WO2000070218A1

WO2000070218A1 - Wave-powered pump

Info

Publication number: WO2000070218A1
Application number: PCT/IB2000/000627
Authority: WO
Inventors: Henry Lemont Wienand
Original assignee: Henry Lemont Wienand
Priority date: 1999-05-12
Filing date: 2000-05-10
Publication date: 2000-11-23
Also published as: AU4600900A

Abstract

A pumping installation (10) pumps a fluid, especially water, more especially seawater, using wave action. The installation (10) is anchored (62) to a bed (60) of a body of water. A large primary float (24) and a small secondary float (28) are tied respectively by a long tie (26) and a short tie (30) to a lever (16) at opposite sides of its fulcrum (18). A wave lifts the large float (24) against bias of the small, submerged float (28) to pivot the lever (16) and a connected shaft (18) in a direction (64). When the wave has passed and the tie (26) slackens, the float (28) returns the lever (16) and shaft (18), thus generating reciprocal motion used to drive a pump such as a squeeze pump (14), a vane pump, or the like.

Description

WAVE-POWERED PUMP

This invention relates to pumping a fluid by means of wave action.

It relates more specifically to a method of pumping a fluid by means of wave action, and to a wave action pumping installation.

The Applicant expects the invention to be particularly

advantageously applicable to the pumping of liquid, for example water, more

especially sea water, but the scope of the invention is not limited to pumping of

liquid, or water or sea water.

According to a first aspect of this invention, there is provided a

method of pumping a fluid by means of wave action, the method including, in a

pump arranged to pump the fluid, cyclically reciprocating a pump member

alternatingly in opposite directions, the pump member being driven in one

direction by means of a buoyancy member subjected to the wave action, and in the opposite direction by means of a biassing force or torque opposing the

^■ buoyancy member.

The method may be carried out in association with a body of water

undergoing wave action. In some methods, the fluid being pumped may then be water of the body of water.

Said buoyancy member may be a primary buoyancy member,

biassing being effected by means of a secondary buoyancy member having less

buoyancy than the primary buoyancy member, the primary and secondary

buoyancy members acting on a lever at opposed sides of a fulcrum of the lever.

The buoyancy of the secondary buoyancy member may be about one half of the

buoyancy of the primary buoyancy member.

Instead, biassing may be effected by means of a counterweight

arranged to counter the buoyancy effect of the buoyancy member, the

counterweight having a weight which is less than the buoyancy force. The coyj-ter weight may be about one half of the buoyancy force.

The pump may include an arcuate pump chamber and the pump

member may be in the form of a vane which can be swept to and fro through the

pump chamber, the buoyancy force by the buoyancy member or the primary buoyancy member sweeping the vane in one direction and the biassing force or

torque sweeping the vane in the opposite direction.

By way of development, the pump may include a plurality of arcuate

pump chambers and the pump member may be in the form of a corresponding

plurality of vanes which can be swept to and fro through the respective pump

chambers.

In yet a further method, the pump may be a squeeze pump, the

pump chamber then being conduit means for the fluid and the pump member

being a squeeze member arranged to squeeze the conduit means. The fluid may

then be a gas, e.g. air.

In accordance with a second aspect of this invention, there is

provided a wave action pumping installation for fluid suitable for location in

association with a body of water undergoing wave action, the pumping

installation including a pump including a pump chamber, a reciprocating pump member reciprocal

to and fro to effect pumping and valve means for controlling flow of fluid toward

and from the pump chamber;

biassing means for biassing the pump member in a predetermined direction

toward a starting condition; a buoyancy member having buoyancy in water and being connected to the

pump member cyclically to drive the pump member from the starting condition

when the buoyancy member is lifted by wave action in use.

In one kind of embodiment, said buoyancy member may be a primary buoyancy member, the biassing means including a secondary buoyancy member

having a predetermined buoyancy which is smaller than the buoyancy of the

primary buoyancy member, the primary and secondary buoyancy members being

connected to a lever at opposed sides of a fulcrum of the lever, the lever being

drivingly connected to the pump member. The secondary buoyancy may be

about one half of the primary buoyancy. The buoyancy members may be in the

form of floats. The floats may be connected to the lever by elongate flexible

elements at positions which may be equidistant from the fulcrum, one of the

floats being larger than the other and being connected to the lever arm by an

elongate flexible element having a length which is greater than that of the other

flexible element.

