GB2231368A - Liquid actuated apparatus - Google Patents

Abstract

The apparatus comprising a liquid immersible and floatable body 14 having means (the contents, which may be solid or liquid) contributing primarily to weight and associated means (the wall structure) contributing to buoyancy when the body 14 is at least partially immersed in liquid (in chambers 12A, 12B), means (for example tank 20, holding chamber 30 and pump 34 operative for varying said liquid level, and drive take-off means 40, 42 connected to said body 14. Beam operated pairs and combinations thereof are disclosed as well as tidal and staircase systems. <IMAGE>

Description

LIQUID DEVICE APPARATUS This invention relates to liquid driven apparatus.

This invention arises from experience of fitting flexible inner containers as liners into outer containers of large size and generally cylindrical shape. Inner containers, even of thick-walled plastics material, tend to twist or buckle in such fitting unless steps are taken to avoid such unwanted effects. One way to do so is to charge and discharge the outer container with liquid, conveniently water, also the inner container, in a controlled way so that the inner container is effectively "floated" down into the outer container and left with its walls externally contacting the interior of the outer container.Even with a substantial charge of liquid inside the inner container and very little liquid in the outer container, the inner container has virtually no weight, in fact can be moved manually even though its wholly unsupported weight is large, requiring heavy lifting gear prior to its entry into liquid in the outer container.

It is an object of this invention to utilise the basis for such effects in apparatus capable of generating power up to ratings as high as may be desired.

According to one aspect of this invention, liquid driven apparatus utilises a chamber where interior volume is chargable with liquid contributing weight to the chamber and whose wall structure affords a volume affording bouyancy to the chamber in liquid at it s exterior so that it lags otherwise natural movement by flotation in the exterior liquid.

A suitable chamber wall structure presents spaced walls, for example of impervious plastics sheet or film material, and the spacing between the walls may be filled with low density material, i.e. contributing little weight to the chamber, for example foamed plastics material. The volume defined between such spaced walls may be greater than the interior volume of the chamber.

An alternative to such a liquid chargable chamber would be a solid weight with associated buoyancy means, for example heavy metal embedded in low-density material or otherwise surrounded by a buoyancy chamber.

A more general apsect of this invention thus comprises a liquid immersible and floatable body having means contributing primarily to weight and associated means contributing primarily, or at least relatively, to buoyancy, preferably, though not essentially with adjustability at least of the weight contributing means.

In use, apparatus of this aspect of the invention is driven by liquid naturally causing cyclic rise and fall of said chamber or alternative, but with such natural rise and fall delayed by said means which means can also afford power take-off from the apparatus.

According to another aspect of this invention, liquiddriven apparatus comprises a pair of outer chambers selectively chargable and dischargable with liquid, a pair of inner chambers also selectively chargable with liquid and each fitting into a different one of said outer chambers with clearance for controlled charging and discharging of liquid into said outer chambers, means for controlling said charging and discharging alternately and oppositely for said outer chambers so that said inner chambers alternatively rise and fall in respective said outer chambers (using a charging head at least equal to maximum desired rise of said inner chambers), and motion controlling and transforming means connected to said inner chambers to convert their rising and falling into desired output power with the inner chambers lagging natural flotation in and by liquid in said outer containers.

In embodiments to be described, the inner chambers are hung from a medially pivotted beam each to a different side of its pivot. There is, of course, no requirement that the inner chambers be of flexible material, though they could be if desired, but preferably as indicated for the first of this invention.

Specific implementation of embodiments of this invention will now be indicated, by way of example, with reference to the accompanying diagrammatic drawings, in which: Figure 1 shows a preferred chamber construction; Figure 2 shows six stages A-E of operation of a pivotting beam apparatus; Figure 3 shows at A and B rotary mechanical and hydraulic piston power take-off means; and Figure 4 indicates one multiple stage apparatus; Figure 5 shows a single chamber tide-driven apparatus; and Figure 6 shows a stream-driven "staircase" type apparatus.

Referring first to Figure 1, the cross-section (1B) shows inner and outer generally circular walls 2 and 3 spaced at 4, and the longitudinal section (1A) shows an inner neck 5 of the inner wall 2 meeting an aperture 6 in the top of the outer wall 3 and fitted with a filler cap 7. A suspension frame, or part thereof, is also indicated at 8 associated with the top of the illustrated chamber, given reference 14 for conformity with Figure 2 to be described. Inner and outer walls 2 and 3 can be of any liquid impervious material, conveniently sheet plastics, and the space 4 between them can be filled with low density material, conveniently foamed plastics. Liquid charged into the chamber 14, i.e. at 9 within the inner wall 2, contributes weight to the chamber 14. The wall structure 2,3,4 contributes buoyancy for the chamber 14 in liquid exterior thereto.The volume of the space 4 may exceed that (9) interior of the inner wall 2. Any desired or prescribed relation between weight and bouyancy contributing features is, of course, achievable, including equality.

