Thermostatic timeflow control cartridge

TECHNOLOGICAL FIELD

Embodiments of the present disclosure relate to a tap cartridge, a tap comprising the tap cartridge, and an appliance comprising the tap.

BACKGROUND

Thermostatic mixing valves are valves which mix hot and cold water to ensure a regulated, constant temperature that prevents scalding water being provided to a user of an appliance.

Previously thermostatic mixing valves have been provided separately to taps. This means there is often standing water in pipes between the thermostatic mixing valve and the tap that has cooled if the tap has not been used for a period of time. This is undesirable if a user is expecting hot water and they use the tap, as the tap will initially provide water at a cooled temperature due to clear the standing water in the pipes. There will therefore be a lag period before water that has been through the thermostatic mixing valve exits the tap, providing the desired temperature of water. This may be particularly undesirable for a user using a self-closing/timeflow tap, as the tap may automatically turn off before the water has reached the desired temperature, and the user will need to activate the tap at least once more to obtain water at the desired temperature.

Installation of a separate thermostatic mixing valve also increases installation cost and time. It is also an extra component to maintain.

BRIEF SUMMARY

According to a first aspect of the invention there is provided a tap cartridge comprising: a self-closing part and a thermostatic mixing part. The self-closing part comprises: a first chamber having a tap cartridge outlet, a second chamber, a valve body between the first chamber and the second chamber, means for causing movement of the valve body to selectively open the tap cartridge outlet in the first chamber, and means for causing movement of the valve body to automatically close the tap cartridge outlet after it has been opened. The thermostatic mixing part comprises: a heat sensitive element, a hot water inlet, a cold water inlet. The heat sensitive element is configured to change shape in response to the temperature of water which has entered the thermostatic mixing part. A change in shape of the heat sensitive element changes the relative amounts of water entering the thermostatic mixing part from the hot water inlet and cold water inlet, thereby regulating the temperature of water that exits the thermostatic mixing part. The tap cartridge is configured so that mixed hot and cold water exiting the thermostatic mixing part enters the first chamber of the self-closing part and exits the cartridge via the tap cartridge outlet when open.

The tap cartridge may additionally comprise one or more channels that at least partially encircle the tap cartridge outlet, thereby enabling water exiting the thermostatic mixing part to enter the first chamber before exiting the cartridge via the tap cartridge outlet when open.

The means for causing movement of the valve body to selectively open the tap cartridge outlet may comprise: a push-button handle and a central channel. The push button handle is configured to connect the second chamber to the central channel to decrease water pressure in the second chamber relative to the first chamber. The decrease in water pressure in the second chamber relative to the first chamber causes the valve body to move to open the tap cartridge outlet.

The thermostatic mixing part may additionally comprise a sledge, wherein the sledge is configured to contact the heat sensitive element and move in response to the change in shape of the heat sensitive element. The sledge is positioned so that movement of the sledge modifies the clearance of the hot water inlet and cold water inlet relative to the sledge to control the relative amounts of water entering the thermostatic mixing part from the hot water inlet and cold water inlet.

The push-button handle may be configured to rotate and may be connected to means for transforming rotational movement of the handle into vertical movement of the sledge and heat sensitive element, thereby modifying the clearance of the hot water inlet and cold water inlet relative to the sledge to influence the temperature of the water that exits the thermostatic mixing part.

In some examples the push-button handle is not configured to modify the clearance of the hot water inlet and cold water inlet relative to the sledge to influence the temperature of the water. In such an example, the tap cartridge is preset to a desired temperature and cannot be adjusted by a user actuating the push-button handle.

The means for causing movement of the valve body to automatically close the tap cartridge outlet after it has been opened may comprise: a biasing member located in the second chamber; and a passage between the first chamber and second chamber. The biasing member and the passage are configured to automatically equalize the water pressure in the first chamber and second chamber after the tap cartridge outlet has been opened, so as to enable the valve body to move to close the tap cartridge outlet.

The passage may be in a sidewall of the cartridge that forms part of the first chamber and second chamber.

According to a second aspect of the invention there is provided a tap comprising the tap cartridge of any preceding paragraph, additionally comprising a tap outlet connected to the tap cartridge outlet.

According to a third aspect of the invention there is provided an appliance comprising a basin and a tap as described in any preceding paragraph.

BRIEF DESCRIPTION

Some example embodiments will now be described with reference to the accompanying drawings in which:

FIG 1A shows an example tap cartridge.

FIG 1 B shows an example tap cartridge. FIG 1 C shows a cross section of an example tap cartridge.

FIG 2A shows an example tap cartridge in a first stage of operation.

FIG 2B shows an example tap cartridge in a second stage of operation.

FIG 2C shows an example tap cartridge in a third stage of operation.

FIG 3 shows part of an example tap cartridge.

