GB2472472A

GB2472472A - A device for operation in a fluid having a hinged flap

Info

Publication number: GB2472472A
Application number: GB0918464A
Authority: GB
Inventors: Peter John Charles Spurgeon
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-08-06
Filing date: 2009-10-22
Publication date: 2011-02-09
Also published as: EP2461874A1; GB0913689D0; WO2011015804A1; GB2472493B; GB2472493A; GB0918464D0; GB201012510D0

Abstract

A device for operation in a fluid is described. The device comprises at least one flap 2 hinged at one side to a frame 1 and adapted to have a greater resistance to movement through the fluid in one direction than the other. A user may generate propulsion by moving the device in a reciprocating motion through the fluid. The device is also provided with flexible tensile components 3, attached between a portion of the flap opposite to the hinge 4 and the frame, that restrict movement of the flap, to a set angle, as the device is moved through the fluid in the direction of greater resistance. The device may be used as a swimming or rehabilitation aid, an item of fitness equipment, or a propulsion or maneuvering means. The device may be operated with one or two hands and may be buoyant.

Description

Flap with Flexible Tensile Components

Background

Oars and paddles are well known as being a one piece design with a rigid blade which is moved in the fluid (water) for the propulsive (power) stroke and is then lifted clear of the fluid (water), into a less dense medium (air), for the idle stroke. A long handle is used to increase the length of the stroke but this adds to the weight of the device because it has to withstand bending stress. The blade has to be lifted against gravity on the idle stroke or weight and inertia has to be added by using a counter-balanced handle at the rower end: the rowlock acting as a fulcrum for the oar. The traditional oars also have the disadvantages of requiring a waterway considerably wider than the craft and needing skill in timing the removal and insertion and rotation of the blades during each part of the stroke.

Pedallo boats use a paddle wheel driven by a crank driven by the feet. Another means of propulsion uses propellers having shaped blades and being moved in a rotary fashion in the fluid. Propellers of this type are more expensive and difficult to fabricate than oars and paddles.

The invention proposed utilizes a flap with flexible or hinged parts mounted on a frame that can be operated by a reciprocating motion without withdrawal from the dense medium (eg water) into the less dense medium (eg air). Swimmers or divers using the invention have the advantage that the area of the flap can be larger than the area of the hand.

Other means of propulsion include punting, but the pole cannot be used in deep water, or when the bottom is very muddy or uneven; whilst paddle wheels and propellers all involve more mechanical components and expense in maintenance and repair.

The pull mode is particularly lightweight because the bending/buckling stresses are less in the operat-ing handle.

The lightweight flaps of the invention are less likely to damage marine anumals and plant life than the rotary propeller devices which suck them into their blades.

In the case of hydrotherapy and aqua fitness equipment the existing fins and dumbells are of limited size on account of portability and storage. Existing designs cannot be easily adapted, or repaired.

Description

The description uses the word water to describe the medium in contact with the flaps, the principle of operation is equally applicable to other liquids or gases or particulate sub-stances such as sand or snow. The device may also be adapted for propulsion on hard surfaces, particularly in rocky or rough terrain where wheeled or tracked vehicles are unsatisfactory.

The invention utilises the forces required to move an object in the water. The minimum force is required when the object is long and thin and smooth. When a flat plate of zero mass is at right angles to the force then movement of the plate involves a pressure being built up by the plate on the one side and a reduced pressure on the other, these pressures reaching a constant state when water flows around the plate and from surrounding areas ofwater. In the case of an open box that has filled with water being moved in the direction of the opening the object being moved has the mass corresponding to the mass of the water inside; the object being moved then has inertia and an addi-tional force P is required to move it, equal to the mass multiplied by the acceleration. Such a force is limited only by the ability to apply it quickly over a distance but the energy so expended is negated when the object has to be pushed forward in the direction of motion again. The invention can in-clude an internal flap hinged at the forward end of the box (the box being the frame). In this case the hinged flap can be arranged so as to enable the faster water to be discharged and replaced by still water with little retarding effect during a forward stroke. The hinged flap or flaps in the forward end of the box may be restrained by tensile members as described below, or may be restrained by a mesh across the forward end of the box or by any protrusions or stops arranged on the flap and body.

A single flap module according to the invention consists of a frame that has a hinged flap and re-straining components such that the flap is able to rotate through an angle relative to the planeof the frame. The hinges are at right angles to the preferred direction of motion and the flap presents a different resistance to motion according to its angle. In one direction of movement the hinges are at the forward edge of the flaps and the flaps are allowed to swing to a low resistance angle so that there is little disturbance of the water. When the frame is moved in the opposite direction, the power stroke, the force of water flow causes the hinged flap to swing outward until it is restrained by the tensile components tied between the flap and the frame. This is a position of greaterresistance to the water. The remaining power stroke then causes an increased force of the water on the flap and consequential propulsive force in the preferred direction.

