Temperature limiting device applicable to single lever valves for mixing hot and cold liquids

• US 8,376,241 B2
• Filed: 09/21/2004
• Issued: 02/19/2013
• Est. Priority Date: 09/25/2003
• Status: Active Grant

• Current Assignee: QL Thermostatic Limited
• Original Assignee: Greens Industries Limited
• Inventors: Green, John William, Moran, Ian
• Primary Examiner(s): Swann, Judy
• Assistant Examiner(s): COX, ALEXIS K
• Application Number:
  US10/573,417
• Publication Number:
  US 20080121282A1
• Time in Patent Office: 3,073 Days
• Field of Search: 236/12.2, 236/12.11, 236/12.23, 236/12.21
• US Class Current: 236/12.11
• CPC Class Codes: F16K 11/0746 with two or more closure plates comprising a single lever control
• CPC Class Codes: F16K 31/002 actuated by temperature variation thermo-electric F16K31/025
• CPC Class Codes: G05D 23/1346 with manual temperature setting means
• CPC Class Codes: Y10T 137/0329 Mixing of plural fluids of diverse characteristics or conditions

Abstract

A single lever valve for mixing hot and cold liquids has a mixer which can internally impose an upper limit on the temperature of any liquid emerging from it. The means used may enable the upper limit to be changed by exchange of a component so that the mixer can be used in any location in an installation even though different locations might have different upper limit requirements. The mixer may take the form of a cartridge able to be exchanged with an existing cartridge to convert an “unsafe” mixer to a “safe” one.

Claims

1. A device for mixing and regulating the output temperature of a hot liquid and a cold liquid in a shower, a bath or a faucet, said device comprising:

a mixing chamber;

a hot liquid entry port into said mixing chamber;

a first cold liquid entry port into said mixing chamber;

an outlet from said mixing chamber;

an outlet passage in communication with said outlet of said mixing chamber;

a movable distributing member and a stationary distributing member, the movable distributing member being operable by a single lever to contact proportions of hot and cold liquid introduced to said hot liquid entry port and said first cold liquid entry port;

flow control means within said mixing chamber for simultaneously altering the proportions of hot and cold liquids admitted through said hot liquid entry port and said first cold liquid entry port into said mixing chamber at any rate of combined output flow;

a temperature sensing device adapted to sense the temperature of the output of the mixed liquids from the mixing chamber for controlling the flow control means so that the output temperature at all output flow rates from the mixing chamber does not exceed a selected maximum temperature; and

a second cold liquid entry port in direct fluid communication with the outlet passage of the device downstream from where the temperature of the output flow from the mixing chamber is sensed, movement of the movable distributing member by the single lever further controlling the proportion of cold liquid introduced to said second cold liquid entry port to reduce the output temperature of the output flow from the mixing chamber to below the selected maximum temperature.

2. The device according to claim 1, wherein the stationary distributing member having ports for the supply of hot liquid and cold liquid to the movable distributing member, wherein the movable distributing member regulates the proportions of hot and cold liquid supplied to the hot liquid entry port and to the cold liquid entry ports and the flow rates thereof, and enables complete shut-off of all flows to said ports.

3. The device according to claim 1, further comprising:

a body supporting the movable and stationary distributing members;

sealing means to seal between parts of the movable and stationary distributing members;

wherein the stationary distributing member comprises;

a hot liquid inlet port;

a cold liquid inlet port;

a hot liquid outlet port;

a first cold liquid outlet port;

a second cold liquid outlet port;

and wherein the movable distributing member includes;

a hot liquid transfer cavity;

a cold liquid transfer cavity;

and wherein;

the mixing chamber is a convergence space formed in the body;

the hot liquid entry port is formed in said body and is in direct fluid communication with said hot liquid outlet port and with said convergence space;

the cold liquid entry port is formed in said body and is in direct fluid communication with said first cold liquid outlet port and with said convergence space;

the flow control means is capable of regulating the flow of hot and cold liquids entering said convergence space by opening the hot liquid entry port while closing the first cold liquid entry port and vice versa and is capable of completely closing said hot liquid entry port;

