WO1991005968A1

WO1991005968A1 - A mixer valve

Info

Publication number: WO1991005968A1
Application number: PCT/SE1990/000676
Authority: WO
Inventors: Bo Axelsson; Stefan Ericsson
Original assignee: Fm Mattsson Ab
Priority date: 1989-10-23
Filing date: 1990-10-19
Publication date: 1991-05-02
Also published as: SE8903504L; AU6623990A; SE8903504D0; SE464889B

Abstract

A mixer valve (1) includes a housing (2) which is provided with a cold water inlet (5) and a hot water inlet (7) and a mixed water outlet (12). The flow delivered by the valve is regulated by means of a knob (15) which acts on a valve body (16). The opposite end of the housing is provided with a screw threaded opening (14) into which one of a number of different types of inserts can be screwed, these inserts functioning to regulate the mixing conditions of the valve. Thus, there can be used alternatively a thermostat control insert (30), a pressure and thermostat control insert (30') and a pressure control insert (30'). The prevailing characteristics of the distribution system determine which type of insert is selected in each individual case. All of the inserts have the same external configuration and dimensions, so that they can be fitted to the mixer housing without needing to be modified or adapted to the housing.

Description

A Mixer Valve

Field of Invention

The present invention relates to a mixer valve of the kind defined in the preamble of Claim 1.

Mixer valves of this kind must be of simple, compact construction and easily serviced, mainly because the space available in the valve housing is very confined.

In order to provide space for the various desired control and regulating functions of such valves, the construction of the valve as a whole is, of necessity, very complicated and the valve members must be manufac¬ tured with great precision, therewith making the costs of these known mixer valves highly expensive.

In addition, space must also be made available for a pressure equalizing device, in addition to the tempera¬ ture and flow regulating devices that are incorporated. Furthermore, it is often necessary to fit non-return valves, in order to prevent overflow from the hot water side to the cold water side of the system, and vice versa.

Prior Art

Those solutions proposed hitherto in this field have followed two main lines.

In the first instance, those members necessary to provide the intended functions or facilities have all been incorported in the actual mixer valveitself. This renders the valve expensive and unnecessarily complex, particularly in those cases when the functioning pro¬ perties of the distribution system concerned are so satisfactory as to render unnecessary all of the facil¬ ities provided.

In the second instance, some of the facilities or functions have been omitted. Consequently, this, valve will not operate satisfactorily when the functional properties of the distribution system vary, either constantly or at different unforseeable times, such that, for instance, large variations in pressure will sometimes occur in the hot water and/or cold water delivered, and in other instances such that the temper¬ ature of the hot water delivered to the tap outlet varies markedly.

An example of this latter type of valve is described in SE,B,7403239-2 (Publication No. 383 404) (Vargarda) , which teaches a mixer valve provided with a temperature control knob. The valve is also pressure controlled, i.e. constructed to accommodate variations in pressure of the hot water and cold water delivered. The mixer valve has no thermostat part and water-volume adjust¬ ments are made with the aid of a lever located adjacent the temperature control knob. Thus, thermostat-control temperature regulation cannot be achieved with this mixer valve.

SE,B,7409845-0 (Publication No. 406 963) (Pont-a- Mousson) describes a mixer tap insert mounted in a mixer housing. This insert is provided with a tempera¬ ture regulating unit and is also constructed to func¬ tion as a flow control valve and includes a temperature control knob adjacent a flow control knob. This mixer valve insert, which is rotationally sym¬ metrical about its longitudinal axis and can te screwed into one end of a mixer housing, lacks pressure equalizing means and will function unsatisfactorily when pressure surges occur in the distribution system.

Other known mixer valves incorporate pressure control pistons and thermostat control chains. These elements are arranged parallel with one another or behind one another, which makes the mixer valve unnecessarily broad or unnecessarily long. Furthermore, since the thermostat part is located in a position close to or in the region of the temperature control body, the ther¬ mostat part will sense another temperature than the final mixed temperature, which impairs the properties of the mixer valve, i.e. the valve is not as effective as would be desired.