DETAILED DESCRIPTION

FIG. 1A illustrates an example tap cartridge 100. FIG. 1A illustrates the example tap cartridge in partial three-dimensional cross section.

The tap cartridge 100 comprises a self-closing part 110 and a thermostatic mixing part 120. The self-closing part comprises: a first chamber 1 11 having a tap cartridge outlet 113, a second chamber 112, a valve body 114 between the first chamber 1 11 and the second chamber 1 12, means 1 15, 116, for causing movement of the valve body 114 to selectively open the tap cartridge outlet 113 in the first chamber 11 1 , and means 1 17, 118 for causing movement of the valve body 114 to automatically close the tap cartridge outlet 1 13 after it has been opened.

The thermostatic mixing part 120 comprises: a heat sensitive element 121 , a hot water inlet 123 and a cold water inlet 124. In this example the heat sensitive element 121 is configured to change shape in response to the temperature of water which has entered the thermostatic mixing part 120. A change in shape of the heat sensitive element 121 changes the relative amounts of water entering the thermostatic mixing part 120 from the hot water inlet 123 and the cold water inlet 124, thereby regulating the temperature of water that exits the thermostatic mixing part 120. The tap cartridge 100 is configured so that mixed hot and cold water exiting the thermostatic mixing part 120 enters the first chamber 1 11 of the self-closing part 1 10 and exits the cartridge 100 via the tap cartridge outlet 1 13 when open. In the example tap cartridge 100 shown in FIG. 1A, the hot water and cold water enter through inlets 123, 124 which are separated by an O-ring between the two inlets. In the example of FIG. 1A a sledge 122 is provided connected to the heat sensitive element 121. The movement of sledge 122 and the clearance between the sledge 122 and each of the hot water inlet 123 and cold water inlet 124 controls the relative amounts of hot and cold water entering the thermostatic mixing part 120. In some examples the thermostatic mixing part 120 is configured to shut off hot water supply from the hot water inlet 123 as a safety mechanism. This may be required if, for example, there is a fault in the supply of cold water. In some examples the thermostatic mixing part 120 is configured to shut off cold water from entering the thermostatic mixing part via the cold water inlet 124.

The heat sensitive element 121 changes shape in response to the temperature of water surrounding the heat sensitive element 121. In the example of FIG. 1A if the heat sensitive element 121 is heated, it changes shape to expand its length and forces the sledge upwards to reduce the amount of hot water entering through the hot water inlet 123. The reverse is true for when the temperature of the water is too cold, the heat sensitive element 121 changes shape to contract in length and this forces the sledge to increase the amount of hot water entering through the hot water inlet 123. A balancing member 125 is provided that is connected to the heat sensitive element 121 and sledge 122. The balancing member 125 returns the sledge 122 to its default position after the contraction or expansion of the heat sensitive element 121. In the example of FIG. 1A the balancing member is a spring.

Hot and cold water that has mixed in the thermostatic mixing part 120 exits the sledge via holes in the sledge 122, and travels up through one or more channels 130 into the first chamber 11 1 of the self-closing part 1 10.

The tap cartridge outlet 1 13 is blocked by the valve body 114 in the example of FIG. 1 A. Therefore, hot and cold water that has been mixed in the thermostatic mixing part 120 enters the first chamber 11 1 of the self-closing part 110 but is prevented from leaving the tap cartridge 100 due to the valve body 1 14 blocking the tap cartridge outlet 1 13. The opening of the tap cartridge outlet 1 13 and the automatic closing of the tap cartridge outlet 113 after it has been opened are controlled by the self-closing part 110. The movement of the valve body 1 14 due to the relative water pressure between the first chamber 11 1 and the second chamber 1 12 controls the opening and the closing of the tap cartridge outlet 1 13.

In the example of FIG. 1A, the opening of the tap cartridge outlet 113 is controlled by the push-button handle 1 15 which causes a central channel 1 16 to be connected to the second chamber 112 and to decrease the water pressure in the second chamber 1 12. In the example of FIG. 1A the handle 1 15 and the central channel 1 16 provide the means 1 15, 1 16 for causing movement of the valve body 1 14 to selectively open the tap cartridge outlet 1 13 in the first chamber 1 11. After the push-button handle 1 15 has been released by a user, the connection between the central channel 1 16 and the second chamber 1 12 is disconnected thereby preventing any further decrease in pressure in the second pressure 1 12. After the handle 1 15 is released, the closing of tap cartridge outlet 1 13 is automatic. In the example of FIG. 1A the automatic closing of the tap cartridge outlet 1 13 is controlled by a biasing member 1 17 in the second chamber and a passage 118 between the first chamber 1 11 and the second chamber 112. In the example of FIG. 1A the biasing member 1 17 and the passage 118 provide the means 1 17, 1 18 for causing movement of the valve body 1 14 to automatically close the tap cartridge outlet 1 13 after it has been opened.