In another kind of embodiment, the biasing means may include a

counterweight arranged only partially to counteract the effect of the buoyancy

member. The counterweight may be about one half of the buoyancy force. The pump may be an arcuately reciprocal vane pump, the pump

chamber being an arcuate pump chamber and the pump member being a vane

arcuately pivotal to and fro in the pump chamber.

By way of development the pump may be a composite arcuately

reciprocal vane pump, which includes a plurality of arcuate pump chambers and

a corresponding plurality of pump members in the form of vanes respectively

arcuately pivotal to and fro in the respective pump chambers.

In another embodiment, the pump may be a squeeze pump, the

pump chamber being a conduit means for the fluid and the pump member being

a squeeze member arranged to squeeze the conduit means.

The invention will now be described, by way of example, with

reference to the accompanying diagrammatic drawings.

In the drawings:

__. Figure 1 shows a schematic side view of a pumping installation in

accordance with the invention;

Figure 2 shows a schematic plan view of a composite squeeze pump

forming part of the pumping installation of Figure 1 ;

Figure 3 shows a side view of the composite squeeze pump shown in

Figure 2; Figure 4 shows another embodiment of a pumping installation in accordance with the invention;

Figure 5 shows, in side view, another embodiment of a pump suitable to form part of a pumping installation in accordance with the invention;

Figure δ shows, in axial section, but without hatching for convenience of

drawing, the pump of Figure 5;

Figure 7 shows a schematic view corresponding to Figure 6, with inlet and

outlet ports and flow conduits leading toward the inlet ports and away from the

outlet ports;

Figure 8 shows a view corresponding to Figure 6 but of a developed

embodiment; and

Figure 9 shows in cross-sectional view (but without hatching for ease of

drawing), yet a further embodiment of a pump suitable to form part of a pumping

installation in accordance with the invention.

In Figures 1 to 3 of the drawings, reference numeral 1 0 refers

generally to a first embodiment of a pumping installation in accordance with the

invention.

The pumping installation 1 0 includes a platform 1 2 anchored to the

sea bed 60 by means of anchors 62. A circular cylindrical drum 14 is mounted

on the platform 1 2, the axis of the drum extending decumbently or generally

horizontally. The installation 1 0 further includes a lever arm 1 6 pivotally mounted intermediate its ends via a fulcrum 1 8 which is coincident with the axis of the

drum 1 4. The pumping installation 1 0 further includes two composite squeeze

pumps 20 in a manner described in more detail below.

In the embodiment shown, the pumping installation 1 0 is intended

for use in pumping sea water making use of wave action or wave energy as the

driving force. To this end, the pumping installation 1 0 includes a primary

buoyancy member in the form of a float 24 connected to the lever arm 1 6

adjacent its one end by an elongate flexible element, e.g. a cable 26, and a secondary buoyancy member in the form of a float 28 connected to the lever arm

1 6 adjacent its other end by an elongate flexible element, e.g. a cable 30.

The cable 26 is substantially longer than the cable 30 and, in

addition, the buoyancy of the float 24 is substantially greater than the buoyancy

of the float 28 e.g. about twice as large. The floats 24, 28 are configured such

that torque applied to the lever arm 1 6 as a result of the buoyancy of the float

24 is approximately double that applied to the lever arm as a result of the

buo-v/ancy of the float 28.

With particular reference now to Figures 2 and 3 of the drawings,

each squeeze pump 20 includes a pair of manifolds 32, 34 and a plurality of

lengths of pipe 36 connected at the one ends to the manifold 32 and at the other

ends to the manifold 34. Both manifolds 32, 34 are connected via flow lines 38, 40, respectively to an inlet 42. Non-return valves 44, 46 are mounted in the

respective flow lines 38, 40.

Similarly, the manifolds 32, 34 are connected via flow lines 48, 50

respectively, to an outlet 52. Once again, non-return valves 54, 56 are mounted

in the flow lines 48, 50.

Each squeeze pump 20 includes a compression member 22.

Each compression member 22 is in a form of a roller 58 rotatably

mounted on the lever arm 1 6 such that the pipes 36 are laterally compressed

between the associated roller 58 and a radially inner surface of the drum 14 in a

fluid tight manner.

In use, as a wave approaches, buoyancy forces acting on the float

24 cause the float 24 to move upwardly and the lever arm 1 6 to pivot in the direction of arrow 64 causing the rollers 58 to move in a corresponding direction.

