GB2164607A - Improvements in or relating to submersible craft - Google Patents

Abstract

A submersible craft with provision for a wing 11; in which an enclosure 1, housing crew, is attached to gas-filled elastic or flexible buoyancy- contributing sealed enclosures 10, and/or is enclosed by a lightweight streamlined shell 6. This is prevented from imploding by virtue of its internal spaces 8 between itself and components 1,2,3,4, and 5 within being filled with gas, or gas and liquid, which is maintained under the same pressure as exists outside by means of ports or openings 9 located near or at the lowest point of the structure which permit water to pass till no pressure difference remains; and in which the gas trapped above the water inside contributes positive buoyancy to the craft, raising its total buoyancy above neutral when at or near sea level. Alternatively, a desired buoyancy can be maintained at any depth by means of addition or removal of gas, from and back to a storage system, under automatic or manual control. <IMAGE>

Description

SPECIFICATION Improvements in or relating to submersible craft Ships boats and conventional submarines are normally designed with positive buoyancy, i.e. to weigh less than the water they displace; and thus they all float in or on the water.

Submarines, additionally, are designed with ballast tanks which can be flooded with water, so that, by increasing the total weight of the craft, its positive buoyancy is reduced to subtantially zero, so that it can thereafter proceed under water at a given depth, or stand still, without the need to expend forces or power to maintain it at the chosen depth. However, this principle severely limits the strength of its hull, due to the weight limitations thereby imposed.

The 'Heavier-than-Water Craft', 'Undersea-Plane' or in short: 'U-Plane', for which a Patent was applied in 1957, Ser. No. 1 5o47/57 (but the application later abandoned,) on the other hand, was designed to be normally heavier-than-water, i.e. with negative buoyancy, although this negative buoyancy could be designed to be so minute as to extend to and include neutral buoyancy. This craft, like its counterpart in the art, operated on the flying principle, using wing-lift and/or motor power for level cruise and climb; although means could be provided for additional, positive, buyoncy for remaining stationary at sealevel or when in harbour, and for emergencies such as total engine failure.

Thus the mode of operation of the 'U-Plane' was opposite to that of the conventional submarine, in that the conventional submarine added water ballast in order to increase its weight to shed its inherent positive buoyancy when intending to dive into the water below sea-level, i.e. it operated by varying its weight; while the 'U-Plane' maintained its constant weight and changed its attitude in the water by varying the lift of its wing(s) or body-shape, and/or thrust (-direction) of its motor(s); and employed external, inflateable bags i.e. extra positive buoyan cy only in special cases, i.e. when stationary at sealevel, in emergencies, and in harbour. In these cases it varied its buoyancy by adding extra dis placement.

It would however be advantageous to extend and improve the utilization of extra buyancy, and its control, for use also below sealevel, and when in motion. A craft utilizing these additional new fea tures forms a new group of submersible craft, and forms the basis of this invention. Best described as a 'Variable Buoyancy Submersible Craft', or alterna tively as a 'Gas-Pressurized Submersible Craft', it is inherently positively buoyant when at sea-level, but negatively buoyant at depth, below a certain datum line, beyond which it requires lift by means of (Hydro-foil-) wings or a lifting-body shape, or a vertical component of propulsion-force or motor power to maintain horizontal motion without un wanted sinking.

Therefore, according to the present invention, this gas-pressurized craft is based on the design of the 'U-Plane'. However, provision is made to maintain all or at least some gas or air in internal, external or retractable flexible or elastic floating bags, and/or internal diving-bell-like compartments, passages, or any unoccupied spaces such as between an outer, preferably streamlined lightweight shell and therein enclosed inner, pressure-resisting stronglyconstructed individual components which can be designed to function under the high pressure of the ocean depth, such as: motors, batteries, fuel cells, fuel, suitable stores and cargo, internally carried weapons, strong containers for the protection of pressure-sensitive equipment & instruments within, & crew module consisting of cockpit and crew quarters.Alternatively, these pressure-resisting stronger and heavier parts and loads may form an integral part of, be attached to, orform an assembly with the lighter, gas-pressurized, preferably streamlined structure, shell orfairing.