Further examples of the prior state of the art are found in DE;A1,3 440 198 (Oventrop Am. Sohn), EP,A1,0 307 738 (Ideal-Standard) and SE,B,432 649 (Oras).

Objects of the Invention

A prime object of the present invention is to provide a mixer valve which will avoid the aforesaid drawbacks and other drawbacks associated with known mixer valves, and also to provide a valve which can be readily adap¬ ted to the properties of the distribution system used.

Another object is to provide a mixer valve which will enable the most purposeful solution to be chosen on each separate occasion, without needing to drastically increase the cost of the mixer valve. Another object is to provide a mixer valve with which the mixer housing is so constructed as to enable vari¬ ous types of mechanisms to be controlled in dependence on those requirements placed on the mixer valve on different, individual occasions, without needing to change the internal configuration of the housing or its internal dimensions.

Still another object of the present invention is to provide a simple insert of small axial dinension which will afford the possibility of both pressure equaliza¬ tion and thermostat control in one and the same valve unit.

These and other objects are fulfilled by a mixer valve constructed in accordance with the present invention, the main characteristic features of which are set forth in the characterizing clause of Claim 1.

The invention provides a choice of mixer inserts depen¬ ding on the properties of the distribution system concerned. For instance, if the conduit system is underdimensioned and both pressure and tenperature vary markedly, an insert is chosen which will enable both of these variables to be controlled.

Thus, it lies within the purview of the invention to initially equip the mixer solely for conventional thermostat control, and thereafter supplement the mixer with another type of insert when circumstances so require, in order to achieve better comfort in use.

In practice, the various types of insert will preferab¬ ly have the same, or essentially the same external configuration and dimensions, or at least that part of the insert which is accommodated in the mixer housing.

It will be understood that no particular modifications need be made to the mixer housing in order to adapt the same to a given, selected type of insert. On the other hand, however, an in depth constructive adaptation must be made to the members of the actual insert, corresponding to the type of insert concerned and to the purpose for which it is intended.

It is important that the hot-water inlet and the cold- water inlet in the peripheral casing part of the insert have the same or essentially the same positions in all of said inserts. This can be achieved in practice, by using one and the same casing part for all of the different insert types that are available. This will enable the inserts to have the same external configur¬ ations and dimensions, while the internal design of the inserts will differ in accordance with the use inten- ded.

In order to achieve the desired function, when the inserts are mounted in the mixer housing they shall ^• extend through apertures in the partition walls between the hot and cold water inlet chambers and in the parti¬ tion wall between one of these chambers and the mixed water chamber.

It is preferred in practice that these openings or apertures will have the configuration set forth in

Claim 3. This affords the simple possibility of provid¬ ing an effective seal between the two chambers, there¬ with enabling the insert itself to exhibit requisite, separate sealing devices. One such suitable sealing arrangement is set forth in Claim 4.

The combination of an O-ring seal and a metal seal results in a saving in space in the radial direction, as distinct from an arrangement in which two 0-rings are used.

The reason why the 100 percent seal afforded by two O- rings is not necessary, is because a mixer valve of the kind concerned will, in practice, be provided with non¬ return valves which prevent overflow between the hot- water and cold-water inlets. However, the arrangement is such that an O-ring seal is provided between the hot-water inlet chamber and the mixing chamber, there¬ with effectively preventing hot water from leaking directly into the mixing chamber in the event of a pressure drop in the cold water circuit.

One type of insert constructed in accordance with the invention is intended for regulating temperature, wherein this insert includes a temperature regulating body which is influenced by a thermostat element and which is movable between two end positions, namely an end position in which the supply of hot water is cut¬ off and the supply of cold water is fully open, and a second end position in which these conditions are the reverse.

In accordance with the invention, this type of insert is characterized in that the temperature regulating body has a preferably central part of essentially the same external diameter as the internal diameter of the surrounding sleeve. The aforesaid part preferably has the form of a collar or flange in which there is formed a groove for an O- ring which provides a seal between the hot and cold water inlet chambers on both sides of the aforesaid, preferably central part.

In the case of another type of insert intended for both pressure and thermostat control, the temperature regu¬ lating body has a smaller external diameter and, in- stead, is accommodated in the concentrically, surrounding hollow pressure control piston.