FIG. 1 B illustrates an example tap cartridge 100. In FIG. 1 B the entire three- dimensional tap cartridge 100 is shown. In the example of FIG. 1 B a cartridge opening 150 is shown. Although not visible in FIG. 1 B, the tap cartridge 100 has another cartridge opening 150 on the opposite side of the tap cartridge 100.

FIG. 1C illustrates a cross-section of an example tap cartridge 100. In the example of FIG. 1C two channels 130 partially encircle the tap cartridge outlet 113 which is located more centrally radially than the channels 130. In FIG. 1 C cartridge outlet 1 13 is not shown as it is underneath the part of the valve body 1 14 which is shown in the cross- section of FIG. 1 C. The channels 130 partially encircling the tap cartridge outlet 113 enable mixed water coming up from the thermostatic mixing part 120 to enter the chamber 11 1 before exiting out of the tap cartridge outlet 130 which is located in the bottom of the first chamber 1 11. Encircling in this context means the channels 130 are located further radially outwards from the centre of the cross section of FIG. 1C. The cross-sectional shape of the channels may vary from the example shown in FIG. 1C. In some examples, the cross-sectional shape of the channels may include straight edges only (rectangular cross-section), curved edges only, or a mixture of straight edges and curved edges or may be circular. Any cross-sectional shape is adequate providing the channel 130 can provide water from the thermostatic mixing part 120 into the first chamber 11 1 of the self-closing part 110. If there are more than one channels 130, the channels 130 in some examples have the same cross-sectional shape, and in other examples the cross-section of the channels have different shapes.

FIG. 1 C also illustrates a zoomed in view of the passage 118. In this example the passage 118 is a cut out in the side wall of the tap cartridge 100, the cut out running from the first chamber 1 11 to the second chamber 1 12. The passage 1 18 bypasses the valve body 1 14 to allow a small flow of water from the first chamber 1 11 to the second chamber 112. In the example of FIG. 1C the passage 118 is rectangular in cross-sectional shape but in other examples the cross-sectional shape is different. For example the cross-sectional shape of the passage 1 18 may be circular.

FIGS. 2A to 2C illustrate an example tap cartridge 100 in two-dimensional cross- section. Due to showing the tap cartridge 100 in two-dimensional cross-section in FIGS. 2A to 2C, the one or more channels 130 are not visible in FIGS. 2A to 2C. As shown in FIG. 1A and FIG. 1 C the one or more channels 130 are present in the tap cartridge 100 and partially encircle the tap cartridge outlet 1 13. For example, the one or more channels 130 are located further away from the central channel 116 than the tap cartridge outlet 1 13 in a direction perpendicular to the length of the central channel 1 16.

FIGS. 2A to 2C illustrate the tap cartridge 100 in different stages of operation. FIG. 2A illustrates the tap cartridge 100 before the push-button handle 1 15 has been actuated, FIG. 2B illustrates the tap cartridge 100 when the handle 115 is being pushed and FIG. 2C shows the tap cartridge 100 after the tap cartridge outlet 1 13 has been opened due to the actuation of the push-button of the handle 115. As illustrated in FIG. 2A the tap cartridge outlet 1 13 is closed by valve body 114. Therefore, water from the thermostatic mixing part 120 cannot exit the tap cartridge 100 via the tap cartridge outlet 1 13 after it has entered the first chamber 1 11.

In FIG. 2B the push-button of handle 1 15 has been actuated and this causes one or more passages to open that allow water from the second chamber 1 12 to enter the central channel 116, so that the second chamber 112 is connected to the central channel 116. A gap 1 161 between the central channel 1 16 and the valve body 1 14 allows water from the central channel 116 to exit the tap cartridge 100 via the one or more cartridge openings 150.

Due to the water exiting the second chamber 112, the water pressure in the second chamber 112 will decrease. The water in first chamber 1 11 is at a higher pressure than the second chamber 1 12 when the water is exiting the second chamber 1 12 into the central channel 116. Due to the difference in water pressure between the first and second chamber, the valve body 1 14 will move up causing the tap cartridge outlet 113 to open.

FIG. 2C illustrates the tap cartridge 100 after the valve body 114 has moved up due to the difference in water pressure in the first chamber 111 and the second chamber 112. In FIG. 2C due to the valve body 114 having moved up, the tap cartridge outlet 113 has been opened and water from the first chamber 11 1 can exit tap cartridge outlet 1 13 and exit the tap cartridge 100 via the one or more openings 150.

