When a wheeled vehicle such as a lorry or a car is in motion, imperfections in the road surface cause the vehicle to be bumped upwards and downwards, this movement being representative of the application of kinetic energy. This energy is generally converted to heat energy and dissipated by way of various suspension systems, which may comprise mechanical springs and/or pneumatic or hydraulic damping systems. The dissipation of this energy is wasteful and it would be advantageous if the energy could be recovered.

It is therefore an object of the present invention to provide a means for recovering at least a part of the kinetic energy associated with non-driven components of a vehicle which are movable relative to each other for supplementing a main power source for a vehicle.

According to one aspect of the present invention there is provided a method of supplementing a main power source for a vehicle having at least two non-driven components which move relative to each other at least when the vehicle is in motion, this relative movement being associated with an amount of kinetic energy, wherein the relative movement of the at least two components is used to pump a fluid relative to a storage vessel so as to

create a store of potential energy in the storage vessel, and wherein controlled flow of fluid relative to the storage vessel is allowed so as to use at least a part of the stored potential energy to drive an auxiliary power source and thereby to supplement the main power source of the vehicle.

According to another aspect of the present invention there is provided an apparatus for supplementing a main power source for a vehicle having at least two non-driven components which move relative to each other at least when the vehicle is in motion, this relative movement being associated with an amount of kinetic energy, wherein the at least two non-driven components are connected to each other by way of a fluid pump which acts, upon relative movement of the at least two components, to pump a fluid relative to the storage vessel so as to create a store of potential energy in the storage vessel, and wherein means is provided for allowing controlled flow of fluid relative to the storage vessel so as to use at least a part of the stored potential energy to drive an auxiliary power source and thereby to supplement the main power source of the vehicle.

Thus the present invention seeks to make use of"free" kinetic energy (that is, kinetic energy which has been imparted to movable parts of the vehicle as a result of inertia or gravity) which would otherwise be dissipated as heat. In this way, fuel consumption and in particular fossil fuel consumption can be reduced, thereby reducing expense and also reducing environmentally damaging emissions.

For the avoidance of doubt, the expression"two non-driven components"is intended to include parts of a vehicle which are not directly driven by the main power source (engine) of the vehicle. For example, one component may be a portion of the chassis or body of the vehicle and the other may be an axle mounting or an actuator riding on an axle. Alternatively, one component may be the driver's seat and the other the base of the driver's cab, or one may be a portion of the chassis or body of the vehicle and the other may be a pivotally mounted inertia arm or a pendulum weight. Components not included in the expression are those such as moving parts of the engine or drive train which are driven by the engine, although components in which such driven components are mounted, such as wheel and axle mountings, are included, as would be an actuating component of the fluid pump which sporadically contacts a driven component such as a rotating axle. The important distinction is that the main power source of the vehicle is not used directly to drive the fluid pump.

For example, when the vehicle is being driven, that is it is in motion, bumps and the like in the road surface, as well as inertial and gravitational effects, cause the axle mounting and the chassis to move relative to each other. This movement is traditionally damped by way of a suspension system which may include mechanical springs and/or a pneumatic or hydraulic damping system which converts the kinetic energy of the moving components into heat. The present invention, which may be provided in addition to or in place of a traditional suspension system, uses the relative movement of the axle mounting and the chassis of the vehicle to pump a fluid, such as air or water, into or out of a storage vessel. The vehicle may be a single unit vehicle such as a car or

truck, or may be an articulated vehicle having one or more trailers. Where the vehicle is towing a relatively light trailer, the trailer tends to bounce on the road surface a great deal and provides a significant amount of "free"kinetic energy which can be employed by way of embodiments of the present invention. The present invention is also applicable to vehicles having caterpillar tracks and also to cars or trucks pulling a trailer or a caravan or the like.