In the event of a pressure surge or an overpressure in either of the hot or cold water supply conduits, the pressure control piston is displaced so as to reduce the area of the corresponding inlet opening in the outer casing of the insert, therewith reducing the flow of water through said opening.

In this case, the pressure control piston has one or more parts whose external diameter corresponds to the internal diameter of the sleeve. A centrally located part can be provided with a recess for accommodating a sealing means, e.g. an O-ring. Furthermore, the exter- nal diameter of the thermostat control body will be so much smaller than the internal diameter of the pressure control piston as to define between the two control devices water-passage chambers dimensioned for the purpose intended. As will be understood, it is essen- tial that the various members which move relative to one another will have appropriate fits, so as to enable them to be displaced without occurring undesirable losses through friction. Further characteristic features of the invention will be apparent from the following description, which is made with reference to a number of preferred exemplify¬ ing embodiments thereof, and also with reference to the accompanying drawings.

Brief Description of the Drawings

Figure 1 is a partly cut-away top view of an inventive mixer valve housing provided with a flow conatrol knob, in which housing three different types of inserts having mutually the same external configuration can be screwed in order to provide a complete mixer valve having properties which correspond to the choice of in- sert.

Figure 2 is a part of Figure 1 with a mixer insert fitted in position.

Figure 3 is a partly cut-away top view of a thermostat control insert according to Figure 1.

Figure 4 is a perspective view of the temperature control body used in the insert illustrated in Figure 3.

Figure 5 is a cross-sectional view of a central part of the temperature control body and a surrounding sleeve part.

Figure 6 is a partially cut-away top view of a pressure and thermostat control insert for alternative use in a mixer housing according to Figure 1. Figure 7 is a perspective view of a pressure control piston and a pressure control body included in this latter insert.

Figure 8 is a cross-sectional view of a central part of the insert illustrated in Figure 6.

Mutually corresponding components in the various figures of the drawings have been identified by the same reference signs. However, because of the different reference to the mutually different inserts with respect to their individual purposes, the components of the thermostat control insert have been identified with conventional numerals, the reference signs identifying the components of the pressure and thermostat control insert have been suffixed with a prime ( ' ) , and the reference numerals identifying the pressure control insert have been suffixed with a double prime (").

Best Modes of Carrying Out the Invention

Figure 1 is a partly cut-away view of the mixer housing 2 of a mixer valve 1 having screw-threaded openings 3 and 4 provided in respective ends thereof.

Screwed into the opening 3 is a flow control knob 15, which is connected with an outlet valve body 16 that functs to control the flow of water delivered by the mixer valve through an outlet opening 12.

The other end of the mixer valve housing 2 has a screw- threaded opening 4, into which a number of alternative¬ ly usable inserts can be screwed, namely an insert 30 for thermostat control, an insert 30' for pressure and thermostat control, and an insert 30" for pressure control. The construction of these different types of insert will be described in more detail here below.

In other respects, the housing presents a cold-water inlet opening, which is sealed by a screw-threaded plate 5a, and a hot-water inlet opening, which is closed by a screw-threaded plate 7a. Non-return valves (not shown) are mounted in these openings in use.

The inlet opening or ports 5 and 7 are each connected to an inlet chamber 6 and an inlet chamber 8 for cold and hot water respectively, these inlet chambers bor¬ dering on one another and being separated by a partition wall 2a.

The mixer valve housing includes a further partition wall 2b, which separates the hot-water inlet chamber 8 from a mixing chamber 9 located on the other side of the partition wall 2b.

The housing 2 includes a third partition wall 2c which has a seating 11 for the outlet valve body 16. This third partition wall 2c separates the mixing chamber 9 from the outlet chamber 10, which communicates with the outlet opening 12 of the mixer valve. The walls 2a, 2b have respective openings 17 and 19.

As mentioned in the aforegoing, different types of insert, referenced 30, 30' and 30" in Figure 1, can be screwed into the opening 4 of the mixer valve housing, so as to impart the desired characteristic to the mixer valve.

