GB2516806A - An electro-pneumatic generator - Google Patents

Abstract

An apparatus generates electrical current using pressure fluctuation in a gas supply valve. A generator 12 may comprise a coil and a magnet, one of which is attached to a diaphragm 4 or pusher pin 5 of the valve. Alternatively movement may be transmitted to a piezoelectric member (figures 6-8). The apparatus may be used with a valve of a breathing apparatus, e.g. for medical or diving use, in which the valve member will be continuously moving as the user breathes. The electrical output may be used e.g. to display a reading of the state of the contents of a gas cylinder.

Description

AN ELECTRO-PNEUMATIC GENERATOR

The invention relates to methods of generating electrical energy from the flow of a fluid issuing from a pressurised gas cylinder. More particularly, this invention relates to means for generating electrical energy from stored gas as it flows to a respirator.

Oxygen therapy for medical patients with breathing problems requires an external supply of oxygen. This is typically provided from a gas cylinder charged with high pressure oxygen which is reduced from a high pressure, usually of some hundreds of atmospheres, to something of the order of four atmospheres. The oxygen in reduced pressure is often connected to a cannula supplying oxygen, in continuous flow, direct to the patient's nasal orifices or, maybe, to some form of mask. Similar arrangements are made to supply gas to masks for scuba divers or for people needing to enter a hostile atmosphere.

To provide the recipient with an accurate reading of the state of the cylinder's contents, an ideal solution is to employ some system of easily accessible, electronics display. This solution requires electrical power, and for ambulatory equipment, some form of battery or other electric storage is needed. Batteries are of various types, and the useable life of any battery depends on the type and size of a battery, and the demands made on it by any particular electronics system.

There is a need for an alternative means of providing electricity to power the electronics or to recharge the battery.

It is known to generate electricity from the relative movement of a magnetic field and an adjacent conductor. This effect is made use of in electricity generators where a coil of wire made from a conductor such as copper or aluminium is subjected to a changing magnetic field. The shape of the magnet and the coil may be adapted to suit the working conditions.

The magnetic field that the coil is subjected to may be changed by altering the relative position of the magnet (otherwise referred to as an armature), and the coil in a reciprocating fashion i.e. a relative movement of the armature with respect to the coil. The moving member, which can be the magnet or coil or both, is moved in a reciprocating motion relative to each other. The magnet or the coil or both may follow any reciprocating path that brings them into close proximity. Preferably the magnet or the coil moves in a reciprocating linear motion or a reciprocating arcuate motion.

The magnetic field that the coil is subjected to may be changed by altering the magnetic permeability of the material around the coil in a reciprocating fashion.

In this description the term "linear generator" is intended to embrace all the different ways of generating electricity by reciprocal movement of a magnetic field relative to a coil and to exclude the use of rotary generators. Examples of the different types of linear generator are known in the literature.

W0201 0043617 describes a device having a magnet mounted on a flexible member that oscillates between coils to induce a current in the coil.

US3883845 describes the movement of a reciprocating member that alters the path of the magnetic flux relative to a surrounding coil and generates an electric current. US5975714 describes the use of a linear generator to power a torch in which a magnet is constrained to slide within the bore of a coil.

Movement of the magnet is caused by shaking or moving the torch.

US5370112 describes a method for powering portable oxygen supplies using a linear generator. In this arrangement, a magnet is enclosed in a pneumatic cylinder surrounded by a coil and through the operation of a system of valves, gas pressure is provided to urge the magnet to reciprocate within the cylinder. The resulting movement induces a current in the surrounding coil which can be used to power electronics associated with the device. A disadvantage of this system is that it requires a complicated arrangement of valves which adds to the cost and complexity of the device.

