WO2003047780A1

WO2003047780A1 - Tank probing equipment

Info

Publication number: WO2003047780A1
Application number: PCT/GB2002/005472
Authority: WO
Inventors: John Philip Frewer; Barry Angus Noble
Original assignee: Liquid Cargo Management Ltd.
Priority date: 2001-12-06
Filing date: 2002-12-04
Publication date: 2003-06-12
Also published as: AU2002349154A1; GB0129257D0

Abstract

The present invention provides tank probing equipment, comprising mounting means (4) which is adapted to be positioned at an opening (7) in a tank (62); a longitudinally extendable arm (1) having opposing proximal (2) and distal (3) ends, which is attached at the proximal end (2) to said mounting means (4) such that the arm (1) can be entered into the tank (62) through said opening (7) and can be extended and retracted relative to the proximal (2) end within the tank (62); said mounting means (4) and the arm (1) being arranged such that the arm (1) can be swung in at least one dimension within the tank (62); a work-head (5) which is adapted to be attached to said distal end (3) of the arm (1); drive means for selectively driving longitudinal extension and retraction and swinging movement of said arm (1); and control means for controlling said drive means, which control means is adapted to be positioned outside the tank (62). The present invention also provides a cleaning head (5) for use with tank probing equipment of the present invention.

Description

TANK PROBING EQUIPMENT

The present invention relates to tank probing equipment, specifically equipment for probing fuel storage tanks such as petroleum tanks or oil tanks. The invention has particular reference to equipment for removing waste residue from the interior of fuel storage tanks such as petroleum tanks or oil tanks.

Oil-based fuels such as petroleum are typically stored in large tanks for the purposes of fuel dispensation. Owing to the environmental hazards associated with accidental fuel leakage, such tanks are usually buried underground, so as to reduce the risk of damage to the tank. To enable access to their interior, especially for cleaning purposes, such tanks are usually provided with one or more apertures cut into the upper face thereof. The storage of such fuels in a tank tends to result in the deposit of a thick sludgy residue around the bottom and lower walls of the tank. The presence of this residue reduces the effective fuel capacity of the tank, and can also result in contamination of the fuel. Accordingly, it is necessary for the interior of a tank to be cleaned at regular intervals, in order to prevent build-up of such residue.

The nature of the residue, and the underground location of the tank, makes the removal of the residue far from straightforward. Owing to its thickness and viscosity, the residue cannot easily be removed by suction without prior loosening. Accordingly, for the purposes of tank cleaning it has conventionally been necessary for a human worker, equipped with a shovel and high pressure hose, to enter into the tank and loosen the residue by a combination of high pressure washing and shovelling. After this, the loosened residue can be pumped or sucked out of the tank.

Evidently, this method is highly unsatisfactory, owing to the risks posed to the human worker in entering into an enclosed space having the highly toxic and inflammable environment of an underground fuel storage tank. Following fatalities, and near-misses in recent years in the course of such operations, the industry is urgently in need of an improved method for tank cleaning. According to one alternative method proposed in the art, a tank may be pumped full of foam, and render the residue in it into a form capable of being absorbed by the foam. Although this method avoids the need for entry of a human worker into the tank, it inevitably results in the production of a large volume of contaminated foam, which must be safely transported for disposal at a certified site. This is clearly disadvantageous and adds to the cost of the procedure.

There is therefore an outstanding need in the art for an improved means for removing waste residue from fuel storage tanks. There is moreover a need in the art for a means of enabling inspection of the interior of a fuel storage tank, without requiring the entry of a human worker into the tank.

According to one aspect of the present invention therefore, there is provided tank probing equipment, comprising mounting means which is adapted to be positioned at an opening in a tank; a longitudinally extendable elongate arm having opposing proximal and distal ends, which is attached at the proximal end to said mounting means such that the arm can be entered into the tank through said opening and can be extended and retracted relative to the proximal end within the tank; said mounting means and the arm being arranged such that the arm can be swung in at least one dimension within the tank; a work-head which is adapted to be attached to said distal end of the arm; drive means for selectively driving longitudinal extension and retraction and swinging movement of said arm; and control means for controlling said drive means, which control means is adapted to be positioned outside the tank, such that the location of said distal end of the arm inside the tank can be remotely adjusted from outside the tank. In preferred embodiments, the work-head is adapted for storing material for removal from or delivery to the interior of said tank, and/or for removing or delivering material to the interior of said tank, and/or for inspecting the interior of said tank. Where the equipment of the invention is to be used for probing an underground tank, the mounting means may be positioned juxtaposed an opening in an upper surface of the tank, and may be entered into said tank through said opening, so as to allow the arm to be moved throughout the tank by extending and retracting said arm within the tank and swinging the arm under the remote control of the control means, thereby enabling the tank to be probed by the distal end of the arm for enabling inspection thereof, or delivery of material thereto, or removal of material therefrom.

Advantageously, the length of said elongate arm, when extended, is sufficient to allow the full extent of the volume of the tank to be probed by said distal end of the arm.

In some embodiments, said arm may be pivotably mounted by the proximal end thereof on said mounting means, such as to enable said arm to be swung within the tank by said proximal end. In other embodiments, said mounting means may include an arm bearing part which is adapted to be attached at the proximal end of said arm, which arm bearing part is arranged to be pivotable relative to the mounting means in at least one dimension; the arrangement being such that said arm bearing part attached to said arm can be entered into said tank and can be pivoted within said tank in said at least one dimension, thereby causing the arm to be swung within the tank. Optionally, said arm may be arranged to swing within the tank in at least two mutually orthogonal dimensions. Thus, by a combination of extension/retraction and swinging of said arm in said two mutually orthogonal dimensions, said distal end of the arm may be easily moved to any accessible point within the tank. In some embodiments, therefore, said arm may be mounted on said mounting means by way of a universal (360o) joint, such that said arm can be pivoted universally within the tank by said proximal end. In other embodiments, said arm bearing part may be attached to said mounting means by way of a universal (360o) joint, such that said arm bearing part and said arm can be pivoted universally within the tank. Preferably, however, said arm may be arranged to swing within the tank in only one dimension. In order to achieve adequate flexibility of movement of said distal end of the arm within the tank, said arm may be arranged to be rotatable about the longitudinal axis thereof, such as to enable the direction of swinging movement of the arm within the tank to be varied. Advantageously, said arm may be arranged to be rotatable through 360o about said axis, such that the direction of swinging movement of the arm within the tank can be varied through 360o. Conveniently, the arm may be arranged to be rotatable relative to said mounting means. Alternatively, the arm and the mounting means, in particular the arm and said arm bearing part, may be arranged to be rotatable together about said longitudinal axis. Preferably, said arm may be adapted to be detachably connected to said mounting means, such as to said arm bearing part. Thus, said mounting means may comprise a socket, and said arm may be adapted to be inserted into and retained within said socket. This will facilitate removal and replacement of said arm, so as to enable the equipment to be adapted for use in tanks of different sizes. Optionally, a retaining means such as a retaining ring may be provided for retaining said arm within said socket. Said retaining means may further comprise sealing means for ensuring that the arm is sealingly maintained within said socket. In preferred embodiments, said drive means comprises a first drive means for driving longitudinal extension/retraction of said arm and a second drive means for driving swinging movement and/or rotation of the arm.

Suitably, said first drive means may comprise extension drive means for driving extension of said arm, and retraction drive means for driving retraction of said arm. Advantageously, said extension drive means and said retraction drive means may be adapted to be operated simultaneously in opposition to one another, such as to enable the length of said arm to be precisely controlled.

Where said arm is arranged to be swung in two mutually orthogonal dimensions, said second drive means may consist of third and fourth swinging drive means for respectively driving swinging movement of said arm in said two mutually orthogonal dimensions. Alternatively, where said arm is arranged to be swung in one dimension and rotated about the longitudinal axis thereof, said second drive means may consist of third swinging drive means and fourth rotation drive means for respectively driving swinging movement and longitudinal rotation of said arm. Suitably, each of said drive means may comprise hydraulic, pneumatic, electromagnetic, and/or mechanical drive means. Where the assembly of the invention is to be utilised in the presence of inflammable materials, such as within the interior of a fuel storage tank, said drive means may preferably comprise hydraulic and/or mechanical drive means, so as to reduce the risk of accidental ignition within the tank.

Thus, in some preferred embodiments said third swinging drive means and/or said fourth swinging drive means may comprise a ram, such as a hydraulically operated ram, which ram is mounted on the mounting means and is arranged to interact with said arm or said arm bearing part for respectively pushing and/or pulling said arm or arm bearing part so as to cause pivotal movement thereof in one dimension.