As can best be perceived from Figures 2 and 3 of the drawings, as

the roller 58 moves in the direction of arrow 64 towards the manifold 32 the

effective length of each of the pipes 36 between the roller 58 and the manifold

32 is decreased so that water is discharged under pressure from the manifold through the non-return valve 54 and the outlet 52. Similarly, the effective length

of each pipe 36 between the manifold 34 and the roller 58 increases thereby

resulting in a decrease in water pressure in the manifold 34 and the lengths of

pipe 36 between the manifold 34 and the roller 58. This causes water to be

drawn in through the inlet 42 and the non-return valve 46 into the manifold 34

and the lengths of pipe between the manifold 34 and the roller 58.

As the wave passes, the water level drops so that the float 24

recedes, the cable 26 slackens, and pull on the lever 1 6 in the directions 64 ceases. By virtue of the buoyancy forces acting on the float 28, the lever arm 1 6

is caused to pivot in a direction opposite to the direction of the arrow 64. This

results in the roller 58 moving toward the manifold 34 thereby compressing water

in the portions of the pipes 36 between the roller 58 and the manifold 34

resulting in the non-return valve 46 being closed and the water being discharged

through the non-return valve 56 to the outlet 52. The non-return valve 54 closes.

Water is drawn through the inlet 42 and the non-return valve 44 into the manifold

32 and into those portions of the pipes 36 intermediate the manifold 32 and the

roller 58.

With reference to Figure 1 , it is to be appreciated that the two

squeeze pumps 20 are operated simultaneously, the arrangements in Figures 2

and 3 being duplicated. In this way, water can be pumped in a more-or-less continuous manner as a result of the action of the waves or swells.

If desired, more than two pumps 20 and corresponding compression

members 22 can be provided.

As mentioned above, the embodiment shown in Figures 1 to 3 is intended for use in pumping sea water and will accordingly be constructed of

components which are resistant to attack from sea water. The pumped water

can be used for any desired application, e.g. for the generation of electricity

and/or for desalination. The Inventor believes that the installation could be used

as a compressor to compress air or the like. In this case a plurality of pumps will

be provided. The lengths of the pipes will be reduced. The Inventor believes that

this arrangement will permit air to be compressed up to a pressure of about 1 2

BAR or more with relatively small movements of the lever arm.

Reference is now made to figure 4 of the drawings, in which

reference numeral 70 refers generally to another embodiment of a pumping

installation in accordance with the invention.

The pumping installation 70 includes pumping apparatus, generally

indicated by reference numeral 72. The pumping apparatus 72 includes a platform 74 which is anchored to the sea bed 60 by anchors 76. A lever arm 78 is pivotally connected toward

its one end via a fulcrum 80 to the platform 74. A float 82 is connected via an

elongate flexible element, e.g . a cable 84 to the lever arm 78 at a position remote

from the fulcrum 80, i.e, adjacent an opposed end thereof. A counterweight 86

is connected via a cable 88 to the lever arm 78 at the same position as the float

82. The weight of the counterweight 86 is about one half of the buoyancy force of the water on the float 82.

The pumping apparatus further includes a double acting piston and

cylinder arrangement 90 which is mounted between the lever arm 78 and the

platform 74.

The cylinder of the piston and cylinder arrangement 90 is

communicated at opposite sides of the piston to an inlet 92 via flow lines 94, 96.

Similarly, an outlet 98 is communicated at opposite sides of the piston, in flow

communication with the cylinder via flow lines 100, 1 02. Non-return valves 1 04,

1 QS, 1 06, 1 05 are mounted in the respective flow lines 94, 96, 100, 1 02.

The inlet 92 is connected to a delivery end of a suction line 1 07 the

other or inlet end of the suction line 107 being positioned below the surface of

the sea bed 60. In use, as a wave or swell arrives causing the surface level to rise,

the buoyancy forces acting on the float 82 cause the lever arm 78 to be displaced

in the direction of arrow 109. The buoyancy force is greater than and overcomes

gravity force on the counterweight 86. This causes the piston to be displaced

upwardly within the cylinder causing water to be drawn through the inlet 92, the

flow line 96 and the non-return valve 108 into the cylinder. Similarly, water in

the cylinder above the piston is pressurized and is discharged through the non¬

return valve 1 06 and the flow line 100 to the outlet 98. As the wave or swell

passes and the surface level drops, the float 82 recedes with the water level the

cable 84 slackens and the pull on the lever end ceases. The force of gravity on

the weight 86 then causes the lever arm 78 to pivot in a direction opposite to the

direction of arrow 109. This results in water being drawn through the inlet 92,

the flow line 94 and the non-return valve 1 04 into the cylinder. Similarly, water

is discharged through the non-return valve 105 and flow line 1 02 to the outlet

98.

