Abstract:
A dual control assembly for a shower fitting comprising a thermostatic valve in the form of a cartridge removably fitted in the mixing chamber of the fitting, and a flow rate valve, the two valves being operatively linked or coupled together, for example by a sleeve. The valves are co-axially aligned and provided with respective control knobs which are disposed at the same end of the shower fitting.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to improvements in or relating to fluid flow control and is more particularly concerned with a dual control assembly, for example for a shower fitting or other water outlet, where the temperature of water can be controlled by a thermostatic valve and the water flow by a flow rate valve. 
     Where dual controls have been provided in, for example, shower fittings, the temperature of the water may be controlled by means of a thermostatic valve governing the mix of hot and cold water flowing into the mixing chamber and the rate at which mixed water flows out of the mixing chamber through the shower head may be independently controlled by means of a flow rate valve. A disadvantage of such controls is that if a fault develops in the thermostatic valve, repair and/or service costs resulting from the need to dismantle or remove the shower body often have to be paid by the end user. In order to overcome this disadvantage with most traditional showers, it is known to provide the thermostatic valve as a cartridge or unit that can be inserted into the mixing chamber and reasonably easily extracted therefrom for instant repair and servicing or replacement, without it being necessary to dismantle or remove the shower body at all. Such cartridges/units are readily available. When such a cartridge is incorporated into a water outlet, it is known for the cartridge to be introduced into a mixing chamber from one end of the water outlet fitting, with an appropriate temperature control knob being provided at that end, and a separate flow rate valve (in the form of a ceramic disc (“CD”) valve) being incorporated at the other end of the fitting with an appropriate independently operable control knob at that end for controlling the flow rate. Such a design is employed on the European Continent but is not generally suitable for the United Kingdom or the United States of America owing to the orientation usually accepted or required, where the thermostatic valve control knob projects forwardly and horizontally from the wall (rater than parallel therewith) and is rotatable about an axis extending at right angles thereto. In such a design, a flow control knob positioned in line with the thermostatic valve control knob at an opposite end of the fitting would have the flow control knob facing the wall and thus could not be accessed properly. 
     It is known, however, to provide dual control assemblies for showers meeting British design requirements where the thermostatic valve is in the form of a cartridge or unit insertable in a mixing chamber which projects forwardly and horizontally from a wall on which the fitting is mounted. However, in order for the flow rate to be controlled a separate independently operable control knob is mounted above the thermostatic control knob and above the mixing chamber in order to control a separate flow rate valve. It is believed that such a design is disadvantageous in certain respects. For example, it is believed that said design is not as aesthetically pleasing as a design in which the thermostatic control knob and flow rate control knob are mounted in line with one another or concentrically and, preferably, operable from the same end of the mixing chamber as may be provided for where the thermostatic valve is not in the form of an insertable/extractable replacement unit or cartridge. Additionally, such a design may be disadvantageous from a cost or manufacturing point of view. In any event, it is believed that a design of dual control assembly has not been optimised more particularly for the British or American Market which includes a thermostatic valve in the form of an insertable/extractable cartridge or unit. 
     It is an object of the present invention to at least alleviate one or more of the aforementioned disadvantages with dual control assemblies and/or to provide a dual control assembly which is improved in at least some respect. 
     BRIEF SUMMARY OF THE INVENTION 
     According to the present invention there is provided a dual control assembly comprising a thermostatic valve in the form of cartridge or unit insertable in a mixing chamber of, for example, a shower fitting or other water outlet, said assembly having an operative link or coupling between the thermostatic valve and a flow rate valve. 
     In one embodiment of the present invention, the operative link or coupling between the thermostatic valve and the flow rate valve is provided by a sleeve surrounding the thermostatic valve which sleeve is operatively connected to the flow rate valve. The flow rate valve is, preferably, co-axially aligned with the thermostatic valve with said sleeve being arranged to turn the body of the flow rate valve relative to an operating stem of said valve, which stem is held still relative to a mixing chamber of the shower fitting or water outlet. The sleeve (or other operative link or coupling) may or may not be part of the cartridge or unit and may or may not be arranged to rotate with the thermostatic valve to operate the flow rate valve. 
