed as a premixing valve and integrated into a thermostatic sanitary fitting. A practical example of the invention is explained in 20 greater detail below with reference to the drawing. The single figure shows a section through a thermostatic mixing valve formed as a premixing valve. The thermostatic mixing valve 10 has a housing 12 with a hot water inlet 16, a cold water inlet 14 and a mixed WO 2006/042656 5 18.04.2007 water outlet 18. Located in the cold water inlet 14 as well as in the hot water inlet 16 are non-return valves 15 and 17, which prevent water from the thermostatic mixing valve 10 from being able to flow 5 back into the supply lines. Arranged in the interior of the housing 12 is an element 20 of extensible material formed as a thermostatic element, which actuates a mixing valve. The extensible material element 20 of a design known 10 in itself, which element is represented here only schematically as a compact component, contains an extensible material, for example a wax, accommodated in a housing, which material expands on heating and pushes a pressure pin 20' out of the housing and 15 contracts on cooling and thus permits the pressure pin 20' to be pushed back in. The mixing valve actuated by the extensible material element 20 has a design that is known in itself. It comprises a first annular space 23, into which hot 20 water flows from the hot water inlet 16, a second annular space 22, into which cold water flows from the cold water inlet 14, and a control sleeve 21, which is arranged movably between the first and second annular space 23, 22. Depending on the position of the control sleeve 21 25 it closes more or less a gap to the annular space 23 and opens more or less a gap to the annular space 22 or vice versa. The control sleeve 21 has several cylindrical WO 2006/042656 6 18.04.2007 holes 21' parallel to the axis, through which holes, if the control sleeve 21 opens a gap to the annular space 22, cold water can flow past the extensible material element 20 through a sleeve 19, which serves 5 as a mixing chamber, to the mixed water outlet 18. If the control sleeve 21 opens a gap to the annular space 23, then hot water can flow through the sleeve 19 to the mixed water outlet 18. The control sleeve 21 sits on a collar of the extensible 10 material element 20 that is offset in a stepped manner. The left-hand end of the extensible material element 20, which end is filled with extensible material, protrudes into the sleeve 19 and there mixed water flows against it. Hotter mixed water thus ensures that the extensible 15 material expands and the pressure pin 20' is pushed further out of the extensible material element 20. In the case of colder mixed water, on the other hand, the extensible material contracts and a pretensioning spring 24 ensures that the extensible material element 20 20 is moved against the pressure pin 20' back into the right-hand position in the figure. The pressure pin 20' presses against a stop 29', which is formed by a plate-shaped end of a rod 29, which is held by a safety spring 26 against the extensible material 25 element 20. The safety spring 29 has a large spring constant and can be assumed to be rigid in normal operation of the thermostatic mixing valve 10. Its task WO 2006/042656 7 18.04.2007 consists in preventing destruction of the extensible material element 20 if, when at maximum expansion, this rests at the left-hand side on the hot water seat at annular space 23 and at the right-hand side on the stop 5 of the rod 29. In this case the safety spring 29 yields so much that the extensible material element 20 is not pressed until it breaks on the stop due to its own expansion. If the pressure pin 20' is pressed further out of the 10 extensible material element 20 by expansion of the extensible material, it pushes the extensible material element 20 with the control sleeve 21 opposite the end of the rod 29 to the left. The admission gap for hot water thereby becomes smaller at the annular space 21 and the 15 admission gap for cold water at annular space 22 becomes correspondingly larger. Thus more cold water and correspondingly less hot water flows into the mixing chamber of the sleeve 19 and the mixed water becomes colder. The extensible material thereby contracts again 20 somewhat and the pretensioning spring 24 pushes the extensible material element 20 and the control sleeve 21 a little to the right again, so that once again more hot water and correspondingly less cold water passes into the mixing chamber. This happens until equilibrium has set 25 in according to the setpoint temperature set. Rod 29 and safety spring 26 are arranged in the hollow axis of an adjusting handle 28, which is used to adjust WO 2006/042656 8 18.04.2007 the setpoint temperature of the mixed water. The adjusting handle 28 sits in a threaded insert 27 in the housing 12 of the thermostatic mixing valve 10 and can be screwed by hand further into the housing 12 or unscrewed s from this. This changes the position of the extensible material element 20 in the thermostatic mixing valve 10 and thus the setpoint temperature set. The extensible material element 20 is sealed relative to the threaded insert 27 by an O-ring 35. The adjusting handle 28 can 10 be locked at the desired setpoint temperature using a grub screw 32 with a hexagon socket, in order to prevent accidental adjustment. At the outer end of the rod 29, which protrudes from the adjusting handle 28 through a hole, an opening lever 30 15 is attached movably by a cylindrical pin 31. The cylindrical pin 31 leads through an elongated hole in the opening lever 30. The opening lever 30 lies close to the end face of the adjusting handle 28 and can be swivelled via a rounded end 30' against the adjusting handle 28. 20 Since the rounded end 30' of the opening lever 30 is longer than half the width of the opening lever 30, on swivelling of the opening lever 30 the rod 29 is pulled against the spring force of the safety spring 26 out of the adjusting handle 28 and thus the counterstop of the 25 extensible material element 20 is raised from this. Since the counterforce for the pretensioning spring 24 is now absent, this presses the extensible material element 20 with the control sleeve 21 into the right-hand WO 2006/042656 9 18.04.2007 position in the drawing, in which position the admission gap to the annular space 22 is completely closed and the admission gap to the annular space 23 is completely open. Thus hot water with the flow temperature can now flow 5 unobstructed through the mixing chamber to the mixed water outlet 18. Since the flow temperature is normally higher than the setpoint temperature set (600 - 700 C) legionella and other microorganisms can now be killed. During normal operation a covering cap 34 conceals the 10 adjusting handle 28 and the opening lever 30. To carry out hot water flushing, the covering cap 34 is removed, which cap hangs on a chain or a cast-on synthetic thread so it cannot be lost, and exposes the opening lever 30. The opening lever 30 can now be actuated. In the 15 actuated state the covering cap 34 cannot be put back on again. This prevents forgetting to reset the opening lever 30 again once hot water flushing is complete. If the opening lever 30 is reset, the extensible material element 20 thus limits the temperature of the mixed water 20 to the preset value again. The protective cap 34 can now be replaced. The grub screw 32 prevents the temperature setting from being accidentally adjusted in the flushing process. In a further embodiment, the opening lever is executed as 25 a removable key. It is thereby achieved that only specialist personnel in possession of such a key can change the setting of the thermostatic mixing valve 10.

