GB1562174A - Devices for deriving opwer from the sea - Google Patents

Description

(54) DEVICES FOR DERIVING POWER FROM THE SEA (71) I, JOHN ROACH BICHARD, a British subject, of Ivybank, Tynass, Arrochar, Dunbartonshire, Scotland, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to devices for deriving power from the sea, and more specifically relates to improvements in or modifications of the invention disclosed in my patent no. 1,447,758.

The term "sea" used hereinbefore and in the following description and claims is to be construed as embracing any expanse of water, including fresh water, subject to tidal flows.

In accordance with the present invention, I provide for use in deriving power from the sea (as hereinbefore defined), a device comprising two rotors made up of co-axial and relatively rotatable hubs or shafts each with a set of rods radiating therefrom and fast with a different one of two axially-spaced annular frames coaxial with the hubs or shafts, and a vane similarly mounted on each rod of each set for swivelling movement between limits about the rod to present a different one of its two major surfaces at an acute angle to the horizontal and to the thrust of a fluid on relative movement between the device and the fluid, whereby each rotor rotates unidirectionally and acquires kinetic energy, the vanes being disposed on the rods of the two sets in such a way that the hubs or shafts turn in opposite directions about the common axis.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, wherein: Fig. 1 is a mid-sectional elevation of a device for use in deriving power from the sea and including two rotors rotatable in opposite senses about a common axis, the blades or vanes of the rotors being omitted for clarity; Fig. 2 is a transverse section looking downwards from above the upper rotor in Fig. 1, and showing the blades or vanes; and Fig. 3 is a sectional view on the line 111-111 of Fig. 2.

Referring now to the drawings, the device comprises two inner and outer solid and hollow co-axial hubs or shafts 10 and 11 with upper and lower spaced sets of bearings 12 and 13 between the two shafts and enabling relative rotation of the two shafts. Similar annular frames or shrouds 14 and 15 are co-axial with the shafts 10 and 11, respectively, and rods 16 and 17 radiate from the shafts 10 and 11 to the shrouds 14 and 15, respectively. The rods 16 and the shroud 14 are hidden from view in Fig. 2 by the rods 17 and the shroud 15, respectively.Single blades or vanes 18 and 19 are mounted on the rods 16 and 17, respectively, each through four similar rings 20 and 21 which encircle the rods 16 and 17, respectively, and extend through openings therefor in the respective blade or vane 18 or 19, the diameter of the rings 20 and 21 in relation to the diameter of the rods 16 and 17 and the spacing of the holes in each blade or vane from the rod-adjacent edge of the blade or vane being such that the rings 20 and 21 are loose and the blade or vane 18 or 19 is free to swivel without being impeded by the rod 16 or 17.

Between the two inner rings of each set of four rings 20 or 21 there is secured to the rod 16 or 17 a two-armed stop member the root of which passes around the rod 16 or 17 and is bounded to the rod, and the arms 24 and 25 of which diverge from one another in the direction away from the root and are located one at each of the opposite major faces of the blade or vane 18 or 19. The arms 24 and 25 are at an acute angle to one another and to the respective one of the planes containing the axes of the rods 16 and 17, respectively, which planes are horizontal or substantially horizontal when the device is in use.

The number of blades or vanes 18 or 19 on each rotor may be varied to suit the particular application. The blades or vanes themselves are hinged at their leading edges through the rings 20 and 21, and are free to rotate between the fixed stops provided by the arms 24 and 25. Movement of the water through each rotor pushes the blades onto one stop, and the rotor then revolves. If the water movement is reversed in direction, the blades move and reverse their pitch, so that the rotor revolves in the same direction gs before.

If each rotor is subjected to a cyclic motion relative to the water, as may be produced by wave action, it will therefore revolve in a single direction, the motion.

being interrupted by short pauses while the vanes reverse their pitch. The rotation may, however, be made continuous by the addition of a simple flywheel to the rotor assembly. It will be noted that the blades or vanes of the two rotors are oppositely disposed (see Figs. 2 and 3) so that rotation of each rotor will be in the opposite direction to that of the other.

The two rotor shafts 10 and 11 are connected to a generator which may simply be in a hub dynamo from a pedal cycle which has given an adequate performance in tests. Preferably, however, as shown in Fig. 1, the generator 26 has two sets of windings 27 and 28. The power generated may be used continuously, or stored and then released in pulses of short duration; such pulses could of course have a much greater intensity than a continuous output.

The generator 26 could be integrated with the device by mounting it within a hollow hub or shaft of larger internal diameter, with the pertaining blades or vanes located in the annular space between said hub and the annular frame or shroud. Devices in accordance with the invention may power a flashing light or a radio beacon, with the further possibility of both being incorporated into a single unit.

The fluid flowing through the rotors may be sea water, or any other fluid whose motion is produced by waves on the surface of the sea.