     Preferably, the dual control assembly is provided with a control knob that actuates the thermostatic valve, co-axially arranged with a second control knob that operates the flow rate valve, said two control knobs being provided at the same end of said shower fitting or other water outlet. The first control knob may be mounted on control stem of the thermostatic valve with said second control knob mounted on a (splined) portion of the cartridge/unit being integral with the body thereof. The cartridge/unit may be of a readily available standard form or may be adapted or modified to suit. Where the cartridge/unit is of a standard form the second control knob may be mounted on the splined portion of the cartridge normally utilised for locating a plastics collar of the thermostat control knob. 
     In another embodiment of the present invention, the operative link or coupling between the thermostatic valve and the flow rate valve is provided by a sleeve surrounding the flow rate valve which sleeve is operatively connected to the thermostatic valve. The thermostatic valve is, preferably, co-axially aligned with the flow rate valve with said sleeve being arranged to turn the body of the thermostatic valve relative to an operating stem of said valve, which stem is held still relative to a mixing chamber of the shower fitting or water outlet. The sleeve (or other operative link or coupling) may or may not be part of the cartridge/unit, or flow rate valve and may or may not be arranged to rotate with the flow rate valve to operate the thermostatic valve. 
     Preferably, the dual control assembly is provided with a control knob that actuates the thermostatic valve, co-axially arranged with a second control knob that operates the flow rate valve, said two control knobs being provided at the same end of said shower fitting or other water outlet. The first control knob may be mounted on a control stem of the flow rate valve with said second control knob mounted on a (splined) portion of the flow rate valve being integral with the body thereof. The flow rate valve may be of a readily available standard form or may be adapted or modified to suit. 
     In either of the two above described embodiments the thermostatic valve may be a shuttle valve and/or the flow rate valve may be a disc valve, preferably a C.D. valve. 
     Further according to the present invention there is provided a shower fitting or other water outlet including a mixing chamber in which can be mounted a thermostatic valve in the form of a cartridge or unit, said fitting or water outlet having a flow rate valve operatively linked or coupled with the thermostatic valve, the thermostatic valve, preferably, being controlled by a control knob mounted coaxially with a control knob for the flow rate valve and said two control knobs, preferably, being mounted at the same end of the fitting or water outlet. Usually, when the shower fitting or water outlet has been installed the thermostatic cartridge will extend forwardly of a vertical wall on which said fitting or outlet is mounted in a generally horizontal plane. 
     Further according to the present invention there is provided the combination of a thermostatic valve comprising a cartridge or unit insertable into a mixing chamber of, for example, a shower fitting or other water outlet, and means which, in use, forms an operative link or coupling between the thermostatic valve and a flow rate valve of said fitting or other water outlet. 
     Further according to the present invention, there is provided a dual control assembly comprising a thermostatic valve and a flow rate valve including an operating stem and a body portion, the arrangement being such that the body of the flow rate valve can be rotated relative to said stem to open and close the flow rate valve. 
     Further according to the present invention there is provided a method of controlling temperature and flow of a liquid medium in, for example, a shower fitting or other fluid outlet, said method comprising setting the temperature of the medium by means of a control knob located at one end of a thermostatic valve in the form of a cartridge or unit and varying the flow rate by means of a second control knob arranged concentrically with the first at the same end of the fitting/fluid outlet. 
