A volumetric control device for a fluid volume

Abstract

Volumetric control device 99 for a fluid volume 55, comprising a fluid inlet 1, an upper control valve 4, a lower control valve 8, a mechanical switch 20 associated with the control valves, where the lower control valve controls the mechanical switch, and the upper control valve is controlled by the mechanical switch. The upper control valve may comprise a pivoting float valve or an electrical switch. The mechanical switch may comprise a float travelling within an internal bore of a vertically arranged cylindrical connecting member or chamber or tube 2. The connecting member may comprise a slot 5 at its upper end for passage of the upper control valve, which in turn comprises an arm 7 travelling in the slot. The lower control valve may comprise a floating ball 11. Also claimed is a tank comprising the device. The upper control valve may control the fluid inlet. The mechanical switch may ensure quick stop and start and prevent oscillation in the system.

Description

Field of the Invention The present invention relates to a volumetric control device for a fluid volume, in particular a means of maintaining a desired level in a volume of fluid; more particularly but not exclusively a means of maintaining a desired level of liquid En a water tank for example. Background In many societies across the world there is an increasing awareness of the need to save energy, limit wear, replacement and maintenance needs in all fields. In the field of water tanks, it is common that in order to maintain a desired level within the tank there will be a valve. This valve will often be a ballcock or similar type, such that the ball drops as the water level falls, the valve will subsequently be opened, to allow more water into the tank. As the level within the volume is maintained within the small range of the ballcock's switching movement on / off cycles are numerous. This causes wear to components especially in large tanks with slow level changes where the valve rarely fully opens or closes but also in small tanks where level changes are rapid and frequent. Prior Art EP 3 101322 (FOMINAYA) discloses a cock for filling tanks, comprising a hollow head that supports a valve device associated with a float by means of an intermediate device, also comprising a vertical tube connected to the hollow head, in which the vertical tube is housed inside a central passage in the float which moves as the level of water in the tank rises and falls. The float is connected to a bush that is coupled around the vertical tube along which the bush moves, and the upward and downward movement of the float drags the bush when the float is anchored thereto. CN 102 080 738 (CHEN) discloses a float ball valve which comprises a valve body connected with a water supplying pipeline, a float ball, a valve core, and a water storing box, wherein the valve body is provided with a switch on-off mechanism which is connected with the valve core; the valve core is matched with the inner wall of a cavity of the valve body; the switch on-off mechanism comprises an upper fixed holder, an lower fixed holder, a positioning rod and a lever, wherein the upper fixed holder and the lower fixed holder keep the valve core in the inner part of the water exhaust side and water intake side of the valve body; the positioning rod and the lever are connected with the valve core; the upper end and the lower end of the valve core are respectively connected with an upper positioning rod and a lower positioning rod. TW 2009 25 360 (HUANG) discloses a multi-float water inlet control valve comprising: a valve body, a valve stem movably disposed within the valve body, the valve stem being fixed with a valve plug for blocking the valve body, a linkage stem pivotally connected to the valve body for carrying the valve stem, the linkage stem extending with a stem having an end face formed as a fully-closed contact slide point, and a valve stem extending from the stem to the stem. Summary of the Invention According to the present invention there is provided a volumetric control device for a fluid volume, comprising: a fluid inlet to the fluid volume; an upper control valve; a lower control valve; and a mechanical switch. The mechanical switch controls when the upper valve opens and closes, dependent on whether the lower valve holds the chamber empty or full. In this way the device may advantageously ensure that the volume of water in a fluid volume may be controlled. It ensures that the level will be required to fall to the lower control valve before the inlet is opened, but rise to the upper control valve before the inlet is closed, meaning that variations in the level are not liable to cause frequent and repetitive filling prompts, and associated problems with equipment and cycling. Additionally, the mechanical switch ensures quick stop and start, preventing oscillation in the system. It may be envisaged that the mechanical switch is arranged to move quickly in relation to the filling or emptying of the volume, for example being comprised by a substantially smaller volume, to provide a quick stop activation means when an upper level is reached for the volume, and a quick stop activation means when a lower level is reached for the volume. The device is therefore also claimed within a tank providing said fluid volume. In some embodiments of the device the device comprises an upper control valve that comprises a pivoting float valve. In some embodiments of the device the mechanical switch comprises a float, which float travels between the control valves, to control open and closing of the upper control valve. In some embodiments of the device the device comprises a connecting member between the upper control valve and lower control valve, so as to allow the device to be formed, transported or installed as a whole unit, for ease and cost concerns. In some such embodiments of the device the connecting member comprises a float chamber for a float travelling within the connecting member, for example under fluid pressure related to or associated with the volume of fluid in the volume. In some such embodiments of the device the connecting member comprises a cylindrical member with an internal bore, for example wherein a close-fitting cylindrical float moves. The cylindrical member may be vertically arranged. In some embodiments of the device the device comprises a fluid ingress in an upper region of the connecting member, which may dispense into the member from the volume for example. Such fluid ingress may for example be in the form of a slot in the member. in some embodiments of the device the connecting member thereby includes a slot for passage of fluid and the upper control valve, which slot may allow water into the member from the volume. The upper control valve rod may travel in the slot under the urging of the float in the chamber. The mechanical switch may comprise a float travelling within the internal bore between the upper control valve at a first end of the internal bore and the lower control valve at a second end of the internal bore. In some embodiments of the device the device lower control valve comprises a float valve, for example with an arm having a distal floatation ball. In further embodiments of the device an electrical on / off switch may replace the control valve so as to operate pumps without pressure switches. According to further aspects of the present invention there is provided a method of forming a fillable volume incorporating the device substantially as described herein, and a fluid