NZ247304A - Thermostatic mixing valve; tempering valve with ceramic disc valve - Google Patents

Description

Patents Form 5 PATENTS ACT 1953 COMPLETE SPECIFICATION After Provisional No. 247304 31 March 1993 THERMOSTATIC MIXING VALVE WE, G. METHVEN & COMPANY LIMITED of 374 Andersons Bay Road, Dunedin, New Zealand being a Company existing under the Laws of New Zealand, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- 2 2.-47 3©4 The invention relates to valves and more particularly to a thermostatic valve suitable for use in controlling the mixing of hot and cold water for a plumbing fitting such as a shower.

At present the thermostatic valves which are available are complex, costly and therefore beyond the means of other than commercial operators. These thermostatic valves are a special unit utilizing either a complicated arrangement of bi-metallic strips or gas units which are complicated and this is the case of them being expensive to produce.

An object of the invention is therefore to provide an inexpensive thermostatic valve suitable for use in controlling a range of plumbing fittings such as a shower.

Further objects and advantages of the invention will become apparent from the following description which is given by way of example only.

According to a broadest aspect of the invention there is provided a thermostatic valve including a tempering valve and a ceramic disc valve which are connected together in series, the tempering valve incorporating a thermostatic element positioned in a mixing chamber thereof, the thermostatic element when heated adjusts the position of a valve member of the tempering valve to thereby adjust the flow of cold and hot liquid to the mixing chamber to maintain the mixed liquids at a desired temperature, the valve member being mounted relative to a control spindle rotation of which 3 Q. -4"73o^ adjusts the temperature of the mixed liquids, the mixing chamber having an outlet connected to an inlet of the disc valve which is used to control the flow volume of the mixed liquid.

The thermostatic element may be a generally cylindrical member filled with a thermally sensitive wax which when it expands or contracts alters the length of the cylindrical member.

Further aspects of the invention which should be considered in all its novel aspects will become apparent from the following description which is given by way of example only.

An example of the invention will be described with reference to the drawing accompanying the provisional specification which shows a cross-section through an example of thermostatic valve assembly according to the invention.

The example will be described with reference to the mixing of hot and cold water and it is to be appreciated that the example can be used in other situations to mix other liquids or combinations of liquids.

In the drawing is shown a valve assembly incorporating a tempering valve generally indicated by arrow 1 and a ceramic disc valve 2.

The valve assembly has a hot water inlet 3 connected to-the tempering valve 1 through a non-return valve 4. The tempering valve 1 has a central housing 5 in which a valve member 6 is mounted. The valve member 6 is held in ft /V **\ 1*7 ~ i5'SEP 1996 • \* - J 4 *2.o<4r by a cover 7 which in the example has a base 8 into which an extension 9 of the valve member 6 extends. The extension 9 has a bore 10 with a piston pin 11 slidingly engaged therein. The base 12 of the piston pin 11 is in contact with a thermostatic element 13 which is supported in position by a conical spring 14. The upper end of the piston pin 11 is in contact with the base of an actuating pin 15. The actuating pin 15 has a threaded bore 16 in which a control spindle 17 is engaged. The spindle 17 is fitted with a control handle 18 which is in association with a face or cover ple*te 19 which may include a temperature dial.

The valve member 6 is between a cold inlet (not shown) which is in the housing 5 directly behind space 20 and a mixing chamber 21 into which hot water flows to be thoroughly mixed with the cold water inflow.

An outlet 22 from the housing 5 is connected to an inlet 23 of the disc valve 2.

The disc valve 2 has a housing 24 in which a ceramic disc assembly 25 is mounted. The position of the assembly 25 in controlled by a spindle 26 on the upper end of which is a control lever 27. The assembly 25 operates in association with a valve seat 28 to control the volume flow of mixed liquid from the chamber 21 to an outlet 29.

In use the flow of liquid through the thermostatic valve is in the direction of the arrows 30. A user dials on the control handle 18 a particular temperature setting. The rotational movement of handle 18 between settings in a range OAT7 of adjustment from 20° - 45°C moves the temperature actuating pin 15 to raise or lower the valve member 6. As the mixed water temperature increases or decreases the thermostatic element 13 expands or contracts to maintain a desired temperature throughout irrespective of the inflow temperatures of the hot and cold water.

The overall volume of flow from the unit is controlled by operation of the disc valve 2.

Thus by this invention there is provided an inexpensive thermostatic valve for controlling the temperature of water from plumbing fittings such as a shower.

A particular example of the invention has been described and it is envisaged that improvements and modifications can take place without departing from the scope thereof. 6 2473o^-

Claims (9)

WHAT WE CLAIM IS:

1. A thermostatic mixing valve comprising a tempering valve and a ceramic disc valve, wherein said tempering valve controls the mixture of hot and cold liquids to achieve the desired temperature and said disc valve controls the flow volume of the mixed liquid, and wherein said tempering valve incorporates a thermostatic element positioned in a mixing chamber thereof, and further wherein said tempering valve and said disc valve are connected together in series, the tempering valve being located in a first housing, and the disc valve being located in a second housing.

2. The thermostatic mixing valve as claimed in claim 1 wherein the thermostatic element, when heated, adjusts the position of a valve member of said tempering valve.

3. The thermostatic mixing valve of claim 2 wherein the temperature of the mixed liquids is automatically adjusted by the thermostatic element.

4. The thermostatic mixing valve of claim 3 wherein said valve member is mounted relative to a control spindle.

5. The thermostatic mixing valve of claim 4 wherein rotation of a control handle, fitted to said control spindle, adjusts the temperature of the mixed liquids.

6. The thermostatic mixing valve as claimed in any one of the preceding claims wherein said mixing chamber has an outlet connected to an inlet of the disc valve.

7. The thermostatic mixing valve as claimed in any one of 7 generally cylindrical member fitted with a thermally sensitive wax.

8. The thermostatic mixing valve of claim 7 wherein expansion or contraction of said thermally sensitive wax alters the length of the cylindrical member.

9. A thermostatic mixing valve substantially as herein described with reference to the drawing accompanying the provisional specification. G. METHVEN & CO LIMITED By Their Attorneys BALDWIN SON & CAREY Per: lf/holdback/ASPECOlOOO z. \ V