In other embodiments, said third swinging drive means and/or said fourth swinging drive means may comprise a gear member such as a toothed annulus or toothed wheel which is attached to each of said arm and said mounting means, which gear member is adapted when driven to cause swinging movement of said arm relative to said mounting means in one dimension. Said gear member may optionally be attached to said arm bearing part and to said mounting means. Advantageously, said gear member may comprise a rotatable sprocket wheel which engages a chain that can be withdrawn in each of two opposing directions for respectively driving clockwise and anti-clockwise rotation of said sprocket wheel, and said chain may be connected to a withdrawing means that is arranged to withdraw said chain in each of said two opposing directions. Said withdrawing means may, for example, comprise a chain- driving winch or a motor, such as a hydraulically-powered winch or motor, or a pair of pistons, such as a pair of pneumatically- or hydraulically-driven pistons, which are respectively attached to the two ends of said chain. Alternatively, said gear member may comprise a ring gear, which is arranged to be driven in two opposing directions by a motor, such as a hydraulically- powered motor.

Where said third and fourth swinging drive means comprise a chain- driving motor and a gear-driving motor as hereinbefore described, said chain-driving motor and said gear-driving motor may be the same motor which may be a hydraulically-powered motor. Alternatively, said chain- driving motor and said gear-driving motor may be different motors, one or both of which may be hydraulically-powered.

In especially preferred embodiments, said extendable arm comprises a series of longitudinal segments which are slidably interconnected with one another such that the segments can "telescope" with respect to one another for respectively retracting or extending said arm. Preferably, each segment comprises a hollow interior which is adapted to house an adjacent segment on the proximal or distal side thereof. Said adjacent segment may, for example, be mounted on runners or any other suitable linear bearing provided within the hollow interior of the segment, and may be adapted to slide on said runners into and out of said hollow interior of the segment. Said extendable arm may comprise between three and ten segments, suitably between four and eight segments, most preferably five or seven segments. The number of segments in the arm will suitably be selected according to the size of the tank to be probed.

Advantageously, each segment may be adapted to house an adjacent segment, preferably on the distal side of the segment. Thus, in the course of retraction of said arm, each segment may be successively withdrawn into the hollow interior of the adjacent segment on its proximal side, such that the segment nests within said adjacent proximal segment. Conveniently, therefore, the cross-sectional diameter of each segment of the arm may be smaller than the cross-sectional diameter of the adjacent segment on its distal side. Thus, the cross-sectional diameter of the extendable arm, when extended, may diminish progressively along the length thereof from the proximal to the distal end, said distal end being narrower than said proximal end. The distal end of the extendable arm may therefore be substantially lighter than the proximal end of the extendable arm, which will facilitate manoeuvre of the arm within the tank. Advantageously, said longitudinal segments may be sealingly connected to one another, so as to prevent the ingress or leakage of fluid into or out of said arm. Thus, said segments may be interconnected with one another by way of O rings, or otherwise.

In preferred embodiments, said extension drive means is a hydraulic drive means. For example, said extension drive means may comprise means for supplying a flow of pressurised fluid to said longitudinal segments, whereby said segments are urged to telescope longitudinally outwardly such as to extend said arm. Suitably, said flow of pressurised fluid may be adapted to be a constant flow. Thus, said arm may be constantly urged to extend under the influence of said flow of pressurised fluid. Preferably, said constant flow of pressurised fluid is adapted to be switched on and off by switch means which may be positioned juxtaposed said control means. Said pressurised fluid may conveniently be pressurised gas, such as pressurised air. However, other inert and non-inflammable fluids capable of being supplied under pressure may be equally suitable for this purpose. Preferably, said retraction drive means may comprise an elongate connecting means such as a chain, wire, tape, cable or retractable rod attached to the outermost (most distal) segment of said extendable arm, which connecting means extends along the length of said extendable arm towards the proximal end thereof, which connecting means is arranged to be selectively withdrawn towards said proximal end of the extendable arm such as to cause said segments to telescope longitudinally inwardly, thereby retracting said extendable arm. Conveniently, said connecting means may be connected at the proximal end thereof to a withdrawing means such as a winch or motor, preferably a hydraulic winch or motor. Said withdrawing means may, for example, be provided on said mounting means.

Thus, the length of the extendable arm may be precisely and sensitively adjusted by regulating the pull applied to said connecting means for retracting the arm. When a slight increase in length is required, the pull may be slightly diminished and the required extension will occur under the influence of said flow of pressurised fluid. Meanwhile, when a slight decrease in length is required, the pull applied to said connecting means may be slightly' increased. Of course, for maintaining a constant length, a degree of pull must be applied to said connecting means such as to balance the extending impulse exerted on said extendable arm by said constant flow of pressurised fluid.

Where the arm is to be fully retracted, said extension drive means may be arranged to be automatically or manually switched off, in order to permit unopposed retraction of the arm by said retracting means. In preferred embodiments, said arm may further comprise a sensor, such as an electronic sensor, which is adapted to monitor the movement of said connecting means relative to said withdrawing means, thereby to monitor the degree of extension of said extendable arm. Said sensor may be adapted to transmit information to a display unit positioned adjacent to said control means, for appraisal by an operator, whereby the operator can be informed of the degree of extension of said extendable arm.

Advantageously, said arm may further comprise a camera positioned for recording images of the distal end of said arm, which camera is adapted to transmit said images to a screen for viewing by an operator, and/or to store said images for visualisation and inspection at a later stage. Suitably, said screen may be adapted to be positioned adjacent to said control means, such that an operator can view images transmitted to said screen whilst simultaneously operating said control means. Visualisation of the distal end of the arm during operation will help the operator to control the manipulation of the arm and ensure that the distal end accesses all the desired areas within the tank. Storage of said images for later visualisation and inspection will enable a visual record to be preserved of the condition of the inside of said tank. To further assist with visualisation, said arm may advantageously comprise illuminating means such as a bulb or LED, said illuminating means being positioned to illuminate the distal end of said arm. Said distal end of the arm may, optionally, comprise or be adapted to be attached to a work head for delivering material to the interior of said tank. For example, said distal end of the arm may comprise a spraying head for spraying a coating or a cleaning material onto the inner wall of said tank, such as a coating of protective material. Accordingly, said equipment may further comprise means for supplying said coating or said cleaning material to the spraying means for spraying.

Alternatively, or in addition, said distal end of the arm may comprise a work head for inspecting the interior of said tank. Accordingly, said distal end of the arm may comprise a camera for enabling visual inspection of the tank; or said distal end of the arm may comprise means for taking measurements of physical properties within the tank, such as temperature, or pressure, or for assessing the nature and/or quantity of material present in the tank. Alternatively, or in addition, said distal end of the arm may comprise a cutting means for cutting material within the tank. This will be especially useful should modifications or repairs be required to the internal structure of the tank.

In most especially prefeπed embodiments, however, said distal end of the arm comprises or is adapted to be attached to a cleaning head for collecting material from the interior of said tank and storing said material for removal from said tank. Said cleaning head may, for example, comprise a container having an aperture therein and a collecting means adapted for scooping up material, transporting said material to said aperture, and causing or allowing said material to enter into said container through said aperture for storage therein.

Such a cleaning head may be used in other applications apart from the tank probing apparatus of the present invention. According to a further aspect of the present invention therefore, there is provided a cleaning head as hereinbelow defined.

Said collecting means may suitably comprise a rotatable member that comprises scooping means for scooping up material, which rotatable member is adapted' to rotate relative to said container such that said scooping means revolves about the outer surface of said container. Suitably, said rotatable member may be disposed around or closely juxtaposed said container. Thus, said rotatable member may for example comprise a rotatable sleeve or ring which is arranged to surround said container, or a rotatable plate which is arranged to rotate relative to said container. To drive rotation of said rotatable member relative to the container, said equipment may further comprise rotatable member driving means, such as a hydraulic driving means. Advantageously, the operation of said rotatable member driving means may be remotely controllable by said control means.

Suitably, said scooping means may comprise one or more elongate and substantially flat fins or brushes, each of which fins or brushes is fixedly attached to said rotatable member and is disposed such that the rotation of said rotatable member relative to said container produces a brushing or sweeping movement of said fins or brushes around said container. Advantageously, therefore, the longitudinal axis of each fin or brush may be parallel or substantially parallel to the axis of rotation of said rotatable member relative to said container, and the fin or brush may be oriented such that the flat surface of each fin or brush protrudes radially outwardly from said axis of rotation. Accordingly, when the outer edge of said fin or brush is placed in contact with an inner wall of said tank, the rotation of said rotatable member relative to said container results in brushing or scraping of said outer edge of the fin or brush against said inner wall, which serves to loosen material from said inner wall of the tank. Said loosened material can then be scooped or swept up by said fins or brushes revolving around said container, and transported to said aperture for storage within the container. In some embodiments, therefore, said rotatable member comprises a plate which is adapted to be mounted adjacent one end of said container and is adapted to rotate relative thereto; and each of said elongate fins or brushes is attached at one longitudinal end thereof to said plate, such as to extend perpendicular to the surface of said plate. Said plate may be mounted at the centre thereof on a bearing, which bearing may advantageously comprise a hydraulic motor serving as the rotatable member driving means.

