GB2502167A

GB2502167A - Chassis mounted vortex generator for attraction towards surfaces

Info

Publication number: GB2502167A
Application number: GB1221490.4A
Authority: GB
Inventors: Gary Sewell; Richard Smith
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-02-08
Filing date: 2012-11-29
Publication date: 2013-11-20
Anticipated expiration: 2032-11-29
Also published as: GB2502250A; GB201202140D0; GB2502167B

Abstract

A vortex generator 1 comprises a chassis or supporting structure, a source of power, a driving motor and an impeller 2 rotating in a hollow, right cylinder 5. The cylinder 5 has a flat closed face, a cylindrical housing and an open face. A vortex is generated in the cylinder having a reduced pressure at its core, so that a force is created attracting the apparatus towards a surface placed adjacent to the open face of the cylinder. The impeller 2 has blades each with a radial leading edge (9 see fig 2) and a trailing edge (10 see fig 2) which lies along a chord of the circle swept by the blade. A flexible skirt 6 is typically provided. The vortex generator 1 is usable in a vehicle so that it can move and/or park on horizontal, sloping, vertical or inverted surfaces and undertake operations there, as so directed by remote means.

Description

VORTEX GENERATOR AND APPLICATIONS THEREOF

This specification relates to devices which can interact with an abufting surface so that the device can retain adhesion with the surface, whether that surface be horizontal, angled to the horizontal or overhead. The devices may have their own motive power or be placed in a particular position.

When an item of equipment or a vehicle is placed on a flat, level surface, it will remain in that place or be able to move if provided with its own motive power. Similarly, this also applies on a gently sloping surface. However as the angle of the slope increases, the coefficient of friction becomes critical and, over a certain angle, the item or vehicle will slide downwards as the acceleration due to gravity acting on the item or vehicle exceeds the frictional force resisting motion. At this, and greater angles, the item may be secured to the surface by an adhesive, by mechanical means or, if the surface was ferro-metallic, by magnetic means. While this is effective for items which are intended to remain static, it is not usually viable for items which have to be moved, or are mobile under their own motive power and certainly not for non-ferro-magnetic surfaces.

Suction cups can be used on smooth, flat surfaces, such as glass, and experienced climbers can scale vertical walls of ice using a pair of ice axes and boots with toe spikes but these principles do not have general industrial application and may damage the surface of the wall or ceiling.

There are many instances where access is required, say, to walls, ceilings, etc. where detailed inspection of the surfaces, monitoring the environment or to undertake a piece of work, is required and access is not readily available, e.g. because the wall I ceiling is part of a confined space where noxious gases might be present. Also, when relatively simple tasks have to be performed in relatively inaccessible locations, it would often be much easier and cheaper to be able to use a simple robotic device than to have to erect scaffolding or get in a cherry picker. Other instances of difficult access are the underwater inspection of ships' hulls, offshore oil I gas rigs and related equipment, e.g. inside tanks, etc. Modern robotic techniques are now so advanced that unmanned ground, hill climbing and aerial vehicles are practical realities and some of the applications that modern robotic devices can undertake, either on these vehicles or in space, would have been Unthinkable only a few years ago. Vertical wall-climbing vehicles would add to these capabilities.

Robotic means able to adhere to, or to move over, steep slopes, vertical walls or inverted surfaces are known (e.g. EP 0 787 646 A2, EP 1 676 613 A and GB 2295799 A) but all employ partial vacuum means whereby air is drawn from near the adjacent surface or extracted from a chamber, the open side of which is adjacent to the surface. To create a s partial vacuum, particularly a high vacuum, requires a great deal of energy as a high speed fan is necessary to generate and maintain the pressure difference (AP) across the fan blades. This level of power can be provided via an umbilical cable for an extended period of time but to supply it with a battery greatly limits the robot's operational time.

Furthermore, whirring blades are noisy, which limits the applicability of such means, e.g. for covert, surveillance activities.

The use of a vehicle which can attract itself to a surface will increase the tractive effort available to move the vehicle or help it remain in a given place. In recent years there has been a steady increase in the usage of unmanned aerial vehicles, unmanned ground vehicles, unmanned wall climbing vehicles and unmanned underwater vehicles to perform inspection and / or maintenance missions in order to keep their human operators at a safe distance from harsh or dangerous environments. Means to attract, and hold, the vehicle against the surface would be highly beneficial, e.g. to hold, say, an aerial vehicle firmly onto the deck of a heaving ship. Similarly, such means would allow an aerial vehicle to land on a roof and rest until needed again.

Thus, there is an urgent need for devices able to adhere to or to climb steep slopes and vertical surfaces and be able to undertake industrial operations, with minimal power requirements, in these inaccessible locations. Ideally, the devices will also be operable on inverted surfaces, i.e. ceilings.

According to a first embodiment of the invention, apparatus is provided for generating a vortex having a reduced pressure at its core, comprising:-i) a chassis or supporting structure or a means to secure fAe apparatus to a supporting structure; ii) a source of power; iii) a driving motor; and iv) a vortex generator, having the general form of a hollow, right cylinder, the cylinder having a flat closed face, an essentially cylindrical housing and an open face and having an impeller rotatable on the axis of the right cylindrical housing with the drive shaft passing through said flat closed face via a seal so that a fluid may not pass from one side of the flat closed face to the other; characterised in that the vortex generator is mounted in the chassis / structure so that its open face is essentially parallel and close to, but not touching an essentially planar surface and that when the drive motor is activated, the impeller is caused to rotate generating a -vortex within the hollow cylinder so that a force is generated attracting the apparatus of the invention towards the surface.

According to a first variation of the first embodiment of the apparatus of the invention, the impeller has a plurality of blades.

According to a second variation of the first embodiment of the apparatus of the invention1 a vortex is created in the space between each pair of adjacent blades of the impeller.