An important feature of the invention is that the swing outward' is in a direction such that it swings to the extent lirnitedby tensile components. Means of ensuring a particular direction of swing may include spring components, stops on the frame restraining the swing in the lowest resistance angle, weights and curved features on the flap or the frame. The flap and frame could be finished in con-trasting colours and patterns to assist in observation of the correct movement, to warn other water users of its presence and to increase visibility in rescue situations.

The hinges are typically only required to open through an angle up to 90 degrees from the idle stroke position and they do not need precision since the flap does not have to fit closely into a frame. This enables straps or ties to be used which require less maintenance than conventional aligned hinges with bearings that have possible corrosion and lubrication effects.

The restraining means for the flap during the power stroke may consist of pure tensile links such as lightweight strings, ropes, wires, cables or chains but it is important that they do not tangle when they are loose during the idle stroke. The restraining links can be provided with means for adjustment, thereby altering the maximum angle of the flap, the quantity of water affected, and the power of each stroke.

The propulsion effect is obtained by applying a reciprocating motion to the frame. If the forces are applied at the end of the frame away from the hinges then the propulsive effect is to pull on the driving member, the frame pulls the person or craft and the forces in the frame are mainly tensile. Tf the forces are applied at the hinge end of the frame then the device works as a pusher.

Devices of this type can be positioned ahead or behind a person or craft for pulling or pushing a craft, a swimmer or a diver. Directional adjustments can be made by operating to one side of the direction of movement.

Assemblies of this type can be produced in right-handed and left-handed types for use on the two sides of a craft or for operation by left and right limbs of a swimmer or diver, or both limbs together.

If hinged mechanisms of this type were fitted to a craft then the craft could be moved in the forward direction by the inertial energy of a reciprocating body, the natural backwards direction caused by the return stroke being resisted by the greater resistance of the flaps, this would even be the case when used on dry land..

The flaps can be made self-compensating so that at all parts of the stroke where the fluid speed is faster than the power stroke speed, the flaps are in their streamlined state.

For a flap that can only move in one direction from the idling position the tensile restraint may be fastened to any point on the flap, thus enabling the hinges to take a different share of the forces. The shape of the flap can be varied from the flat rectangular shape to be shown in the diagrams in order to produce different degrees and areas of disturbance in the water, the parameters controlling propulsive forces being area, volume of water affected in each stroke, strength of components and the difference between the resistance to the water when idling than when on the power stroke.

Tn the case of a flap which is free to swing to either side of the idle position the positioning of the tension components is determined by the need to prevent them wrapping around parts of the flap or frame and for the flap to have a useful effect whichever way it swings.

Tn the case of a flap hanging from a floating frame it may have weights in order for it to make a quicker transition from the idle to the power position.

A flap may have a thin very flexible central portion if it has stiffeners or framing components.

Since each flap is very simple and automatic in operation devices can be constructed having large numbers of them, shorter flaps can be operated with shorter strokes. Short stroke devices are more suited to electrical or mechanical reciprocation at high frequencies. Such a device would have a propulsive effect from transmission of vibrational energy to the frame.

Detailed Description

An example of a single flap according to the invention is shown in figure 1. Tn figure lathe frame (1) is stationery relative to the flow (12), the flap (2) hangs loosely and the tension components (3) are loose. The hinges (4) are in an intermediate free position. In figure lb the water (12a) is flowing from left to right relative to the frame, wafting the flap (2a) towards the frame (1) with a light force, relating to an idle stroke, the frame 1 or flap 2 has means to prevent the flap 2 from moving in the upwards' direction. In figure 1 c the water (1 2b) is flowing from right to left relative to the frame (1) forcing the flap (2b) to take the position shown where the tension component (3) is tight. This relates to a power stroke.

Figure 2a, 2b and 2c show three unconventional hinge arrangements, two or more hinges being required for the flap (2). In figure 2a each hinge comprises a circular section nylon fishing line (4) passing through a hole (14) in the frame (1) and through hole (15) in the flap (2). The line is pre-vented by means of crimps (5) from pulling through the holes. In figure 2b each hinge is formed by a nylon cable tie (4a)that forms a loose loop when its end is pushed through the ratchet head (17). In figure 2c the margin (18) of the flap (2) is secured to the frame, the flexibility of the material of the flap (2) or a pre-formed angle, or a weakened area allows the flap to hinge' to the idle and power positions.

