Patent Description:
Thermostatic radiator valves (TRVs) are devices which are connected to radiators to control the flow of fluid to the radiator. TRVs have traditionally contained a wax plug, connected to a pin which is in turn connected to a valve. The wax plug expands or contracts based on the surrounding (room) temperature, which moves a pin and the connected valve. As the room temperature increases, the wax plug expands, which closes the valve and restricts the flow of hot fluid into the radiator. In this way, the temperature of a room can be controlled.

Electrical TRVs have become increasingly popular in recent years. Electrical TRVs can use electrical temperature sensors to give an accurate temperature reading with reduced latency in comparison to the wax plug of traditional TRVs. Electrical TRVs can also have programmers so that individual or groups of radiators may be programmed for different temperatures at different times of the day and may be connected to a "smart" network which allows interconnectivity between appliances, and control from one or more central controllers. Electrical TRVs typically use a battery-powered electric motor to drive a linear actuator (in place of the wax plug of traditional TRVs) to move a pin which is connected to a valve. This arrangement often requires a gearbox between the motor and the linear actuator.

An example of a thermostatic radiator valve is described in <CIT>).

<CIT> relates to a return temperature limiter remote sensor and actuator.

Some drawbacks have been identified with the above-mentioned arrangements. For example, the linear actuator and/or gearboxes used these electrical TRVs can be noisy, inefficient and/or bulky.

The present invention seeks to mitigate the above-mentioned problems. Alternatively or additionally, the present invention seeks to provide an improved thermostatic radiator valve.

The present invention is defined by the independent claims, and optional dependent claims.

The present invention provides, according to a first embodiment, a thermostatic radiator valve comprising a valve head and a valve body. The valve head comprises an actuation assembly for moving a valve pin of the valve body. The actuation assembly comprises: a pressure chamber; a pneumatic pump, which is according to the invention a peristaltic pump, and which is arranged to adjust the pressure inside the pressure chamber; and an output element for abutting the valve pin. The output element is arranged to move in response to a change of pressure inside the pressure chamber such that the change of pressure effects movement of the valve pin. The use of such an actuation assembly may avoid the need for a mechanical actuator and/or associated gearbox to move the valve pin, which may thereby simplify and reduce the noise and bulk of the TRV.

In the present invention, the output element is flexible. The output element is a diaphragm. The output element being a diaphragm may reduce the number of moving parts and sliding contacts, which is advantageous in terms of simplicity. The output element being a diaphragm may enable actuation whilst also enabling effective sealing of the pressure chamber. There may be reinforced portions of the diaphragm to control the movement of the diaphragm. The reinforced portions of the diaphragm may be arranged to control the shape of the diaphragm when the diaphragm is displaced due to pressure change within the pressure chamber. The reinforced portions of the diaphragm may be plastic, rubber or any material which can provide a reinforcing effect.

In some embodiments not part of the present invention, the output element may be a piston.

In the present invention, the output element may have an interior face, facing inwardly into the pressure chamber. The output element may have an exterior face, facing outwardly from the pressure chamber. The exterior face of the output element may be in contact with the valve pin. It may be that movement of the output element effects movement of the valve pin.

The TRV may comprise a housing which houses the actuation assembly. The pneumatic pump may be located within the housing of the TRV. In some embodiments, the pneumatic pump may be located within the housing of the TRV and outside the pressure chamber. In some embodiments, the pneumatic pump may be located inside the pressure chamber. Such an arrangement may be beneficial because it may reduce the extent of sealing between the pump and the pressure chamber.

The pneumatic pump is a peristaltic pump. A peristaltic pump has been identified as being especially advantageous in the context of a pneumatically actuated TRV. For example, peristaltic pumps may relatively compact, and therefore suitable in a TRV. The peristaltic pump may be arranged to adjust the pressure within the pressure chamber. The peristaltic pump may be operated to increase the pressure within the pressure chamber. The peristaltic pump may be operated to decrease the pressure within the pressure chamber. The peristaltic pump may be operated to maintain the pressure within the pressure chamber. Using a peristaltic pump in a TRV may be advantageous for the reduction of noise, size, energy requirements and/or frictional losses.

The peristaltic pump may be arranged to use the housing, and more preferably the pressure chamber wall, as a part of the pump. For example, the housing, and more preferably the pressure chamber, may be arranged as a reaction surface against which a tube may be deformed. The peristaltic pump may extend across the full width of the pressure chamber.