Suitably, said fins or brushes may comprise a hard, strong and durable material, such as rubber. Advantageously, said brushes or fins may be designed to scrape and/or scoop or sweep up liquid, viscous or semi- viscous sludge, and/or small solid particles. To assist with the brushing-up of said material, the cleaning head may further comprise an outer cover which is arranged circumferentially around said fins or brushes so as to encircle said fins or brushes, which outer cover comprises an opening on one side thereof, through which opening each fin or brush can be successively outwardly exposed for brushing and scooping up said material. Suitably, said cleaning head is configured such that said outer edge of each successive fin or brush will protrude from said opening as said rotatable member rotates.

Preferably, said outer cover is configured and arranged so as to be closely juxtaposed or in loose contact with said outer edge of each fin or brush, such that each pair of adjacent fins or brushes can define a closed or substantially closed space together with the inner wall of said outer cover and the outer wall of said container.

In use, the cleaning head can be disposed such that said opening in the outer cover is wholly or partly immersed in said material. As the rotatable member rotates relative to said container, each fin or brush is successively immersed in said material, and produces a sweeping or brushing movement which results in the scooping up of said material. As the fin or brush moves past said opening and back under the outer cover, said material becomes trapped in said closed or substantially closed space between adjacent fins or brushes, the outer cover, and the container. Thus, said material is precluded from dropping off said fin or brush back into the tank.

Advantageously, said opening in the cover may be configured such that larger particles which are not swept or scooped up by the fins or brushes are pushed away from the cleaning head by the fins or brushes as the fins or brushes move past the opening and back under the cover, and do not clog up or block the fins or brushes.

Preferably, said cleaning head may be aπanged to be oriented when in use such that said opening is located on a lower face of said cover, so that said fins or brushes are downwardly-exposed on said cleaning head. Advantageously, said cleaning head may comprise wheels, suitably a pair of wheels one of which may be located on either side of said opening. Said wheels may be adapted to support the cleaning head when brought into contact with an inner surface of a tank, thus maintaining the cleaning head at a pre-determined separation from said inner surface. In especially preferred embodiments, said wheels may be arranged such that the axis of rotation of each wheel is parallel to the longitudinal axis of said container, so as to assist the alignment of said longitudinal axis of the container with the longitudinal axis of a cylindrical tank. Said wheels facilitate the movement of the cleaning head across the surface of the tank. Advantageously, said cleaning head may be arranged to be oriented when in use such that material released from the collecting means above said aperture will fall into the container under the influence of gravity. Thus, said aperture may preferably be arranged to open upwardly. For example, said aperture may be located on an upper face of said container. Suitably, said cleaning head may be screwed fixedly onto the distal end of the arm for use, or may be locked or welded thereto. Said cleaning head may preferably be detachably connected to said distal end of the arm. In some preferred embodiments, said cleaning head may be pivotably mounted on the distal end of the arm, such as to allow the orientation of said cleaning head with respect to said arm to be altered in use. This will assist the achievement of alignment of the cleaning head with the configuration of the inner surface of a tank in use.

In preferred embodiments, said cleaning head further comprises closing means for selectively closing said aperture in the container. Optionally, said closing means may be provided on the collecting means. Thus, said closing means may for example comprise a plate which is shaped to fit over said aperture, so as to close off said aperture. Where said control means is adapted for enabling remote control of the revolution of said sleeve by said operator, the arrangement may advantageously be such that said operator can selectively cause the closure of said aperture by halting rotation of said rotatable member relative to the container such that said plate closes off the aperture.

Said material may comprise waste material for disposal, such as fuel residue. However, said material may optionally comprise material which may be used for testing or inspection. In order to enable said material to be removed from the cleaning head, for example for the purpose of disposal, or for testing or inspection, said arm can be retracted and said cleaning head can be withdrawn from the tank and can be emptied of said material.

Conveniently, said aperture may be adapted to enable material to be removed from said container through the aperture. Said container may, for example, be adapted to be oriented such that material in said container can be emptied out of said container through said aperture in the container. Said container may, in addition or in the alternative, comprise a second opening means which can be selectively opened for allowing material in the container to be removed and/or for enabling the inside of the container to be accessed for cleaning. Preferably, said second opening means may comprise a panel which can be bolted, screwed or otherwise securely fixed in position, and which can be removed for opening said container.

Advantageously, said cleaning head may further comprise a sensing means which is adapted for sensing when a pre-determined quantity of material is stored in said container. Said pre-determined quantity of material may for example be a pre-determined weight of material, or a predetermined volume of material. Where said pre-determined quantity of material is a pre-determined volume, said sensing means may comprise means for sensing the level of material in said container; such as a float switch.

Suitably, said sensing means may be operatively connected to an alerting means and may be adapted for activating said alerting means when said pre-determined quantity of material is stored in said container, said alerting means being arranged when activated for alerting an operator of the equipment. For example, said alerting means may comprise a bell, siren, or light, which bell, siren or light may advantageously be located in proximity to said control means so as to enable an operator of said control means to be alerted by activation of said alerting means. Alternatively, or in addition, said sensing means may be operatively connected to said control means, and may be arranged for automatically causing said cleaning head to cease collecting material when said predetermined quantity of material is stored in said container.

Said mounting means may preferably comprise an elongate moiety which is adapted to be attached to said arm or to said arm bearing part, which elongate moiety is arranged to be entered or partly entered into said opening in a tank. This is particularly important where, as is customary, the tank to be probed is located underground and the opening of the tank can only be accessed through a hole in the ground. Said elongate moiety may therefore be adapted to be inserted into said hole in the ground, such that the arm can be entered into said tank underground.

Suitably, said mounting means may comprise a deployment means adapted for attachment to said arm, which deployment means is adapted for locating said arm at said opening of a tank and for entering said arm into the tank. Conveniently, said deployment means may be connected to said elongate moiety and may further be arranged for locating said elongate moiety at said opening of the tank and for entering said elongate moiety or said part thereof into said tank. Where said arm is adapted to be longitudinally rotated, said elongate moiety may preferably be rotatably mounted on said deployment means, so as to enable said elongate moiety and said arm to swivel. Thus, said rotation drive means may be adapted for driving rotation of said elongate moiety relative to said deployment means. Advantageously, said deployment means may be adapted to be mounted on a vehicle, for enabling easy transport of the tank probing equipment. Suitably, said deployment means may comprise a jointed member comprising a plurality of longitudinal struts which are pivotably attached to one another at respective ends thereof such as to allow said jointed member to be manipulated between folded and extended configurations. Suitably, each strut may be adapted to be pivoted relative to each adjacent strut through an angle of approximately 180o. Thus, said jointed member may be adapted to be manipulated between a fully extended configuration in which the joint angle between each adjacent strut is approximately 180o, and a fully folded configuration in which the joint angle between each adjacent strut is approximately Oo. This will permit ready and flexible variation in the extension and angle of said jointed member.

Advantageously, said jointed member may comprise joint driving means associated with each joint thereof, which joint driving means is operable to drive and control relative pivotal movement of the two struts which are adjacent to said joint. Conveniently, each joint driving means may comprise a thrusting member which is mounted on one of said two struts adjacent to said joint, and which is adapted to interact with the other of said two struts adjacent to said joint, said thrusting member being operable to push said other strut away from said one strut so as to cause said joint angle to increase, and/or to pull said other strut towards said one strut so as to cause said joint angle to decrease. Said thrusting member may advantageously comprise a ram, which ram may be arranged to be driven by hydraulics. Suitably, said joint driving means may be arranged to be remotely controllable by said control means, so as to enable an operator at the control means to control the bending of said joint. In prefeπed embodiments, each joint of said jointed member may comprise at least one rod V-linkage pair connecting said two adjacent struts, which rod V-linkage pair comprises two rigid elongate rods, both of which rods are pivotably attached to one another at one end thereof, each of which rods is pivotably attached at the other end thereof to a respective one of said struts. Thus, said rods serve to connect said struts one to another and to support adjacent struts; whilst pivotal movement of said rigid elongate rods relative to one another, opening or closing the angle of the "V", can produce pivotal movement of said struts relative to one another. Suitably, each joint may comprise two identical rod V-linkage pairs, which rod V-linkage pairs are respectively attached to opposing sides of said struts. This will produce increased stability and strut support at the joints of said member.