The power generated by a device in accordance with the invention depends upon the extent and the rapidity of its movement through the water. In cyclic motion, a certain amount of movement is inevitably spent in reversing the pitch of the vanes, although a rotor with a large number of short vanes could be used to minimise this. It is thus found that the efficiency of power production is low for cycles of small amplitude, but improves rapidly as amplitude is increased. In practice the motions produced by even a moderate swell will generate appreciable power from a compact (0.5 m diameter) rotor unit.

It is considered that devices in accordance with the invention have two major advantages over alternative distress equipment. Firstly, they are not dependent upon external sources of power (e.g.

batteries or engine-driven generators) which may become victims of the weather conditions. Secondly, the amount of power available to the beacon increases with the severity of the weather, and so will produce a stronger signal in more difficult search conditions.

In a modification, there are a number of pairs of contra-rotating rotors, all rotating about a common axis.

WHAT I CLAIM IS:- 1. For use in deriving power from the sea (as hereinbefore defined), a device comprising two rotors made up of co-axial and relatively rotatable hubs or shafts each with a set of rods radiating therefrom and fast with a different one of two axially-spaced annular frames coaxial with the hubs or shafts, and a vane similarly mounted on each rod of each set for swivelling movement between limits about the rod to present a different one of its two major surfaces at an acute angle to the horizontal and to the thrust of a fluid on relative movement between the device and the fluid, whereby each rotor rotates unidirectionally and acquires kinetic energy, the vanes being disposed on the rods of the two sets in such a way that the hubs or shafts turn in opposite directions about the common axis.

2. A device according to claim 1, comprising a number of pairs of contra-rotating rotors, all rotating about a common axis.

3. A device for use in deriving power from the sea (as hereinbefore defined), said device being substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (3)

**WARNING** start of CLMS field may overlap end of DESC **. through the rings 20 and 21, and are free to rotate between the fixed stops provided by the arms 24 and 25. Movement of the water through each rotor pushes the blades onto one stop, and the rotor then revolves. If the water movement is reversed in direction, the blades move and reverse their pitch, so that the rotor revolves in the same direction gs before. If each rotor is subjected to a cyclic motion relative to the water, as may be produced by wave action, it will therefore revolve in a single direction, the motion. being interrupted by short pauses while the vanes reverse their pitch. The rotation may, however, be made continuous by the addition of a simple flywheel to the rotor assembly. It will be noted that the blades or vanes of the two rotors are oppositely disposed (see Figs. 2 and 3) so that rotation of each rotor will be in the opposite direction to that of the other. The two rotor shafts 10 and 11 are connected to a generator which may simply be in a hub dynamo from a pedal cycle which has given an adequate performance in tests. Preferably, however, as shown in Fig. 1, the generator 26 has two sets of windings 27 and 28. The power generated may be used continuously, or stored and then released in pulses of short duration; such pulses could of course have a much greater intensity than a continuous output. The generator 26 could be integrated with the device by mounting it within a hollow hub or shaft of larger internal diameter, with the pertaining blades or vanes located in the annular space between said hub and the annular frame or shroud. Devices in accordance with the invention may power a flashing light or a radio beacon, with the further possibility of both being incorporated into a single unit. The fluid flowing through the rotors may be sea water, or any other fluid whose motion is produced by waves on the surface of the sea. The power generated by a device in accordance with the invention depends upon the extent and the rapidity of its movement through the water. In cyclic motion, a certain amount of movement is inevitably spent in reversing the pitch of the vanes, although a rotor with a large number of short vanes could be used to minimise this. It is thus found that the efficiency of power production is low for cycles of small amplitude, but improves rapidly as amplitude is increased. In practice the motions produced by even a moderate swell will generate appreciable power from a compact (0.5 m diameter) rotor unit. It is considered that devices in accordance with the invention have two major advantages over alternative distress equipment. Firstly, they are not dependent upon external sources of power (e.g. batteries or engine-driven generators) which may become victims of the weather conditions. Secondly, the amount of power available to the beacon increases with the severity of the weather, and so will produce a stronger signal in more difficult search conditions. In a modification, there are a number of pairs of contra-rotating rotors, all rotating about a common axis. WHAT I CLAIM IS:-

1. For use in deriving power from the sea (as hereinbefore defined), a device comprising two rotors made up of co-axial and relatively rotatable hubs or shafts each with a set of rods radiating therefrom and fast with a different one of two axially-spaced annular frames coaxial with the hubs or shafts, and a vane similarly mounted on each rod of each set for swivelling movement between limits about the rod to present a different one of its two major surfaces at an acute angle to the horizontal and to the thrust of a fluid on relative movement between the device and the fluid, whereby each rotor rotates unidirectionally and acquires kinetic energy, the vanes being disposed on the rods of the two sets in such a way that the hubs or shafts turn in opposite directions about the common axis.

2. A device according to claim 1, comprising a number of pairs of contra-rotating rotors, all rotating about a common axis.

3. A device for use in deriving power from the sea (as hereinbefore defined), said device being substantially as hereinbefore described with reference to the accompanying drawings.