a temperature sensing portion of said temperature sensing device is located in said outlet;

said second entry port for the cold liquid is in direct fluid communication with said second cold liquid outlet port; and

wherein

the movable distributing member is movable to each of the following positions;

a first position where the hot liquid inlet port is in direct fluid communication with the hot liquid transfer cavity which is in direct fluid communication with the hot liquid outlet port and at the same time the cold liquid inlet port is in direct fluid communication with the cold liquid transfer cavity which is in direct fluid communication with the first cold liquid outlet port;

or

a second position where the hot liquid inlet port is in direct fluid communication with the hot liquid transfer cavity which is in direct fluid communication with the hot liquid outlet port and at the same time the cold liquid inlet port is in direct fluid communication with the cold liquid transfer cavity which is in direct fluid communication with the first cold liquid outlet port and the cold liquid transfer cavity also is in direct fluid communication with the second cold liquid outlet port;

or

a third position where the hot liquid inlet port and the cold liquid inlet port do not communicate with any outlet port.

4. The device according to claim 3, wherein said movable distributing member is movable in an infinitely variable manner between said positions.

5. The device according to claim 4, wherein said movable distributing member is arranged so that, in use, when moved between said first position and said second position, the flow rate from said outlet is maintained when there are substantially equal supply pressures of hot and cold liquids.

6. The device according to claim 5, wherein said movable distributing member is arranged so that, in use, when moved from said first or second positions to said third position, the flow rate from said outlet is reduced.

7. The device according to claim 1, wherein said flow control means is arranged so that, in use, it may be moved into a position effecting complete closure of said first cold liquid entry port.

8. The device according to claim 1, wherein the convergence space has an axis, a cylindrical wall coaxial with said axis and wherein said flow control means includes a movable member capable of moving within a cylindrical mixing chamber defined by said cylindrical wall.

9. The device according to claim 8, wherein said movable member comprises a partition across said cylindrical wall, slidable to and fro along said axis to provide a seal, and wherein an orifice is formed through said partition, said orifice providing communication between said hot and cold entry ports.

10. The device according to claim 9, wherein said first cold liquid entry port communicates with said convergence space via said cylindrical wall and said partition includes a further cylindrical wall which may be positioned over said cold liquid entry port.

11. The device according to claim 10, wherein said further cylindrical wall of said partition is shaped so that it forms a skirt that may be positioned over said cold liquid entry port in a position where the cold liquid entry port is completely closed so that, in use no cold liquid can then enter said convergence space.

12. The device according to claim 9, wherein a hot liquid entry passage communicates with said convergence space at or adjacent an end of said convergence space via said hot liquid entry port.

13. The device according to claim 12, wherein a mixing chamber inlet port is circular in cross-section and is coaxial with said axis.

14. The device according to claim 13, wherein said second cold liquid entry port includes a recess formed in said cylindrical wall lying substantially between surfaces which are normal to said axis.

15. The device according to claim 9, wherein said axis is parallel to an axis about which said movable distributing member may be rotated.

16. The device according to claim 9, wherein said temperature sensing device is arranged within said body so that, in use, the temperature sensing device expands in a direction along said axis on sensing an increase in liquid temperature and contracts along said axis on sensing a decrease in liquid temperature.

17. The device according to claim 16, wherein said temperature sensing device includes a housing and a piston capable of expanding and contracting and thereby being moved axially to and fro with respect to said housing, coaxially with said axis.

18. The device according to claim 17, wherein said piston is positioned so that it can directly contact said partition.

19. The device according to claim 18, further comprising a resilient bias which biases said partition and said piston towards the most contracted position of the piston of the temperature sensing device.

20. The device according to claim 19, wherein said resilient bias is a compression spring located between said mixing chamber inlet port and said partition.

21. The device according to claim 20, wherein said partition is cupped and said spring partially surrounds said piston.

22. The device according to claim 16, further comprising means for protecting said temperature sensing device, said protecting means preventing pressure above a pre-determined maximum pressure from developing within said housing.