In especially preferred embodiments, each joint of said jointed member may comprise three or four rod V-linkage pairs, at least one of which pairs is arranged such that the apex of the "V" of said pair opposes the apex of said joint, whilst at least one other of said pairs is aπanged such that the apex of the "V" thereof is substantially aligned with the apex of said joint. Suitably, said thrusting member mounted on one of said struts may be adapted to interact with one or more of said V-bar linkage pairs opposing the apex of said joint, such as to be capable of opening and/or closing the "V" of each pair, thereby indirectly interacting with and causing pivotal movement of the other of said struts relative to said one strut. Meanwhile, said one or more pairs aligned with said apex of the joint serve primarily for joining the two struts together and for supporting adjacent struts.

Advantageously, said jointed member may comprise between two and four struts, preferably two or three struts. Each of said struts may suitably be manufactured from a composite material. Such materials are light and inexpensive and are suitable for this application.

Said jointed member is adapted to be mounted at one end thereof to said arm, optionally by way of one or more intermediate connecting parts. Said intermediate connecting parts may, for example, include said elongate moiety. In preferred embodiments, said jointed member may be adapted to be mounted at the other end thereof to a rigid member such as a frame.

Suitably, said jointed member may be pivotably mounted to said arm. In the alternative, or more preferably in addition, said jointed member may be pivotably mounted to said rigid member. Accordingly, said jointed member may further comprise pivotable joints at either or both ends thereof for pivotal mounting of said jointed member to either or both of said rigid member and said arm. Either or both of said pivotable joints may comprise one or more rod V-linkages, preferably of the kind described above. Advantageously, jointed member driving means may be provided at either or both of said pivotable joints, for driving and controlling pivotal movement of said jointed member relative to said rigid member and/or relative to said arm. Each jointed member driving means may for example comprise a thrusting member mounted to one of said jointed member and said rigid member or arm respectively, which thrusting member is adapted to interact with the other of said jointed member and said rigid member or arm respectively, and is operable to push and/or pull said jointed member to pivot relative to said rigid member or arm respectively. Said thrusting member may comprise a ram, preferably a hydraulically driven ram. Preferably, each of said jointed member driving means may be adapted to be remotely controllable by said control means, such as to permit an operator at said control means to control pivotal movement of said jointed member relative to said rigid member and/or to said arm.

Said jointed member may advantageously be rotatably mounted on said rigid member, such that said jointed member can be swivelled relative to said rigid member. Thus, said jointed member may for example be mounted on said rigid member by way of a rotatable kingpost, or otherwise. This will enable the jointed member to be deployed relative to said rigid member in a range of different directions. Advantageously, said jointed member may be arranged to be swivelled relative to said rigid member through 180o or more.

Said rigid member may comprise a frame or plate which can be fixedly attached to a surface of choice, such as a vehicle for transporting the tank probing device. This will enable the tank probing equipment to remain fixedly attached to the vehicle during transport to and from and probing of a tank.

Said vehicle may preferably be a truck or lorry suitable for carrying heavy equipment. Advantageously, said vehicle may include a carrying surface for carrying said tank probing equipment. Said vehicle may be provided with stabilising legs which can be extended from said carrying surface into contact with the ground, for stabilising and supporting the vehicle during deployment and use of the tank probing equipment. Suitably, said stabilising legs may be arranged to be extended from the vehicle in a direction orthogonal to the normal direction of deployment of said tank probing equipment.

Optionally, said mounting means may be arranged such that when said arm is disposed within said tank, said mounting means rests against a stabilising surface, such as the ground. This will enable the arm to be stabilised during the probing operation. As a preferred alternative, or in addition, a stabilising means may be provided for stabilising said mounting means against the ground or against the walls of a tank access hole in the ground providing access to an opening in a tank. Said stabilising means may be attached to or may be adapted to be attached to said mounting means. In preferred embodiments, said stabilising means comprises a clamp which is operable to clamp said mounting means between said walls of the tank access hole. Said clamp may comprise one or more clamping members which are arranged to be attached to said mounting means, and are movable between a retracted position and a deployed position, in which the clamping members are positioned to clamp the mounting means between said walls of the tank access hole. Said clamp may be pneumatically operated. Alternatively, said clamp may comprise one or more clamping members having rollers, which rollers permit the clamping members to locate around the tank access hole. Optionally, said clamp may be arranged to be fitted manually onto the mounting means. As set out above, in accordance with the present invention, said control means may be adapted for effecting remote control of one or more of the extension and retraction of said arm, swinging movement of the arm and longitudinal rotation of the arm, so as to control the positioning of the distal end of said arm. Said control means may furthermore be adapted for effecting remote control of one or more of the pivotal movement of said jointed member relative to said arm, pivotal movement of said jointed member relative to said rigid member, and bending of the joints of said jointed member, so as to control the deployment of said jointed member. Said control means may furthermore be adapted for controlling the rotation of said rotatable member within the cleaning head. Accordingly, said control means may typically include one or more control centres which can be occupied by an operator, each of which control centres comprises means for controlling each of said aforementioned movements, such as to allow convenient and co-ordinated control of the whole of the operation of said assembly by one operator remaining in one place. Advantageously, said control means comprises one main control centre and one or more subsidiary control centres, each located in different places. This will enable the equipment to be controlled and operated from a plurality of different places. Advantageously, said screen for visualising the distal end of the arm, and/or said alerting means for alerting the operator when the collecting means is full, and/or said display unit for informing the operator of the degree of extension of said arm, are each located in proximity to said main control centre. This will enable the operator to achieve efficient and coordinated operation of the assembly from said main control centre. Said main control centre may conveniently be located within said vehicle. Meanwhile, each one of said subsidiary control centres may preferably be located outside said vehicle, preferably within sight of said opening and/or said tank.

Thus, the tank probing equipment of the present invention may be operated directly by an operator positioned in one of said control centres.

Said tank probing equipment may further be adapted for automatic operation under the control of a computer. Thus, said tank probing equipment may further comprise a computer which is capable of receiving information concerning the degree of extension of said extendable arm, and/or the position of said distal end of the arm, and/or the nature of the inside of a tank, and/or the quantity of material within said cleaning head, which may be transmitted to said control centre in accordance with the invention; processing said information together with information input into the computer by an operator concerning the desired function of the equipment; and controlling the operation of said extendable arm, and/or said cleaning head, and/or said jointed member so as to achieve said function. Suitably, said computer may be located in said main control centre.

Said tank may be adapted for storing combustible and/or toxic substances. Typically, said tank may be a fuel storage tank, such as a petroleum tank or an oil tank. To reduce coπosion or damage to said equipment, and/or to reduce the risk of accidental ignition within the tank, said equipment may advantageously be wholly or partly formed from or coated with an anti-inflammatory, and/or non-abrasive, and/or corcosion- resistant material, such as carbon fibre or rubber. In many embodiments, said tank may be wholly or partly underground. Thus, said opening in the tank may be provided in an upper surface thereof, and may be aπanged to communicate with a tank access hole for enabling said opening to be accessed from above ground.

Advantageously, the equipment of the present invention may be arranged to be disassembled for storage. Thus, said cleaning head may be adapted to be removed from the distal end of the arm, and/or said arm may be aπanged to be detached from the mounting means for storage. According to another aspect of the present invention therefore, there is provided a kit of parts which is adapted to be assembled into equipment in accordance with the present invention.

Following is a description, by way of example only and with reference to the accompanying drawings, of embodiments of the present invention.

In the drawings: Figure 1 shows a side view of tank cleaning equipment in accordance with the present invention, assembled for use and inserted into a tank for cleaning.

Figure 2 shows a side view of the tank cleaning equipment of Figure 1, in the course of deployment for use. Figure 3 shows a side view of the tank cleaning equipment of Figure

1, mounted on a truck and stored ready for use.

Figure 4 shows a side view of the tank cleaning equipment of Figure 1, illustrating the full-length deployment thereof.

Figure 5 shows a perspective view of the tank cleaning equipment of Figure 1, in the course of deployment for use.

Figure 6 shows a perspective view of an alternative embodiment of a jointed member, elongate member and extendable arm, for use in tank cleaning equipment in accordance with the invention.

Figure 7 shows a perspective view of the jointed member shown in Figure 6.

Figure 8 shows a detailed view, partly in cross-section, of a hydraulic ram, V-bar linkage and strut, for use in tank cleaning equipment in accordance with the invention.

Figure 9a shows a detailed view, partly in cross-section, of the proximal end of an extendable arm for use in tank cleaning equipment in accordance with the invention, illustrating the pivotal mounting of the arm on an elongate member.

Figure 9b shows another detailed view, partly in cross-section, of the proximal end of the extendable arm shown in Figure 9a. Figure 10a shows a detailed view of the proximal end of an alternative embodiment of an extendable arm for use in tank cleaning equipment in accordance with the invention, illustrating the pivotal mounting of the arm on an elongate member.

Figure 10b shows a side view of the elongate member and extendable arm of Figure 10a, and illustrates the pivotal movement of the arm on the elongate member.