These inserts 30, 30' and 30" have the same external configuration and dimensions, and all are provided with a temperature control knob 35, a central sleeve part 33 provided with slot-like inlet openings 36, 37 for cold and hot water respectively, and an external hot-water seat 38 in the end remote from the knob 35.

Figure 2 illustrates the manner in which the inserts are sealed in relation to the housing 2. Thus, located at a distance from the forward end of respective in¬ serts is a groove 31 which accommodates an O-ring 32. This O-ring functions to seal the partition wall 2b in the housing 2 so as to separate the hot water inlet chamber 8 from the mixing chamber 9, as before men¬ tioned.

In the partition wall 2a located between the cold water inlet chamber 6 and the hot water inlet chamber 8, the inserts present another type of seal, namely a seal consisting solely of mutually contacting metal sur¬ faces. Thus, there is provided with the partition wall 2a a shoulder or abutment 2e which corresponds to a similar shoulder or abutment 33a located on the outer periphery of the sleeve part 33, in which the sleeve part 33 undergoes a slight increase in diameter.

It has been found in practiced that a metal seal of this kind is quite sufficient when the hot-water inlet and the cold-water inlet are provided with non-return valves. This provides a not inconsiderable space saving in the radial direction.

The internal construction of the thermostat control insert 30 illustrated in Figures 3-5 will now be des¬ cribed in more detail. The aforementioned temperature control body 51 having a centrally arranged flange or collar 51a is mounted centrally within the sleeve 33 containing the slot- shaped cold and hot water inlets 36 and 37 respective- ly. The collar 51a includes a peripheral groove 51b which accommodates an O-ring 52.

The temperature control body 51 can be moved between two end positions. In one end position, the left end surface of the control body 51 is in contact with an opposing end surface of the aforesaid hot water seat 38 (which forms the left end part of the insert 30) and therewith cuts-off the hot water supply through the inlet opening 37, the space 53 between the control body 51 and the sleeve 33, and the gap 54 to the interior of the insert 30.

Correspondingly, when the control body 51 occupies its right end position, the other end surface of the body will abut a cold water seat 55 and therewith cut-off the supply of cold water to the interior of the insert 30 through the inlet 36, the space 56 and the gap 57.

Movement of the body 51 between said two end positions is controlled by a thermostat element 50 which expands when heated, in a conventional manner, and therewith displaces a transfer element 59 to the left.

This movement takes place against the action of a return spring 65 which is held positioned between a shoulder or abutment on the hot water seat 38 and an end surface of an axially extending strip element 66 which connects the transfer element 59 with the control body 51. The setting of the thermostat element 50 is adjusted by means of the temperature control knob 35, in a conven¬ tional manner. The thermostat element is therewith actuated through a part 50a and a stem part 50b, one end of which is accommodated in a spindle extender 67. The spindle extender is surrounded by a plastic guide 68 and abuts an adjacent spindle inner part 69, which is actuated by means of a safety spring 70.

A scalding protection ring 71 prevents the temperature control knob 35 from being turned too far.

Figure 3 shows the temperature control body 51 in its centre position, in which equal volumes of hot water and cold water flow through the space 39 in the in¬ terior of the hollow control piston 51 and into the space 40 surrounding the body 50c of the thermostat element 50.

The set temperature is obtained by displacement of the temperature control body 51 to the right or to the left in the aforedescribed manner, such as to reduce the area of the respective gap 54 or 57.

Figure 5 is an enlarged view of the temperature control body 51 surrounded by the sleeve 33, and shows the central collar or flange 51a provided with a groove 51b for accommodating an O-ring 52.

The insert 30 also includes other components which are more or less of a conventional kind in inserts of the kind concerned and have not therefore been illustrated or described. The distinguishing elements or components of the pres¬ sure and thermostat control insert 30' will now be described with reference to Figures 6-8.

As before mentioned, the temperature control body 51' has a smaller external diameter than the body of the embodiment illustrated in Figures 3-5, although the general function of the body with the thermostat ele¬ ment 50 corresponds to the aforedescribed embodiment. The control body 51' is displaceably mounted in a surrounding hollow pressure control piston 61 having parts whose outer diameters correspond to the internal diameter of the sleeve 33, so that the piston 61 is movable in the sleeve under the influence of separate pressures in the cold water and hot water inlets 36 and 37 respectively, this pressure acting on the end sur¬ faces of the piston 61.