Practical use of liquid exterior to the chamber 14 does not rely solely on such liquid moving the chamber 14 up and down according to cyclic changes of level of such exterior liquid. Rather, power take-off means hereof takes advantage of weight and buoyancy by controlling up-and-down movement of the chamber to lag respective rise-and-fall of exterior liquid. Generally, rises and falls of exterior liquid take less time than rises and falls of the chamber 14. This should be borne in mind throughout ensuing description of Figures 2 to 4.

Referring first to Figure 2, liquid driven apparatus 10 comprises a pair of outer chambers 12A and 12B each with an associated one of a pair of inner chambers 14A and 14B, respectively, fitting therein with desired small clearance for which minimum requirement is simply to avoid unwanted capillarity effects and/or undue manufacturing tolerance requirements. The outer chambers 12A and 12B are shown with liquid charging feed pipes 16A and 16B, respectively, for liquid, conveniently water. Control valves 18A and 18B are shown in the feed lines 16A and 16B respectively.

The feed pipes 16A and 16B are shown coming from a reservoir tank 20, the former down to a low inlet 22A and the latter up then down to a high discharge position 22B, see Fig. 1A only. It will be appreciated that both could be the same, either to low inlets or to high discharge positions. Moreover, charging head provided by the tank 20 could be otherwise afforded, say from a stream of utilisable water effectively running through the illustrated apparatus, see also later for Figure 6.

As shown, the outer chambers 12A and 12B have discharge outlets 24A and 24B, respectively, to a holding chamber 30 and there will be associated discharge valves either into the holding chamber 30 or out of the chambers 12A and 12B, see 26A and 26B, respectively (Fig. 1A only). Liquid feed back from the holding chamber 30 to the tank 20 is also shown, see pipe 32 and pump 34.

It will be appreciated that the system of Figure 2 can operate using a constant volume of liquid. Also, the outer chamber 12B can be charged only when the pump 34 is operative, as required for discharging the outer chamber 12A. It is then, of course, feasible, may be preferable, to operate without the valve 18B, i.e.

relying only on opening of the valve 18A to starve the charge pipe 16B for the outer chamber 12B. However, charge valve 18B would be required in the case of downward only feeding to the outer chamber 12B (like shown for chamber 12A). In that case, a variable volume of liquid can be utilised, say via a mains water ballvalve feed to the tank 20. At least then, charging feeds for the inner chambers 14A and 14B could be taken off the tank 20, see dashed at 36 valves 38A and 38B of Figure 1A. However, with separate charging feeds to vary the liquid contents of the inner chambers 12A and 12B, it will further be appreciated that a constant volume liquid system for the outer chambers 14A and 14B could be simply by way of a reversible pump in a direct connection between their discharge outlets 24A and 24B.

The inner chambers 14A and 14B are shown suspended at 42A and 42B, respectively, from a beam 40 medially pivotted at 44 to a frame or tower 46. That is shown equidistantly relative to the pivot 42 and balance is assumed, being achievable by adjusting liquid contents of the inner chambers 14A and 14B. There can be alternative suspension positions along the beam 40, for the inner chambers 14A and 14B,- and corresponding spacings for the outer chambers 12A and 12B. Such variation could be by carriages for the outer chambers 12A and 12B with appropriate drive means, whether motors, rams or screws, and corresponding traversing means for the suspensions 42A and 42B along the beam 40.

Together with variation for liquid contents of the inner chambers 14A and 14B, such provisions afford a highly flexible adjustability of output power for the apparatus of Figure 2.

In operation, as shown, opening valve 18A controls charging of the outer chamber 12A by gravity or with the assistance of circulation by the pump 34, as may be called for at that time, owing to the discharge valve 24B for the outer chamber 12B also being open and that chamber necessarily being discharged. The discharge valve 24A for the outer chamber 12A must, however, be closed to fill that chamber. The inner chamber 14A will rise and that 14B fall, see from Figure 1A to Figure 1C, but lagging liquid rise and fall in the corresponding outer chambers 12A, 12B. Then, discharge valve 24B will close and that 24B will open with closure of charge valve 18A and opening of charge valve 18B, whereupon the inner chamber 14B will rise and that 14A fall, see Figures 1D and lE, again lagging liquid level changes in the outer chambers 12A,B.Operation of the various valves is preferably automatic according to positions of the inner chambers 14A and 14B and/or rocking of the beam 40, and the cycle will repeat for as long as required.

Rocking movement of the beam 40, hence movement of the inner chamber 14A and 14B, is effectively controlled and utilised for taking output power1 say using either or both of upper and lower extensions 52A,52B as shown for upper extension 52A in Figure 3. In Figure 3A a connecting rod or arm 54 has one end pivotted at 56 to the upper extension 42A and the other end pivotted at 58 to a slider 60 also pivotted to one end of another connecting rod or arm 62 pivotted at 65 by its other end eccentrically to a wheel 66 which will thus be rotated by rocking movement of the beam 40 and can provide a further drive by gearing or a drive belt shown at 68 to a shaft 70. Figure 3B shows power generated in a hydraulic or pneumatic ram 80 that "falls" and "empties" slower than the outer chambers 12A,B.