There is substantial theoretical analysis of the design and performance of linear generators -see for example paper by Rohan Dayal et. al., A New Design for Vibration-based Electromagnetic Energy Harvesting Systems Using Coil Inductance of Microgenerator. Paper 201 O-IPCC-008.R1 presented at the 2009 Applied Power Electronic Conference Washington, DC, USA 15-19 February 2009 or the paper by Jiabin Wang, et.al A General Framework for the Analysis and Design of Tubular Linear Permanent Magnet Machines Jiabin Wang, et.al. IEEE TRANSACTIONS ON MAGNETICS, VOL.

35, NO. 3, MAY 1999. Optimising the arrangement of the magnet and the coil is the subject of numerous patents. US6936937 describes one such improvement.

An alternative method for generation of electrical charge or voltage utilises the piezoelectric effect, as known in the art.

Piezoelectricity is the electrical charge generated in certain solid materials when those materials are subjected to mechanical force or stress.

Deformation of the structure in piezoelectric materials leads to the generation of an electrical charge, and this charge can be harnessed by connecting the piezoelectric material to an electrical circuit. As known in the art, piezoelectric materials include quartz and other natural-occurring materials together with man-made materials e.g. gallium orthophosphate crystals, ceramics, and polymers such as polyvinylidene fluoride.

In this specification, the term "piezoelectric generator" means an arrangement including a piezoelectric material which is capable of producing an electrical charge. A piezoelectric generator typically includes a piezoelectric material described above together with means to inflict a stress or force on the material, thereby generating an electrical charge. The means for inflicting a stress or force may be a mechanical means.

The present invention provides a means of generating electricity from the pressure variations arising during the provision of breathable gas to a recipient without the need for additional pneumatic circuits. The invention utilises either magnetic induction or the piezoelectric effect, to generate an electrical charge and thus produce a voltage due to the potential difference (PD) between the generated charge and an electrical circuit.

When breathable gas is provided to a recipient from a high pressure gas cylinder it is necessary to reduce the pressure and to control the flow of gas to a cannula or mask by means of control gear that responds to the pattern of breathing of the recipient.

Typically, the control gear is designed to trigger a supply of oxygen each time the patient inhales, and stops the supply of oxygen during the exhalation part of the breathing cycle. Each cycle of breathing in and out generates a pulse in the fluid pressure and may also be associated with the movement of mechanisms within the control valves This invention provides a means for harnessing the pressure variations or the associated movements of the valve control mechanisms to generate electricity using magnetic induction or the piezoelectric effect.

The control gear employs a valve to govern the flow of gas from the high pressure cylinder to the recipient. Valves of the type described in GB2298026 or 1JS2009026681 6 may be used for this purpose. The gas may feed into a pressure regulator of the type described in US20030000529 that controls the flow of gas to the recipient.

Pressure regulators of this type react to the breathing cycle of the recipient. A typical breathing cycle comprises a pattern of three seconds duration; inhalation for one second, and exhalation for two seconds. Hence, the breathing rate is nominally 20 cycles per minute. During each cycle, the pressure in the pressure regulator fluctuates and it is this fluctuation that may be used to drive a linear generator or piezoelectric generator.

The moving element of the linear generator may be placed in the breathing connector where the coil or the magnet is moved relative to each other by the pulsed flow of gas during inhalation and/or exhalation. The magnitude of the pressure of the pulsed flow may be amplified by provision of a venturi in association with the moving element.

Alternatively the moving element of the linear generator may be attached to a flexible membrane or diaphragm that flexes in response to pressure changes occurring as a result of the recipient inhaling and exhaling.

In another alternative the coil or magnet may be attached to a lever that moves in response to the changes in pressure in each breathing cycle.

The linear generator may operate continuously whilst the recipient demands a supply of gas and ceases to generate when there is no demand. The output from the generator may be used to charge a battery or other electricity storage device such as a super condenser or it may directly power the electronic devices associated with monitoring the provision of gas.

The moving piezoelectric element may be placed in the breathing connector where the element is moved relative to a percussion surface by the pulsed flow of gas during inhalation and/or exhalation. The magnitude of the pressure of the pulsed flow may be amplified by provision of a venturi in association with the moving element.