Those gas-filled spaces and/or containers or compartments formed by structures with rigid walls, i.e.

not elastic bags with compressible sides, are ported or open at their substantially lowest point(s), and in communication with the outside water, and thus behave like a diving-bell, with the inside space always at the same pressure as the outside water, so that no pressure differential exists across the wall of the outer streamlined shell of the craft and its interior, and the shell therefore can be quite thin and light. When diving from sea-level, the outside water pressure rises, and water enters through the ports or openings into the gas-filled spaces, compressing the therein contained gas, until a pressure equilibrium exists. At the same time the gas in the elastic & BR< flexible buoyancy-bags is compressed into a smaller volume, thus reducing the amount of positive buoyancy contributed by the contracted bags.Since at sea-level the total buoyancy of the craft is - normally designed to be positive, a downward force must be produced by the wing(s) and/or body shape and/or motor thrust in order to begin the dive, and this is done as in aircraft practice by a tilting downward on the craft and/or its wing(s).

The greater the depth, the greater the amount of water from outside which enters through the ports into the interior space(s) of the outer shell, and the greater the compression of the gas contained therein, and hence the reduction of its volume and contribution to positive buoyancy of the craft. At a certain depth and pressure a point of equilibrium will be reached at which total buoyancy of the craft is neutral, neither positive nor negative.Descending even deeper will reduce the air or gas-volume even further, and hence the craft will become negative buoyant, requiring wing- or motor lift for mainte nance of a constant cruising depth or a climb back to the datum-line of zero i.e. neutral buoyancy, from whereon further climb will be assisted by the then rising positive buoyancy due to the further expan sion of the trapped air expanding the size of the flexible buoyancy bags and expelling water from the space(s) inside the outer streamlined shell back through the ports.

When traveling at the datum line of neutral buoyancy, no wing lift is required; hence the wing can be designed to be retractable, or at least can be reduced in size by telescoping, unless required for the purpose of pylon-mounting of cargo and/or weapons. As this level is also the depth at which wing drag is least, it affords greatest range & speed.

Any change in depth is accompanied with a corresponding change in buoyancy in a direction to increase the momentum of change, i.e. regenerative.

In order to prevent instability, the ports or openings at the lowest point of the gas-containing spaces can be controlled by valves which can be closed or opened with manual or automatic control, or springloaded, so that opening occurs only after a pre-set pressure difference between inside and outside gas/water pressure has been reached, within the strength & design limits of the outer shell. Additionally these valves are arranged to function as safetyvalves, preventing excess pressure built-up, or gas spill in the event of negative 'G' forces.

In another embodiment of the invention, neutral buoyancy can be extended to a greater depth by means of increasing the amount and pressure of the gas contained within the space(s) between the outer shell and the therein enclosed components, and/or flexible bags, i.e. by adding gas from a stored supply such as high-pressure containers, and/or a cooled thermos flask wherein the gas is stored in liquified form, or by means of gas production through chemical reaction by stored chemicals. When climbing to a level where outside pressure is lower, this process has to be reversed and the now surplus gas again be stored, or, as e.g. in an emergency, the gas is permitted to spill out through the port and/or safety vents (of the elastic gas bags) provided. Gas generation, and storage of gas in liquid form may well be the preferred method, and is well known.

Since this process requires some time to operate, any change of depth by the craft would have to be made with regard to this time factor, so that the internal pressure change remains in step with the external pressure change. Further, it would be advisable to choose a gas which requires the least amount of energy when being changed from one state to the other, and is otherwise suitable.

Since it is possible to extend the admission and increase of gas pressure within the craft's unoccupied space in step with the increase of water pressure outside the craft during a descent, and under automatic control, this can be arranged so as to adjustthe buoyancy of the craft from a positive value at sea-level, to a neutral value maintained all the way down to the bottom of the ocean, with reversal of this process during a climb back to sea-level, or even with a climb assisted by excess positive buoyancy, which could be selected at any depth. Such a craft would not need wings for lift, and would therefore form a new type of submersible craft, possibly best described underthe name: 'Pressurized Submersible Craft'.