Figure 11 shows a perspective view of an elongate member and extendable arm for use in tank cleaning equipment in accordance with the invention. Figure 12 shows an end view of a cleaning head for use in tank cleaning equipment in accordance with the invention.

Figure 13 shows a cross-sectional side view of the cleaning head of Figure 12.

Figure 14 shows an end view of the rotatable member of the cleaning head shown in Figure 12.

Figures 15a-15c show end, plan and cross-sectional side views respectively of a vehicle carrying and storing tank cleaning equipment in accordance with the invention.

Referring first to Figure 1, equipment in accordance with the present invention for cleaning an underground fuel storage tank 62 comprises an elongate extendable arm 1 having a proximal end 2 and a distal end 3, which arm is pivotably mounted at said proximal end 2 to an elongate support member 4, which arm is removably attached at said distal end 3 to a cleaning head 5. Said elongate support member 4 is adapted to extend down a tank access hole 6 through opening 7 in the upper surface of said underground tank 62, for entering the arm 1 into the tank 62. Said elongate support member 4 is rotatably mounted on a jointed member 8, which jointed member 8 is in turn mounted, by means to be described in more detail hereinafter, on a vehicle 26. Extendable arm 1 comprises a series of hollow, substantially cylindrical segments lla-llg, of progressively diminishing diameter. These cylinders lla-llg are slidably interconnected in series by way of airtight O rings, each cylinder being arranged to slide into and out of the hollow interior of the adjacent (larger) cylinder in a telescoping movement, whereby arm 1 can be extended or retracted. In the fully retracted state, as shown for example in Figure 3, all of the cylinders lla-llg are substantially aligned with one another and are housed within the largest cylinder 11a which is positioned proximal to said elongate support member 4. In the fully extended state, as best shown in Figure 1, a substantial part of the length of each cylinder lla-llg is exposed. The proximal end 2 of the arm 1 is defined by the upstream end of the largest cylinder 11a; whilst the distal end 3 of the arm 1 is defined by the downstream end of the smallest cylinder llg, as shown in Figure 1.

Although seven interconnecting cylinders lla-llg are shown in the present embodiment, a common alternative embodiment includes only five interconnecting cylinders. The number of cylinders used determines the maximum length of the arm 1, and thus is selected by reference to the intended use of the equipment. As shown in Figure 1, the maximum length of arm 1, when fully extended, should be sufficient to enable the distal end 3 of the arm to access the most distant areas of said tank 62.

Said arm 1 is pivotably mounted at the proximal end 2 thereof to said elongate support member 4 by way of an arm bearing part 10. Arm bearing part 10 comprises a gripping member 12 and a cylindrical sleeve 9, which sleeve 9 is gripped by the gripping member 12 as illustrated in Figures 9a and 9b. Optionally, the sleeve 9 and gripping member 12 may be integral one with the other.

Said sleeve 9 defines a socket 13, which is adapted to engage the upstream end of said largest cylinder 11a, such as to close the upstream end of the cylinder 11a. As best seen in Figure 9b, said sleeve 9 is formed with two annular notches around the inner surface thereof, which notches are shaped to engage with coπesponding annular shoulders 16 provided on the outer surface of said largest cylinder 11a, so that the cylinder 11a can be securely engaged within said socket 13. The cylinder 11a is clamped in position by way of a clamping ring 14, which is adapted to be fitted snugly around the outer circumference of the cylinder 11a, and to seat against the sleeve 9. Said clamping ring 14 also serves as a sealing ring, for sealing the cylinder 11a against the sleeve 13. The clamping ring 14 is adapted to be screwed firmly into position by way of a retaining collar 15. This arrangement facilitates removal of the arm 1 when this is required, for example during transport of the equipment, or for the purpose of replacing the arm with an alternative arm 1.

Said arm bearing part 10 includes a conduit connected to a source of pressurised air (not shown), which conduit opens in socket 13 so as to enable communication with the hollow interior of said arm 1. Said source of pressurised air can be controlled by way of a switch (not shown) which is operable by a user to switch the source of pressurised air on and off. When the source of pressurised air is switched on, a constant flow of pressurised air is supplied to said conduit and is channelled therethrough into the interior of arm 1. This has the effect of applying a constant degree of hydraulic pressure to the cylinders lib- llg, which hydraulic pressure urges the cylinders llb-llg to slide outwardly in relation to said cylinder 11a and to one another, such as to cause the arm 1 to extend.

As seen in Figure 10a, a cable 17 is provided in the hollow interior of said arm 1. The cable 17 is fixedly connected at one end thereof to said smallest cylinder llg at the distal end of the arm. The cable is attached at the other end thereof to a hydraulic winch 18 which is mounted on said arm bearing part 10. The hydraulic winch is operable to pull in the cable, so as to urge said cylinders llb-llg of the arm to telescope progressively inwardly towards the proximal end 2 of the arm, such that the arm 1 is urged to retract. The operation of the winch can be remotely controlled by way of a winch lever 19.

The length of said arm 1 can hence be precisely regulated by an operator, through use of said switch and winch lever. When the arm is to be fully retracted, in particular when the equipment is to be stored away out of use, said switch can be turned off, thereby shutting off the supply of pressurised air to the interior of said arm 1. Said winch lever can then be operated for pulling in said cable, so as to fully retract the arm, as shown for example in Figure 3.

When the arm is to be extended for use, said switch can be turned on, resulting in the channelling of pressurised air into the interior of said arm 1 through said conduit in the arm bearing part 10. The consequent hydraulic pressure will urge the arm to extend. The speed and extent of extension can be controlled through the operation of said winch lever. Evidently, the arm will continue to extend to its maximum extent unless a pulling force sufficient to overcome said hydraulic pressure is applied to said cable by the winch lever. For retracting the arm, a pulling force greater than the force exerted by said hydraulic pressure must be applied to the cable 17 by the winch lever 19.

A sensor 20 is provided on the arm bearing part 10 adjacent the wiϊich, and is adapted to detect movement of the cable relative to the winch, so as to enable measurement of the extension of said arm 1. Said sensor 20 is arranged to transmit information concerning the degree of extension of said arm 1, to a remote display unit (not shown).

A camera (not shown) is provided on the distal end 3 of the arm, and is aπanged to transmit images therefrom to a screen that is positioned outside the tank 62 for providing visual information concerning the interior of the tank 62. Sensors (not shown) may optionally also be included, for enabling the interior of the tank 62 to be scanned for the purpose of creating a 3D image of the interior of the tank, as hereinafter described. As shown in Figure 1, said arm bearing part 10 is pivotably attached to said elongate support member 4. A hydraulically driven piston 21 is provided on the support member 4 and is attached to the arm bearing part 10, such that longitudinal movement of said piston 21 will result in pivotal movement of said arm bearing part 10 relative to the support member 4. This will in turn produce a swinging movement of said arm 1 connected to the arm bearing part 10 relative to the support member 4 in one dimension. Said hydraulically driven piston 21 accordingly is operable to drive and control swinging movement of said arm 1 attached to said arm bearing part 10 relative to said support member 4. An optional alternative arrangement for mounting the arm bearing part 10 on the elongate support member 4 is illustrated in Figure 10a. A toothed sprocket wheel 22 is rotatably mounted on the elongate support member 4, and is fixedly attached to said arm bearing part 10 such that rotation of said sprocket wheel 22 produces coπesponding pivotal movement of said arm bearing part 10 and the arm 1 relative to the support member 4. Said toothed sprocket wheel 22 engages a non-stretchable chain 23 which is wound around a part of the circumference of the wheel 22. The two ends of the chain 23 are respectively attached to two hydraulic pistons 24, which are each slidable longitudinally towards and away from the sprocket wheel 22. As one piston 24 is driven away from the sprocket wheel 22, the chain 23 will be pulled longitudinally around the sprocket wheel 22, causing the sprocket wheel 22 to rotate and causing the other piston 24 to slide towards the sprocket wheel. As the sprocket wheel 22 rotates, the arm bearing part 10 and the arm 1 are caused to pivot coπespondingly. The driving mechanism for the pistons 24 (not shown) is a hydraulic mechanism which is arranged such that only one piston 24 is driven at a time. This is because simultaneous movement of each piston 24 away from the sprocket wheel 22 would result in the chain 23 being pulled at both ends, thereby risking snapping of the chain. Said arm 1 is detachably connected by way of a bracket 25 at the distal end 3 thereof to a cleaning head 5, which is adapted for collecting and storing waste residue 27 from the interior of said tank 62. The cleaning head is aπanged to be universally pivoted relative to said distal end 3 of the arm, such as to permit variation in the orientation of said cleaning head 5 relative to the arm 1. Cleaning head 5 is shown in greater detail in Figures 12-14. As seen in Figures 12 and 13, said cleaning head 5 comprises an inner drum 30 defined by an incomplete cylindrical inner sleeve 31 that is closed at one end thereof by a circular inner end plate 32; which inner drum 30 is contained within a outer drum 33, defined by an incomplete cylindrical outer sleeve 34 that is closed at the end thereof adjacent said inner end plate 32 by a circular outer end plate 35. The respective other ends of sleeves 31 and 34 are concentric and are closed by a circular cleaning head end plate 36. Inner and outer drums 30 and 33 are accordingly coaxial and are radially spaced from one another by a small gap.