According to a third variation of the first embodiment of the apparatus of the invention, the leading edge of each of the impeller blades lies along a radius of the impeller axis.

According toa fourth variation of the first embodiment of the apparatus of the invention, the trailing edge of each of the impeller blades lies along a chord of the circle swept by the impeller blades.

According to a fifth variation of the first embodiment of the apparatus of the invention, the * leading and trailing faces of each of the impeller blades are flat surfaces lying in a plane normal to the plane of rotation of the impeller.

According to a sixth variation of the first embodiment of the apparatus ofthe invention; the clearance between the tips of the impeller blades and the cylindrical housing lies between 0.05-0.150, where D is the internal diameter of the cylindrical housing.

According to a second embodiment of the invention, apparatus for accessing horizontal, sloping, vertical and / or inverted surfaces and capable of undertaking operations there is provided, comprising:..

i) a chassis, or supporting structure, having a means of motive power; ii) a source of power; iii) a driving motor: and iv) a vortex generator, having the general form of a hollow, right cylinder, the cylinder having a flat closed face, an essentially cylindrical housing and an open face and having an impeller rotatable on th! axis of the right cylindrical housing with the drive shaft passing through said flat closed face via a seal so that a fluid may not pass from one side of the flat closed face to the other; characterised in that the vortex generator is mounted in the chassis / structure so that its open face is essentially parallel and close to, but not touching an essentially planar surface and that when the drive motor is activated, the impeller is caused to rotate creating a s vortex, having a reduced pressure at its core, within the hollow cylinder so that a force is generated attracting the apparatus of the invention towards the horizontal, sloping, vertical or inverted surface on which the apparatus of the invention is located and further characteriseci in that the apparatus is able to move over the horizontal sloping, vertical or inverted surface on which the apparatus is located and undertake operations there.

According to a first variation of the second embodiment of the apparatus of the invention, the means of providing motive power includes wheels.

According to a second variation of the second embodiment of the apparatus of the is invention, the means of providing motive power includes tracked members.

According to a third variation of the second embodiment of the apparatus of the.inventiori the means of providing motive power includes steerable means.

According to a fourth variation of the second embodiment of the apparatus of the invention, the source of power is either electrical, hydrocarbon or pneumatic.

According to a fifth variation of the second embodiment of the apparatus of the invention, the electrical power is either from an on-board battery or supplied by a cable from an external source.

According to a sixth variation of the second embodiment of the apparatus of the invention, the motive power is sufficient to move the apparatus of the invention over the surface, despite the vortical attraction towards that surface.

According to a seventh variation of the second embodiment of the apparatus of the invention, the chassis and other components of the apparatus of the invention are constructed of strong, light materials.

According to an eighth variation of the second embodiment of the apparatus of the invention, the strong, light materials include metallic alloys and / or glass and / or carbon fibre.einforced plastics.

S

According to a ninth variation of the second embodiment of the apparatus of the invention1 the means to undertake operations from a position on the sloping1 vertical or inverted surface includes apparatus for monitoring of the environment.

According to a tenth variation of the second embodiment of the apparatus of the invention, the monitoring of the environment includes using apparatus for sending visual images for viewing at a remote location.

According to an eleventh variation of the second embodiment of the apparatus of the invention, the monitoring of the environment includes the use of apparatus to detect particular gases or radiations.

According to a twelfth variation of the second embodiment of the apparatus of the invention the means to undertake operations from a position on the horizontal, sloping, vertical or inverted surface includes apparatus for the maintenance of items, and / or replacement of items, in the environment and the tools required for the work and visual means to be able to use those tools and means to control the use of the tools.

According to a thirteenth variation of the second embodiment of the apparatus of the invention the means to undertake operations from a position on the horizontal sloping, vertical or inverted surface includes apparatus for performing work in the environment According to a fourteenth variation of the second embodiment of the apparatus of the invention, the means to undertake operations from a position on the horizontal, sloping, vertical or inverted surface includes installing items of equipment in the environment.

According to a fifteenth variation of the second embodiment of the apparatus of the invention, an articulated arm is provided with gripping means at the distal end for holding and using tools.

According to a sixteenth variation of the second embodiment of the apparatus of the invention, a location is provided for holding tools and / or equipment for use by the articulated arm.

According to a seventeenth variation of the second embodiment of the apparatus of the invention, the tools and equipment for use by the articulated arm include a powered drill, a drill bit and the means to use them.

According to an eighteenth variation of the second embodiment of the apparatus of the invention, a camera or viewing means is provided able to transmit images for viewing at a remote location.

According to a nineteenth variation of the second embodiment of the apparatus of the invention, instructions are sent from the remote location to components of the apparatus of the invention to cause them to drive and / or steer the apparatus and I or to undertake monitoring of the environment and / or maintenance or replacement of items in the environment and I or to perform work in the environment and I or to use such tools or other equipment available to the apparatus of the invention as may be required to complete any or all of the above tasks or accomplish any other tasks within the capabilities of the apparatus of the invention According to a twentieth variation of the second embodiment of the apparatus of the invention, two, or more, itemS of the apparatus of the invention are connected together nominally at right angles so that the combined apparatus' of the invention can move from a floor to a wall and I or from a wall to a ceiling and! or vice versa.

According to a twenty first variation of the second embodiment of the apparatus of the invention, the connection between the two apparatus' of the invention includes a rotational element for accessing two planar surfaces which are not mutually aligned at right angles to each other.

According to a twenty second variation of the second embodiment of the apparatus of the invention, two, or more, items of the apparatus of the invention are connected together either end-to end or side-by-side or end-to-end and side-by-side to provide a larger operating platform, more securely attracted to the surface.

According to a twenty third variation of the second embodiment of the apparatus of the invention, the connection between two items of the apparatus of the invention includes means to lift one of the units over, or around, a discontinuity in Ion the surface being traversed or past a discontinuity between otherwise planar surfaces.