     Still further according to the present invention there is provided a dual control assembly having one or more of the following features: 
     (a) a thermostatic valve in the form of a cartridge or unit mounted in line with a flow rate disc valve, preferably a CD valve, the body of which may be rotated relative to an operating stem held fixed, in use, relative to a mixing chamber of a shower fitting or other water outlet in which the dual control assembly is mounted; 
     (b) a thermostatic valve in the form of a cartridge or unit with two concentrically mounted control knobs, the one control knob being for controlling the thermostatic valve and the other control knob being for controlling the flow rate valve preferably operatively coupled to the thermostatic valve, and 
     (c) a thermostatic valve (in the form of a cartridge) aligned with a flow rate valve in a fluid mixing chamber of a fitting or water outlet, the thermostatic valve and flow rate valve being controlled from the same end of the fitting or outlet by co-axially arranged control knobs. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of a dual control assembly for a shower fitting in accordance with the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: 
     FIG. 1 shows a side view of a known thermostatic valve in the form of a cartridge or unit to be incorporated in a dual control assembly in accordance with the present invention; 
     FIG. 2 shows a sectional view through a known type of CD valve (which is a self-contained unit) to be incorporated in a dual control assembly in accordance with the invention; 
     FIG. 2 a  shows an end view of the CD valve looking in the direction of arrow A in FIG. 2 a;    
     FIG. 3 shows a simplified schematic view of a cartridge similar to that shown in FIG. 1 incorporated in a sleeve in accordance with the present invention that is inserted into the mixing chamber of a dual control assembly and which also includes a flow rate valve being a CD valve similar to that shown in FIG. 2; 
     FIG. 4 shows a more detailed part-sectional view through a shower fitting in accordance with the present invention; 
     FIG. 5 shows a cross-sectional view through an alternative cartridge designed as a single replacement unit for seals (not shown) to be mounted thereon directly; 
     FIG. 5 a  shows an outside detail of a left portion of an elevational side view of the cartridge; and 
     FIG. 6 shows a sectional view through a shower fitting including an alternative embodiment of a flow control assembly according to the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following is a detailed description and explanation of the preferred embodiments of the invention. 
     In the drawings the same reference numerals are used to designate similar parts. 
     FIG. 1 shows a known type of thermostatic valve  1  in the form of a cartridge or unit that can be inserted into a mixing chamber of a water outlet fitting such as a shower fitting, which cartridge  1  can be readily easily extracted therefrom should a fault arise with the valve or if there is a need for a service. A service may be recommended to take place annually. The cartridge  1  is known per se and commercially available as an off-the-shelf product and the use of such a cartridge is seen as a significant advantage over more traditional showers that might require the whole shower body to be dismantled or removed in the event of a fault developing with the thermostatic valve. It is known to incorporate such a cartridge in British style shower fittings; the cartridge is mounted at right angles to the wall in a mixing chamber necessitating a separate variable flow rate valve control being mounted above the mixing chamber and above the control knob operating the thermostatic valve. In such an arrangement, therefore, separate controls are provided to vary the temperature (thermostatic valve) and to vary the flow rate (flow rate valve), said controls being entirely independent from one another and mounted in a generally non-compact way which usually is not seen as being neat, convenient or aesthetically desirable. On the other hand, where such a cartridge or unit has been used on the European Continent it has been provided at one end of a mixing chamber with a variable flow rate valve (CD valve) and appropriate independent control being mounted at the other end of the chamber, the cartridge and associated control knob being mounted in line or co-axial with the flow rate valve and its associated control knob at the other end of the fitting. Thus, in such an arrangement, the cartridge  1  is arranged with its axis parallel to the wall an din a horizontal plane which thereby allows the thermostatic valve control knob and the flow rate control valve to be mounted more neatly in line with one another, the control knobs still being operable independently of one another from a respective end of the fitting. Such an arrangement is generally not acceptable for the British and American markets as previously explained in the introductory part of this Patent Specification. 
     The cartridge  1  has a brass body  1   a  and a splined stem  1   b  of reduced diameter which is rotatable through about 330° in a particular direction to either open or close the shuttle valve contained therein. 
     The cartridge  1  has a wire mesh M, and a splined portion  1   e  (of wider diameter than stem  1   b ) integral with the brass body  1   a  relative to which the splined stem  1   b  can be rotated. In prior art arrangements, the splined portion  1   c  acts to fixedly locate a plastics collar (not shown) introduced over the splined portion and on which is mounted the thermostatic valve temperature control knob (not shown) said control knob being marked with degree settings and rotatable with the stem  1   b  relative to the plastics collar mounted on the splined portion  1   c.    