Said cleaning head 5 further comprises a rotatable member 37 which is interposed in said gap between said inner and outer drums. Said rotatable member 37 comprises a hub 28, which is positioned between circular end plates 32 and 35, in axial alignment with the respective centres of these circular end plates; and a plurality of radial spokes 29 which radiate outwardly from said hub 28, each of which radial spokes is attached at the outermost point thereof to a fin assembly comprising an elongate rod 38 juxtaposed and coextensive with an elongate and substantially flat fin 39. Each fin assembly is disposed orthogonal to the respective radial spoke 29, and extends parallel to the longitudinal axis of said cylindrical drums 30, 33 within said gap interposed said inner sleeve 31 and said outer sleeve 34. The width of the flat surface of each elongate fin 39 is radially disposed in relation to said drums 30 and 33, and extends across said gap from the inner sleeve 31 to the outer sleeve 34, such that each fin 39 closes said gap widthwise.

Said hub 28 is mounted on a spindle, which extends through a central opening 42 provided in said outer end plate 35, and which is rotatably drivable by way of a hydraulic motor that is housed within a stem 44 affixed to said outer end plate 35. Said hydraulic motor is consequently adapted for driving rotation in either direction of said hub 28, radial spokes 29 and said fin assemblies 38, 39 relative to the inner drum 30 and the outer drum 33. Said hydraulic motor is controlled by way of a fin motor control (not shown) which is adapted for enabling remote control of the hydraulic motor by an operator. As seen in Figure 12, said incomplete cylindrical outer sleeve 34 defines a longitudinal aperture 45 in said outer drum 33, which aperture exposes a corresponding longitudinal portion of said inner drum 30. Meanwhile, as seen in Figure 12, said incomplete cylindrical inner sleeve 31 defines a longitudinal slot 46, which is substantially diametrically opposed to said longitudinal aperture 45.

In use, as shown in Figure 12, the cleaning head 5 is typically oriented such that the longitudinal axis thereof is horizontal, said longitudinal aperture 45 in the outer drum 33 opens vertically downwardly, and said longitudinal slot 46 in the inner drum 30 opens vertically upwardly. Typically, the longitudinal aperture is arranged to extend at an angle of around 10-30o to the horizontal, as shown in Figure 12, in order to assist collection of waste material. The longitudinal aperture 45 in the outer drum is wholly or partly immersed in a waste material 27, such as a viscous oil residue, such that the waste material enters through said aperture into contact with one or more of said fin assemblies and the inner sleeve 31, as shown in Figure 12. A pair of wheels 40 are provided on the outer surface of the outer drum adjacent said longitudinal aperture 45, the axis of rotation of the wheels 40 being disposed parallel to the longitudinal axis of said cleaning head 5. Being arranged to contact the inner wall of a cylindrical tank and support the' cleaning head thereon, the wheels 40 serve to ensure that the aperture 45 is spaced at a small distance from the inner wall of the tank, thus helping to ensure that the aperture does not become obstructed or blocked. The orientation of the supporting wheels 40 furthermore assists alignment of the axis of cleaning head 5 with the longitudinal axis of a cylindrical tank, which is important for efficient operation of the equipment, as described hereinafter.

Said spindle is driven by said hydraulic motor to rotate, thereby urging each fin assembly to revolve around said inner drum 30. The spindle may be driven to rotate in either direction; anti-clockwise rotation being shown in Figure 12. The fin assembly initially juxtaposed said aperture 45 in the outer sleeve in contact with said waste material accordingly travels forwards under said outer sleeve 34, pushing a quantity of said waste material into said gap between the outer and inner sleeves. As said fin assembly travels upwards around said inner sleeve 31, said quantity of waste material 27 is pushed upwards around said inner sleeve until it reaches the longitudinal slot 46 in the inner sleeve, whereupon said quantity of waste material 27 is caused to fall into said inner drum 30 under the force of gravity. Thereafter, said fin assembly completes its revolution around the inner sleeve 31, to become re-immersed in said waste material and thus re- start the waste material collection process.

As seen in Figure 12, the width of said aperture 45 in the outer sleeve is such that a fin assembly juxtaposed said aperture in the outer sleeve will protrude below the two longitudinal edges of said outer sleeve which define said aperture 45. Furthermore, said outer end plate 35 and said cleaning head end plate 36 are shaped such that a fin assembly juxtaposed said aperture 45 in the outer sleeve will protrude below the outer circumference of said outer end plate and said cleaning head end plate. Thus, the cleaning head 5 can be disposed relative to an inner wall of a tank such that only the outward edge of a fin 39 juxtaposed said aperture in the outer sleeve contacts the inner wall of the tank. Subsequent rotation of said hub 28 will produce a scraping movement of said and successive fins 39 against said inner wall of the tank, which will serve to loosen and dislodge waste material 27 which adheres to said inner wall, hence facilitating the removal of said waste material. Said inner drum 30 houses a sensor (not shown) which is adapted for sensing the depth of waste material in the drum. When said depth of waste material reaches a pre-determined level, the sensor automatically causes said motor to be switched off, thereby halting further collection of waste material. The sensor is also connected to an external alarm, which is arranged for alerting an operator to the fact that the depth of waste material in the inner drum has reached said pre-determined level. The operator can then cause said arm 1 to be retracted, as hereinbefore described, for the purpose of withdrawing the cleaning head 5 from the tank 62 for emptying. After withdrawal from the tank, said cleaning head end plate can be manually removed, thereby facilitating cleaning of the inside of said inner drum 30, as illustrated in Figure 13. Alternatively, said inner drum 30 may be manually rotated by an operator relative to said cleaning head end plate, such that the slot 46 is aligned with the aperture 45 for emptying said waste material out of the inner drum. Said cleaning head 5 is adapted to be releasably attached by way of a bracket 25 to said distal end 3 of the arm 1, as shown in Figure 1.

As described above, the arm 1 is mounted at the proximal end 2 thereof to one end of elongate member 4. Said elongate member 4 is meanwhile rotatably connected at the other end thereof to a stabilising member 50. The means of connection between the elongate member 4 and the stabilising member 50 are not shown in detail in the accompanying Figures. Said means of connection are however arranged to permit the elongate member to swivel through 360o relative to the stabilising member 50. Thus, said means of connection may for example comprise a sprocket and chain arrangement, with the sprocket being attached to the axial circumference of the elongate member 4, whilst the chain is associated with the stabilising member 50 and is arranged to interact with the sprocket for driving rotation of the elongate member 4 relative to the stabilising member 50. The chain is attached to a hydraulic chain-driving motor which is adapted to cause and control the movement of the chain. In some embodiments, said stabilising member 50 is arranged to rest on the ground juxtaposed said tank access hole 6, such as to stabilise said elongate member 4 and the arm 1 during deployment of the elongate member 4 and arm 1 within the tank 62. In other embodiments, not illustrated here, means are provided for locating and clamping the elongate member 4 within or against the tank access hole 6, for holding and stabilising the equipment during use.

As seen in Figures 5-7, said stabilising member 50 is attached via a jointed member 8 to a frame 47, which frame 47 can be bolted fixedly onto the back of a vehicle 26. Said jointed member 8 comprises two rigid elongate struts 48a, 48b, which struts are connected to one another at respective ends thereof by way of an elbow joint 49, such that the jointed member 8 is bendable at said elbow joint 49. In a prefeπed embodiment, illustrated in Figures 1-5, said elbow joint 49 comprises two butterfly linking members which are respectively attached to opposing sides of the struts 48, each of which butterfly linking members comprises a pair of wings 51 which are pivotably attached one to another, each of which wings 51 is pivotably attached to one of said struts 48, substantially in alignment with said strut 48. Accordingly, as the wings 51 of the butterfly linking members open and close in a scissor-like movement, the struts 48 will open and close about the elbow joint 49 in a coπesponding scissor-like movement. The butterfly linking members accordingly serve to connect the struts 48 and provide support thereto, whilst permitting relative movement of the struts about joint 49. In an alternative embodiment, illustrated in Figures 6 and 7, said butterfly linking members are replaced by a pair of fork connecting members 52, each of which fork connecting members is pivotably attached at one point thereof to one of said struts 48, and is fixedly attached at two points thereof to the other of said struts 48. Thus, the fork connecting members 52 fulfil the same function fulfilled by said butterfly linking members, namely the function of connecting struts 48 and providing support thereto, whilst permitting relative movement of the struts about joint 49.