With motors, their supply, weaponry and other suitable items designed to operate under the outside pressure, only the structure containing or forming the cockpit and crew living quarters and areas for containment of pressure-sensitive equipment, wherein a comfortable gas or air pressure is maintained and which would be hermetically sealed before departure or diving, would have to be designed and constructed to withstand the full differential, i.e. outside pressure; and since this structure only forms a small part of the whole craft, it can be made exceedingly strong, without any limitation being imposed by considerations of weight penalties.

This invention of buoyancy manipulation and control can also be applied to containers of civil or military loads and equipment attached to or carried by these craft, so that the combined system maintains these ideal characteristics whether loaded or clean. It can also be applied to any pushed, towed, remote-controlled craft, trailer, container, object or device mounted on pylons of an optional wing, or hydro-foil.

Further, in order to prevent corrosion orcontami- nation of the inside of the craft, the space(s) above the port(s) can be sealed from the outside by means of a flexible balloon or balloon-type membrane fitted to the inside of the port, functioning similar to the inner tube of a car tyre, and extending into or conforming substantially to the contours of the surrounding space when filled and inflated with water from the outside through the port in the structure, shell orfairing.

Also, pressurized gas-filled spaces may be subdivided into smaller sections or compartments. And, additional retractable or foldable or elastic external positive buoyancy-adding bags or containers, and/or purpose-built internal compartments may be arranged to form part of or be attached to the structure of the craft or its outside load, for buoyancy and/or trim adjustment purposes or attitude control.

All pressurization-ports may incorporate filters, as well as noise silencers. Or else, separate ports or openings may be interconnected, connected to one common outlet/inlet, and/or one common filter and silencer unit.

For the construction of the craft any material or combination of materials may be used, including, for the gas-pressurized parts i.e. the outer shell, elastic, flexible or transparent types.

Improvements in or relating to submersible craft A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 shows a side-on view of the craft, on firm ground.

Figure 2 shows a view as seen from above.

Figure 3 shows a head-on view of the craft, on land, priorto entering the water.

Referring to Figure 1 the craft comprises strongly built pressure- resisting internal components such as a crew compartment 1 Fuel supply or battery 2 motor 3 electronics container 4 and cargo (a mine) 5, surrounded by the light-weight outer shell 6 which is attached to all the major internal components by sealed bulkheads in the form of rings or frames 7, which also partition the intermediate space 8 into separate compartments. This space is filled with air in connection with the outside through the openings or ports 9 in the lower part of the outer shell 6.

Gas-inflated flexible or elastic sealed containers 10 are shown attached to the sides of the craft. Also shown is the main wing 11 and the canard control surface 12. Crew entrance is through the hatch 13 shown in the closed position.

When the craft rolls down a slipway into the sea, no substantial amount of water can enter through the lower ports 9 because of the air trapped above in the space formed between the internal components 1,2,3,4, & 5, and the surrounding light-weight outer shell 6.

Additional buoyancy is contributed by the water displacement of the sealed gas-filled flexible or elastic enclosures 10. The combined volume and hence water displacement of the internal space 8 and of the enclosures 10 is designed to be sufficient to confer positive buoyancy to the craft when otherwise, without this additional buoyancy, the strongly-built and therefore heavy pressure-resisting internal components on their own would sink.

When at some forward speed and the correct control input a downward force is applied to the craft by its canard 12 and hence by its main wing 11 and it therefore descends deeper into the water, the rising outside pressure will force water through the ports or openings 9 into the internal spaces 8 until the therein contained trapped internal air will have reached the same presure, at a reduced volume. At the same time the volume of the gas-filled elastic or flexible enclosures 10 and hence their displacement will be reduced as well, the result being an overall reduction of positive buoyancy ofthe craft. When the descent is contained to a greater depth, the craft will first become neutrally buoyant, followed by negative buoyancy, i.e. the craft will now require lift from its wings to prevent sinking and in orderto maintain a constant depth.