The peristaltic pump may comprise a tube and a wheel with at least one lobe. The wheel may be driven by a motor. The peristaltic pump may comprise a tube and a wheel with at least two lobes. Preferably, the wheel of the peristaltic pump comprises a multiplicity of lobes. The tube of the peristaltic pump may be arranged to transfer air between inside the pressure chamber and outside the pressure chamber. The tube of the peristaltic pump may be arranged to transfer air through the wall of the pressure chamber. The tube of the peristaltic pump may comprise two openings. The tube of the peristaltic pump may comprise a first opening which transfers air between the tube and outside of the pressure chamber, and a second opening which transfers air between the tube and the pressure chamber. The tube of the peristaltic pump may be a resiliently deformable material, such as silicone. The tube of the peristaltic pump may be disposed against the pressure chamber wall, such that the lobe of the wheel compresses the tube against the pressure chamber wall. The lobe of the wheel compresses the tube to form a seal. The peristaltic pump drives air between inside the pressure chamber and outside the pressure chamber by rotating a lobe of the wheel against the tube. Rotating the wheel transfers air between two openings in the tube.

The pneumatic pump may be powered by an electric motor. Providing an electric motor in the pump has been found to be especially advantageous as it may allow commonality with some features in existing electrical TRVs (e.g. use of common motors/power and /or control of the motor). The electric motor may be housed within the housing of the TRV. More preferably, the electric motor may be housed within the pressure chamber; such an arrangement may reduce the degree of sealing required for the pressure chamber. The power source for the electric motor may be outside of the pressure chamber. The power source for the electric motor may be within the housing of the TRV. Such an arrangement may be beneficial because it allows the power source to be readily replaced (for example to replace batteries). The power for the electric motor may transfer from the power source to the electric motor through a pressure-sealed arrangement in the pressure chamber wall.

The thermostatic radiator valve may be configured to receive a temperature measurement signal. The pneumatic pump may be controlled in dependence on the temperature measurement signal. The TRV may comprise a controller configured to control the pneumatic pump in dependence on the temperature measurement signal.

The thermostatic radiator valve may be fitted to a radiator. The radiator may be part of a heating system, for example a domestic heating system.

According to a further aspect there is provided a thermostatic radiator valve head according to claim <NUM>.

According to a second aspect of the invention there is also provided a method of controlling a thermostatic radiator valve according to the first aspect of the invention. The method comprises the steps of: receiving a temperature measurement; comparing the temperature measurement to a temperature set point;
adjusting the pressure inside a pressure chamber of the thermostatic radiator valve to the required pressure such that an output element moves the valve pin to a valve set point required to achieve the temperature set point.

According to a third aspect of the invention there is also provided a boiler valve in a heating system according to claim <NUM>. The boiler valve comprises a valve body with a valve pin and a valve head comprising an actuation assembly for moving said valve pin, the actuation assembly comprising: a pressure chamber; a pneumatic pump arranged to adjust the pressure inside the pressure chamber; and an output element for abutting the valve pin; wherein the output element is arranged to move in response to a change of pressure inside the pressure chamber such that the change of pressure effects movement of the valve pin. The output element is a diaphragm and the pneumatic pump is a peristaltic pump. Using a peristaltic pump in such a boiler valve has been found to be especially beneficial.

The boiler valve may be a three-way valve.

<FIG> illustrates a thermostatic radiator valve (TRV) <NUM> according to a first embodiment of the invention. The TRV <NUM> comprises a valve head <NUM> connected to a valve body <NUM> via a securing ring <NUM>. The valve body <NUM> comprises an angled connector pipe <NUM> for connecting to pipework on a radiator (not shown). Flow through the connector pipe <NUM> is selectively controlled via movement of a valve element <NUM> connected to a valve pin <NUM>. A valve body <NUM> having these features per se is well known and will be understood by the person skilled in the art.

The TRV head <NUM> comprises a housing <NUM> which houses an actuation assembly <NUM> for effecting movement of the valve pin <NUM>. The actuation assembly <NUM> comprises a pressure chamber <NUM> and is powered by a power source <NUM> in the form of a battery, located in the housing <NUM> above the pressure chamber <NUM>.

Further details of the actuation assembly <NUM> in the valve head <NUM> are shown in <FIG> and <FIG> to which reference is now made. <FIG> shows a sectional view of the TRV <NUM> in <FIG>; the section is taken along section A-A of <FIG> and <FIG> shows a sectional view of the TRV <NUM> in <FIG>; the section is taken along section B-B of <FIG>.

Referring first to <FIG>, the pressure chamber <NUM> is located within the housing <NUM>. The pressure chamber <NUM> has within it a motor <NUM> configured to drive a peristaltic pump <NUM>. The peristaltic pump <NUM> comprises a tube <NUM> and a wheel <NUM> comprising a multiplicity of lobes <NUM> (shown in <FIG>) around its perimeter, and bearings <NUM>. The tube <NUM> is disposed between the lobes <NUM> of the wheel <NUM> and the interior wall of the pressure chamber <NUM>. The tube <NUM> has an inlet <NUM> and an outlet <NUM> (shown in <FIG>). The tube enables air transfer between the pressure chamber <NUM> and the outside environment such that the pressure in the chamber <NUM> can be decreased, increased, or maintained, via a suitable rotation of the wheel <NUM>. The motor <NUM> is configured to drive the rotation of the wheel <NUM> of the peristaltic pump <NUM>. The motor <NUM> driving the wheel <NUM> of the peristaltic pump <NUM> in a forward direction increases the pressure within the pressure chamber <NUM>, while driving the wheel <NUM> in the rearward direction decreases the pressure within the pressure chamber <NUM>. When the wheel <NUM> is held in position by the motor <NUM> there is no substantial increase or decrease in pressure within the pressure chamber <NUM>.