According to a twenty fourth variation of the second embodiment of the apparatus of the invention, the area of the chassis is increased so that a plurality of vortex generators is

mountable therein.

According to a twenty fifth variation of the second embodiment of the apparatus of the invention, the means of steering the apparatus of the invention includes turning it through angles, including 180°.

According to a twenty sixth variation of the second embodiment of the apparatus of the invention, means is provided to move the power cable to the apparatus of the invention to stop it getting entangled with the articulated arm.

According to a twenty seventh variation of the second embodiment of the apparatus of the invention, one, or more, apparatus' of the invention are operated in conjunction with, or as part of, other robotic systems to form composite units for specific operations.

According to the first embodiment of the invention, a method of generating a vortex having a reduced pressure at its core is provided, comprising the steps of:-is i) providing a chassis or supporting structure or means to secure the apparatus to a supporting structure; ii) providing a source of power; iii) providing a driving motor; and iv) providing a vortex generator, having the general form of a hollow, right cylinder, the cylinder having a flat closed face, an essentially cylindrical housing and an open face and having an impeller rotatable on the axis of the right cylindrical housing with the drive shaft passing through said flat closed face via a seal so that a fluid may not pass from one side of the flat closed face to the other; characterised in that the vortex generator is mounted in the chassis I structure so that its open face is essentially parallel and close to, but not touching an essentially planar surface and that when the drive motor is activated, the impeller is caused to rotate generating a vortex within the hollow cylinder so that a force is generated attracting the apparatus of the invention towards the surface. I. H

According to the second embodiment of the invention, a method of accessing horizontal, sloping, vertical and I or inverted surfaces and having the capability of undertaking operations there is provided, comprising the steps of:-I) providing a chassis, or supporting structure, having a means of motive power; S ii) providing a source of power; iii) providing a driving motor; iv) providing a vortex generator, having the general form of a hollow, right cylinder, the cylinder having a flat closed face, an essentially cylindrical housing and an open face and having an impeller rotatable on the axis of the right cylindrical housing with the drive shaft passing through said flat closed face via a seal so that a fluid may not pass from one side of the flat closed face to the other; v) providing a means of accessing the horizontal, sloping, vertical or inverted surfaces; and vi) providing means of undertaking operations there; characterised in that the vortex generator is mounted in the chassis / structure so that its open face is essentially parallel and close to, but not touching, an essentially planar surface and that when the drive motor is activated, the impeller is caused to rotate creating a vortex, having a reduced pressure at its core, within the hollow cylinder so that a force is generated attracting the apparatus of the invention towards the horizontal, sloping, vertical or inverted surface on which the apparatus of the invention is located and the means of accessing is used to reach a particular location on the horizontal, sloping; vertical and I or inverted surface and the means to undertake operations used at the said location.

According to a first variation of the second embodiment of the method of the invention, the apparatus of the invention is used to climb I descend slopes or walls to predetermined positions from where predetermined operations can be carried out. -According to a second variation of the second embodiment of the method of the invention, the apparatus of the invention is used to descend / climb slopes or walls to predetermined positions from where predetermined operations have been carried out.

According to a third variation of the second embodiment of the method of the invention, the means of accessing the horizontal, sloping, vertical or inverted surfaces are provided with a steering capability.

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According to a fourth variation of the second embodiment of the method of the invention, the means to undertake operations at the said location includes using means to image the location and items at the location and to transmit the images to a remote location from where operational instructions are sent to the apparatus of the invention.

S

According to a fifth variation of the second embodiment of the method of the invention, the means to undertake operations at the said location includes using articulated means able to undertake the required operations.

According to a sixth variation of the second embodiment of the method of the invention, two items of the apparatus of the invention are connected together nominally at right angles to each other so that the combined apparatus' of the invention can be used to enter a chamber, move along the floor to a wall, transfer to and climb the wall and, if required, turn through 1800 and climb to and transfer to the ceiling and move alOng the ceiling to its predetermined operational point, undertake an operation at that point and, when the operation is complete, return by thesame, similar or a different route to its starting point or to another required destination.

According to a seventh variation of the second embodiment of the method of the invention, the chassis/ supporting structure is of a size to accommodate a plurality of vortex generators, either end-to-end or side-by-side or both end-to-end and side-by-side.

According to an eighth variation of the second embodiment of the method of the invention, a means to move the power cable is provided and used to stop the cable from yelling entangled with any articulated arm(s) or other components on either apparatus when the combined apparatus of the invention is turning [turned through 1800 or otherwise manoeuvred.

According to a ninth variation of the second embodiment of the method of the invention, the respective means to move the power cable and to move the articulated arm are used together to avoid entangling the power cable or to disentangle the power cable should it have become entangled during the turning of the combined apparatus of the invention through 180° or during other manoeuvres.

According to a tenth variation of the second embodiment of the method of the invention, the connection between two items of the apparatus of the invention is used to lift one of the units over, or around, a discontinuity mi on the surface being traversed or past a discontinuity between otherwise planar surfaces.

In a preferred application of the principle of the invention, the vortex chamber is a right cylinder, with the diameter many times greater than the depth. One face is closed by a flat plate, which extends beyond the limits of the cylinder to provide means to mount the vortex generator in other apparatus. The other face is open. A motor, mounted on the plate but outside the cylinder, drives an impeller mounted axially in the cylinder. The impeller has flat leading and trailing edges so that its rotation does not generate any pumping action but merely spins the fluid round in the cylinder. This action generates a vortex between each pair of adjacent blades. Vortices, like natural tornados, have an annulus of rapidly spinning air and a core of reduced pressure. The effect of the plurality of low pressure cores is to draw a flat surface towards the open face of the vortex generator, or conversely, to hold the vortex generator against a flat surface, whether that surface be horizontal, angled to the horizontal, vertical or inverted. Vortices can be generated in any fluid, i.e. gas or liquid.