Alternatively the piezoelectric element of the linear generator may be attached to a flexible membrane or diaphragm that flexes in response to pressure changes occurring as a result of the recipient inhaling and exhaling.

In another alternative the piezoelectric element may be attached to a lever that moves in response to the changes in pressure in each breathing cycle.

The piezoelectric generator may operate continuously whilst the recipient demands a supply of gas and ceases to generate when there is no demand.

The output from the generator may be used to charge a battery or other electricity storage device such as a super condenser or it may directly power the electronic devices associated with monitoring the provision of gas.

As a person operating, for example a diving mask including the inventive valve breathes, this will cause pulses of electricity as the piezoelectric element is repeatedly flexed or moved in response to the breathing cycle.

However, where the flow of fluid through the valve is continuous, in an application other than a diving mask, for example in a gas supply valve to supply a continuous stream of gas, it is envisaged that the element would not be moved repeatedly. To overcome this problem, the applicants devised a fluid chamber to be located in the inlet area of the valve, capable of holding a volume of fluid. The chamber is sealed by an openable sealing member which seals the chamber until a certain pressure is reached. When the threshold pressure is reached in the chamber, the sealing member is forced out of sealing proximity with the chamber and moves. Movement of the sealing member against the piezoelectric member causes the generation of electricity. Meanwhile, as the fluid escapes from the chamber via the open seal, the pressure in the chamber reduces and the sealing member may return to its sealing position. The cycle of filling the chamber with fluid, then releasing, with concurrent movement of the sealing member, begins again.

This sequence of events causes a repeated movement of the piezoelectric element, thereby causing continuous charge generation even when fluid flows continuously through the valve.

An equivalent chamber with sealing member arrangement can be put in place in the linear generator for magnetic induction, to ensure repeated movement of the coil and/or magnet.

The relative movement between the components of the invention is preferably a linear movement and is preferably not a rotational movement. A linear rather than rotational movement is simpler and is less likely to cause the generator to fail in use.

Where there is a need to generate electricity in the absence of demand for gas, for example when the level of charge in the battery or condenser or whatever device is used to store the power falls to a low level, provision may be made to discharge gas from the cylinder to power the linear generator or piezoelectric generator. The gas discharged under these conditions may be discharged in pulses and the amount regulated to be just sufficient to operate the linear generator or piezoelectric generator and much less than would be used to provide breathable gas to a recipient.

The electrical output from the linear or piezoelectric generator may need to be rectified before use and the voltage may need to be adjusted to suit the applications. Suitable rectification circuits are known in the art -see U55975714 referred to above or the paper by Edward Sazonov et. Al. Self-Powered Sensors for Monitoring of Highway Bridges IEEE SENSORS JOURNAL, VOL. 9, NO. 11, NOVEMBER 2009.

The power generated may be used to operate an electronic display to provide the recipient with an accurate reading of the state of the contents of the cylinder. Information on the contents of the cylinder, the rates of usage and the need for replacement and information about the cylinder itself may be provided to a central data collection point for analysis by the cylinder provider or the medical advisor. The information may be transmitted electrically or by wireless.

According to the present invention, there is provided an apparatus for generating electrical current by harnessing pressure fluctuation in a gas supply valve, the apparatus comprising a generator having a first charge-producing element which produces electrical charge in response to relative movement of the element with respect to a second element: wherein said first and/or said second element or elements is or are moveable to produce said relative movement in response to a pressure fluctuation in said gas supply valve.

Preferably the first element is an electrically conductive coil and the second element is a magnetic armature, wherein the coil and armature are mutually arranged for electromagnetic induction, whereby relative movement of the coil with respect to the armature generates an electrical current, Advantageously said coil and/or armature is moveable by the fluctuation of fluid pressure downstream of a Venturi, acting on one or both ends of the generator.