tank incorporating such a device. A preferred embodiment of the invention will now be described by way of example only and with reference to the Figures in which: Brief Description of Figures Figure 1 shows an isometric view of an embodiment of the device according to the present invention with the upper control valve open; Figure 2 shows a sectional embodiment of the device according to the present invention, with upper control valve open; Figure 3 shows an isometric view of the embodiment of the device shown in Figure 1, with the upper control valve closed; Figure 4 shows a sectional view of the embodiment of the device according to the present invention with upper control valve closed; Figure 5 shows an exploded isometric view of the embodiment of the device shown in Figure 1; Figure 6 shows a sectional view of the embodiment of the device with an electrical switch, replacing the upper control valve, showing the pump switch on; Figures 7 show a sectional views of an embodiment of the device according to the present invention, with an electrical switch in the off position. Detailed Description of Figures With reference to the embodiment shown in Figure 1, there is shown an embodiment 99 of a volumetric control device for a fluid volume 55, generally comprising: a fluid inlet 1; an upper control valve 4; a lower control valve 8; and a mechanical switch 20, shown in Figures 2 and 5, between the control valves; wherein the lower control valve controls the mechanical switch, and the upper control valve is controlled by the mechanical switch to open and close the fluid inlet. In particular reference to the pictured embodiment the embodiment comprises an upper control valve 4 provided by a pivot, pivoted at an upper pivot so as to allow an upper arm 7 to move in a vertical orientation, as driven by a mechanical float switch 20 moving vertically within a cylindrical tubular connecting member internally providing the float chamber 2,. The fluid inlet 1 is provided with fluid from a pipe 3 that in the first pictured embodiment extends upwards from below and outside the volume 55, and provides pressurised water such as from a mains water supply or pump. This fluid fills the volume 55 to a level when the fluid enters the float chamber and moves the float switch, where it rapidly fills the float chamber and closes the fluid inlet by closing the upper control valve 4. When the level in the volume 55 is below the lower control 8 valve the lower control valve will be opened, the fluid will exit the float chamber 2, and the float switch 20 will drop and open the upper control valve 4, so as to fill the volume 55 again. At the proximal end of the upper arm 7 there is a closure means for the fluid inlet 1, associated with the pivoting upper arm 7. When the closure means is displaced from the fluid inlet the fluid inlet allows passage of fluid into the volume. The upper arm is arranged to travel in a slot 5 in the sides of the cylindrical tubular float chamber 2 which contains the mechanical switch 20. The slot 5 maintains upper arm 7 in line with the centre of the top of float 20, and acts as the fluid ingress to the float chamber 2 from the volume 55. The bottom of the slot controls where the upper desired level of fluid in the volume 55 will reach. This level is where the float chamber 2 fills as the fluid enters the chamber through the slot. The float chamber 2 has a small bore so will fill rapidly, preventing oscillations in the system. When the chamber is full the float 20 forming a part of the mechanical switch will rise and push the upper arm upwards and closing the upper valve. Draining the float chamber opens the inlet as the float 20 drops and allows the upper arm to pivot down, opening the inlet. The slot allows the upper arm free movement in the vertical plane, at least the ful range of the upper arm 7 operating valve 4, with extra provision at the top end for wear in valve 4 and at the bottom for full valve opening. The upper arm may be envisaged never to touch the top or bottom of the slot. As shown in the pictured embodiment the float chamber 2 is provided by a connecting member between the upper control valve and the lower control valve. This connecting member is cylindrical and is vertically arranged, and contains the floating mechanical switch 20 within it, so that around the switch there is little space. At the bottom end of the member there is a bend, leading to a spur 13 so as to provide an attachment means 12 for a side of the volume or tank (not shown) and on the proximal end of the bend is located the lower control valve 8. The lower control valve comprises a floating ball valve, as known in the art, which comprises a lower arm 14 having at the proximal end the pivot and a fluid outlet closure means 10, and at the distal end of the pivoted arm 14 a floating ball 11. The ball 11 thereby floats on or in the fluid within the volume, such that when the fluid level in the volume is below the ball, or more particularly when the closure means is displaced from the fluid outlet, the outlet is opened by displacement of the closure means, and fluid flows from the member and empties it, thereby allowing the float 20 forming the mechanical switch to drop to the member’s bottom, and consequently allowing the upper arm 7 to drop towards the bottom of the slot 5. The mechanical switch 20 comprises a length of cylindrical tube, with caps at either end. The outer diameter of the tube may be envisaged to be close to the internal bore diameter of the float chamber 2. The mechanical switch 20 contacts and drives the upper arm 7 when the float chamber 2 is filled. The length of the mechanical switch 20 may be subject to variation in further embodiments, for example by variation of factors such as length of float chamber or desired upper and lower volume levels. In the pictured embodiments the small volumetric variance between the mechanical switch 20 and its float chamber 2 results in rapid movement of the mechanical switch, achieving quick stop in any size of tank volume. Fluid enters the member 2 through the slot 5 near the top of the member. When the fluid level is below the lower control valve the fluid outlet allows the member bore to empty, the internal float to drop, and the arm dropping accordingly to allow the upper control valve 4 to open the inlet 1, such that the fluid is let into the volume. When the fluid level is above the lower control valve but below the upper control valve, the lower control valve is closed and the chamber outlet is closed, and the upper control valve is open, such that the inlet is open. In this way the volume is enabled to fill until the level of the volume reaches the bottom of the slot, when the member is filled. When the fluid level, in the chamber, is such that the float 20 reaches the upper control valve the inlet will be closed. The volume is enabled to be emptied through other means and may be added to only when the lower control valve is reached, avoiding repeated stresses on valves, or control and storage apparatus in general, as well as a continuous reversal of fluid levels and activation of the fluid inlet. With referenceto the second pictured embodiment shown in Figures 6 and 7 the upper control valve may be envisaged to be replaced with an electrical switch, for example in relation to water that is pumped into the volume. The invention has been described by way of examples only and it will be appreciated that variation may be made to the above-mentioned embodiments without departing from the scope of protection as defined by the claims.