Alternatively or in addition, any other at least two non-driven components which move relative to each other as the vehicle is being driven may be used. Examples include the driver's seat (if fitted with a suspension system) and the base of the driver's cab, the lead unit and trailer of an articulated vehicle, the main body shell and the bogeys of a railway locomotive or carriage, the wheel mountings and frame of a bicycle or motorcycle and so forth.

The fluid pump may comprise a piston mounted within a cylinder or a diaphragm pump.

The fluid may comprise, for example, air, water or other hydraulic fluid.

One of the at least two non-driven components may comprise a non-driven wheel of the vehicle, and the other may be selected from a portion of a chassis and a portion of a body of the vehicle, and the fluid pump may be selected from a rotary pump and a peristaltic pump, the pump having an impeller connected to the non-driven wheel. The non-driven wheel may be adapted to be lowered such that it contacts a road surface when the vehicle is travelling downhill or is braking (that is, when the main

power source (engine) is in over-run or idle conditions), and to be raised at other-times. The non-driven wheel may be provided with a clutch mechanism connecting it to the impeller of the fluid pump, the clutch mechanism being adapted to be engaged when the vehicle is travelling downhill or is braking, and to be disengaged at other times.

The vehicle may be provided with a tilt detector, the fluid pump being provided with at least an inlet valve and at least an outlet valve for fluid entering and leaving the fluid pump, the inlet and outlet valves being operable so as to prevent ingress or egress of fluid to or from the fluid pump upon detection of a tilt condition.

The flow of fluid relative to the storage vessel may be controlled by means of a valve.

The auxiliary power source may comprise a generator for generating electricity which is used to drive an electric motor which directly supplements a torque available from the main power source of the vehicle.

Alternatively or additionally, the auxiliary power source may comprise a generator for generating electricity which is used to charge a battery adapted to drive one of the main and auxiliary power sources.

Alternatively or additionally, the auxiliary power source may comprise a fluid engine which directly supplements a torque available from a main power source of the vehicle.

One of the at least two non-driven components may be connected to the other by way of a lever and fulcrum

mechanism, such as a type 1 mechanism, adapted to enhance the mechanical advantage of the operation of the fluid pump.

The pump may be adapted to pump fluid into the storage vessel so as to create a store of pressurised fluid in the vessel, the controlled flow of fluid relative to the storage vessel being a controlled release of fluid therefrom.

Alternatively, the pump may be adapted to pump fluid out of the storage vessel so as to create at least a partial vacuum within the storage vessel, the controlled flow of fluid relative to the storage vessel being a controlled flow of fluid thereinto.

For a better understanding of the present invention and to show more clearly how it may be carried into effect reference will now be made, by way of example, to the accompanying drawings in which: Figure 1 shows in schematic form a first embodiment of the present invention; Figure 2 shows in schematic form a second embodiment of the present invention incorporating a lever mechanism; and Figure 3 shows in schematic form a third embodiment of the present invention.

Figure 1 shows in outline a pair of road wheels 1 mounted on a pair of axles 2 of a road vehicle indicated at 13 and 50. A pair of cylinders 3 is mounted on the vehicle chassis 50 above the axles 2, each cylinder 3 being

provided with a piston 4 mounted therein in a substantially fluid-tight manner. The pistons 4 each have depending therefrom an actuator 5 acting as one of the non-driven components of the vehicle as defined above, the chassis of the vehicle being the other non-driven component. Each cylinder 3 has provided at its blind end 6 a non-return inlet valve 7 and a non-return outlet valve 8. Each inlet valve 7 connects to atmosphere and each outlet valve 8 connects to a conduit 9 which leads to a pressure storage vessel 10.

Instead of a piston and cylinder arrangement, the fluid pump may take the form of a simple compression pump, such as diaphragm pump or the like. The only requirement of the fluid pump is that a generally reciprocating motion can be used to pump air into the storage vessel under pressure.