In this way, a more-or-less continuous pumping process can be

achjeved .

Positioning the inlet end of the suction line 1 07 below the surface

of the sea bed 60 results in the water being drawn into the suction line first

passing through the material of the sea bed 60 adjacent to the inlet end of the suction line which serves as a natural filter for the water. If desired a further inline or series filter can be provided in the inlet 92.

It should be appreciated, that the pumping apparatus of the pumping

installation 70 can take any suitable form and, for example, may be in the form

of the pumping apparatus 10.

The Inventor believes that the pumping installation in accordance

with the invention will provide pumped water which, as mentioned above, can be

used to drive a generator, e.g. via a turbine, to generate electricity or be used for

desalination in a cost effective manner.

With reference to Figures 5 and 6 of the drawings, a pump suitable

to form part of a pumping installation in accordance with the invention is

generally indicated by reference numeral 1 1 0. The pump 1 1 0 can, for example,

be used instead of the squeeze pumps 20 in Figure 1 , or instead of the plunger

and cylinder pumping arrangement 90 of Figure 4.

The pump 1 1 0 includes a shaft assembly generally indicated by

reference numeral 1 1 2 and comprising a shaft 14 and end flanges 1 1 6

incorporating rotation means such as sealed bearings rotatably supporting the

shaft 1 14 in the end flanges 1 1 6. The pump 1 1 0 further comprises a round cylindrical barrel 1 1 8 having end flanges 1 20 at opposed ends thereof. The pump 1 10 is assembled

in concentric fashion such that the end flanges 1 1 6, 1 20 and the barrel 1 1 8 are

concentric with the shaft 1 1 4. At each end of the pump 1 10, the respective end

flange 1 1 6 rotatably supporting the shaft 1 14 and the corresponding end flange

1 20 fixed to that end of the barrel 1 1 8 are secured together by means of nut and

bolt arrangements 1 22. A gasket is preferably provided intermediate the

corresponding faces of the flanges.

With reference more specifically to Figure 6, there is provided a

composite vane generally indicated by reference numeral 1 24 which extends

diametrically through the shaft 1 14 and which is fixed to the shaft 1 1 4. Thus,

to either side, radially and longitudinally extending vanes 1 24.1 and 1 24.2 are

provided .

Also with reference more specifically to Figure 6, internally of the

barrel 1 1 8, there is provided an opposing pair of radially and longitudinally

extending compartment baffles 1 26 dividing the interior of the barrel 1 8 into

semi-cylindrical, longitudinal, chambers. Inner free ends of the compartment

baffles 1 26 stop just shy of a periphery of the shaft 1 14 to allow running

clearance for the shaft 1 1 4. The compartment baffles 1 26 are anchored at their

outer radial ends by means of bolts or studs and nuts 1 28 thus rendering the

compartment baffles integral with the barrel 1 8. Outer radial ends of the vane 1 24.1 and 1 24.2 have little, but

nevertheless running, clearance with an internal periphery of the barrel 1 1 8.

So as not to clutter up the drawing, hatching is generally not shown

in Figure 6 and inlet and outlet ports and corresponding flow conduits which are described herebelow are not shown in Figure 6.

With reference to Figure 7, inlet and outlet ports, flow conduits

leading toward the inlet ports and away of the outlet ports and the like are now described. It is to be appreciated that the compartment baffles 1 26 divide the

cylinder 1 1 8 in upper and lower symmetrical halves. Each half forms a chamber

1 50. To one side of the vane 1 24.1 , a first sub-chamber 1 50.1 is formed. To

an opposed side of the vane 1 24.1 , a second sub-chamber 1 50.2 is formed.

Similarly, to one side of the vane 1 24.2 a third sub-chamber 1 50.3 is formed, and

to an opposed side of the vane 1 24.2, a fourth sub-chamber 1 50.4 is formed.

Closely adjacent the inner periphery of the barrel 1 1 8, and proximate

one_baffle 1 26, at one end of the chamber, more specifically in one end plate

1 20, in the first sub-chamber 1 50.1 , there is provided a first inlet port 1 30.1 .