Said elbow joint 49 further comprises two rod V-linkages which are respectively attached to opposing sides of the struts 48, each of which rod V-linkages comprises a pair of rods 53 which are pivotably attached one to another to form a "V" having an apex 54. Each rod 53 is pivotably attached to one of said struts 48.

As seen in Figures 5-7, said rod V-linkages are each aπanged such that the apex 54 of each "V" opposes the apex of said joint 49. Accordingly, said rod V-linkages are each arranged to bend in a direction opposing joint

49 during flexing of said joint.

The respective apices 54 of the two rod V-linkages are connected to one another by way of a hydraulic ram 55 mounted on strut 48a, which ram is adapted to push and pull said apices relative to said strut 48a. This will have the effect of respectively decreasing and increasing the pitch of each

"V", causing the V-bar linkages to adopt a scissor-like motion. Owing to the orientation of the V-bar linkages in opposition to joint 49, the scissor-like movement of the V-bar linkages will produce a significant impulse acting on the struts 48, causing the struts to mimic the scissor-like motion of the V-bar linkages. Thus, the action of the hydraulic ram 55 will be transmitted to the struts 48, enabling the ram 55 to drive and control flexing of the elbow joint

49.

Strut 48b is connected at the end thereof remote from said elbow joint 49 to said stabilising member 50, by way of a joint 56 which is similar to said elbow joint 49 as hereinbefore described. A hydraulic ram 57 is mounted on said strut 48b for driving and controlling the flexing of joint 56, in a manner similar to ram 55.

As shown in Figure 5, strut 48a is connected at the end thereof remote from said elbow joint 49 to a kingpost 58 which is mounted on said frame 47, by way of a joint 59. Said joint 59 comprises two rod V-linkages which are similar to the rod V-linkages of said elbow joint 49, and which are connected at opposite ends thereof to said strut 48a and to said kingpost 58 respectively. The apices of said rod V-linkages are joined to one another by way of a hydraulic ram 60 which is mounted on said strut 48a, and 5 which is arranged for pushing and pulling said apices relative to strut 48a for driving and controlling the flexing of said joint 59, in the manner hereinbefore described. Said joint 59 further comprises two pivotable linking members 61, each of which is pivotably attached to said strut 48a and to said kingpost 58 respectively, for connecting said strut 48a to said kingpost

10 58.

Each of hydraulic rams 55, 57 and 60 are arranged to be independently driven by hydraulic driving means (not shown). This enables independent flexing of said joints 49, 56 and 59 respectively, permitting flexible movement of said jointed member 8, and in particular facilitating

15 flexible deployment of the elongate member 4 and arm 1 which are attached to said jointed member 8 in three dimensions relative to the kingpost 58.

Kingpost 58 is rotatably mounted on said frame 47, so as to enable rotation of said kingpost through 180o relative to said frame 47. Said frame 47 is adapted to be fixedly but removably mounted on the back of a vehicle

20 26, as seen in Figure 1. Thus, when said frame 47 is mounted on a vehicle 26, said kingpost 58 can be oriented such that said jointed member 8 extends in a direction parallel to the vehicle, so as to access a tank positioned directly behind the vehicle; or the kingpost can be oriented such that said jointed member 8 extends at an angle to said vehicle, so as to access a tank

25 which is positioned otherwise than directly behind the vehicle. Optionally, said vehicle 26 may be fitted with stabilising legs (not shown) which can be extended from the back and/or the sides of the vehicle 26 to provide additional support to the vehicle when the tank probing equipment is extended.

30 For placing the tank cleaning equipment in the storage position on a vehicle 26, as shown in Figure 3, said kingpost 58 is oriented such that the jointed member 8 is deploy able backwards from the vehicle 26. Hydraulic rams 55, 57 and 60 are operated to cause the struts 48 to pivot relative to one another, to the kingpost 58 and to the stabilising member 50, such that the struts 48 are folded inwardly to lie substantially parallel to one another and substantially parallel to said elongate member 4. Hydraulic piston 21 is operated to cause the arm 1 to pivot relative to said elongate member 4, such that the arm 1 is substantially in line with said elongate member 4. The winch is operated to fully retract the arm 1. Optionally, the cleaning head 5 may be detached from the distal end 3 of arm 1, and placed beside said arm 1 for storage.

For use for cleaning a tank 62, said vehicle 26 is parked in front of said tank access hole 6 which is aligned with said opening 7 in the tank 62. The cleaning head 5 is attached to said distal end 3 of arm 1. Kingpost 58 is caused to pivot such that the jointed member 8 attached to the kingpost can be deployed in a straight line from the kingpost 58 to the opening of the tank access hole 6. Hydraulic rams 55, 57 and 60 are then operated to cause the jointed member 8 to move upwards and outwards from the rear of vehicle 26, as illustrated in Figure 2, until the elongate member 4 is positioned vertically above the tank access hole 6. The elongate member 4 is thereafter lowered into the tank access hole 6 by further manipulation of the jointed member 8, such that the arm 1 enters the tank 62 through opening 7, as seen in Figure 1.

Thereafter, the arm 1 can be extended and retracted by an operator, as hereinbefore described, in order that the full extent of the tank 62 is probed by the distal end 3 of arm 1 bearing said cleaning head 5. The position of the cleaning head 5 within the tank can be visualised by the images on said screen, hence enabling the operator properly to control the operation of the arm. For scraping waste material from the inner walls of the tank 62, the cleaning head 5 is aligned with each of said inner walls, such that a fin assembly juxtaposed said aperture 45 in the outer drum 33 of the cleaning head is in contact with the wall, and said hydraulic motor is operated to cause said fin assembly to rotate. Rotation of the fin assemblies within the cleaning head 5 produces a scraping movement against the inner wall of the tank, which will serve to loosen and dislodge adherent waste material.

For collecting waste material from the tank for cleaning purposes, said cleaning head 5 can be disposed by the operator such that the longitudinal axis of the head is substantially horizontal, and said aperture 45 in the outer drum 33 faces downwards and is submerged in loosened waste material 10 within the tank. Said hydraulic motor can then be operated to drive the fin end plate and said fin assemblies to rotate, thereby collecting said waste material as hereinbefore described and storing the waste material within said inner drum 30. When the level of waste material in the inner drum 30 reaches said pre-determined level, the hydraulic motor is automatically switched off by said float switch, and the operator is alerted to this fact by the sounding of said alarm outside the tank. The operator can then switch off the supply of pressurised air to said arm 1, hence enabling said arm to be retracted under the pulling action of said winch; and the elongate member 4 can be caused to move upwards and outwards through the operation of hydraulic rams 55, 57 and 60. The elongate member 4 and arm 1 can thus be withdrawn from the tank access hole 6, enabling the operator to manipulate the cleaning head as hereinbefore described for emptying said waste material from the inner drum. Thereafter, the arm can be reinserted into the tank for continuing the cleaning operation.

Typically, the equipment of the invention is adapted for cleaning waste oil residue out of tanks, such as petroleum tanks which may be up to 12m in length and 3m in depth. In the highly inflammable environment of an oil tank, it is clearly important that heat levels and the probability of raising a spark be kept to a minimum, and for this reason, the components of the equipment which are to be inserted into the tank, including the components of the arm and cleaning head, are typically made of a light and non-abrasive material, such as carbon fibre or fibreglass or another composite material. The fins, which must be capable of withstanding immersion in potentially coπosive material, and scraping movement against the potentially rough and uneven surface of a tank, are typically made of a hard and resilient material, such as hardened rubber. Typically, the cleaning head may have a length of approximately 0.6m and a diameter of approximately 0.4m, with a resulting volume of about 0.072m3. For convenience, controls for remotely controlling the operation of the tank probing equipment, including the pressurised air switch and winch lever which drive extension retraction of said arm 1; said hydraulic piston 21 which drives pivotal movement of said arm 1; the hydraulic chain-driving motor which drives longitudinal rotation of the elongate member 4 and arm 1; said fin motor in the cleaning head 5 which drives revolution of the fin assemblies relative to the inner and outer drums; and hydraulic rams 55, 57 and 60 which drive the deployment of said jointed member 8; are conveniently located outside the tank in a main control centre within the vehicle 26, as shown in Figure 15, and in a subsidiary control centre (not shown) which is located juxtaposed said tank access hole 6. Said screen for enabling visualisation of the distal end 3 of said arm within the tank, and the alarm for alerting an operator when the depth of waste material stored within said cleaning head 5 has reached a pre-determined level, and the display unit for communicating to the operator the degree of extension of arm 1, are typically located in or near said main control centre. This will enable convenient co-ordination of the operation of the cleaning equipment from the main control centre by an operator, who will be able to observe the results of this operation within the tank by way of the images thereof transmitted to the screen. The subsidiary control centre is used primarily for controlling the deployment and positioning of the jointed member 8, and the entry of the elongate member 4 and arm 1 into the tank 62, operations for which a direct line of sight by the operator is advantageous.