Conveniently the armature or coil is mechanically coupled to an actuating member of the valve and wherein said movement of said armature or coil is provided by movement of the actuating member when the valve is in use.

Preferably the actuating member is a diaphragm.

Advantageously said armature or coil is biased to a first position in a closed configuration of said valve and is moveable to a second position in an open configuration of said valve.

Conveniently said bias is provided by a spring.

Alternatively said bias is provided by a lost motion device.

Conveniently the armature or the coil is attached to the diaphragm and is moveable from a first position in a closed configuration of said valve to a second position in an open configuration of said valve.

Preferably the armature is a pivotable magnetic blade configured to be moved past a coil or passed between or past a pair or a plurality of coils.

Advantageously each coil in the pair of coils is wound in an opposite sense to provide continuous-flow current.

Conveniently the blade is moveable via coupling to the valve actuating mechanism Preferably the blade is coupled to an inlet valve actuating pin.

Advantageously the first charge-producing element comprises a piezoelectric material and the second element provides a mechanical force to the first element, thereby generating an electrical charge in the first element.

Conveniently the first element is in the form of a block, strip or disc comprising or consisting of a piezoelectric material.

Preferably the piezoelectric material is a crystalline, ceramic or polymeric material in the form of a strip, disc, block, sheet or film.

Advantageously the first element is anchored to the valve at a first end or side thereof, the second end or side thereof being moveable.

Conveniently the valve comprises a poppet arranged in a gas inlet of the valve, the poppet being configured to impinge on the first element causing movement thereof, when fluid enters the valve via the inlet.

Preferably the first element is attached to a diaphragm of the valve, and wherein movement of the diaphragm when the valve is in use causes movement of the first element.

Advantageously the valve includes a chamber in an inlet of the valve, the chamber having a moveable seal, wherein fluid may enter the chamber until a threshold pressure is reached, at which point the seal may move to release pressure, said movement of the seal being transmitted to cause movement of the first element.

Preferably said movement is not rotational movement.

The invention also provides an oxygen mask or scuba mask comprising a gas supply valve and the apparatus of the claims.

Embodiments of the invention are described below by way of example with reference to the accompanying drawings in which: FIGURE 1 is a cross section of a first embodiment of the present invention; FIGURE 2 is a cross section of a second embodiment of the present invention; FIGURE 3 is a cross section of a third embodiment of the present invention; FIGURE 4 is a cross section of a fourth embodiment of the present invention; FIGURE 5 is a cross section of a fifth embodiment of the present invention; FIGURE 6 is a cross section of a sixth embodiment of the present invention; FIGURE 7 is a cross section of a seventh embodiment of the present invention; FIGURE 8 is a cross section of an eighth embodiment of the present invention; FIGURE 9 is a cross section of a ninth embodiment of the present invention; and Figure 10 is a cross-section of an arrangement including a block of piezo-electric material, for use in the present invention.

As a basis for comparative illustration, Figures 1 to 9, are based on the layout shown in particular, in GB2298026, for a reactive breathing valve.

Figure 1 depicts an advantageous arrangement, wherein there is no direct mechanical connection involved between the valve assembly and the armature. A valve body 1 comprises an inlet valve 2, based on for example the arrangement of GB2298026, which is a KIM Module supplied by gas (11).

The valve 2 is actuated by diaphragm 4, by way of a pusher pin 5, which passes through baffle plate 3. Suction applied by the user or patient, at outlet 8 causes a drop to negative pressure in the space between the underside of the diaphragm 4 and the upper side of the baffle plate 3, causing the diaphragm 4 to move downward, and the pusher pin 5 opens the inlet valve 2.

Outlet flow from inlet valve 2 passes into the Venturi area 7, causing further pressure drop on the underside of the diaphragm 4 due to the Venturi Effect.