This principle is used practically by mounting a vortex generator in a mobile vehicle and a tracked vehicle is preferred. The vortex generator is aligned parallel to and adjacent to, but not in contact with, the surface on which the vehicle is located and that surface may be horizontal, angled to the horizontal, vertical or inverted. As the vortex generator is close to, but not in contact with, the surface, the vehicle can move over the surface, e.g. climb a wall, to undertake an operation high on the wall, out of reach of normal access. The principle of the invention is adaptable to a wide range of applications, including transferring from a vertical wall to a ceiling. Power for the motor may be from an on-board source or provided externally via an umbilical cable or tube.

For a clearer understanding of the invention and to show how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings in which:-Figure 1 is a perspective view of a vortex generator according to the invention; Figure 2 is a plan view of the open face of the vortex generator shown in Fig. 1; Figure 3 is a plan view of the open face of the vortex generator shown in Fig. 1 indicating a possible air flow pattern within the vortex generator; Figure 4 is a perspective view of the vortex generator of the invention filled to a tracked vehicle; Figure 5 is a plan view of the open face of the vortex generator shown in Figs. 1-3 fitted with a protective mesh; Figure 6 is a side elevation of the apparatus shown in Fig. 4 climbing a vertical surface; Figure 7 is a side elevation of the apparatus shown in Fig. 4 carrying a load via an S articulated arm; Figure 8 is a side elevation of the apparatus shown in Fig. 4 perching against an underwater surface and connected to an underwater Remotely Operated Vehicle (ROV); Figure 9 is a side elevation of two items of the apparatus shown in Fig. 4 deployed from a vertical take-off and landing aerial vehicle perching on a sloping surface; Figure 10 is a side elevation of two of the apparatus' shown in Fig. 4 connected together moving along a floor, up a wall and onto a ceiling; Figure 11 is a side elevation of an apparatus of the invention perching against a vertical surface and drilling a hole therein; Figure 12 is a side elevation of an apparatus of the invention perching against a vertical wall and provided with a multifunctional handling and gripping means; and Figure 13 is a side elevation of two apparatus' of the invention perching against a vertical surface and connected together by a multifunctional member 43 able to lift one of the apparatus' off the surface relative to the other apparatus, and manoeuvre it as required so that the combined apparatus' may move over, around or past an obstacle.

In the following description the same reference numeral is used for identical components in different Figures or for different components fulfilling an identical function Referring to Figs. 1, 2 and 3, a vortex generator 1 consists of impeller 2, provided with multiple blades 3, driven by motor 4, mounted on plate 7, and rotating within an essentially right cylindrical housing 5. As shown in Fig. I the upper face of vortex generator 1 is flat, fast with housing 5, closed and formed by part of plate 7, which is extended, as shown, and provided with holes 8 to allow it to be secured to other components. The lower face of vortex generator I (Fig. 1) is open and housing 5 may be extended downwards by means of a flexible skirt 6, or simply by extending housing 5 away from plate 7 beyond the plane swept by impeller 2. To minimise air resistance, housing 5 should have as smooth a surface as possible, e.g. be made of an engineering grade plastic. z

Fig. 2 shows a plan view of impeller 2 in its housing 5 looking inwards through the open, lower face of housing 5. A four bladed impeller 2 is shown for illustrative purposes only.

Drive shaft 2A passes through plate 7 via a seal (not shown) so that air! gas I water cannot pass through from the inside of vortex generator 17. Impeller 2 is of unusual shape as it is not designed to be a pump, moving fluid from one of its sides to the other. Each blade consists of a leading edge (side) 9, which is a flat face (see Fig. 1) with its plane normal to the plane of rotation 11 of impeller 2. Trailing edge 10 is another planar face normal to the plane of rotation 11 of impeller 2, or it may be faired symmetrically about the mid-line of the plane of rotation of impeller 2, so that it does not generate any pumping action. As shown, blades 3 taper and have rounded or flat tips 12 and there is a large clearance 13 between tips 12 and housing 5. Impellers 2 rotate 11 in cylindrical housing 5.

Fig. 3 shows a possible air (or gas or liquid) flow pattern within housing. As impeller 2 turns 11, the air in each of the quadrants, between two adjacent blades will be subject to is the following forces:-i) a positive pressure from the leading edge 9; ii) a negative pressure from the trailing edge 10 (Form drag); and iii) drag near the circumference from contact with the boundary layer 15 adjacent to housing 5.

The combination of these forces is likely to generate a clockAse, spinning vortex 14, as shown (Fig. 3). It is a known fact that spinning vortices generate a reduced pressure in the central, core or axial zone-As shown, there are as many vortices 14 as blades on the impeller so that an essentially balanced reduced pressure is generated over the whole area of the vortex generator 1. The exact pattern of the air flow in chamber 17 is not known but Fig. 3 shows one possibility. As impeller 2 turns 11, vortices 14 will orbit axis 2A and continuously exchange air with the annular, circumferential zone, i.e. between boundary layer 15 and vortices 14. Adjacent to housing Swill be a very thin boundary layer 15; this may be only a few molecules thick and may exhibit laminar flow but it will have a drag effect on the highly-turbulent mass of rotating air in vortex chamber 17. As shown (Fig. 3), the air in the annulus near housing 5 wit! be dragged round 15 by impeller 2 but may be rotated locally 16 by the interaction with a vortex 14, possibly giving a hypocycloid-type of flow pattern 16. As shown, the hypocycloidal flow could create a number of mini-vortices 16A, which should add to the effect generated by the main vortices 14.