Axially opposite the inlet port 1 30.1 , in the opposed end flange 1 20, in the first

sub-chamber 1 50.1 , there is provided a first outlet port 1 40.1 . In Figure 7, the

outlet port 140.1 is shown in dotted adjacent the first inlet port 1 30.1 . In fact

it will be in register with the inlet port 1 30.1 but in the opposite end flange. Correspondingly, in the opposite sub-chamber 1 50.2, there is

provided a second outlet port 140.2 in the end flange 1 20 having the inlet port

1 30.1 . Similarly, in the opposite end flange 1 20, axially opposite to the second

outlet port 140.2 i.e. in register therewith, there is provided a second inlet port

1 30.2 shown in dotted. Thus the sub-chamber 1 50. 1 has, at opposite ends

thereof, the inlet port 1 30.1 and the outlet port 1 40.1 . Similarly, the second sub-

chamber 1 50.2 has, at opposite ends thereof, the inlet port 1 30.2 and the outlet port 140.2.

Similarly, the third and fourth sub-chambers 1 50.3, 1 50.4 have

respective inlet ports 1 30.3 and 1 30.4, and outlet parts 140.3 and 1 40.4.

A supply conduit leading from a source of fluid to be pumped as

indicated by reference numeral 1 36 extends via an inlet one way valve 134 into

a branch 132.4 leading to the fourth inlet port 1 30.4 in the sub-chamber 1 50.4.

A branch 1 32.2 parallel to the branch 1 32.4 extends to the inlet port 1 30.2 in

the sub-chamber 1 50.2.

Similarly, branch conduits 142.1 and 142.3 lead from the first and

third outlet ports 140.1 and 140.3 via a one way valve 144 into a delivery line

146 extending to a sink for the fluid to be pumped. A similar inlet system serves the sub-chambers 1 50.1 and 1 50.3.

Also, a similar outlet system serves the sub-chambers 1 50.2 and 1 50.4.

However so as not to clutter up the drawing, the duplicated systems are not shown in the drawing.

In use, assume that the vanes 1 24.1 and 1 24.2 are in positions

pivoted anti-clockwise from the positions shown in Figure 7, i.e. adjacent the

respective compartment baffles 1 26 and proximate respectively the first inlet port

1 30.1 and the first outlet port 140.1 ; and the third inlet port 1 30.3 and the third

outlet port 1 40.3. When in those positions, the first sub-chambers 1 50.1 and

1 50.3 between the vanes 1 24.1 and 1 24.2 and the proximate compartment

baffles 1 26 are at minimum volume. Correspondingly, the second and fourth sub-

chambers 1 50.2 and 1 50.4 intermediate the vanes 1 24.1 , 1 24.2 and the remote compartment baffles 1 26 are at maximum volume.

The shaft 1 1 4 is pivoted clockwise through an angle less than 1 80°

to sweep the vanes 1 24.1 , 1 24.2 to angular positions proximate the opposed

compartment baffles 1 26 adjacent respectively the second outlet port 140.2 and

the second inlet port 1 30.2; and the fourth outlet port 140.4 and the fourth inlet

port 1 30.4. While this stroke takes place, the first sub-chamber 1 50.1 with

which the inlet port 1 30.1 is in communication, and the third sub-chamber 1 50.3

with which the inlet port 1 30.3 is in communication increase in volume with a

consequent decrease in pressure. Thus, fluid is drawn from the source via the duplicated inlet system (not shown) and the ports 1 30.1 and 1 30.3 into the first

and third sub-chambers 1 50.1 and 1 50.3 thus filling the first and third sub-

chambers 1 50.1 , 1 50.3.

During a return stroke of the vanes 1 24.1 , 1 24.2 in which they are

pivoted in anti-clockwise direction to angular positions respectively adjacent the

first inlet port 1 30.1 and first outlet port 140.1 ; and the third inlet port 1 30.3

and the third outlet port 140.3 the second sub-chamber 1 50.2 and fourth sub-

chamber 1 50.4 are charged via the supply line 1 36, one-way valve 1 34, branch

lines 1 32.2, 1 32.4 and inlets 1 30.2, 1 30.4 in a similar manner to what was

described for the first and third sub-chambers during the first stroke of the vanes

1 24.1 , 1 24.2. Simultaneously, during the reverse stroke, the first and third sub-

chambers 1 50.1 , 1 50.3 decrease in volume with a consequent increase in

pressure. The fluid is pressurized through the first and third outlet ports 1 40.1 ,

1 40.3 via the flow conduits 142.1 , 142.3 the corresponding one way valve 1 44

and the delivery conduit 146 to the sink.