The tank cleaning equipment may optionally further include a computer (not shown) which is adapted to enable the equipment to function automatically without the need for control by a human operator. For this purpose, sensors (not shown) are provided on the arm 1 which are adapted to scan the tank 62 for its dimension, shape and physical condition, and transmit data to the computer which enable the creation and storage by the computer of a 3D image of the interior of the tank. The computer can be programmed for a particular operation, such as a visual inspection, sludge removal, or spraying and suction cleaning. The programmed computer will then utilise the 3D image of the tank interior to direct the operation of the tank cleaning equipment within the tank, by controlling the extension and retraction of the arm, pivotal movement and rotation of the arm, and the operation of the cleaning head.

Although the equipment described herein is adapted to serve the purpose of cleaning a tank, it is also envisaged that the cleaning head 5 may be replaceable by a variety of different functional heads, such as a head incorporating a device for monitoring conditions such as temperature within the tank, a cutting means for cutting material within the tank, or a head incorporating means for transporting material into the tank, such as a protective material to be sprayed onto the inner walls of the tank.

Claims

1 Tank probing equipment, comprising mounting means which is adapted to be positioned at an opening in a tank; a longitudinally extendable elongate arm having opposing proximal and distal ends, which is attached at the proximal end to said mounting means such that the arm can be entered into the tank through said opening and can be extended and retracted relative to the proximal end within the tank; said mounting means and the arm being aπanged such that the arm can be swung in at least one dimension within the tank; a work-head which is adapted to be attached to said distal end of the arm; drive means for selectively driving longitudinal extension and retraction and swinging movement of said arm; and control means for controlling said drive means, which control means is adapted to be positioned outside the tank, such that the location of said distal end of the arm inside the tank can be remotely adjusted from outside the tank.

2 Tank probing equipment as claimed in claim 1, wherein said arm is pivotably mounted by the proximal end thereof on said mounting means, such as to enable said arm to be swung within the tank by said proximal end.

3 Tank probing equipment as claimed in claim 1 or claim 2, wherein said arm is arranged to swing within the tank in at least two mutually orthogonal dimensions.

4 Tank probing equipment as claimed in claim 1 or claim 2, wherein said arm is arranged to swing within the tank in only one dimension, and is aπanged to be rotatable about the longitudinal axis thereof, such as to enable the direction of swinging movement of the arm within the tank to be varied. 5 Tank probing equipment as claimed in any preceding claim, wherein said mounting means comprises a socket, and said arm is adapted to be inserted into and retained within said socket.

6 Tank probing equipment as claimed in any preceding claim, wherein said drive means comprises a first drive means for driving longitudinal extension/retraction of said arm and a second drive means for driving swinging movement and/or rotation of the arm.

7 Tank probing equipment as claimed in claim 6, wherein said first drive means comprises extension drive means for driving extension of said arm, and retraction drive means for driving retraction of said arm, which extension drive means and retraction drive means are adapted to be operated simultaneously in opposition to one another, such as to enable the length of said arm to be precisely controlled.

8 Tank probing equipment as claimed in claim 7, wherein said extension drive means comprises means for supplying a flow of pressurised fluid to said longitudinal segments, whereby said segments are urged to telescope longitudinally outwardly such as to extend said arm.

9 Tank probing equipment as claimed in claim 7 or claim 8, wherein said retraction drive means comprises an elongate connecting means such as a chain, wire, tape, cable or retractable rod attached to the outermost (most distal) segment of said extendable arm, which connecting means extends along the length of said extendable arm towards the proximal end thereof, which connecting means is aπanged to be selectively withdrawn towards said proximal end of the extendable arm such as to cause said segments to telescope longitudinally inwardly, thereby retracting said extendable arm. 10 Tank probing equipment as claimed in any of claims 7-9, wherein said extension drive means is aπanged to be automatically or manually switched off where the arm is to be completely retracted, in order to permit unopposed retraction of the arm by said retracting means.

11 Tank probing equipment as claimed in any of claims 6-10, wherein said second drive means comprises hydraulic, pneumatic, electromagnetic, and/or mechanical drive means.

12 Tank probing equipment as claimed in claim 11, wherein said second drive means comprises a ram, such as a hydraulically operated ram, which ram is mounted on the mounting means and is aπanged to interact with said arm or respectively pushing and/or pulling said arm so as to cause pivotal movement thereof in one dimension. '

13 Tank probing equipment as claimed in any preceding claim, wherein said extendable arm comprises a series of longitudinal segments which are slidably interconnected with one another such that the segments can "telescope" with respect to one another for respectively retracting or extending said arm.

14 Tank probing equipment as claimed in any preceding claim, wherein said arm further comprises a sensor, such as an electronic sensor, which is adapted to monitor the movement of said connecting means relative to said withdrawing means, thereby to monitor the degree of extension of said extendable arm.

15 Tank probing equipment as claimed in any preceding claim, wherein said arm further comprises a camera positioned for recording images of the distal end of said arm, which camera is adapted to transmit said images to a screen for viewing by an operator, and/or to store said images for visualisation and inspection at a later stage.

16 Tank probing equipment as claimed in any preceding claim, wherein said distal end of the arm comprises or is adapted to be attached to a cleaning head for collecting material from the interior of said tank and storing said material for removal from said tank.

17 Tank probing equipment as claimed in claim 16, wherein said cleaning head comprises a container having an aperture therein and a collecting means adapted for scooping up material, transporting said material to said aperture, and causing or allowing said material to enter into said container through said aperture for storage therein.

18 Tank probing equipment as claimed in claim 17, wherein said collecting means comprises a rotatable member that comprises scooping means for scooping up material, which rotatable member is adapted to rotate relative to said container such that said scooping means revolves about the outer surface of said container.

19 Tank probing equipment as claimed in claim 18, wherein said scooping means comprises one or more elongate and substantially flat fins or brushes, each of which fins or brushes is fixedly attached to said rotatable member and is disposed such that the rotation of said rotatable member relative to said container produces a brushing or sweeping movement of said fins or brushes around said container.

20 Tank probing equipment as claimed in claim 19, wherein said rotatable member comprises a plate which is adapted to be mounted adjacent one end of said container and is adapted to rotate relative thereto; and each of said elongate fins or brushes is attached at one longitudinal end thereof to said plate, such as to extend perpendicular to the surface of said plate.

21 Tank probing equipment as claimed in claim 19 or claim 20, wherein 5 said cleaning head further comprises an outer cover which is arranged circumferentially around said fins or brushes so as to encircle said fins or brushes, which outer cover comprises an opening on one side thereof, through which opening each fin or brush can be successively outwardly exposed for brushing and scooping up said material. 10

22 Tank probing equipment as claimed in any of claims 16-21, wherein said cleaning head comprises supporting means for supporting the cleaning head against and spaced from a wall of the tank.

15 23 Tank probing equipment as claimed in claim 22, wherein said supporting means comprises a pair of wheels which are arranged such that the axis of rotation of each wheel is parallel to the longitudinal axis of said container, so as to assist the alignment of said longitudinal axis of the container with the longitudinal axis of a cylindrical tank.

20

24 Tank probing equipment as claimed in any of claims 16-23, wherein said cleaning head comprises a sensor for sensing the quantity of material within said cleaning head.

25 25 Tank probing equipment as claimed in any preceding claim, wherein said mounting means comprises an elongate moiety which is adapted to be attached to said arm, which elongate moiety is arranged to be entered or partly entered into said opening in a tank.

30 26 Tank probing means as claimed in any preceding claim, wherein said mounting means comprises a deployment means adapted for attachment to said arm, which deployment means is adapted for locating said arm at said opening of a tank and for entering said arm into the tank, which deployment means is adapted to be mounted on a vehicle, for enabling easy transport of 5 the tank probing equipment.

27 Tank probing equipment as claimed in claim 26, wherein said deployment means comprises a jointed member.

10 28 Tank probing equipment as claimed in any preceding claim, further comprising a stabilising means for stabilising said mounting means against the ground or against the walls of a tank access hole in the ground providing access to an opening in a tank.

15 29 Tank probing equipment as claimed in any preceding claim, wherein said control means includes one or more control centres which can be occupied by an operator, each of which control centres comprises means for controlling movement of different parts of said equipment, such as to allow convenient and co-ordinated control of the whole of the operation of said

20 equipment by one operator remaining in one place.

30 A kit of parts which is adapted to be assembled into equipment in accordance with any preceding claim.

25 31 A cleaning head for tank probing equipment as claimed in any of claims 16-24.