     The present invention is concerned with utilising a generally known form of thermostatic valve cartridge or unit such as that shown in FIG. 1 in a new way in a water outlet mixing chamber which is represented schematically in section in FIG.  3  and indicated by the reference numeral  2 . Once again the mixing chamber  2  is generally of a known form and will not be described in further detail. 
     FIG. 3 shows, in a simplified way, how, in accordance with this embodiment of the present invention, a thermostatic valve cartridge  1  (corresponding generally to cartridge  1  shown in FIG. 1) has been incorporated into a sleeve  3  which has in turn been introduced into the mixing chamber  2  from the left hand end of the fitting as shown in FIG.  3 . Prior to the insertion of the sleeve  3  and cartridge  1  into the mixing chamber  2  a flow rate control valve  4  (CD valve) has been already introduced into the mixing chamber with a splined stem  4   a  being seated in a matching circular recess in base portion  5  at the right hand end of the mixing chamber in such a manner that the stem  4   a  is gripped and prevented from rotating relative to the base  5  and mixing chamber  2 . 
     In the mixing chamber  2  as shown in FIG. 3, hot water enters the mixing chamber through the bottom opening in the direction of the arrow H and cold water flows into the mixing chamber from above in the direction of arrow C (or vice versa if preferred). The rotation of thermostatic valve stem  1   b  operates the shuttle valve SV (see FIG. 4) in the cartridge  1  and thereby governs the mix of hot and cold water flowing through respective, circumferential slot openings O 1  and O 2  inside the mesh M of the cartridge  1  into the body of the shuttle valve in known manner. The cartridge has two equiangularly spaced slot openings O 1  (one shown in in dashed lines in FIG. 3) and two equiangularly spaced slot openings O 2  (one shown in dashed lines in FIG.  3 ). Water flows axially inside the cartridge  1  from the shuttle valve SV in the cartridge  1  to the CD valve  4  and the angular rotation of the sleeve  3  and body  4   b  relative to stem  4   a  varies the flow rate possible through the CD valve into the chamber  2   a  of the mixing chamber  2  which leads to the shower head (not shown) of the shower fitting. 
     A more detailed view of a flow rate CD valve  4  is shown in section in FIG. 2, this CD valve  4  only differing slightly from the CD valve  4  shown in FIG. 3, for example by the slightly wider diameter splined head  4   a . The CD valve  4  in both cases comprises two co-axial ceramic discs CD formed with opposed quadrant holes, one of the discs being connected to the splined stem  4   a  by an intermediate part  4   c  and being held fixed by the stem relative to base portion  5  when mounted in the assembly. The other CD disc is arranged to be rotatable with the sleeve  3  so that the quadrant holes in that disc move into and out of registration with the holes in the fixed disc to thereby control the flow of water through the holes into the chamber  2   a  and to the shower head. 
     One disc CD (the stationary disc connected to stem  4   a ) is shown in FIG. 2 in solid lines. The dashed lines represent a position of part registration only of quadrant holes Q in the other disc CD. The dashed arrows X represent the direction of rotation of the turnable disc to close off registration. 
     Simultaneously as the quadrant holes Q in the turnable disc move into and out of registration with the quadrant holes Q in the other disc, the quandrant holes in the turnable disc move into an dout of registration with the circumferential side apertures CA (see FIG. 5 a ) in the body of the CD valve  4  allowing water to pass axially through the circumferential apertures CA into chamber  2   a.    
     As is very well known, in normal operation, the CD valve  4  is utilised in a water outlet fitting with the splined stem  4   a  being rotated relative to the valve body  4   b  by a flow rate control valve knob (not shown), said body  4   b  being held still relative to the water outlet. 
     The sleeve  3  forms a very important part of the present invention and acts as an operative link r coupling between the thermostatic valve cartridge  1  and the CD valve  4 . In use, the sleeve  3  being mounted in the mixing chamber  2  by various rotary seals S forms an operating link or coupling between said valve  1  and the flow rate valve  4 . The arrangement is such that on rotation of the sleeve  3  about its axis said sleeve, being positively coupled to the body  4   b  of the CD valve, acts to open and close the CD valve by rotating said body relative to the stem  4   a  which is held fixed relative to base portion  5  and mixing chamber  2  as previously explained. 