This increased pressure drop also applies suction at one end of the magnetic armature of linear generator 9. Movement of the armature within the coils of generator 9 induces an electrical current in the coils. Dependent on the associated electronics system a battery, or condenser 10, will receive a charge current, at each interval in the breathing cycle, at a nominal 20 cycles per minute i.e. each time the armature is moved during gas delivery. The whole valve assembly is closed off with a flat top cover 6.

Figure 2 is based on the same general layout as the embodiment in figure 1, but is a configuration in which the generator 9 is located above the diaphragm 4, with the armature mechanically attached to the diaphragm. Electrical current is generated directly by movement of the diaphragm 3 which in turn moves the armature in the coils. The height of the generator 12 requires a domed top cover 13, providing within it, possible space 14 for housing associated electronic equipment.

Figure 3 illustrates certain similarities to figure 2 in a slightly different form, the result of which is to lower the height of top cover 19. A flat magnetic disc 17 is attached to the top of the diaphragm 16. Above the magnetic disc 17 is located a flat coil 15. The gap between the flat magnet 17 and the underside of flat coil 15 generates an electric current with the rhythmic rising and falling of the diaphragm 16, as the user inhales and exhales. In an alternative arrangement the magnetic disc 17 may be replaced by a coil, possibly a flat coil and the coil 15 can be replaced by a magnet.

Figure 4 shows a manner in which it is possible to use the principle of electrical current generation by moving a flat object 22 across the face of a coil 23. A convenient, but not exclusive, way of achieving this is shown by pivoting a flared member 22, attached to, say, the pusher pin 5, thus providing an arcuate movement of member 22, across the face of a coil as gas is delivered and the pusher pin moves along its axis. In this case, the use of a flat top cover 20 is possible, and any associated electronics equipment can be housed in the valve body space beneath, or beside, the baffle plate 3.

Additionally, as shown in Figure 4A, the flared member 22 can pass between a pair of coils 21 to increase the induced electrical output. If these two coils are wound in opposite senses, the state of flow of the current, as the flared member passes to and fro is smoothed out.

Alternatively, the blade 22 may be caused to move upwards by suction from a venturi acting in place of or in addition to the pusher pin 5.

Figure 5 shows a means for providing electrical current which is mechanically and physically independent, of the operation of, any associated mechanism, such as a breathing valve, or any other rhythmic working device. An electrical current can thereby be generated even in the absence of an occasional or rhythmic flow of fluid through the valve. This embodiment of the invention allows for pulses of fluid to be generated within the valve, thereby generating an electrical current through magnetic induction, when the fluid entering the valve is not pulsed but is continuous.

The principle of this independent electro-fluid design employs a body part 31 which is attached by such as a threaded portion to a source of pressure. This pressure source can be such as, but not necessarily, a gas container.

Passing through the threaded portion of the body 31 is a small orifice 30, which may be flow-restricted, and proportioned to allow the minimum of gas flow. The orifice is closed off, by an elastomeric seated poppet 32, which is attached to a diaphragm 29. Above the diaphragm 29 typically, is a magnetic disc 27, with a flat coil 26 located above it. The poppet 32 is held in the closed condition by a coil spring 25.

When applied pressure builds up under the poppet sufficiently to overcome the closing thrust of the spring 25, the valve opens, lifting the diaphragm and its associated magnetic disc, causing current to be induced in the coil. The chamber under the diaphragm 24 is vented to atmosphere, or to a recipient, through a controlled orifice 28, which is of some chosen area greater than the restricting orifice 30, and the chamber pressure falls. As a result of the falling pressure under-diaphragm, the spring 25, causes the diaphragm 29, and the attached magnetic disc 27, to move downward, away from the flat coil 26, to seal off the inlet flow; and the generating cycle repeats.

The outlet orifice 28 could be made variable to provide means of adjustment of the rate of oscillation. Electrical pulses are continuously generated for as long as supply pressure 34 is applied. The assembly is closed off by top cover 33 that fits on the main body 23. Alternatively, the positions of the coil 26 and the magnet 27 can be inverted so that the coil fits onto the diaphragm.