When the push button on the handle 1 15 has been released the handle 115 is biased to return to a default position and the second chamber 1 12 and the central channel 1 16 are disconnected due to the passages between them no longer being open. The biasing member 117 in the second chamber is configured to move the valve body 114 back to closing the tap cartridge outlet 113. Additionally, the small passage 118 causes a small flow of water from the first chamber to the second chamber which increases the water pressure in the second chamber 112. Therefore, after the handle 1 15 has been released, the biasing member 117 and the passage 118 act to equalise the water pressures in the first chamber 1 1 1 and the second chamber 112 and to close the tap cartridge outlet 113. The period the cartridge outlet stays open is determined by the flow speed of water in the passage 118 from the first chamber to the second chamber, and depends on the water pressure, the water temperature, the volume of the chambers and the dimensions of the passage 1 18. The strength of the biasing member 1 17 may also determine how quickly the tap cartridge outlet 1 13 is closed after the handle 1 15 is released.

FIG. 3 illustrates means 140 for transforming a rotational movement of the handle 115 into vertical movement of the sledge 122 and heat sensitive element 121. In the example of FIG. 3 the handle 115 is configured to rotate the handle 115 is connected to means 141 , 142 for transforming rotational movement of the handle 115 to rotational movement of spindle 143. The threads of spindle 143 engage with a inner screw 144 that has engaging threads that engage with the threads of spindle 143. Due to the threads of the inner screw 144 engaging with the threads of spindle 143, the threads of the inner screw 144 counter rotate relative to the rotation of the handle 115 and this causes axial/vertical movement of inner screw 144. Spring 145 and engaging member 146 are connected to inner screw 144. Engaging member 146 is in contact with the heat sensitive element 121 and movement of the engaging member 146 due to movement of the inner screw 144 causes the heat sensitive element 121 and the sledge 122 to move axially/vertically to change the clearance of the hot water inlet 123 and cold water inlet 124 relative to the sledge 122. This allows a user of the tap cartridge to influence the temperature of the mixed hot and cold water that exits the tap cartridge 100.

In this example the spring 145 is provided as a safety device in case the heat sensitive element overcharges and the spring is pre-compressed through inner screw 144. In other examples the spring 145 is not provided and engaging member 146 is connected directly to inner screw 144.

In this example the tap cartridge 100 allows the user to influence the temperature of the mixed water by rotating the handle 1 15. In other examples the tap cartridge 100 is provided without means 140 for transforming rotational movement of the handle into vertical movement of the sledge 122 and heat sensitive element 121 so that the user cannot influence the temperature of the water that exits the cartridge 100.

In the examples above, the thermostatic mixing part 120 may be a thermostatic mixing valve with a wax element as the heat sensitive element 121. The wax element may for example be a metal capsule containing wax, which expands in response to heat and contracts if it is cool. As the wax expands it forces a piston out of the top of the heat sensitive element 121 causing movement of the sledge 122. In other examples any suitable thermostatic mixing part may be used. For example, a thermostatic mixing valve with a bi-metallic coil connected to a shuttle as the heat sensitive element 121 may be provided. When water flows over the coil changing its temperature, the coil expands or contracts accordingly. The movement of the coil and shuttle changes the relative amounts of hot and cold water entering the thermostatic mixing part 120. In other examples, the thermostatic mixing part 120 may be provided by a thermostatic mixing valve which uses electronic sensors in combination with valves, pumps or motorised controls to control the relative amounts of hot and cold water entering the thermostatic mixing part.

In some examples the biasing member 1 17 is a spring, however any suitable biasing member, such as rubber, may be used to provide the necessary function of the biasing member 1 17.

In the examples provided above the self-closing part 1 10 uses handle 1 15. Any self closing system may be used in the tap cartridge 100 providing it has a first cartridge 1 11 for storing water prior to it exiting the cartridge, and a second chamber 112, and that the cartridge tap outlet 113 is closed automatically after it has been opened.

In the examples above channels 130 are used to transfer water from the thermostatic mixing part 120 to self-closing part 110. In other examples, tubes may transfer the water. In this example, the self-closing part 1 10 and thermostatic mixing part 120 are still provided in a single cartridge with shared structural features.

Examples of the present disclosure provide the advantage that thermostatic control and self-closing control are provided in a single tap cartridge 100. Therefore, this provides the advantage of minimising the amount of standing water that has to be emitted from the tap before water at the correct temperature is being emitted from the tap. A self-closing tap with this thermostatic control has the advantage that it may prevent scalding. In some examples of the disclosure, the tap cartridge 100 also provides means for the user to influence the temperature of the water that exits the tap by rotating the handle 115. In other examples the temperature of the tap cartridge 100 is fixed and is not adjustable by the user, therefore temperature regulation is provided only by the thermostatic mixing part 120 regulating the temperature of the water that exits the tap cartridge 100. For example, the tap cartridge 100 may be configured so that it regulates the temperature of the water that exits the tap cartridge to be hot but without scalding a user of the tap.

The tap cartridge can be used in any suitable tap or operating member and can be used for a variety of appliances. For example, the tap cartridge may be inserted into a tap that is then used in an appliance such as a bath, a sink or shower.