The lobes <NUM> of the wheel <NUM> seal the pressure chamber <NUM> when the wheel <NUM> is held in a fixed position, by preventing air from passing through the tube <NUM> past the position of the lobe <NUM>.

The motor <NUM> according to the first embodiment of the invention is an electric motor. The motor <NUM> receives power from the battery <NUM> (not shown in <FIG> but schematically illustrated in <FIG>) via a power cable <NUM> which passes through the wall of the pressure chamber <NUM>. The interface between the power cable <NUM> and the wall is sealed <NUM> to prevent air egress from the pressure chamber <NUM>.

On the bottom of the pressure chamber is a <NUM> diameter diaphragm <NUM>. The diaphragm has an interior face <NUM> and an exterior face <NUM>. The exterior face <NUM> is configured to contact the valve pin <NUM> of the valve body <NUM>. The interface between the diaphragm <NUM> and the pressure chamber <NUM> is sealed by seals <NUM> which prevent pressure egress from the pressure chamber <NUM>.

The exterior surface <NUM> of the diaphragm <NUM> is configured to abut a first end of the valve pin <NUM>. The valve pin <NUM> is connected at its other end to the valve element <NUM> (see <FIG>) such that downward movement of the valve pin <NUM> closes the valve. Increasing the pressure within the pressure chamber <NUM> increases the force applied to the valve pin <NUM>. Decreasing the pressure within the pressure chamber <NUM> decreases the force applied to the valve pin <NUM>.

The diaphragm has a range of movement. The range of movement of the diaphragm <NUM> is the maximum difference in displacement of the diaphragm when the pressure chamber <NUM> is at its extremes of low- and high-pressure achievable in operation. The diaphragm <NUM> is arranged to have a possible range of movement of between <NUM> and <NUM> to make it useable on a range of valves. In the first embodiment of the invention, the diaphragm typically undergoes a range of movement of between <NUM> and <NUM> because that is the range of movement of the valve pin in this embodiment.

An arrangement in which the actuation assembly comprises a peristaltic pump has been found to be especially beneficial. For example, it has been found that the above-mentioned arrangement is able to exert a 90N force on the valve pin <NUM> with around <NUM>. 5bar within the pressure chamber <NUM>. Thus, there is no need for a gearbox, that might otherwise be needed for the motor to directly drive the valve pin. This may enable the noise, bulk and/or complexity of the TRV to be reduced, and facilitates a relatively quiet and compact TRV.

The TRV <NUM> is configured to connect wirelessly to the smart network and the TRV <NUM> comprises a receiver configured to receive signals from a thermostat, that control the operation of the TRV <NUM> within the heating system.

A controller (not shown) controls the operation of the peristaltic pump <NUM> to alter the position of the valve pin <NUM>. <FIG> shows a flow diagram of a control scenario in a second embodiment of the invention. The controller receives <NUM> a temperature measurement input from a thermometer and compares <NUM> this to a desired temperature set point (communicated by a central thermostat in a heating system). The controller generates <NUM> a value for a valve set point which will achieve the desired temperature set point and calculates the motor position required to obtain the pressure within the pressure chamber which will achieve the valve set point. The controller then instructs <NUM> the required motor position to the TRV <NUM>.

Whilst the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein, the scope of the invention being defined in the appended claims.

In a further embodiment of the present invention, the peristaltic pump may be located outside the pressure chamber and comprises an outlet that feeds into the pressure chamber. In yet another embodiment of the invention, the actuation assembly may be located in a boiler valve of a heating system as defined in claim <NUM>.

Reference should be made to the claims for determining the true scope of the present invention.

Claim 1:
A thermostatic radiator valve (<NUM>), comprising a valve head (<NUM>) and a valve body (<NUM>), the valve head (<NUM>) comprising an actuation assembly (<NUM>) for moving a valve pin (<NUM>) of the valve body (<NUM>), wherein the actuation assembly (<NUM>) comprises:
a pressure chamber (<NUM>);
a pneumatic pump (<NUM>) arranged to adjust the pressure inside the pressure chamber (<NUM>); and
an output element for abutting the valve pin (<NUM>);
wherein the output element is arranged to move in response to a change of pressure inside the pressure chamber (<NUM>) such that the change of pressure effects movement of the valve pin (<NUM>); and
wherein the output element comprises a diaphragm (<NUM>) and the pneumatic pump (<NUM>) is a peristaltic pump.