     Rotation of the sleeve  3  relative to the mixing chamber  2  can be effected by rotating the cartridge  1  with the sleeve  3  by means of a control knob (not shown in FIG. 3) mounted on wider diameter splined portion  1   c  of cartridge  1 . A second control knob (not shown) is mounted on the splined stem  1   b , the rotation of which opens and closes the shuttle valve contained within the thermostatic valve cartridge  1 . 
     In an alternative embodiment, it is possible that the sleeve  3  could be arranged to rotate relative to the cartridge  1  and mixing chamber  2  in order to rotate the body of the CD valve  4 . In such an embodiment a plastics collar could be fixedly located on splined portion  1   c  with the sleeve being mounted on, and rotatable relative thereto. 
     FIG. 4 shows a more detailed view through a shower fitting  100  including the cartridge  1 . This cartridge may be mounted into a sleeve. 
     FIG. 4 shows a first control knob  101  mounted on splined stem  1   b  of cartridge  1  as shown in FIG.  1 . The control knob  101  is rotatable with the stem  1   b  relative to wider diameter splined portion  1   c  and control knob  102 , which has an internal collar  102   a  gripping said wider diameter splined portion  1   c . Control knob  101  may be operated by a radially protecting handle and control knob  102  may be operated by an angled handle. It is to be appreciated that various forms and shapes may be chosen for the control knobs  101  and  102  with handle means to suit. 
     FIG. 4 shows a further detail of the cartridge  1 , namely a temperature responsive wax capsule T arranged to expand and contract to operate the thermostatic valve, and a further detail of the flow control valve, namely the ceramic discs CD. The valve stem  1   b  of the thermostatic valve is operatively connected to the shuttle valve SV so that turning of the stem sets the valve to the appropriate position or the required temperature. The capsule T is arranged to move a stem T 1  axially as it expands and contracts in response to changes in the temperature of the incoming water, and the stem T 1  adjusts the setting of the shuttle valve to maintain the required temperature. 
     Plate P is a retaining plate that is screwed onto the fitting  100  by means of screws (not shown) each of which locates in an associated hole or slot in the plate. The plate P radially overlaps the cartridge  1  thereby retaining the cartridge  1  securely in the fitting  100 . Circumferential flange P 1  of plate P overlaps and securely and snugly seats on a stepped portion of the fitting. Radially inward directed semi-circular flange F overlaps the widest diameter rim portion of the cartridge  1  preventing removal of the cartridge  1  from the fitting  100  until plate P is removed by unscrewing the screws. 
     CD valve  4  has splined stem  4   a  seated in base portion  103 . Base portion  103  is screwed tightly into the fitting  100  by means of screws (not shown). The sleeve may be secured to the cartridge  1  by means of a screw (not shown) screwed through a hole in the sleeve into a hole in the cartridge  1 . The sleeve may be coupled to the body of the CD valve  4  by any suitable means for example by a screw thread fixing. 
     In the aforedescribed embodiments of the present invention the cartridge  1  may be readily extracted from the mixing chamber o the fitting  100  by: 
     1) readily removing the control knobs  101  and  102  (a radial screw may be provided preventing control knob  101  from moving axially off stem  1   b  until the screw is undone), 
     2) Unscrewing the screws securing plate P and removing the plate, 
     3) if appropriate the fastening screw retaining the sleeve to the cartridge  1  then being undone, so that the cartridge can simply be removed from the sleeve and fitting  100 . 
     However, in the alternative embodiment the cartridge and sleeve may be designed as a single replaceable unit that may be easily inserted and extracted from the mixing chamber. The flow rate valve may or may not also be designed as part of the replaceable unit or cartridge. 
     Several modifications may be possible with regard to the cartridge/sleeve design. 