Thus, whereas in a conventional submarine for it to begin a dive and continue submerged on its way it is necessary to open valves usually at the top oftheir ballast tanks and allow the internal air to escape in orderto allowwaterto enter through other ports or valves and thus to ballast the craft from positive buoyancy to neutral buoyancy; and later, when again surfacing, replace the lost air from storage, no such action is required in this embodiment of this invention, neither on the descent nor the return to sea-level, since the original internal air or gas remains in its enclosures throughout the journey.

Further, in a conventional submarine an increase in the strength and hence weight of the crew compartment for an improved depth capability would result in the submarine becoming neutrally or even negatively buoyant even with the ballast tanks empty, and thus unable to surface or even maintain a constant depth. Instead it would sink. To prevent this occurring, it then would require lifting wings, which would change it into a copy of the 'U-Plane', or it would require oversized permanently empty ballast tanks, which however would implode under the outside pressure or else would themselves have to be so strong and therefore heavy as not to be able to add the required positive buoyancy. Nor could they then be properly called 'ballast tanks' anymore, and would in fact have to be more correctly called buoyancy tanks. Conventional submarines are therefore inherently limited to only a shallow depth capability.

No such limitation exists in the craft according to this invention because it is an inherent feature of this embodiment that at all times no substantial pressure differential exist between the outside water pressure and the internal air pressure of the outer shell 6, and the internal gas pressure of the gas-filled enclosures 10, whose weight therefore is kept low and thus is not negating their effectiveness in providing added buoyancy.

It is also a feature of this embodiment that a lifting wing is provided to replace with its lift the gradual loss of buoyancy due to the reduction in volume of the air in the internal spaces 8 and the volume and hence displacement of the enclosures 10, resulting when descending to a greater depth.

Claims (26)

1. A submersible craft, comprising a pressure resisting non-buoyant assembly of primary components and enclosures; being connected, attached to or at least partly surrounded by at least one secondary further enclosure for a fluid in the form of gas, or gas and liquid, which is collapsible or has normally open ports or openings nearthe bottom, and which increases the total buoyancy of the craft to a positive value when at or near the water surface, or which permits adjustment to a selected value at any depth.

2. A submersible craft according to Claim 1, in which the assembly includes a pressure resisting enclosure for crew and equipment and filled with a breathable gas mixture at a suitable pressure.

3. A submersible craft according to Claim 1, in which the secondary enclosure for the fluid comprises at least one flexible or elastic gas-tight container, bag or tyre positioned outside the main primary pressure resisting components and enclosures and exposed to the pressure of the surrounding water.

4. A submersible craft according to Claim 1, in which the secondary enclosure comprises at least one semi-rigid or substantially rigid vessel, shell, container or enclosure which is normally closed in its upper part and normally open to the water at a lower level.

5. A submersible craft according to Claim 3, in which the internal space of the secondary enclosure is subdivided into at least 2 compartments sealed from each other.

6. A submersible craft according to Claim 4, in which the internal space of the secondary enclosure is subdivided into at least 2 compartments sealed from each other, and each compartment is individually open or ported to the water at a lower level.

7. A submersible craft according to Claim 6, in which at least some individual openings or ports are connected to form a common port.

8. A submersible craft according to Claim 4, in which the secondary enclosure is semi-rigid or substantially rigid, and the space or volume within the secondary enclosure or any of its compartments formed by subdivision is occupied by a flexible or collapsible bag or membrane which prevents physical contact of water with the internal surfaces of the enclosure and the trapped air within.

9. A submersible craft according to Claim 4, in which the secondary enclosure at least partially encloses the primary pressure-resisting components and/or enclosures.

10. A submersible craft according to any of the preceding claims, in which any number of secondary enclosures connected to the primary components or enclosures are a mix of the collapsible type and the semi-rigid or substantially rigid type.

11. A submersible craft according to any of the preceding claims, including valve means for controlling the admission of water into the rigid or semi-rigid secondary fluid-filled enclosures.

12. A submersible craft according to Claim 11, in which the valve means are controlled automatically in response to a selected pressure difference between the pressures outside and inside the secondary enclosures.