The above procedure is repeated cyclicly.

It is to be appreciated that diagonally opposed quadrants of the

pump work in combination to render the pump double acting. Branch lines

leading to the respective inlet ports and outlet ports are appropriately connected

to respectively the supply conduit 1 36 and the delivery conduit 146. It is further to be appreciated that the embodiment of Figure 7 can

have only a single vane 1 24, or a double vane (as described) or multiples. It is

believed that only four one-way valves will be required for two or more vanes.

With reference to Figure 8, by way of development, seal assemblies

generally indicated by reference numeral 1 60 are provided at the radially outer

ends of the vanes 1 24 and at the radially inner ends of the compartment baffles 1 26 to minimize or prevent leakage.

The Applicant regards it as a first advantage that a simple,

inexpensive and elegant pump is provided to use a rocking or to and fro pivoting

action which can be obtained, for example from wave action, to pump a fluid, for

example water.

The Applicant regards it as a further advantage that to and fro

pivoting or rocking action obtained from other sources can be used to drive a

pump as disclosed . For example, the Applicant envisages that water can be

pumped in rural areas by using drive from a see-saw to pump water while children

are using the see-saw. This can also be used in amusement parks for purposes

not necessarily utilitarian.

With reference to Figure 9, yet a further embodiment of a pump

suitable to form part of a pumping installation in accordance with the invention is generally indicated by reference numeral 21 0. The pump 21 0 is similar to the

pump 1 1 0 of Figures 6 and 7. Like reference numerals refer to like components

or features, and the pump of Figure 9 is not described in detail. Differences between the pump of Figures 6 and 7 on the one hand and the pump of Figure

9 on the other hand will merely be emphasized.

The pump 210 includes a spherical pump body 21 8 which is provided in two halves with circular flanges which are closed onto and secured

to each other as indicated at 21 7 to form the spherical body. It is envisaged that

the pump body may be formed of mouldings of synthetic polymeric material.

In this embodiment, the pump 21 0 has a single pump chamber only,

but it will readily be understood by a person skilled in the art that it can be provided with two or even more pump chambers similarly to the pump of Figures

6 and 7.

The pump 21 0 has a single baffle 226 in the form of a semi-circle.

Thfi. baffle 226 is secured, for example by welding, or by being integrally moulded

along its semi circular periphery to an inner periphery of the pump body 21 8.

Along a free, diametrical extremity of the baffle 226, it is sealed as indicated by

reference numeral 260. 1 to a shaft 214 to allow for relative rotation of the shaft. The pump 210 has a single semi-cylindrical vane 224 which is secured, for example by means of welding, to the shaft 214. A semi cylindrical

free extremity of the vane 224 is sealed as indicated by reference numeral 260.2

against an inner periphery of the pump body 21 8 to allow sliding of the vane 224

through the pumping chamber indicated by reference numeral 250. The vane is

swept through an angle marginally short of 360 ° though the pumping chamber

250 by appropriate pivoting of the shaft 214. It is to be appreciated that the

shaft 214 is pivoted by means of wave action, which fluctuates and it is thus to

be appreciated that the shaft 21 4 does not necessarily pivot through its entire arc at every stroke. This, however, does not influence the principle of operation of

the pump 210.

To one side of the baffle 226, there is provided an inlet 230.1 and

an outlet 240.1 which inlet and outlet are shown as a single port. Two ports are

in fact provided of which only one is shown in the drawing. Similarly, to the

other side of the baffle 226, there is provided a second inlet port 230.2 and a

second outlet port 240.2, again only one being shown in the drawing.

The inlet ports 230.1 , 230.2 are communicated via appropriate non¬

return valves to a source of fluid to be pumped. Similarly, the outlet ports 240.1 ,

240.2 are communicated via appropriated non-return valves to a sink to which

fluid is to be pumped. The arrangement is similar to the arrangements shown and

described above. Operation of the pump 21 0 is similar to that of the pump 1 1 0 in

that, when the vane 224 moves from a position proximate the inlet valve 230.1

in a direction which is clock-wise in Figure 9, fluid such as water is drawn into the chamber via the inlet 230.1 , while water which has perviously been drawn

into the chamber 250 is expelled under pressure via the outlet 240.2. At the end

of the stroke, the vane 224 is returned to charge the chamber 250 at the traling

side of the vane 224 via the inlet 230.2, while water is expelled under presure

at the leading end of the vane 224 via the outlet 240.1 .

