AU2003261545B1 - A Pump - Google Patents

Description

S&F Ref: 655918

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: Philip Malcolm Le Bas Unit 14/42-50 Helen Street Lane Cove New South Wales 2066 Australia Philip Malcolm Le Bas Spruson Ferguson St Martins Tower Level 31 Market Street Sydney NSW 2000 (CCN 3710000177) A Pump ASSOCIATED PROVISIONAL APPLICATION DETAILS [33] Country [31] Applic. No(s) AU 2003901605 [32] Application Date 28 Mar 2003 The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5815c 1 A PUMP Field of the Invention The present invention relates to pumps and in particular to a gravity driven tidal power pump to be used where tidal change is reliably predictable.

Background of the Invention With the increasing concern about greenhouse gases and the ozone layer there has been a push towards the development of "clean energy" alternatives to existing systems. One of those "clean" alternatives is to utilise the power of tides to drive machines. Existing tidal pumps are generally complicated, low duty, low efficiency, heavy maintenance and involve substantial capital costs.

Object of the Invention It is an object of the present invention to provide a simple, heavy duty, low maintenance pump which ameliorates some of the disadvantages, or at least to provide a useful alternative.

Summary of the Invention There is disclosed herein a pump activated by changes in water level, said pump including: a first pump chamber having a variable volume and provided by a co-operating first cylinder and associated first piston means; a second pump chamber having a variable volume and provided by a cooperating second cylinder and associated second piston means; an inlet for said first chamber to provide for the flow of water into said first chamber; an outlet for said first chamber to provide for the flow of water therefrom; an inlet for said second chamber to provide for the flow of water into said second chamber; an outlet for said second chamber to provide for the flow of water therefrom; coupling means fixing the first and second piston means together; coupling means fixing the first and second cylinders together; a float to be partially submerged in said water so to be moved by changes in said water level; [R:\LIBLL] 14220speci.doc:keh:hxa said first and second piston means being separated by a predetermined length, said coupling means providing for adjustment of said length; and connection means connecting the float to said cylinder or piston means so that movement of said float causes relative movement between the cylinders and piston means to vary the volume of the chambers to pump water from the inlets to the outlets.

Preferably, said coupling means includes co-operation screw threads.

Preferably, said inlets and outlets include one way valves restricting water to flow from the inlets to the outlets.

Brief Description of the Drawings A preferred form of the present invention will now be described by way of example only with reference to the accompanying drawings wherein: Figure 1 is a cutaway side view of a pump of an embodiment of the invention; and Figure 2 is a further embodiment of a cutaway side view of a pump of an embodiment of the invention.

Detailed Description of the Preferred Embodiments Referring to the drawings, there is disclosed a pump 1 activated by changes in water level such as those of a tidal change. The pump 1 includes a first pump chamber having a variable volume and provided by a cooperating first cylinder 10 and associated first piston means 15. The pump 1 further includes a second pump chamber 20 having a variable volume and provided by a cooperating second cylinder 25 and associated second piston means 30. An inlet 35 for the first chamber 5 is provided for the flow of water into the first chamber 5. An outlet 40 is also provided for the flow of water therefrom. The inlet 35 and outlet 40 preferably include one way clack valves 45. The second chamber also includes corresponding inlet and outlet valves 35, 40 and clack valves 45. As shown in the drawings, the chambers 5, 20 can include two or more inlet and outlets 35, 40 if required. The pump 1 further includes coupling means 50 fixing the first and second pistons 15, 30 together. The piston coupling means 50 is preferably an opposing screw thread whose length between the pistons 15, 30 is equal to the change in the water level or a tidal change. Further coupling means 55 fix the first and second cylinders 10, together. A float 60 is included which is partially submerged in the water so as to be moved by changes in the water level. The float 60 is preferably a concrete and steel [R:\LIBLL] 14220specidoc:keh:hxa reinforced block which has positive buoyancy. Connection means 65 connects the float to the cylinders 10, 25 or piston means 15, 30 so that movement of the float 60 causes the relative movement between the cylinders 10, 25 and piston means 15, 30 to vary the volume of the chambers 5, 20 to pump water from the inlets 35 to the outlets 40. The pump 1 further includes a base member 70 in the form of a heavy concrete block to stabilise the pump 1. The pump 1 can include many pistons located on top of each other and connected by extending coupling means 50 as shown in Figure 2.