Upon relative movement of the axles 2 and the vehicle chassis 50 caused, for example, by bouncing movements in the suspension of the vehicle as it travels, the axles 2, optionally by way of axle mountings 58 will sporadically push the actuators 5 and hence the pistons 4 into the cylinders 3. Air in the cylinders 3 will be pumped through the outlet valves 8 into the storage vessel 10, the inlet valves 7 being held shut by the pressure in the cylinders 3. When the chassis rises relative to the axles 2, the actuators 5 and hence the pistons 4 will drop, either under gravity alone or by way of a biasing mechanism (not shown), thereby drawing air into the cylinders 3 through the inlet valves 7, the outlet valves 8 being held shut by way of pressure from the storage vessel 10. This pumping process is repeated for as long as the axles 2 and the vehicle chassis 50 move relative to each other.

It will be apparent that an initial period of vehicle running time will be required to charge the storage vessel before it can be used to supplement the main power source of the vehicle.

In addition to the pumping mechanism operated by the axles 2, an inertia arm 11 having a pendulum weight 12 may be pivotally mounted at a point along its length on a vehicle part 13. The end of the inertia arm 11 remote from the pendulum weight 12 is attached to a piston 4 by way of an actuator 14, the piston 4 being mounted in a cylinder 3 connected to the storage vessel 10 as described above. Upon acceleration and deceleration of the vehicle, the inertia of the pendulum weight 12 will cause the inertia arm 11 to swing in one direction or the other, thereby actuating the piston 4 to pump air into the storage vessel 10.

A number of pendulums 11,12 may be provided aligned along different axes so as to make use of a number of spatial acceleration components, such as those experienced when the vehicle changes direction as well as simply speeding up or slowing down along a given straight path.

The storage vessel 10, which may be made from plastics, metals or any suitable material, is provided with a safety valve 15 so as to allow (dangerous) excess pressure to be released. An outlet 16 from the storage vessel 10 passes through an electrically operated and controlled valve 17 to an air motor 18. By controlling the valve 17, the speed of the air motor 18 can be controlled. The air motor 18 is used to drive an auxiliary power source in the form of a generator 19 which in turn may be used to charge a battery 20. The

battery 20 may then be used to power a geared electric motor 21 which is used to drive the axles 2 or at least to supplement the drive power of a main internal combustion engine 51 of the vehicle 13, In an electrically powered vehicle, the main vehicle batteries can be charged, thereby prolonging battery life.

A propeller 22 may be provided externally or internally of the vehicle, for example it may be provided internally behind the radiator grille (not shown) of the vehicle or mounted horizontally on the roof (not shown) of the vehicle. The propeller 22 is driven by wind as the vehicle moves, and also to a lesser extent when the vehicle is stationary, given suitable weather conditions.

The propeller 22 drives an electric generator 23 which can be used to charge the battery 20 and therefore to drive the motor 21. Controllable input ducts (not shown) can be provided if desired so as to control the flow of air onto the propeller 22. The input ducts could be opened or closed, either automatically or manually, depending on whether the additional auxiliary energy available through the propeller is required or not.

A further additional source of auxiliary energy may be provided in the form of at least one auxiliary road wheel 52 connected to an electric generator 53. The auxiliary road wheel 52 is movable between a first, raised position (shown in dashed lines) in which it is clear of the road surface, and a second, lowered position (shown in solid lines) in which it rolls along the road surface. The auxiliary wheel 52 may be manually or automatically moved to its lowered position when the vehicle is going downhill or braking (that is, when the engine is in over- run or idle conditions), thereby using"free"kinetic energy to generate an electricity supply to supplement

the main power source of the vehicle. To this end, a switch 54 may be provided on an accelerator pedal of the vehicle such that the auxiliary wheel is automatically raised when the accelerator pedal is depressed and is automatically lowered when the accelerator pedal is not depressed. Instead of or in addition to being connected to the electric generator 53, the auxiliary wheel 52 may be connected to a pump 56 and thereby help to pump air into of the storage vessel 10. The pump 56 may be a standard rotary pump or a peristaltic pump, depending on requirements. Alternatively, instead of using a drop-down auxiliary wheel, use may be made of non-driven but road-contacting wheels such as those commonly found on a trailer. In this case, it is advantageous to provide a clutch mechanism whereby the generator and/or pump is engaged only when the vehicle is travelling downhill or braking. The clutch mechanism may be manual or automatic, and may be located inside or adjacent to the wheel in question.