Deriving from Figure 5 above, the electrical energy generating function could be achieved in a more compact manner by substituting a self-contained element, such as a piece of piezoelectric material, in any chosen shape or configuration, for the linear generator. Additionally the arrangement of Figure 5, which generates electrical impulses even when the fluid flow to the valve is continuous and not pulsed, can be adapted to include a piezoelectric generator instead of an electromagnetic generator.

Figure 6 shows a first example of a piezoelectric generator in a valve 45, employing a strip of piezoelectric material 40, clamped firmly at one end.

Preferably the strip 40 is clamped to the valve housing 45 at an electrical connector end of the strip 40, where the strip of piezoelectric material is connected to an electrical circuit 47. The free end of the strip 40 is deflectable by the thrust of the springiness of the piezoelectric material itself, or a suitable spring, onto a projection or tappet 43, on the opposite end of which is an elastomeric seating. Gas pressure from the inlet 44 is capable of lifting a moveable poppet 41 off its seating, when the valve is in use, thereby deflecting the piezoelectric material, causing an electrical charge to be momentarily generated in the material. The potential difference between the material 40 and the electrical circuit 47 to which it is connected, causes a voltage to flow around the circuit.

If the fluid supply is of an impulsive nature, for example the breathing pattern of a diver using a diving mask, then a series of electrical impulses will ensue resulting from successive deflections of the piezoelectric material. It is also envisaged that a disc of piezoelectric material in plain or modified form, and of metallic or plastics construction, could be fitted instead of a strip.

Figure 7 illustrates a piezoelectric equivalent to the variant of Figure 3 embodying a generating strip of piezoelectric material 66 attached at one end 68 to the valve top cover 4, with the free end trapped between a pair of anvils that are attached to the valve's actuating diaphragm. Thus, pulses of electrical energy are generated at each inhale and exhale part of, say, a breathing cycle.

Whilst all of these variants require tidal, or pulsed flow to the actuating piston or diaphragm, to provide generating cycles, Figure 8 shows how a constant fluid pressure, for example from a constant gas supply, can be converted to provide a series of impulses. This is the piezoelectric variant of the electromagnetic embodiment depicted in Figure 5.

In Figure 8 a piezoelectric element 50 is employed in a valve 55 in such a way that, whilst anchored at one end, the free end is provided with an arrangement such as an elastomeric seat 52, which is held sealingly onto a seating orifice 57. Pressurised fluid, such as gas can be supplied through a restrictor orifice 59 into a capacity volume 58 below the sealing orifice. When the volume in the capacity reaches a point sufficient to overcome the closing thrust in excess of the seating orifice, the free end of the generating strip will lift upwards. At a certain clearance height, generally of the order of 1/3 the orifice diameter, the pressure in the capacity will drop, and the elastomeric seat will close once again, until the capacity pressure has recovered, and the cycle repeats continuously, and at a frequency that is a function of; pressure x capacity x comparison of the two orifices x the closing resistance of the sealing orifice. Closing resistance can be additionally provided with a spring or similar resilient means.

Figure 9 is a derivation of the diaphragm and generator element of Figure 3 harnessed to what is preferably, a parabolic reflector. This form is suitable for deriving power from large volume fluctuating flows such as is found in tidal waters. The arrangement could, as an alternative, employ the diaphragm arrangement of Figure 7. In any of these arrangements, some form of piezoelectric sensor, suitable to the particular application, could be Finally, figure 10 illustrates a block of piezoelectric material that can be used in the present invention. Figure 10 bears similarity to figures 6-8, except that in figure 10 there is illustrated a block of piezoelectric material 50 instead of a strip. Again the piezoelectric material is connected to an electrical circuit 51 and is stuck by a thrust plate 52 in use, in order to generate a charge through the piezoelectric effect. The thrust plate 52 strikes block 50 in response to fluid entering the valve through the region generally designated 60, which can either provide a tidal or pulsed fluid flow, as described above in connection with figures 6 and 7, or a continuous flow converted to pulses, as described in connection with figure 8.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims (24)