     It is generally desirable for the thermostatic valve to have as wide a diameter as possible in order to increase the flow rate there through given the diameter of the fitting involved and one way that this may be achieved is by splitting up the sleeve into separate annular portions. Thus, the sleeve can be replaced by two or three separate annular portions which is less expensive since less material needs to be used. 
     Depending upon the design of cartridge, the sleeve could be omitted completely by redesigning the outer peripheral surface of the cartridge to take the seals S directly. In this manner, the diameter of the thermostatic valve could be increased by another 3 mm to 5 mm, advantageously increasing the flow rate still further for the same size of mixing chamber orifice. An example of such a wider cartridge  300  (having a wider chamber for the shuttle valve and being a single replacement unit made without separate sleeve/s) is shown in FIG.  5 . FIG. 5 shows the direction of water flow (see arrows Y) from the shuttle valve SV through the ceramic discs CD, which flow is applicable to the cartridge shown in FIGS. 3 and 4. FIG. 5 a  shows a detail of part of the cartridge  300  in side view revealing one of four equiangularly spaced circumferential apertures CA. Clockwise rotation of the cartridge relative to stem  4   a  closes the aperture CA as the static disc CD (shown in dashed lines) closes the aperture. 
     FIG. 6 shows a sectional view through a shower fitting which includes an alternative flow control device. The arrangement is similar to that illustrated in FIG. 3, the fitting including a mixing chamber  400  with a ceramic disc (CD) flow control valve  401  and thermostatic valve cartridge  402 . However, the arrangement differs in that the flow control valve cartridge is incorporated into a sleeve  403  and is mounted towards the front of the mixing chamber, toward the controls, and the thermostatic valve cartridge is mounted toward the rear. 
     The thermostatic valve cartridge  402  includes a splined stem  404  which is seated in a matching circular recess  405  in the rear portion of the mixing chamber  400 , in such a manner that the stem  404  is gripped and prevented from rotating relative to the mixing chamber  400 . 
     The body of the thermostatic valve cartridge  402  is also incorporated into sleeve  403 . The sleeve  403  operatively connects the thermostatic valve cartridge  402  to the flow control valve  401 . The flow control valve  401  includes a control stem  406 , connected to inner control  407  and a splined portion  408 , integral with the valve body and connected to control  409 . 
     In use, hot water enters the mixing chamber through connection  410 , in the direction of arrow H and cold water enters the mixing chamber through connection  411  in the direction of arrow C, (or vice versa if preferred). Water flows into the thermostatic valve cartridge  402 . The rotation of the valve stem  404 , relative to the valve body governs the mix of hot and cold water. Adjustment is effected by rotation of outer control  409  which causes rotation of the body of the flow control valve  401  and hence the sleeve  403  and body of the thermostatic cartridge valve, relative to the valve stem  404 . 
     Water then flows up the cartridge to the CD flow control valve  401 . The rate of flow of water through the CD valve  401  is controlled by rotation of the valve stem  406  relative to the valve body. This may be effected by rotation of the inner control  407 , relative to the outer control  409 . 
     In an alternative arrangement the sleeve  403  could be connected directly to the outer control  409 . 
     An advantage of the arrangement illustrated in FIG. 6 is that the sleeve torque and flow control torque are separated. That is, the flow control valve can be operated without rotation of the sleeve. Provided that the temperature is adjusted after the flow control is on, then the sleeve only has to turn against the dynamic flowing pressure, not the full static pressure of the water supply. Thus the torque required to adjust the temperature, or, as would be the case in the arrangement illustrated in FIGS. 3 and 4 the rate of flow is reduced. 
     It is to be understood that the scope of the present invention is not to be unduly limited by the particular choice of terminology and that a specific term may be replaced or supplemented by an equivalent or generic term. Further it is to be understood that individual features, method or function related to the dual control assembly or coupling arrangement might be individually patentably inventive. 
     Although embodiments and examples of this invention have been shown and described, it is to be understood that various modifications, substitutions, and rearrangements of structural parts, features and components, as well as other uses thereof, can be made by those skilled in the art without departing from the novel spirit and scope of this invention.