A key factor in the efficiency of the invention is the clearance 13 between blade tips 12 and housing 5. When this was reduced, e.g. to the sort of clearance normal for a vacuum pump, the force attracting vortex generator ito a surface 23 decreased greatly (by up to 20%). This attractive force was maximised when clearance 13 was between O.05-0.i5D, S where D (Fig. 2)is the.internal diameter of housing 5. This is strong evidence that vortices 16A are generated and contribute significantly to the net force attracting vortex generator 1 to a surface 23.

Thus, as impeller 2 turnsll, a plurality of vortices 14 is generated, as well as probably a lb plurality of mini-vortices i6A, which will form a fixed pattern rotating 11 with impeller 2 in a form of standing wave'. So, the effect of the vortices 14 (and probably 1 6A) is to generate zones of a substantial negative pressure in chamber 17, which will attract vortex generator 1 towards any surface placed adjacent to the open face of chamber 17. The force holding vortex generator against an adjacent surface is the pressure difference (AR) between ambient air (or water) pressure acting on the top of surface 7 (Fig. 1) over the area of cylinder 17 and the reduced pressure generated by the vortices 14 (and probably 16A) inside cylinder 17.

Fig. 4 shows a vortex generator I incorporated into a tracked vehicle 18. Cross members 19 are bolted fast 20, via holes 8, with plate 7 to make a chassis 7 to which wheels 22 and tracks 21 are attached. Normally, each track 21 would have one driven wheel 22 and one idler 22 but two driven wheels 22 may be used if greater tractive effort is required. Vehicle 18 would have an appropriate power supply (e.g. an on-board battery or remotely via an umbilical 37 (Fig. 10)) and control systems, which are not shown to avoid confusing detail.

Fig. 6 shows vehicle 18 climbing a vertical wall 23. As shown the dimensions of tracks 21 and wheels 22 and their location relative to chassis 7 gives a clearance 25 between housing 5 and surface 23. Clearance 25 is an important aspect of the invention. Natural vortices, e.g. tornados, extend beyond the actual, rotationally driving mass of air which originally created them and a similar thing happens here. But, because the vortex here is small in diameter, clearance 25 must be kept small too. Vortices 14 (and possibly 16A too) extend beyond the volumetric cylindrical disc 17 swept by blades 3, away from plate 7 down to surface 23 and exert the low pressure, suctional attraction, which holds vehicle 18 against wall 23. As the partial vacuum in vortices 14 is maintained by a rapidly rotating 33 tube of air, it is not disrupted by a short clearance distance 25.

It should be noted that other types of prior art, wall-climbing vehicles which have conventional suction fans or Pumps, essentially require some form of seal between housing and surface 23 to minimise the inflow of air (or water) into the partially evacuated chamber as ingress of air (water) reduces the partial vacuum and hence the net force holding the vehicle against the wall. The presence of clearance 25 allows vehicle 18 to pass over irregularities on surface 23, e.g. bolt or rivet heads, etc., without losing adhesion.

By using the vortex principle, vehicle 16 could ascend a porous surface, which the prior art vehicles might not be able to manage, If surface 23 has loose material on it, e.g. flaking paint, a protective mesh 24 (Fig. 5) may be provided to prevent ingestion into chamber iT Another significant point of difference between the invention and the prior art wall climbers is that the prior art devices create a partial vacuum; this is a process requiring a great deal of energy -higher vacuums require Proportionately much more energy input. In contrast, in the invention, air is just rotated rapidly and vortices form naturally, generating their own partial vacuums Thus, there is no actual pumping so low energy usage gives the apparatus of the invention a significant operational advantage over prior art devices, e.g. an operational duration of up to three hours with current battery technology Vehicle 18 and vortex generator i may be powered by on-board means, e.g. a battery or an internal combustion engine of by external means, e.g. via an umbilical connection using electrical or pneumatic power. Clearly for wall climbing activities and the need to be able to undertake operations on the wall, overall weight will be a key factor. Thus, the weight of vehicle 18 must be minimised, dictating the use of strong light materials of construction, such as high strength alloys engineering plastics and glass, or carbon, fibre composites.

The apparatus of the invention has been tested with a number of different impellers 2 and in a range of different housings with different clearances. In a preferred embodiment of the invention, viable relative dimensions were found to be:-For a housing of internal diameter D (Fig. 2): Impeller diameter was between 0.85-0.950, tip clearance (13) between 0.15-0.050 and blade face depth between O.06-0,ioD Clearance between blades 3 and plate 7 was between o.oi -0.04D and clearance 25 between housing 5 and surface 23 was O.03-0.O9D, In the preferred embodiment, the design of impeller 2 has the reading edges 9 of blades 3 lying along radii of impeller 2 and the trailing edges 10 lying along chords of the circle swept by blades 3. Impellers 2 with three, four or five blades performed best. In the Figures, anticlockwise rotation 11 of impeller 2 is shown; the direction of rotation is not critical and clockwise rotation is equally viable provided impeller 2 is fitted with the leading and trailing edges and clearances, as taught. Rotational speeds of up to 40k r.p.m. in air have been used and vertical suctions of up to 6000N/m2 have been generated. For use in S water, slower rotational speeds would be used and the other dimensions may have to be adjusted accordingly. Clearance 25 between housing 5 (or skirt 6) is important but, as taught previously, tip clearance 13 is particularly critical; these dimensions govern the strength of the vortices.

Fig. 7 shows a vehicle 18 of the invention carrying a heavy load 27 via articulated arm 26.

The use of the vortex generator in housing 5 provides an additional downward force (not shown) preventing vehicle 18 from overturning about point A. Fig. 8 shows an underwater vehicle 18 perching against the vertical side of a ship's hull or oil rig leg 28. Here1 the vortices (not shown) are created in water. Item 30 represents an unmanned, underwater Remotely Operated Vehicle, commonly termed a ROy, and vehicle 18 is parking' the ROV between operations. In this case, both vehicle 18 and ROy 30 could be powered by the same umbilical (not shown).