Figure 4 indicates a multiple stage apparatus with rocking beams 40A-D, which could be any number as desired or required, and each associated with its own paired inner/outer chamber liquid drive (specifically indicated for beam 40A only) and power take-off systems (specifically indicated by opposed rams 80A,80B also for beam 40A only). Pivots for the beams 40A-D will, in such case, be separate and operation not synchronised for the various stages.

Figure 5 shows a tide-driven apparatus of single-sided type having a chamber 14T operating a rocking arm 40T pivotted on a stand 46T from which it extends into a tide-filled well or basin 12T. Rocking single-acting hydraulic rams 80T,82T are shown between base 46B and arm 40T to opposite sides of its pivot 44T to the stand 46T. Again, power take-off via the rams will lag rise and fall of tide water.

Figure 6 shows a stream operated apparatus arranged in a multi-stage staircase configuration of which two stages are shown at 102 and 104 having inner chambers 114A, 114B and 114C, 114D, respectively, in outer chambers 112A-D arranged at successively lower levels so that water emptying from chamber 112A fills chamber 112B and so on, if desired via holding chambers (not shown).

The inner chambers 114B and 114D require longer suspension from their rocking beams Hydraulic cylinder type power take-offs are indicated.

Generally, where dead-spots occur in cycles of operation, other stages of multi-stage apparatus can be suitably timed to compensate and smooth overall power take-off.

Typical power take-off from hydraulic rams utilises controlled rate of release therefrom of hydraulic fluid, say through a regulator effectively determining flow rate and thus power take-off, hence to an hydraulic motor or turbine that may conveniently be associated with an electrical generator, for example of alternator type. Shaft output power may, of course, be monitored to produce a control signal for the regulator and associated control system involving timing and/or rate of flow control for raising and lowering drive liquid levels.

There are no inherent size limitations for apparatus hereof, hence none regarding actual take-off power.

Moreover, considerable scope for adjustment of take-off power arises simply from varying liquid contents of the inner chambers 14A,B and/or rates of liquid flow.

In general, highly efficient use of available drive water is attained, at least compared with water wheels or turbines directly driven by water flow.

Claims (15)

1. Liquid driven apparatus comprising a liquid immersible and floatable body having means contributing primarily to weight and associated means contributing to buoyancy when the body is at least partially immersed in liquid, means operative for varying said liquid level, and drive take-off means connected to said body.

2. Apparatus according to claim 1, wherein the body comprises a solid weight embedded in low density material, and comprising a surrounding buoyancy chamber.

3. Apparatus according to claim 1, wherein the means contributing to weight is adjustable.

4. Liquid driven apparatus comprising a chamber with an interior volume, means for charging that volume with liquid then contributing to weight of the chamber, the chamber having a wall structure of a volume and nature to afford buoyancy when the chamber exterior is also in liquid, and drive take-off means connected to said chamber and means operative to vary level of said liquid.

5. Apparatus according to claim 4, wherein the wall structure comprises spaced walls.

6. Apparatus according to claim 5, wherein its spaced walls are of liquid-impervious plastics material.

7. Apparatus according to claim 5 or claim 6, wherein the spaced walls are filled with low density material.

8. Apparatus according to claim 7, wherein the low density material is foamed plastics material.

9. Apparatus according to any one of claims 5 to 8, wherein volume defined between the spaced walls is greater than the interior volume of the chamber.

10. Liquid drive apparatus comprising a pair of outer chambers selectively chargable and dischargable with liquid, a pair of inner chambers also selectively chargable with liquid and each fitting into a different one of said outer chambers with clearance for controlled charging and discharging of liquid into said outer chambers, means for controlling said charging and discharging alternately and oppositely for said outer chambers so that said inner chambers alternatively rise and fall in respective said outer chambers (using a charging head at least equal to maximum desired rise of said inner chambers), and motion controlling and transforming means connected to said inner chambers to convert their rising and falling into desired output power with the inner chambers lagging natural flotation in and by liquid in said outer containers.

11. Apparatus according to claim 10, wherein the inner chambers hang from a radially pivotted beam each to a different side of its pivot.

12. Apparatus according to claim 11, wherein the drive take-off means is connected to the beam.

13. Apparatus according to claim 10, 11 or 12, comprising liquid flow control means between the two chambers, liquid drive means between said flow control means and a liquid reservoir, and liquid feed from the reservoir to one of the chambers.

14. Apparatus according to claim 11 or 12 or claim 13 or appendent to claim 11, comprising a plurality of beams and associated pairs of said chambers.

15. Liquid driven apparatus arranged and adapted to operate substantially as herein described with reference to and as shown in the accompanying drawings.