WO 2006/042656 10 18.04.2007 In the practical example, the thermostatic mixing valve 10 is formed as a premixing valve, which is installed upstream of a normal sanitary fitting (not shown). The premixing valve 10 is connected below a wash pedestal to s the cold water and hot water pipe. The cold water pipe is additionally connected via a T-piece directly to the cold water connection of the sanitary fitting above the wash pedestal. The hot water connection of the sanitary fitting, on the other hand, is connected to the mixed 10 water outlet 18 of the premixing valve 10. At the sanitary fitting, water from cold up to the maximum temperature set at the premixing valve can thus be drawn off. Such premixing valves are used preferably in the case of persons requiring protection, such as e.g. 15 children, senior citizens and disabled people, in order to prevent these persons from being able to scald themselves with water that is set too hot. The thermostatic mixing valve according to the invention can also be integrated into other thermostatic sanitary 20 fittings, however. Other alternatives to the embodiment described in the practical example, in which embodiment an opening lever 30 bends the safety spring together, are also possible for moving the extensible material element 20 into a 2S flushing position. Thus for example instead of the opening lever 30, an engageable cover with a handle can be provided on the adjusting handle 28, which cover can -11 be unlatched and twisted out with a half rotary movement and thus unbends the safety spring to the extent that the pretensioning spring 24 pushes the extensible material element 20 into the flushing position. Once hot water 5 flushing is complete, the cover is pressed down and engaged at the handle once more against the safety spring by a half turn. While various embodiments of the present invention have 10 been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. it will be apparent to a person skilled in the relevant art that various changes in form and detail can be made therein without departing from the 15 spirit and scope of the invention. Thus, the present invention should not be limited by any of the above described exemplary embodiments. Throughout this specification and the claims which 20 follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or 25 group of integers or steps. The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as 30 an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

Claims

1. Sanitary thermostatic mixing valve with a) a housing, which has a cold water inlet, a hot water 5 inlet and a mixed water outlet; b) a temperature-sensitive thermostatic element disposed in the housing, against which element the mixed water flows and which element normally rests unilaterally on a stop; 10 c) a control element controlled by the thermostatic element; and d) an adjusting member for the setpoint temperature of the mixed water, with which member the position of the control element can be varied in the housing, 15 wherein e) a flushing member which is independent from the adjusting member and with which the stop for the thermostatic element can be raised at least to the extent that this completely opens the hot water inlet without 20 affecting the setpoint temperature as determined by the adjusting member.

2. Thermostatic mixing valve according to claim 1, wherein the flushing member comprises an opening lever. 25

3. Thermostatic mixing valve according to claim 2, wherein thethermostatic element is held by a pretensioning spring against the stop and the stop is supported via a safety spring on the adjusting member and wherein the 30 opening lever is formed such that when operated it bends the safety spring together and the control element is moved by the pretensioning spring into a position in - 13 which it opens the hot water inlet.

4. Thermostatic mixing valve according to claim 1, wherein the thermostatic element is held by a 5 pretensioning spring against the stop and the stop is supported via a safety spring on the adjusting member and wherein the flushing member is formed such that when operated it unbends the safety spring and the control element is moved by the pretensioning spring into a 10 position in which it opens the hot water inlet.

5. Thermostatic mixing valve according to one of the preceding claims, further including a removable covering cap, which when fitted conceals the flushing member and 15 which is formed so that it can only be fitted in the unactuated state of the flushing member.

6. Thermostatic mixing valve according to one of the preceding claims, further including a set screw for 20 locking the adjusting member.

7. Thermostatic mixing valve according to one of the preceding claims, wherein the flushing member comprises a removable key. 25

8. Thermostatic mixing valve according to one of the preceding claims, which is formed as a premixing valve.

9. A sanitary thermostatic mixing valve substantially 30 as hereinbefore described with reference to the drawing and/or Examples.