Background Art There are many types of machinery, appliances, and other devices that use a change in the volume of a chamber as the basis for their operation. Most of these, but not all, use one way valves so that material such as a liquid or gas enters the chamber through an inlet valve and is discharged through an outlet valve.

Many such products use a piston that slides back and forth in a cylinder, to provide the changes of volume needed for operation. Examples of such usage can be seen in a wide variety of pumps for various liquids, in vacuum pumps, and in air compressors. Motors such as electric motors operate some of these, and others are operated manually or by other means.

There are also many domestic or consumer products that use some form of piston and cylinder in their operation. These include such things as car tire pumps, hand cream dispensers, garden pressure sprayers, and bicycle pumps.

Most devices that use a piston and cylinder require a rigid or firm housing, although not made necessarily of metal, for operation of the moving parts. While it may not matter for items that are discarded after a short period of use, pistons and cylinders are subject to wear so that there can be a loss of efficiency and a leakage of material from the chamber past the piston. The need for a housing to support moving parts can increase the weight and cost of some devices, thereby limiting their usefulness.

There are many water pumps, including ones operated by hand, windmitt or other motive power, that use a pump rod to operate a piston and cylinder located down a well or borehole. Reliability, repair and maintenance can be a serious problem with such pumps, particularly when the piston and cylinder are a long way below ground level.

There are other devices where the change in volume of a chamber is achieved by the use of a flexible container or a bellows. Where these are used in roles such as pumps, they typically use one way valves so that material being pumped enters the chamber through an inlet valve and is discharged through an outlet valve.

Examples of the use of a flexible container or bellows are air or liquid pumps where a chamber is formed using a thin flexible material such as rubber or plastic. In these examples the primary pumping action is by"squashing"the chamber to reduce its volume. For a continuation of the pumping cycle, the chamber is then pulled open, unless there are springs or other means to restore its original volume. A blacksmith's bellows is an example of such use.

Where a chamber is formed of thin flexible material and used in this way, there are considerable limitations in the loads and pressures that can be applied, and it is only likely to be suitable for low pressure operation. The flexible nature of the chamber provides further limitations if it is to be driven by a motor, with the need for a framework or housing to support the various associated components.

There are instances where it is necessary to pump liquids, gases or other materials so that they are totally isolated from the environment outside the pump.

These circumstances can apply to hazardous materials or in dangerous environments, or for reasons of safety, health or hygiene. There are various types of seal-less pumps, but the need to seal off working or moving parts can in turn create problems for maintenance or in operation.

There are other devices such as pressure tanks or pressure cells, where changes in their internal volume are used to smooth pressure variations, for

example in water pumping installations or in water pipes. These devices are connected to the pipes concerned, so that their internal volume increases and decreases as the pressure in the pipes increases and decreases.

By way of illustration, if water flow in a pipe is suddenly stopped, there can be a sudden increase in pressure known as water hammer, which can cause damage to equipment connected to the pipe system. As another illustration, with pumps such as piston pumps, windmills, and hydraulic ram pumps, water flows unevenly from the pump into the delivery pipe with a consequent loss of efficiency. As a further illustration automatic electric water pressure systems, such as used on farms where there is no town water supply, automatical switch on when the water pressure drops to a certain level and then switch off when the pressure rises to the maximum working pressure. Many such automatic electric water pressure systems therefore use a pressure tank to store some water under pressure, so that the pump does not turn on and off more than necessary and waste electricity. In these three illustrations, the fitting of pressure tanks or pressure cells can moderate the above problems and improve the efficiency of operation.

While there are various types of pressure tanks or pressure cells used, one type widely used consists of a flexible diaphragm within a container, so that air under pressure on one side of the diaphragm is separated from a fiquid such as water on the other side. Disadvantages of this type of pressure cell are that the container must be strong enough to contain the pressures involved, and the correct air pressure needs to be maintained for efficient operation.

There are many other devices not considered above where the principe of operation involves a change in the volume of a chamber. The disadvantages referred to above also apply to many of these devices.

Disclosure of Invention The object of the invention is to overcome such disadvantages by the use of a flexible device, where the primary method of operation is to apply forces or

pressures to extend the device and cause an increase in the interior volume of the device.

In one broad form the present invention provides a flexible cell assembly comprising : A flexible member which, either alone or in conjunction with other components, forms a chamber with one or more ports to communicate with liquids, gases or other materials, Such that the volume of the said chamber increases when forces or pressures are applied to extend the said flexible member, And such that the volume of the said chamber will then decrease when the said forces or pressures are reduced.

The flexible cell assembly may be configured as a pump and further comprise one-way inlet and outlet valves connected to one or more of the said ports.