23. The device according to claim 22, wherein said temperature sensing device is located in said body so that it is movable along said axis and said body is provided with a seat, and wherein said protecting means includes a second resilient bias which biases movement of said temperature sensing device relative to said body against expansion of said piston, said second resilient bias acting to locate said temperature sensing device against said seat, so that when a pressure within said mixing chamber exceeds a pre-determined maximum pressure said temperature sensing device moves against the action of said second resilient bias thereby moving away from said seat.

24. The device according to claim 3, wherein the movable distributing member and the stationary distributing member each comprise ceramic discs.

25. The device according to claim 3, wherein the movable distributing member has a convex spherical surface and the stationary distributing member has a concave spherical surface.

26. The device according to claim 3, wherein the movable distributing member has a convex cylindrical surface and the stationary distributing member has a concave cylindrical surface.

27. The device according to claim 1 wherein the device is in the form of a cartridge for a valve.

28. The device according to claim 1, wherein the device is a valve and the valve further comprises a single operating lever.

29. The device according to claim 1, further comprising:

a body supporting the movable and stationary distributing members;

sealing means to seal between parts of the movable and stationary distributing members;

wherein the stationary distributing member includes;

a hot liquid inlet port;

a cold liquid inlet port;

and wherein the movable distributing member includes;

a hot liquid transfer cavity;

a cold liquid transfer cavity;

and wherein the device further comprises the following, all wholly or partly contained in the body, or all wholly or partly contained in the moveable distributing member, or all wholly or partly contained in the stationary distributing member;

said mixing chamber is a convergence space;

said hot liquid entry port is in direct fluid communication with said hot liquid transfer cavity and with said convergence space;

said cold liquid entry port is in direct fluid communication with said cold liquid transfer cavity and with said convergence space;

and wherein;

said flow control means is located within said convergence space and is capable of regulating the flow of hot and cold liquids entering said convergence space by opening the hot liquid entry port while closing the first cold liquid entry port and vice versa and is capable of effecting complete closure of said hot liquid inlet port;

a temperature sensing portion of said temperature sensing device is located in said outlet;

said second entry port for the cold liquid is in direct fluid communication with said cold liquid transfer cavity; and

wherein

the movable distributing member is movable to each of the following positions;

a first position where the hot liquid inlet port is in direct fluid communication with the hot liquid transfer cavity which is in direct fluid communication with the hot liquid outlet port and at the same time the cold liquid inlet port is in direct fluid communication with the cold liquid transfer cavity which is in direct fluid communication with the first cold liquid outlet port;

or

a second position where the hot liquid inlet port is in direct fluid communication with the hot liquid transfer cavity which is in direct fluid communication with the hot liquid outlet port and at the same time the cold liquid inlet port is in direct fluid communication with the cold liquid transfer cavity which is in direct fluid communication with the first cold liquid outlet port and the cold liquid transfer cavity also is in direct fluid communication with the second cold liquid outlet port;

or

a third position where the hot liquid inlet port and the cold liquid inlet port do not communicate with each other and block communication from both said hot liquid inlet port and said cold liquid inlet port with any outlet.

30. A method of mixing and hot and cold liquid and regulating the temperature of the mixture in a shower, a bath or a faucet, the method comprising the steps of:

providing hot liquid into a mixing chamber via a hot liquid entry port;

providing cold liquid into the mixing chamber via a cold liquid entry port;

providing an outlet from said mixing chamber;

providing an outlet passage in direct fluid communication with said outlet of said mixing chamber;

altering the proportion of hot to cold liquid admitted through said hot liquid entry port and said cold liquid entry port into said mixing chamber at any rate of combined output flow with a flow control means within said mixing chamber;

sensing the temperature of an output of the mixed liquids from the mixing chamber with a temperature sensing device and controlling the flow control means so that an output temperature at all output flow rates from the mixing chamber does not exceed a selected maximum; and

introducing cold liquid into said outlet passage of said mixing chamber via a second entry port controlled by the flow control means downstream from where the temperature of the output flow from the mixing chamber is sensed to reduce the output temperature of the output flow from the mixing chamber to below the selected maximum temperature.