Although operation of the pump 210 is similar to operation of the

pump of Figures 6 and 7, the Applicant believes that a pump having a spherical

body has a number of advantages, for example that a sphere is the strongest

constructional form for withstanding pressure, thus requiring merely a thin shell thus saving on weight and costs. Furthermore, it is believed that the sperical

form will render the pump less prone to drag by currents in the water. An

important advantage is that the seals employed in the pump 21 0 will not extend

around corners, but will extend merely along smooth arcs. Such an arrangement

promotes integrity in sealing .

Claims

1 . A method of pumping a fluid by means of wave action, the method

including, in a pump arranged to pump the fluid, cyclically reciprocating a pump

member alternatingly in opposite directions, the pump member being driven in one

direction by means of a buoyancy member subjected to the wave action, and in

the opposite direction by means of a biassing force or torque opposing the

buoyancy member.

2. A method as claimed in Claim 1 which is carried out in association

with a body of water undergoing wave action.

3. A method as claimed in Claim 2 in which the fluid being pumped is

water of the body of water.

4. A method as claimed in any one of Claim 1 to Claim 3 inclusive in

which said buoyancy member is a primary buoyancy member and in which

biassing is effected by means of a secondary buoyancy member having less

buoyancy than the primary buoyancy member, the primary and secondary buoyancy members acting on a lever at opposed sides of a fulcrum of the lever.

5. A method as claimed in any one of Claim 1 to Claim 3 inclusive in

which biassing is effected by means of a counterweight arranged to counter the buoyancy effect of the buoyancy member, the counterweight having a weight which is less than the buoyancy force.

6. A method as claimed in any one of Claim 1 to Claim 5 inclusive in

which the pump includes an arcuate pump chamber and in which the pump

member is in the form of a vane which can be swept to and fro through the pump

chamber.

7. A method as claimed in Claim 6 in which the pump includes a

plurality of arcuate pump chambers and in which the pump member is in the form

of a corresponding plurality of vanes which can be swept to and fro through the

respective pump chambers.

8. A method as claim in any one of Claim 1 to Claim 5 inclusive in

which the pump is a squeeze pump, the pump chamber being conduit means for

the fluid and the pump member being a squeeze member arranged to squeeze the

conduit means.

9. A wave action pumping installation for fluid suitable for location in

association with a body of water undergoing wave action, the pumping

to and fro to effect pumping and valve means for controlling flow of fluid toward and from the pump chamber;

biassing means for biassing the pump member in a predetermined direction

toward a starting condition;

a buoyancy member having buoyancy in water, and being connected to the

pump member cyclically to drive the pump member from the starting condition when the buoyancy member is lifted by wave action in use.

1 0. A pumping installation as claimed in Claim 9 in which said buoyancy

member is a primary buoyancy member, in which the biassing means includes a secondary buoyancy member having a predetermined buoyancy which is smaller

than the buoyancy of the primary buoyancy member; the primary and secondary

buoyancy members being connected to a lever at opposed sides of a fulcrum of

the lever, the lever being drivingly connected to the pump member.

1 1 . A pumping installation as claimed in Claim 9 in which the biasing

means includes a counterweight arranged only partially to counteract the effect

of the buoyancy member.

1 2. A pumping installation as claimed in any one of Claim 9 to Claim 1 1

inclusive in which the pump is an arcuately reciprocal vane pump, the pump chamber being an arcuate pump chamber and the pump member being a vane arcuately pivotal to and fro in the pump chamber.

1 3. A pumping installation as claimed in any one of Claim 9 to Claim 1 1

inclusive in which the pump is a composite arcuately reciprocal vane pump, which

includes a plurality of arcuate pump chambers and a corresponding plurality of

pump members in the form of vanes respectively arcuately pivotal to and fro in

the respective pump chambers.

14. A pumping installation as claimed in any one of Claim 9 to Claim 1 1

in which the pump is a squeeze pump, the pump chamber being a conduit means

for the fluid and the pump member being a squeeze member arranged to squeeze

the conduit means.