There are many means of securing the tensile components (3) to the frame and to the flap (2). Sev-eral means are shown in figures 4a, 4b, 4c and 4d in which a tensile component (3) is fastened to the frame (1) and to the flap (2); many other means ofjoining one component to another could be used.

Tn figure 4a the tensile component (3) is a plastic line which passes through holes (19) in the frame (1) and the two ends then pass through holes (20) in the flap (2) then being secured by plastic weld (21). In figure 4b the tensile component (3) is a plastic line which passes through holes (19) in the frame (1) and the two ends then each pass through two holes (20) in the flap (2) and are secured by a crimp (5). In figure 4c the tensile component (3) is a plastic line which passes through holes (19) in the frame (1) and the two ends then pass through holes (20) in the flap (2) and are secured by means of a screw clamp connector (22). In figure 4d the tensile component (3) is a plastic line which is secured into a loop (23) by means of crimp (5), the loop (23) is then attached to the frame (1) by means of a replaceable fixing into the side of the frame (1) at one of the chosen points (25); the other end of the tensile component (3) is secured to the flap (2) by passing it through a crimp (5) and holes (20) in the flap (2) and then securing to the end through the crimp (5).

The prior examples demonstrated various means for assembling the device to a simple rectangular frame (1) of the type shown in figure 1. These means and others can be used to adapt the device for use with diverse forms of frame, each being advantageous for particular applications in relation to range of sizes, strengths and weights. Smaller sizes, for personal use, require means for attachment to the person in the case of amputees, or for holding in the hand by swimmers, divers, and other pool and water users.

Figure 5 shows an assembly of a frame (1) having flaps (2) that are able to swing to either side of the idle position and a suitable means for providing hinges and attaching the tensile component (3). The frame is also shown in a vertical plane in order that the flaps 2 are equally submerged in each posi-tion of swing, even when the device is near the surface.

Figure 5 shows a plate (25) having handgrips (26) at each end and flap devices (27) attached to each side. A simple evaluation model could be constructed using folding dvd boxes and a vegetable chopping board. The handles at each end enable it to be used in a push or pull exercise mode, or as a push or pull propulsion device operated with one or both hands. The assembly can be used on the surface or under water.

Figure 6a shows a flap (2) attached to the outside of a hollow cylinder (35), by similar means to the attachment to a flat frame. Further similar flaps can be attached at other positions. Such a construc-tion has the advantage that certain flaps can be temporarily secured in the idle position using the elastic band (33) or other means. In the case of an amputee the cylinder (35) could slip over the limb and be secured using suitable straps and padding. A handle (28) can be provided for a person to grip. A simple evaluation model was produced by using a CD Cakebox cover, dowelling and hose clips to prevent the dowel from slipping out: flaps were produced from the lids of food boxes. In figure 6b, flaps (2) are attached to the inside of the hollow cylinder (35) and a handle is attached to the outside, having the advantage that the flaps (2) will not strike surrounding objects or persons and added propulsive effort is produced from the movement of the contained body of water.

Figure 7 shows a square or rectangular section open ended box section (30) with a flap (2) mounted inside it. Handles (31) can be provided in the different ends of the different sides. As in figure 6 the design benefits from the extra thrust of the contained body of water. A heavy-duty model was prepared by cutting the base of a plastic washing-up bowl to form two flaps, hinged at opposite sides. n figure 8 flaps (2) are attached to all four sides and a handle (31) is fitted inside. Such a construction has the advantage that certain flaps can be temporarily secured in the idle position using the elastic band (34) or other means. This construction is suitable for a wide range of sizes due to its advantageous stress distribution. If required the internal space (36) could contain bouyancy or ballast materials.

An example of the invention for use on the surface of water is shown in figure 9. The frame (1) mounts three flaps (2). Flaps may be opened by weights (37) and may also be encouraged to open from the idle position by stops (38) in the frame (1). Such a device can be used in small sizes by swimmers or in larger sizes operated by a man from a boat using a long handle attached to the frame at end (48) to pull the boat or to push it by means of a handle attached to the other end (47).

In figure 10 a floating craft (41) contains a crank shaft (39) driven by the feet (40) which drives a connecting rod (38) and thus propels the craft by the reciprocating motion of the floating device (37). A frame enclosing a body of water (fig 6a or fig 7) would give extra thrust. Also the crankshaft may be driven by an engine, electric motor or pneumatic or hydraulic device.