The flexible cell assembly may also be configured as a pump in an alternative configuration and further comprise a container surrounding the flexible cell assembly with one-way inlet and outlet valves connected to the said container.

The flexible cell assembly may be actuated manually, or by a motor, or by other means that is appropriate for its role and the nature of liquids, gases or other materials with which it is used.

The flexible cell assembly may also be configured as a pressure tank or pressure cell where one or more of the said ports communicates with a source of liquid, gas or other material under pressure.

Brief Description of Drawings Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, in which : FIG. 1 is a schematic cross-sectional view showing one example of a flexible cell assembly arranged to work as a pump.

FIG. 2 is a schematic cross-sectional view showing another example of a flexible cell assembly arranged to work as an in-line pump.

FIG. 3 is a schematic cross-sectional view showing an example of a flexible cell assembly arranged to work as a pressure tank or pressure cell.

FIG. 4 is a schematic cross-sectional view showing an example of how a flexible cell assembly can be constructed of more than one component.

FIG. 5 is a schematic cross-sectional view showing another example of how a flexible cell assembly can be constructed of more than one component.

FIG. 6 is a schematic cross-sectional view showing an example of a flexible cell assembly mounted in a container, and arranged to work as a pump by means of forces applied to the inside of the flexible cell assembly.

Best Mode for Carrying Out the Invention.

Reference is made to FIG. 1, which shows the preferred embodiment of a flexible cell assembly configured to work as a pump. The flexible cell assembly in this example consists of one component, a flexible member 1, having a first port 41 at one end, a second port 42 at the other end, and a chamber 43.

In this example, the flexible member 1 is constructed of a suitable single or composite material, such as plastic or a reinforced rubber compound. Flexible member 1 can also be made from other materials, both alone or in composite

construction and incorporating reinforcing as necessary, so that it is used as a single component.

The construction of flexible member 1 allows it to withstand the internal and external pressures that occur without bursting or collapsing. The construction of flexible member 1 also allows it to extend when a tension force is applied to it and retract when that force is removed, such characteristics being similar to those of a spring which extends and contracts as loads in tension are applied and removed. The construction of flexible member 1 is also such that its internal volume changes as it extends and retracts.

The change in volume of chamber 43 from extension and retraction of a flexible cell assembly according to this invention is therefore the means whereby it can be used to pump liquids such as water, gases such as air, or other materials that are capable of being pumped.

Referring to the example of FiG. 1 again, a nipple 2 is fixed to one end of the flexible member 1 and further held in place and sealed by a clamp 3. At the other end of the flexible member 1, a nipple 4 and clamp 5 are similarly used.

A cap 6 is fitted to nipple 2, thereby sealing off first port 41, so that nothing can enter or leave from that end of the flexible member 1.

At the other end of flexible member 1 is fitted a tee 7, an inlet valve assembly 8, and an outlet valve assembly 9. The entry to intet vatve assembly 8 forms an inlet port 44. The exit from outlet valve assembly 9 forms an outlet port 45. An inlet pipe from the source of liquid, gas or other material to be pumped would be connected to inlet valve assembly 8, and an outlet pipe to take the pumped liquid, gas or other material away would be connected to outlet valve assembly 9. With this arrangement, second port 42 provides a means of communication between inlet port 44 and chamber 43, and between chamber 43 and outlet port 45.

To further explain the example of FIG. 1, its operation as a water pump will be described.

As depicted in FIG. 1, inlet valve assembly 8 and outlet valve assembly 9 are shown as simple non-return flap valves. Flap 10 within inlet valve assembly 8 is hinged so that water can enter but not return to the inlet pipe. Flap 11 within inlet valve assembly 9 is hinged so that water can exit to the outlet pipe but not return.

While simple non-return flap valves are suitable for some water pumping applications, for the purposes of FIG. 1 the construction of inlet valve assembly 8 and outlet valve assembly 9 as depicted should be regarded as illustrating any suitable non-return valve. Many types of non-return valve can be used, although in particular applications some will be better than others.

Referring to FIG. 1, it is assumed that inlet and outlet water pipes are connected and filled with water, and that chamber 43 of flexible member 1 is also full of water. If a force is applied near cap 6 to stretch the flexible member 1, water will enter through inlet valve assembly 8 because of the increase in volume of chamber 43. As water enters, the outlet valve assembly 9 will remain closed.

If the force used to stretch the flexible member 1 is removed, the flexible member 1 will contract and reduce the volume of chamber 43. As a consequence, inlet valve assembly 8 will close and outlet valve assembly 9 will open, so that water is forced into the outlet pipe.

If the flexible member 1 is extended and contracted repeatedly by the application and removal of a force, water can be pumped to a higher pressure in the outlet pipe than exists in the inlet pipe.