The piston 61 has slot-like inlet openings 62, 63 provided on both sides of a central sealing part 61b, this part being described in more detail here below with reference to Figure 8.

Formed between the pressure control piston 61 and the temperature control body 51'are spaces 75, 76 through which cold water and hot water respectively is de¬ livered to the interior spaces 39 and 40 of the insert.

In the Figure 6 illustration, the pressure control piston 61 is shown in a position in which mutually the same pressure prevails in the cold water and hot water inlets 36, 37. When the pressure increases, e.g. in the cold water inlet 36, the piston will be moved to the left and therewith reduce the area of the cold water inlet 36 and increase the area of the hot water inlet 37. The desired pressure equilization is achieved in this way.

The central sealing part 61b includes a groove 61c, as is best seen from the section shown in larger scale in Figure 8.

The groove 61c accommodates an O-ring 64, the function of which is described here below. The diameter of the O-ring 64 is slightly smaller than the depth of the groove 6lc, so that the O-ring will accompany movement of the control piston 61 without fictional engagement against the inner wall of the sleeve 33.

In normal cases, the O-ring 64 will have only a slight sealing effect between the hot water side and the cold water side of the control body 61. This sealing effect is quite sufficient, however, since the hot water inlet and the cold water inlet will normally include non- return valves (not shown) .

In the end position illustrated in Figure 8, in which the inlet 37 is closed, a drop in pressure in the cold water inlet 36 could well cause hot water to leak onto the cold water side in the narrow gap between the control body 61 and the sleeve 33, with a corresponding risk of scalding hot water exiting through the mixer outlet 12 (Figure 1).

Leakage of hot water along this route is prevented, however, by the presence of the O-ring 64 in the groove 6lc. In the event of overpressure on the hot water side, the O-ring will namely move to the end position shown in Figure 8 and therewith seal effectively against sleeve 33. The groove 61c has a curvature in the ends which force the O-ring against the sleeve such as to completely seal the control piston 61.

The embodiment illustrated in Figure 8 also has an 0- ring 52', corresponding to the O-ring 52 of the Figure 1 embodiment (although of smaller diameter than the first mentioned) placed in a groove 51'b in the tem¬ perature control body 51'. This O-ring 52' also func- tions to provide a seal at the same time as the O-ring 64 against possible leakage between the piston 51' and the part 61b in the event of a drop in pressure in the cold water inlet 36. The O-ring 52' will not normally prevent the temperature control body 51' from moving freely relative to the outwardly lying pressure control piston 61.

The internal configuration of the pressure control insert 30" illustrated solely in Figure 1 has not been illustrated in further detail.

This insert is used together with a pressure control piston of the same external dimensions and general configuration as the pressure control piston 61 of the embodiment illustrated in Figures 6-8, and has the same function as said piston 61.

The insert 30", however, lacks a thermostat element 50 and associated parts, and the temperature control knob 35 acts mechanically on a control or regulating body, in a conventional manner, such as to open and close the respective cold-water and hot-water inlets.

In the event of pressure surges in one of the delivery conduits, this pressure control piston will operate in the same manner as that described with reference to Figures 6-8.

It will be evident from the aforegoing that the alter¬ native inserts 30, 30' and 30" can be fitted to one and the same mixer housing according to the desired proper¬ ties or characteristics of the distribution system concerned, without needing to make particular modi¬ fications thereto.

It will also be evident that each type of insert has a design which incorporates simple arid reliable, essen¬ tially standard components which can be readily fitted together with the aid of the outer sleeve 33 having screw-threaded ends and being of the same configuration and dimensions for all of the insert types.

Each of the different inserts includes separate sealing devices which will not impede normal relative movement between mutually adjacent components but which in the event of a pressure drop or pressure surge in the hot water inlet or cold water inlet will activate a sealing function. These sealing devices are effective primarily in preventing the risk of scalding as a result of the leakage of hot water into the cold water circuit of an insert, a risk which has been particularly manifest in earlier known mixer valves.