1'l Li n-v n T'nn in r'g-vrnnn-n n-ntc Dc rn A Figure 12 shows the invention having an inflateable frame (42), that may be brightly coloured for visibility in rescue situations. The inflateable frame (42) may have compartments in order to provide dimensional stability to the positions of the brackets (46) for securing the flaps (44) at the hinge side and the tension component (3). Weights (45) are to ensure that the flaps open at the start of the power stroke. An adjustable buoyancy could also be realised by having a frame with rigid compart-ments that could be filled or part-filled with water, liquid, sand or granular material.

The invention depends on the fact that the resistance of a fluid to the motion of a body depends on the size and shape of the body. The resistance also changes according to the speed of the body relative to the fluid, often in a square law relationship but becoming a hyperbolic increase as the velocity of sound in the fluid is reached. Reciprocating such an asymetric section may also produce a propulsive or fluid movement effect.

In the case of a multi-stroke powered design, having flap assemblies operating at alternate times, the several frames may be moved from a common motor on the craft itself, possibly using belts, pulleys, crankshaft, flywheel and piston rod components. Short strokes at high speed with many small flaps will enable the device to be operated in shallow or restricted waters.

Electrically powered motors, particularly those of the linear electromagnetic type, can be controlled for different speeds during the various parts of the stroke of the flaps, for example a slow idle stroke will offer an even lower resistance and a higher speed power stroke will produce a higher propelling force.

A light or beacon may be attached to the device to indicate its position for rescue or for illumina-tion.

The typical reciprocating action of the devices described can be performed at varying speeds or at various fixed speeds and the length of stroke can be shorter, longer or variable. The included angle between the hinged flaps for the power and idle strokes can also be varied or various. The drive mechanism can be manual or mechanical. Mechanical drives can include those driven by wind, wave action, steam, internal combustion, pnuematic, chemical or electrical engines. Energy could also be transmitted to the device by wave motion, including sound and light waves.

The device could also be used on land, typically in muddy or sandy terrain where wheels or tracks are inneffective.

Tt is thought that the action of the device could be used with air as the fluid, with a sufficient plurality of flaps and motive power, for propulsion of land or aircraft by the flaps acting on the air at very high speed during the power strokes.

Claims

Flap with Flexible Tensile Components Claims 1. The device consists of a flap hinged at one side to a frame and connected to it at other points by flexible tensile components such that, when immersed in a moving fluid the flap will rotate according to the direction of flow, rotating to an angle of lesser resistance in one direction of relative flow but to an angle of higher resistance in the opposite direction of relative flow, it being restrained in this angle of higher resistance by the tensile components, the higher force therefore being transmitted to the frame.
2. A device according to claim 1 having hinges formed by passing a flexible strap through holes in the frame and or the flap.
3. A device according to claim 1 having hinges formed by passing an adjustable ratchet fastening tie loosely through holes in the frame and the flap.
4. A device according to claim 1 in which part of the flap is fixed relative to the frame whilst a part restrained by tensile components is able to flex, in the manner of a hinged connection between the two parts.
5. A device according to previous claims having the flexible tensile flap restraining components consisting of single strand material.
6. A device according to claims 1 to 4 having the flexible tensile flap restraining components consist-ing of chains.
7. A device according to claims ito 4 having the flexible tensile flap restraining components secured to the frame by adjustable means.
8. A device according to preceding claims having a frame consisting of an open ended cylinder and having a flap hinged on the outside ofthe cylinder.
9. A device according to claims ito 7 having a frame consisting of an open ended cylinder and having a flap hinged on the inside of the cylinder.
10. A device according to claims 1 to 7 having a frame consisting of an open ended body with square or rectangular cross-section having a flap hinged on the outside.
11. A device according to claims 1 to 7 having a frame consisting of an open ended body with square or rectangular cross-section having a flap hinged on the inside.
12. A device according to previous claims having a duplicity of hinged flaps.
13. A device according to previous claims used as a swimming aid.
14. A device according to claims 1 to 12 used as a rehabilitation aid.
15. A device according to claims 1 to 12 used as an item of fitness equipment.
16. A device according to claims 1 to 12 used as a means of propulsion.
17. A device according to claims 1 to 12 used as a means for manoevre.
18. A device according to previous claims for operation with one hand.
19. A device according to claims ito 17 for operation with two hands.
20. A device according to claims 16 and 17 for operation with a crank mechanism.
21. A device according to claim 16 and 17 for motorised operation.
22. A device according to previous claims having air filled compartments that may be variably filled with material.
23. A device according to previous claims that floats on water.
24. A device according to previous claims having a frame with inflateable compartments.
25. A device according to previous claims finished in high visibility colours.
26. A device according to previous claims having flaps finished in a striped pattern.