A water pump as shown in FIG. 1 can lift water from a level below the intet vatve assembly 8, but to no greater extent than corresponds to the vacuum the flexible cell assembly can create in the intet pipe. The force that is available from the flexible pressure cell itself to reduce the volume of chamber 43, in conjunction

with any additional forces applied externally, determines the height to which water can be raised.

Although not shown in FIG. 1, cap 6 could be replaced by other components that stop water escaping from that end of flexible member 1, and also provide a handle for manual operation or an attachment for another form of driving force.

FIG. 1 has shown how the flexible pressure cell that is the subject of this invention can be used to pump water. It can also be used to pump other fluids, or other materials that are capable of being passed through suitable inlet and outlet valves.

It can be seen that the same arrangement of components can be used as a pump to compress air, where air at atmospheric pressure is brought in through inlet valve assembly 8 and forced through outlet valve assembly 9 to a higher pressure.

Similarly, the arrangement of FIG. 1 can be used as vacuum pump when the inlet valve assembly 8 is connected to the space to be evacuated, and air extracted is then exhausted to atmosphere through outlet valve assembly 9.

As is also the case for pumping water, the construction of inlet valve assembly 8 and outlet valve assembly 9 as depicted should be regarded as illustrating any non-return valve suitable for use in other roles that the invention can perform.

In all of the pumping roles considered so far, it can be seen that the fluid or material being pumped is isolated from the actuating forces and from the outside environment. When constructed of suitable materials, the flexible cell assembly can therefore work with fluids, gases or materials where it is necessary or desirable to handle them in isolation. This could apply for example to hazardous products or also for example for reasons of safety, health, hygiene or convenience.

Reference is made to FIG. 2, which shows the preferred embodiment of a flexible cell assembly configured to work as an in-line pump.

Flexible member 1, inlet valve assembly 8 and outlet valve assembly 9 are the same as used in the example of FIG. 1 but assemble in a different way. Inlet valve assembly 8 is fixed to flexible member 1 at second port 42, and further held in place and sealed by clamp 5. Outlet valve assembly 9 is fixed to flexible member 1 at first port 41 and further held in place and sealed by clamp 3.

If the flexible hose 1 is extended and contracted repeatedly by the application and removal of a force at the outlet valve assembly 9 or inlet valve assembly 8, it can pump liquids, gases or materials through it as previously described in the example of FIG. 1.

However, with the arrangement of FIG. 2, the outlet pipe connected to outlet valve assembly 9 can also be the means whereby the operating force is applied.

This arrangement is relevant, for example, when it is wanted to pump water out of a borehole or a well from below ground level. In this instance if the inlet valve assembly 8 is instatted betow water tevet (or sufficiently close that water can be sucked up through the inlet pipe) operating forces can be applied from ground level through the outlet pipe so that water is pumped to ground level or higher.

Reference is made to FIG. 3, which shows the preferred embodiment of a flexible cell assembly configured to work as a pressure tank or pressure cell.

The flexible cell assembly in this illustration consists of one component that is a flexible member 12. One end of the flexible member 12 is sealed with a plug 13 that is further retained in position by a clip 14. At the other end of the flexible hose 12 a nipple 15 is attached and further retained by a clip 16. The nipple 15 is threaded so that it can be connected to a pipe where it is desired to smooth out or slow down pressure changes, for example, in liquids or gases.

When a flexibfe cell assembly is connected to a pipe under pressure, it will extend in length until the pressure in chamber 43 is the same as that in the pipe.

If the pressure in the pipe then increases, the volume of chamber 43 inside the flexible cell assembly witt accordingty increase as it extends, thus moderating the rate of pressure change. If the pressure in the pipe decreases, there will be a similar moderation in the rate of pressure change. In this way the invention can work as a pressure tank or pressure cell.

When used as a pressure tank or pressure cell, the characteristics of a flexible cell assembly need to suit the operating conditions involved. For example, the working pressure involved and the volume change required affect the design, construction and size of a flexible cell assembly for that application. For these reasons, FIG. 3 should be regarded as illustrating how a flexible pressure cell works as a pressure tank, rather than showing the construction for all applications.

Reference is made to FIG. 4, which shows an example of how a flexible cell assembly can be constructed of more than one component.

The example of FIG. 1 shows a flexible cell assembly consisting of one component, which is a flexible member 1 constructed of a suitable material, such as plastic or a rubber compound. While such construction is suitable for many applications, it may not be possible in all applications to have one single component provide all the characteristics needed for use as a flexible cell assembly.

FIG. 4 shows an example of how a flexible cell assembly can be constructed of more than one component. Portion only of the length of a flexible cell assembly in cross section is shown for simplicity of explanation. The full length of the flexible cell assembly would be a continuation in both directions of what is drawn, with suitable end fittings so that it can be used in its chosen role.