A further advantageous development is the incorporation of an anti-tilt mechanism. Where the pump or pumps is or are associated with a vehicle suspension system and evenly distributed on either side of the vehicle, this may be achieved by providing active control of the inlet and outlet valves to the pumps. A tilt detector 57, such as a laterally mounted mercury switch or the like, is provided in the vehicle and/or trailer, and is arranged by way of a solenoid 55 to close the inlet and/or outlet valves of the pumps on one or other or both sides of the vehicle depending on the degree and/or direction of vehicle and/or trailer tilt thereby stabilising the pressure within the various cylinders. By closing the inlet and/or outlet valves, further tilting may be prevented, at least until the vehicle and/or trailer has

stabilised, at which point the tilt detector 57 will provide a signal to open the inlet and/or outlet valves of the pumps once again.

It should be noted a pneumatic (i. e., a gas other than air) or hydraulic fluid can be employed in place of air, a supply of such fluid being provided to the non-return inlet valve 7. The supply of pneumatic or hydraulic fluid may form part of a sealed circuit, such that pressurised fluid which is released from the storage vessel 10 and used to drive an auxiliary power supply is then recycled to the inlet valve 7. The pneumatic or hydraulic fluid may comprise a non-flammable gas, water or a commercially available hydraulic fluid, among others. Instead of a piston and cylinder arrangement, the pump may take the form of a simple compression pump, such as diaphragm pump or the like. In hydraulic embodiments, an hydraulic ram could be used.

Referring now to Figure 2, there is shown a similar arrangement to that of Figure 1, except in that an actuator 5', which is operated by movements of the axle 2, is linked to a piston 4'in a cylinder 3'by way of a first class (type 1) lever 24. The lever 24 is pivotally mounted on a fulcrum 25 which is attached to the chassis 50 of the vehicle, as is the cylinder 3'. The pivot point 26 of the lever 24 is closer to the end of the lever 24 attached to the piston 4'than the end of the lever 24 attached to the actuator 5'. The lever 24 thereby serves to provide a mechanical advantage, amplifying the force available from the actuator 5'to operate the piston 4'. This means that the cross-sections of the cylinder 3'and piston 4'can be made larger than in the embodiment of Figure 1, since more force is available for the operation thereof, and

accordingly that a greater volume of air can be pumped into the storage vessel 10 for each stroke of the piston 4'. This makes the apparatus of Figure 2 more efficient than that of Figure 1.

Referring now to Figure 3, there is shown another similar arrangement to that of Figure 1, except in that the pump comprises a vacuum pump in the form of a piston 4" mounted in a substantially fluid-tight manner inside a cylinder 3". When the piston is urged away from closed end of the cylinder 3"by biasing means 51, such as a spring, air is drawn into the cylinder through the non-return inlet valve 7"from the storage vessel 10", with the non-return outlet valve 8"remaining closed.

Conversely, when the piston is pushed into the cylinder, the inlet valve automatically closes and air is pumped from the cylinder through the non-return outlet valve which is open to the atmosphere.

Upon relative movement between the piston and cylinder, air is pumped out of the storage vessel 10"so as to form at least a partial vacuum in the vessel. It will be apparent that an initial period of vehicle running time will be required at least partially to empty the storage vessel 10"before it can be used to supplement the main power source of the vehicle.

The inlet 16"to the storage vessel may be provided with controllable valve means 17, preferably an electrically operated valve means, and is connected to air motor 18 and an auxiliary power source in the form of a generator 19.

In other respects, the construction and operation of the embodiment of Figure 3 is the same as that of Figure 1, except that the air flows are reversed.

It should be noted the various options described above in relation to one of the embodiments are equally applicable to the other options.