Fig. 9 shows an Unmanned Aerial Vehicle (UAV) 31, perching on a roof 33, using two vehicles 18 of the invention. As with Fig. 8, this is a parking' application. UAV 31 would hover over roof 33, deploy 32 vehicles 18, start their vortex generators and gradually lower itself until vehicles 18 contacted roof 33 and established a grip thereon. Then UAV 31 would stop its engine and wait. When UAV 31 was instructed to go into action again, it would start its engine and, when it was running normally, stop the vortex generators and take off, retracting 32 vehicles 18 into its fuselage. The principle of this application may be applied to landing on the heaving decks of ships in rough seas.

Fig. 10 shows how two vehicles ISA, 1 SB connected together 35, nominally at right angles, can be used to gain access to a ceiling 34C. In this case, a rotational means 36 is provided to allow for corner angles other than 900. The combined vehicle 1 8A and 1 SB is placed on floor 34A and vehicle iSA drives 21A to wall 346, where vortex generator 16 (not shown) is started. (Vortex generator 1A need not be started on floor 34A unless the encastre loading of.vehicle 18 (Fig. 7) would otherwise overbalance vehicle 18A.) When vortices 18 are established, vehicle 18B starts climbing 218 wall 346. Part way up, vehicle 216 turns through 180° and continues to the top, where vortex generator 1A is started.

When vortex 1A is effective (and it may be necessary to use rotational means 36, if the wall-ceiling angle is not exactly 90°), vortex generator I B is turned off and vehicle 1A drives 21A along ceiling 34C.

In practical operations, vehicles iSA and B would be provided with a camera(s) on articulated means (not shown) to relay moving pictures to a remote viewing station (not shown) from where instructions would be sent to the articulated arms to collect tools, or* equipment from storage points (not shown) on vehicles 18A or B and use it (them to undertake predetermined operations. Remotely controlled robotic operations are commonplace and the skilled person will be familiar with appropriate ones for particular applications.

For clarity, articulated arm(s) 26 are not shown but, when vehicle18B executes its 1800 turn, there will be a risk of umbilical power cable 37 becoming entangled with an arm 26.

Umbilical handling device 38 is provided to manoeuvre cable 37 to avoid entanglement, or to untangle it, should entanglement have occurred. Arm(s) 26 may be moved in conjunction with handler 38, if required. Handler 38 may be provided with lateral, rotational and telescopic freedom of movement, as required.

As a practical example of the capabilities of the apparatus of the invention (Fig. 11), a vehicle 18 could climb a wall 23 to a predetermined point, use its articulated arm 26 to retrieve a drill 39 from its storage location (not shown), fit an appropriate size of bit and drill 39 a hole in wall 23. One duty vehicle 18 might undertake is in nuclear decommissioning to assess radioactive contamination in concrete containment walls 23. This could involve drilling 39, say, 10mm into the wall, using a linear actuator 40, and collecting the debris from the hole in a container (not shown); this could be stored for subsequent analysis or an on-board detector could measure the radiation directly and report the reading in real time.

If the reading was too high, it would drill 39 in, say, another 5mm 40 and repeat the sampling. In this way, the decommissioner would know how deep the contamination had penetrated and what thickness of concrete had to be removed. (The debris collection pots and radiation detection means are not shown to avoid confusing detail. It will be noted that drill 39 is operated below vehicle 18 so that debris from the hole is not ingested into vortex generator 1 (not shown). Debris collection pot (not shown) could be mounted on and below drill 39.) On completion of this task, vehicle 16 could undertake further tasks or remain perched on wall 23 monitoring the environment and awaiting further instructions. Fig. 12 shows vehicle 18, provided with a universal handling means 41. Arrows 42 indicate lateral, translational *and rotational movement capabilities and a universal mounting (not shown) on chassis 7 gives the further degrees of freedom required to hold tools, etc. and so to perform a wide range of operations.

One problem when vehicles climb walls 23 in industrial facilities is that pipes 46, etc. often run across, or close to, walls. Fig. 13 shows how two vehicles 16C and D may be connected by a composite means 43. Means 43 is rotatable 44 about pivots 45A and B and telescopic 44. When vehicle 18C reaches pipe 46, bath vehicles 1SC and D would S stop. Vortex generator 1C (not shown) in vehicle 18C is switched off allowing vehicle 18D to move 45A vehicle 1SC off wall 23 to a distance to clear pipe 46. Vehicle 18D then moves up to pipe 46 and stops. Means 43 is extended 44 to allow vehicle 18C to be replaced 45A against wall 23 and vortex generator 1C restarted. When this has restored vehicle 18Cs grip on wall 23, vortex generator 1D (not shown) in vehicle 18D is switched off allowing vehicle 1 8C to lift 45B vehicle 180 clear of wall 23, move upwards and replace it on wall 23. -Connection 43, with its multiple degrees of freedom 44 and 45A and B would allow a pair of vehicles 1 8C and D to negotiate a wide range of obstacles, e.g. climb the outside of a cupboard and move onto its top surface. Connections 43 can be designed to suit a variety of specialised duties, e.g. climbing a house wall, reaching around the guftering and transferring onto the roof. . The above description will teach the skilled person the scope and capabilities of the invention and he I sh will be able to adapt the principle to other applications all falling within the scope of the invention.