1. CLAIMS1. An apparatus for generating electrical current by harnessing pressure fluctuation in a gas supply valve, the apparatus comprising a generator having a first charge-producing element which produces electrical charge in response to relative movement of the element with respect to a second element: wherein said first and/or said second element or elements is or are moveable to produce said relative movement in response to a pressure fluctuation in said gas supply valve.
2. 2. An apparatus according to claim 1, wherein the first element is an electrically conductive coil and wherein the second element is a magnetic armature, wherein the coil and armature are mutually arranged for electromagnetic induction, whereby relative movement of the coil with respect to the armature generates an electrical current,
3. 3. An apparatus according to claim 2 wherein said coil and/or armature is moveable by the fluctuation of fluid pressure downstream of a Venturi, acting on one or both ends of the generator.
4. 4. An apparatus according to claim 2 wherein the armature or coil is mechanically coupled to an actuating member of the valve and wherein said movement of said armature or coil is provided by movement of the actuating member when the valve is in use.
5. 5. An apparatus according to claim 4, wherein the actuating member is a diaphragm.
6. 6. An apparatus according to claim 4 or 5 wherein said armature or coil is biased to a first position in a closed configuration of said valve and is moveable to a second position in an open configuration of said valve.
7. 7. An apparatus according to claim 6 wherein said bias is provided by a spring.
8. 8. An apparatus according to claim 6 wherein said bias is provided by a lost motion device.
9. 9. An apparatus according to Claim 5, wherein the armature or the coil is attached to the diaphragm and is moveable from a first position in a closed configuration of said valve to a second position in an open configuration of said valve.
10. 10. An apparatus according to claim 4 wherein the armature is a pivotable magnetic blade configured to be moved past a coil or passed between or past a pair or a plurality of coils.
11. 11. An apparatus according to claim 10 wherein each coil in the pair of coils is wound in an opposite sense to provide continuous-flow current.
12. 12. An apparatus according to claim 10 or claim 11 wherein the blade is moveable via coupling to the valve actuating mechanism
13. 13. An apparatus according to claim 12 wherein the blade is coupled to an inlet valve actuating pin.
14. 14. An apparatus according to claim 1, wherein the first charge-producing element comprises a piezoelectric material and the second element provides a mechanical force to the first element, thereby generating an electrical charge in the first element.
15. 15. An apparatus according to claim 14, wherein the first element is in the form of a block, strip or disc comprising or consisting of a piezoelectric material.
16. 16. An apparatus according to claim 14 or claim 15 wherein the piezoelectric material is a crystalline, ceramic or polymeric material in the form of a strip, disc, block, sheet or film.
17. 17. An apparatus according to any one of claims 14 to 16 wherein the first element is anchored to the valve at a first end or side thereof, the second end or side thereof being moveable.
18. 18. An apparatus according to any of claims 14 to 17 wherein the valve comprises a poppet arranged in a gas inlet of the valve, the poppet being configured to impinge on the first element causing movement thereof, when fluid enters the valve via the inlet.
19. 19. An apparatus according to any one of claims 14-17 wherein the first element is attached to a diaphragm of the valve, and wherein movement of the diaphragm when the valve is in use causes movement of the first element.
20. 20. An apparatus according to any one of claims 14-17 wherein the valve includes a chamber in an inlet of the valve, the chamber having a moveable seal, wherein fluid may enter the chamber until a threshold pressure is reached, at which point the seal may move to release pressure, said movement of the seal being transmitted to cause movement of the first element.
21. 21. An apparatus according to any preceding claim wherein said movement is not rotational movement.
22. 22. An oxygen mask or scuba mask comprising a gas supply valve and the apparatus of any preceding claim.
23. 23. An apparatus or method substantially as herein described, with reference toFiguresitolO.
24. 24. Any novel feature or combination of features described herein.