13. Asubmersible craft according to any of the preceding Claims, incorporating noise silencers, and/or contamination-filters in the path of the water.

14. A submersible craft according to any of the preceding Claims, including means for introducing further gas under pressure into the secondary enclosures, from a stored high pressure fluid supply orfrom a gas production plant such as a chemical gas generator, or from a store of gas in liquid form.

15. A submersible craft according to Claim 14, including means for automatically controlling the admission and/or generation of gas under pressure, and/or its removal, in response to the sensed depth of the craft or the differential between a selected or programmed volume of gas and the actual quantity inside the secondary enclosures.

16. Asubmersible craft according to Claim 14, in which the extra gas admitted during a descent into a region of higher water pressure is vented again when climbing to a region of lower water pressure through the openings or ports, safety vents, or pre-set or automatically controlled valved means.

17. A submersible craft according to Claim 14, in which means are provided to return the extra gas again to a storage system, orthe storage system from which it originated.

18. A submersible craft according to any of the preceding Claims, in which automatic valve means are provided to release any excessive internal gas pressure.

19. Asubmersible craft according to any of the preceding Claims, in which means are provided to manually override any automatic control.

20. A submersible craft according to any of the preceding Claims, including at least one generally horizontal extending wing orfin and means for altering the angle of incidence of a fin or of a trim tab to vary the attitude of the vessel when in motion.

21. A submersible craft according to Claim 20, in which the wing or fin is at least partly retractable or otherwise adjustable in size and/or sweep.

22. A submersible craft according to any of the preceding Claims, in which any of the secondary enclosures of the collapsible type are arranged to be retractable into suitable fairings, compartments within the contours of the outer semi-rigid or rigid shell, wing, or any other part ofthe craft, and in communication with and exposed to the water pressure.

23. A submersible craft according to any of the preceding Claims, which incorporates a propulsion system with an adjustablethrustline providing a lift, depression and/or steering component.

24. A submersible craft according to any of the preceding Claims, of an unmanned type operated by automatic, pre-set, programmed or remotecontrolled means.

25. A submersible craft according to any of the preceding Claims, in the form of trailers, robots, drones or weapons, whether powered or pulled, pushed, and/or remote-controlled or carried aboard; and/or cargo, extra power modules, power supplies, loads, attached to the submersible or any of its parts orto each other.

26. A submersible craft substantially as described herein with reference to Figures 1-3 of the accompanying drawing.

26. Asubmersible craft substantially as described herein with reference to Figures 1-3 of the accompanying drawing.

Amendments to the claims have been filed, and have the following effect: (a) Claims 1 to 26 above have been deleted or textually amended.

(b) New or textually amended claims have been filed as foilows: CLAIMS

1. A self-contained submersible craft, comprising a pressure-resisting non-buoyant assembly of primary components and enclosures, most of which are contained within a lightweight gas and watertight hull or shell, and/or which are connected to at least one sealed, secondary enclosure for a fluid in the form of air or gas, which is collapsible, and which is designed to contribute to the total buoyancy of the craft towards a positive value when at or near the water surface, and/or which permits adjustment to a selected value at any depth by on-board means physically independent from any auxiliary and/or surface vessel.

2. A submersible craft according to Claim 1, in which a hull or shell is an integral part with the assembly and defining a self-contained craft.

3. A submersible craft according to Claim 1, in which the secondary enclosure for the air or gas comprises at least one contractable/expandable, foldable, flexible or elastic side-wall or part of a wall defining a gas-tight container, bag, tyre, rigid or semi-rigid compartment, positioned outside the main primary pressure-resisting components and enclosures and exposed to the pressure of the surrounding water.

4. A submersible craft according to Claim 1 and 2, in which the hull is constructed to contain a fluid in the form of gas, or gas and liquid, within the space unoccupied by the primary components and enclosures within, and is normally open or capable of being opened to the surrounding water at a lower part permitting water to pass on its own accord whenever a suitable pressure difference develops between the internal and ambient pressure.