In use, the pump 1 works with the change of a tide, with the maximum water level being high tide and the lower water level being low tide. In the high tide position, 0to as shown in Figure 1, the first pump chamber 5 is at its maximum volume and can be filled with the surrounding water through valve 45 of inlet 35. When the water level or tide drops the float 60 will lower urging first piston 15 along cylinder 10 to compress first chamber 5. As valve 45 of inlet 35 is a one-way valve the added pressure from first piston 15 will urge any water within first chamber 5 through the outlet 40 to do work, is such as, move a turbine. When the water level is at a minimum or low tide, the first subchamber 5 is at a minimum volume and the second sub-chamber 20 is at a maximum volume. This volume 20 is filled with water from the surrounding by inlet 35 through one-way valve 45. As the float 60 proceeds towards the high tide mark second piston means 30 is urged to compress the volume within second pump chamber 20 urging the water therein through one-way valve 45 in the outlet 40 to drive a machine such as a turbine.

As the pump 1 is activated by the changes in water level, the pump 1 can continuously move between filling each chamber 5, 20 respectively and emptying each chamber 5, 20 thereby continuously feeding water to outlets 40 to drive a machine (not shown).

It is important that the distance between the pistons 15, 30 being the coupling means 50 is precisely calibrated at the rise and fall range to ensure the tidal change is effectively captured to ensure continuous operation of the pump 1. The opposing screw thread, in the form of piston coupling 50, conveniently allows adjustment of this distance throughout the year. The pump 1 could also be used in a multiple stack operation of coupled cylinders where the depth of water is considerable. There could also be a number of cylinder stacks working side-by-side to drive the same output 40. The device could further includes filtration systems to prevent incursion of any destructive matter or the like into the system.

[R:\LIBLL] 14220speci.doc:keh It is foreshadowed that such a system could be used to move large quantities of sea water to drive turbine generators or the like or pump sea water into arid areas. It is possible in shallow water that the swept volume may be increased by increasing cylinder diameter or by multiplying units in parallel. Indeed water and swept volume may be increased by extending downwards in multiples of unit as shown depending upon the depth available. Further, preventing the pistons from the turning in the cylinders could be achieved by means of a suitable sliding key or the like.

Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

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Claims (4)

1. A pump activated by changes in water level, said pump including: a first pump chamber having a variable volume and provided by a co-operating first cylinder and associated first piston means; a second pump chamber having a variable volume and provided by a co- operating second cylinder and associated second piston means; an inlet for said first chamber to provide for the flow of water into said first chamber; an outlet for said first chamber to provide for the flow of water therefrom; l0 an inlet for said second chamber to provide for the flow of water into said second chamber; an outlet for said second chamber to provide for the flow of water therefrom; coupling means fixing the first and second piston means together; coupling means fixing the first and second cylinders together; a float to be partially submerged in said water so to be moved by changes in said water level; said first and second piston means being separated by a predetermined length, said coupling means providing for adjustment of said length; and connection means connecting the float to said cylinder or piston means so that movement of said float causes relative movement between the cylinders and piston means to vary the volume of the chambers to pump water from the inlets to the outlets.

2. The pump according to claim 1, wherein said coupling means includes co-operation screw threads.

3. The pump according to claim 1 or claim 2, wherein said inlets and outlets include one way valves restricting water to flow from the inlets to the outlets.

4. A pump activated by changes in water level, said pump substantially as herein described with reference to any one of the embodiments of the invention shown in the accompanying drawings. Dated 29 April, 2004 Philip Malcolm Le Bas Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON [R:\LIBLL] 14220speci.doc:keh:hxa