In this example flexible member 1 consists of a flexible spiral hose 17. The flexible spiral hose 17 can be made of any suitable material, and may itself be of composite construction with other materials incorporated into its structure. In

this example, the flexible spiral hose 17 is shown in conjunction with an internal reinforcement spring 18 and an external reinforcement spring 19.

The use of the internal reinforcement spring 18 and external reinforcement spring 19 together, or the use of only one of them, allows the flexible cell assembly to have different characteristics to those obtained when flexible spiral hose 17 is used on its own.

For example the internal reinforcement spring 18 will increase the resistance of the flexible cell assembly to inward collapse, and external reinforcement spring 19 will increase the resistance of the flexible cell assembly to bursting outwards.

Either or both springs together can be used to increase the force needed to extend the flexible cell assembly.

Reference is made to FIG. 5, which shows another example of how a flexible cell assembly can be constructed of more than one component.

In this example flexible member 1 consists of a thin flexible tube 20.

While FIG. 5 is diagrammatic in nature rather than showing full details of construction, it indicates how a thin flexible tube 20 can be restrained by an external sleeve 23 and an internal sleeve 24.

The thin flexible tube 20 is fastened to end connector 27 by clamp 21, which also locates external sleeve 23 at that end. The other end of thin flexible tube 20 is fastened to end connector 28 by clamp 22, which also locates external sleeve 23 at that end. Internal sleeve 24 is located in position between ring 25 and ring 26, which are fixed respectively to end connector 27 and end connector 28.

With this construction, the external sleeve 23 and internal sleeve 24 can move longitudinally against other components when operating forces are applied to end connectors 27 and 28 to extend the flexible cell assembly. With this arrangement it may also be necessary to incorporate springs or otherwise apply

forces so that the flexible cell assembly will contract appropriately when the operating force is then reduced.

Reference is made to FIG. 6, which shows an example of a flexible cell assembly mounted in a container, and arranged to work as a pump by means of forces applied to the inside of the flexible cell assembly.

In the examples of flexible cell assemblies considered so far, the operating forces were applied externally and the liquids, gases, or other materials passed through the inside of the flexible cell assembly. While this is a satisfactory way to use a flexible cell assembly for many applications, there are other applications where operation can have liquids, gases or other materials outside the flexible cell assembly.

Referring to FIG. 6, a flexible cell assembly 29 is mounted inside an enclosure 30. The flexible cell assembly 29 is drawn as the one in FIG. 3, but inverted.

However, any other suitable form of flexible cell assembly could equally be used.

The enclosure 30, which is otherwise sealed, has an inlet valve 31 and an outlet valve 32. For simplicity of description, enclosure 30, inlet valve 31 and outlet valve 32 are shown diagrammatically.

With the arrangement shown in FIG. 6, an operating force can be applied to the inside of flexible cell assembly 29. As drawn, a rod 33 is shown as a means of applying the operating force. However, an operating force can also be applied, for example, by allowing a gas or liquid pressure into the flexible cell assembly 29 through the fitting shown at its top.

As the operating force within the flexible cell assembly 29 is increased and decreased, the flexible cell assembly will be extended and contracted. As this occurs, the space within enclosure 30 will decrease and increase, so that liquids, gases, or other materials from outside enclosure 30 can enter enclosure 30 through inlet valve 31 and be pumped out through outlet valve 32.

One advantage of the arrangement shown in FIG. 6 is that the substance being pumped will come out of outlet valve 32 at the same time as the operating force is applied. This advantage can be seen where the arrangement is hand operated through rod 33 and used to dispense a substance through outlet valve 32. Better control of the quantity to be dispensed is achieved, because the substance will stop coming from the outlet valve 32 when the operating force is stopped.

As an example of the use of the invention in this way, an enclosure 30 and flexible cell assembly 29 in accord with the principle of FIG. 6 are inserted into the body of another container, containing for example hand cream. In this example, outlet valve 32 would remain outside the container of hand cream.

Operation of rod 33 would then dispense hand cream through outlet valve 32.

While the detailed design for a dispenser of hand cream or other substances is not shown, this shows the ability of a flexible cell assembly to provide the basis of design for such dispensers.

A flexible cell assembly can be used to provide the air pressure needed in the operation of a pressurized garden sprayer or other pressurized sprayer. As one example of this, an enclosure 30 and flexible cell assembly 29 generally in accord with the principe of FIG. 6., are fitted into the body of the sprayer to be pressurized. In this example however the inlet valve 31 would need to be located to take air in from the atmosphere, and outlet valve 32 would be located to discharge air into the body of the sprayer to pressurize it.