Claims

1. A mixer valve having a housing (2) provided with openings, preferably screw-threaded end-openings, namely a first opening (3) for accommodating an operat¬ ing knob (15) for manipulation of an outlet valve body (16), and a second opening (4) which accommodates a control insert provided with an operating knob (35), said housing (2) including a) a cold water inlet (5) and a hot water inlet (7); b) a first partition wall (2a) which separates a cold- water inlet chamber (6) from a hot-water inlet chamber (8) ; c) a second partition wall (2b) which separates one of the inlet chambers from a mixed-water chamber (9) ; d) a third partition wall (2c) which separates the mixing chamber (9) from an outlet chamber (10), said third partition wall (2c) having a seat (11) for the outlet valve body (16), and e) an outlet opening (12) from the outlet chamber (10), c h a r a c t e r i z e d by two or more different types of inserts for varying the control of the liquid flow in the mixer valve (1), such as for instance an insert (30) for thermostat control, an insert (30') for pressure and thermostat control, and an insert (30") for solely pressure control, said inserts being capable of being screwed into the other end opening (4) of the mixer valve.

2. A mixer valve according to Claim 1, c h a r a c ¬ t e r i z e d in that the different types of inserts have the same or substantially the same outer con¬ figuration and dimensions, at least at the part thereof that is accommodated in the mixer housing (2).

3. A mixer valve according to Claim 1 or 2, c h a r a c t e r i z e d in that the opening (17) for the inserts (30, 30', 30") in the partition wall (2a) between the cold water inlet chamber (6) and the hot water inlet chamber (8) has a greater diameter than the opening (19) in the partition wall (2b) between the hot water inlet chamber (8) and the mixed water chamber (9).

4. A mixer valve according to Claim 3, c h a r a c ¬ t e r i z e d in that the inserts (30, 30', 30") present a groove (31) for an o-ring (32) which func¬ tions to provide a seal between the mixing chamber (9) and the hot water inlet chamber (8), and in that a shoulder-like metal surface (33a) functions to provide a seal against the partition wall (2a) located between the inlet chambers (6, 8) for cold water and hot water.

5. A mixer valve according to any one of Claims 1-4, wherein respective inserts (30, 30', 30") include a central outer sleeve (33) having preferably slot-shaped inlets (36, 37) for cold water and hot water respec¬ tively, c h a r a c t e r i z e d in that the ends of the outer sleeve (33) have screw threads (33c, 33d), the rear screw thread (33d) being intended for connec¬ ting a part (55) which incorporates the operating knob (35), a spindle extender (67) and the cold water seat, and the front screw thread (33d) is intended for con- necting a part (38) which includes a mixing chamber (40).

6. A mixer valve according to any one of Claims 1-5, wherein the insert fitted to the valve has a tempera- ture control body (51) which is actuated by a thermo- stat element (50) and which is movable between two end positions, namely an end position in which the supply of hot water is cut-off and the supply of cold water is fully open, and an end position in which the conditions are reversed, c h a r a c t e r i z e d in that the temperature control body (51) of the thermostat control insert (30) has a preferably central part (51a) whose outer diameter is substantially the same as the inter¬ nal diameter of the sleeve (33).

7. A mixer valve according to any one of Claims 1-5, which is fitted with a pressure and thermostat control insert, said insert including both a pressure control piston (61) and a temperature control body (51'), c h a r a c t e r i z e d in that the external dia¬ meter of the temperature control body (51') is smaller than the internal diameter of the sleeve (33); in that the body (51') is disposed concentrically in a sur¬ rounding hollow pressure control piston (61) which in the event of an overpressure in either of the inlets (36, 37) is moved so as to reduce the area of a cor¬ responding inlet opening (62, 63); and in that the pressure control piston (61) has a part (61a) whose external diameter corresponds to the internal diameter of the sleeve (33).

8. A mixer valve according to any one of Claims 1-5, which is fitted with a pressure control insert (30"), c h a r a c t e r i z e d in that the insert includes a pressure control piston whose external diameter corresponds to the internal diameter of the sleeve (33); and in that the operating knob (35) of said insert is connected with a temperature control body in the absence of influence of a thermostat element