Claims

1. A volumetric control device for a fluid volume, comprising: a fluid inlet to the fluid volume; an upper control valve; a lower control valve; and a mechanical switch associated with the control valves; wherein the lower control valve controls the mechanical switch, and the upper control valve is controlled by the mechanical switch to open and close the fluid inlet.

2. A volumetric control device for a fluid volume according to claim 1 wherein the upper control valve comprises a pivoting float valve.

3. A volumetric control device for a fluid volume according to claim 1 wherein the upper control valve comprises an electrical switch.

4. A volumetric control device for a fluid volume according to claim 1, 2 or 3 wherein the mechanical switch comprises a float.

5. A volumetric control device for a fluid volume according to any preceding claim comprising a connecting member between the upper control valve and lower control valve.

6. A volumetric control device for a fluid volume according to claim 5 wherein the connecting member comprises the mechanical switch.

7. A volumetric control device for a fluid volume according to claim 5 or 6 wherein the connecting member comprises a cylindrical member with an internal bore.

8. A volumetric control device for a fluid volume according to claim 7 wherein the mechanical switch comprises a float travelling within the internal bore between the upper control valve at a first end of the internal bore and the lower control valve at a second end of the internal bore.

9. A volumetric control device for a fluid volume according to any of claims 5 to 8 wherein the connecting member is vertically arranged.

10. A volumetric control device for a fluid volume according to any of claims 5 to 9 comprising a fluid ingress in an upper region of the connecting member.

11. A volumetric control device for a fluid volume according to any of claims 5 to 10 wherein the connecting member includes a slot for passage of the upper control valve.5      12. A volumetric control device for af luid volume according to claim 11 wherein theupper control valve comprises an arm travelling in the slot.

13. A volumetric control device for a fluid volume according to any of the preceding claims wherein the lower control valve comprises a float valve.

014. Apparatus comprising a device according to any of the preceding claims, and a tank providing the fluid volume.

Images