5. A submersible craft according to Claim 3, in which the internal space of the secondary enclosure is subdivided into at least 2 compartments sealed and independent from each other.

6. A submersible craft according to Claim 4, in which the internal space of the hull is subdivided into at least 2 compartments normally sealed from each other, and each compartment is individually open or ported to the water at a lower level.

7. A submersible craft according to Claim 6, in which at least some individual openings or ports are connected to form a common port.

8. A submersible craft according to Claim 4, in which the hull is semi-rigid or substantially rigid, and the space or volume within the hull or any of its compartments formed by subdivision is occupied by a flexible or collapsible bag or membrane which prevents physical contact of water with the internal surfaces of the hull and the fluid and components contained within.

9. A submersible craft according to Claim 4, in which hull is constructed with a form or outline conferring a delta-wing or lifting-body shape to the craft.

10. A submersible craft according to any of the preceding claims, in which in addition to any number of contractable/expandable gas-filled secondary enclosures connected to the primary components or enclosures are also added known gas, or gas and water-filled non-collapsible rigid types, as for example in the form of a diving bell.

11. A submersible craft according to any of the preceding claims, including valve means for controlling the flow of water into and out of the hull and/or of any secondary non-collapsible rigid, semirigid or known type of additional enclosure.

12. A submersible craft according to Claim 11, in which the valve means are controlled automatically in response to a selected pressure difference between the pressures inside and outside the hull.

13. A submersible craft according to any of the preceding Claims, incorporating noise silencers, and/or contamination-filters in the path of the water.

14. A submersible craft according to any of the preceding Claims, incorporating self-contained means to produce and/or provide further gas for introduction under pressure into the internal spaces within the hull or shell, and/or into the secondary enclosures, from a stored high pressure fluid supply or from a gas production plant such as a chemical gas generator or from a store of gas in liquid form, carried on board the craft.

15. A submersible craft according to Claim 14, including means for automatically controlling the introduction and/or generation of gas under pressure, and/or its removal, in response to the sensed depth of the craft or the differential between a selected or programmed volume of gas and the actual quantity inside the hull and/or secondary enclosures.

16. A submersible craft according to Claim 15, in which the extra gas introduced during a dive into a region of higher water pressure is vented again when climbing to a region of lower water pressure through the openings or ports, safety vents, or pre-set or automatically controlled valved means.

17. A submersible craft according to Claim 15, in which means are provided to return the extra gas again to a storage system, or the storage system from which it originated.

18. A submersible craft according to any of the preceding Claims, in which automatic valve means are provided to release any excessive internal gas pressure.

19. A submersible craft according to any of the preceding Claims, in which means are provided to manually override any automatic control.

20. A submersible craft according to any of the preceding Claims, including at least one generally horizontal extending lifting wing or fin constructed with an aquafoil-section for wing-borne underwater flight as a 'Heavier-than-Water Flying Machine', and means for altering the angle of incidence and/or angle of attack of any lifting wing or fin or of trim tabs to vary the lift of the wing when in flight mode.

21. A submersible craft according to Claim 20, in which the wing or fin is at least partly retractable or adjustable in size and/or sweep.

22. A submersible craft according to any of the preceding Claims, which incorporates at least one propulsion system with a fixed or adjustable thrustline providing a lift or depression component, a tilt-rotor, adjustable shrouded fan or jet nozzle arrangement and/or at least one fixed substantially vertical axis rotary wing arrangement.

23. A submersible craft according to any of the preceding Claims, in which any of the secondary enclosures of the contractable/expandable type are arranged to be retractable into suitable fairings, compartments within the contours of the hull or wing, or any other part of the craft, while remaining exposed to the ambient water pressure.

24. A submersible craft according to any of the preceding Claims, of an unmanned type operated by automatic, pre-set, programmed or remotecontrolled means.

25. A submersible craft according to any of the preceding Claims, in the form of trailers, robots, drones or weapons, whether powered or pulled, pushed, and/or remote-controlled or carried aboard; and/or cargo, extra power modules, power supplies, loads, attached to the submersible or any of its parts orto each other.