Claims

Claims:- 1. Apparatus, according to a first embodiment of the invention, for generating a vortex having a reduced pressure at its core, comprising:-i) a chassis or supporting structure or a means to secure the apparatus to a supporting structure; ii) a source of power; iii) a driving motor; and iv) a vortex generator, having the general form of a hollow, right cylinder, the cylinder having a flat closed face, an essentially cylindrical housing and an open face and having an impeller rotatable on the axis of the right cylindrical housing with the drive shaft passing through said flat closed face via a seal so that a fluid may not pass from one side of the flat closed face to the other; characterised in that the vortex generator is mounted in the chassis I structure so that its open face is essentially parallel and close to, but not touching, an essentially planar surface and that when the drive motor is activated, the impeller is caused to rotate generating a vortex within the hollow cylinder so that a force is generated attracting the apparatus of the invention towards the surface.
2. Apparatus for generating a vortex, as claimed in claim 1 wherein the impeller has a plurality of blades.
3. Apparatus for generating a vortex, as claimed in claim 2, wherein a vortex is created in the space between each pair of adjacent blades of the impeller.
4. Apparatus for generating a vortex, as claimed in claim 2. wherein the leading edge of each of the impeller blades lies along a radius of the impeller axis.
Apparatus for generating a vortex, as claimed in claim 2, wherein the trailing edge of each of the impeller blades lies along a chord of the circle swept by the impeller blades.
6. Apparatus for generating a vortex, as claimed in claim 2, wherein the leading and trailing faces of each of the impeller blades are flat surfaces lying in a plane normal to the plane of rotation of the impeller.
7. Apparatus for generating a vortex, as claimed in claims 1-6, wherein the clearance between the tips of the impeller blades and the cylindrical housing lies between 0.05-0.1 5D, where D is the internal diameter of the cylindricalhousing.
Apparatus, according to a second embodiment of the invention, for accessing horizontal, sloping, vertical and / or inverted surfaces and capable of undertaking operations there is provided, comprising:-I) a chassis, or supporting structure, having a means of motive power; ii) a source of power; iii) a driving motor; and iv) a vortex generator, having the general form of a hollow, right cylinder, the cylinder having a flat closed face, an essentially cylindrical housing and an open face and having an impeller rotatable on the axis of the right cylindrical housing with the drive shaft passing through said flat closed face via a seal so that a fluid may not pass from one side of the flat closed face to the other; characterised in that the vortex generator is mounted in the chassis I structure so that its open face is essentially parallel and close to, but not touching an essentially planar surface and that when the drive motor is activated, the impeller is caused to rotate creating a vortex, having a reduced pressure at its core, within the hollow cylinder so that a force is generated attracting the apparatus of the invention towards the horizontal, sloping, vertical or inverted surface on which the apparatus of the invention is located and further characterised in that the apparatus is able to move over the horizontal, sloping, vertical or inverted surface on which the apparatus is located and undertake operations there.
9. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claim 8, wherein the means of providing motive power includes wheels.
10. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claim 8, wherein the means of providing motive power includes tracked members.
11. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claims 9 or 10, wherein the means * of providing motive power includes steerable means.
12. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claims 8-11, wherein the source of power is either electrical, hydrocarbon or pneumatic
13. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claim 12, wherein the electrical power is either from an on-board battery or supplied by a cable from an externél source.
14. Apparatus for accessing horizontal sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claims 12 or 13, wherein the motive power is sufficient to move the apparatus of the invention over the surface, despite the vortical attraction towards that surface.
15. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claims 8-14, wherein the chassis and other components of the apparatus of the invention are constructed of strong, light materials.
16. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claim 15, wherein the strong, light materials include metallic alloys and I or glass and I or carbon fibre reinforced plastics.
17. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claims 8-16, wherein the means to undertake operations from a position on the sloping, vertical or inverted surface includes apparatus for monitoring of the environment.
18. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claim 17, wherein the monitoring of the environment includes using apparatus for sending visual images for viewing at a remote location.
19. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claims 17 of 18, wherein the monitoring of the environment includes the use of apparatus to detect particular gases or radiations.
20. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claims 8-19, wherein the means to undertake operations from a position on the horizontal, sloping, vertical or inverted surface includes apparatus for the maintenance of items, and / or replacement of items, in the S environment and the tools required for the work and visual means to be able to use those tools and means to control the use of the tools.
21. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claim 20, wherein the means to undertake operations from a position on the horizontal, sloping, vertical or inverted surface includes apparatus for performing work in the environment.
22. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claim 20, wherein the means to undertake operations from a position on the horizontal, sloping, vertical or inverted surface includes installing items of equipment in the environment.
23. Apparatus for accessing horizontal, sloping; vertical or inverted surfaces and capable of undertaking operations there, as claimed in claims 8-22, wherein an articulated arm is provided with gripping means at the distal end for holding and using tools.
24. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claim 23, wherein a location is provided for holding tools and / or equipment for use by the articulated arm.
25. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claim 24, wherein the tools and equipment for use by the articulated arm include a powered drill, a drill bit and the means to use them.
26. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claims 8-25, wherein a camera or viewing means is provided able to transmit images for viewing at a remote location.
27. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claim 6-26, wherein instructions are sent from the remote location to components of the apparatus of the invention to cause them to drive and I or steer the apparatus and / or to undertake monitoring of the eñvironmepg and I or maintenance or replacement of items in the environment and / or to perform work in the environment and I or to use such tools or other equipment available to the apparatus of the invention as may be required to complete any or all of the above tasks or accomplish any other tasks within the capabilities of the apparatus of the invention.
28. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claims 8-27, wherein two, or more, items of the apparatus of the invention are connected together nominally at right angles so that the combined apparatus' of the invention can move from a floor to a wall and / or from a wall to a ceiling and / or vice versa.
29. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claim 29, wherein the connection between the two apparatuà' of the invention includes a rotational element for accessing two planar surfaces which are not mutually aligned at right angles to each other.
30. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claims 26 or 29, wherein two, or more, items of the apparatus of the invention are connected together either end-to end or side-by-side or end-to-end and side-by-side to provide a larger operating platform, more securely attracted to the surface.3t Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claims 28-30, wherein the connection between two items of the apparatus of the invention includes means to lift one of the units over, or around, a discontinuity in / on the surface being traversed or past a discontinuity between otherwise planar surfaces.32. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claims 5-31, wherein the area of the chassis is increased so that a plurality of vortex generator.s is mountable therein.33. Apparatus for accessing horizontal, sloping, vertical orinverted surfaces and capable of undertaking operations there, as claimed.in claims s-u, wherein the means of steering the apparatus of the invention includes turning it through angles1 including 1800.34. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claims 8-33, wherein means is provided to move the power cable to the apparatus of the invention to stop it getting entangled with the articulated arm.35. Apparatus for accessing horizontal, sloping, vertical or inverted surfaces and capable of undertaking operations there, as claimed in claims 6-34, wherein one, or more, apparatus' of the invention are operated in conjunction with, or as part of, other robotic systems to form composfte units for specific operations.36. A method, according to the first embodiment of the invention, of generating a vortex having a reduced pressure at its core is provided, comprising the steps of:-i) providing a chassis or supporting structure or means to secure the apparatus to a supporting structure: ii) providing a source of power; iii) providing a driving motor; and iv) providing a vortex generator, having the general form of a hollow, right cylinder, the cylinder having a flat closed face, an essentially cylindrical housing and an open face and having an impeller rotatable on the axis of the right cylindrical housing with the drive shaft passing through said flat closed face via a seal so that a fluid may not pass from one side of the flat closed face to the other; characterised in that the vortex generator is mounted in the chassis / structure so that its open face is essentially parallel and close to, but not touching an essentially planar surface and that when the drive motorS activated, the impeller is caused to rotate generating a vortex within the hollow cylinder so that a force is generated attracting the apparatus of the invention towards the surface.37. A method, according to the second embodiment of the invention, of accessing horizontal, sloping, vertical and / or inverted surfaces and having the capability of undertaking operations there is provided, comprising the steps of:-i) providing a chassis, or supporting structure, having a means of motive power; S ii) providing a source of power; iii) providing a driving motor iv) providing a vortex generator, having the general form of a hollow, right cylinder, the cylinder having a flat closed face, an essentially cylindrical housing and an open face and having an impeller rotatable on the axis of the right cylindrical housing with the drive shaft passing through said flat closed face via a seal so that a fluid may not pass from one side of the flat closed face to the other; v) providing a means of accessing the horizontal, sloping, vertical or inverted surfaces; and vi) providing means of undertaking operations there; characterised in that the vortex generator is mounted in the chassis I structure so that its open face is essentially parallel and close to, but not touching, an essentially planar surface and that when the drive motor is activated, the impeller is caused to rotate creating a vortex, having a reduced. pressure at its core, within the hollow cylinder so that a force is generated attracting the apparatus of the invention towards the horizontal, sloping, vertical or inverted surface on which the apparatus of the invention is located and the means of accessing is used to reach a particular location on the horizontal, sloping, vertical and I or inverted surface and the means to undertake operations used at the said location.38. A method of accessing horizontal, sloping, vertical or inverted surfaces and the capability of undertaking operations there, as claimed in claim 37, wherein the apparatus of the invention is used to climb / descend slopes or walls to predetermined positions from where predetermined operations can be carried out.39. A method of accessing horizontal, sloping, vertical or inverted surfaces and the capability of undertaking operations there, as claimed in claims 37 or 38, wherein is used to descend I climb slopes or walls to predetermined positions from where predetermined operations have been carried out.40. A method of accessing horizontal, sloping, vertical or inverted surfaces and the capability of undertaking operations there, as claimed in claims 37-39, wherein the means of abcessing the horizontal, sloping, vertical or inverted surfaces are provided with a steering capability.41. A method of accessing horizontal sloping vertical or inverted surfaces and the capability of undertaking operations there, as claimed in claims 37-4o, wherein the means to undertake operations at the said location includes using means to image the location and items at the location and to transmit the images to a remote location from where operational instructions are sent to the apparatus of the invention 42. A method of accessing horizontal sloping, vertical or inverted surfaces and the capability of undertaking operations there, as claimed in claims 37-41, wherein the means to undertake operations at the said location includes USifl9 articulated means able to undertakethe required operations 43. A method of accessing horizontal, sloping, vertical or inverted surfaces and the capability of undertaking operations there, as claimed in claims 37-42, wherein Iwo items of the apparatus of the invention are connected together nominally at right angles to each other so that the combined apparatus' of the invention can be used to enter a chamber, move along the floor to a wall, transfer to and climb the wall and, if required turn through 180° and climb to and transfer to the ceiling and move along the ceiling to its predetermined operational point, undertake an operation at that point and, when the operation is complete, return by the same, similar or a different route to its starting point or to another required destination.44. A method of accessing horizontal, sloping, vertical or inverted surfaces and the capability of undertaking operations there, as claimed in claims 37-43, wherein the chassis I supporting structure is of a size to accommodate a plurality of vortex generators, either end-to-end or side-by-side or both end-to-end and side-by-side 45. A method of accessing horizontal sloping vertical or inverted surfaces and the capability of undertaking operations there, as claimed in claims 37-44, wherein a means to move the power cable is provided and used to stop the cable from getting entangled with any articulated arm(s) or other components on either apparatus when the combined apparatus of the invention is turning I turned through 1800 or otherwise manoeuvred 46. A method of accessing horizontal, sloping, vertical or inverted surfaces and the capability of undertaking operations there, as claimed in claim 45 wherein the respective means to move the power cable and to move the articulated arm are used together to avoid entangling the power cable or to disentangle the power cable should it have become entangled during the turning of the combined apparatus of the invention through i 800 or during other manoeuvres 47. A method of accessing horizontal, sloping vertical or inverted surfaces and the capability of undertaking operations there, as claimed in claims 43-45; wherein the connection between two items of the apparatus of the invention is used to lift one of the units over, or around, a discontinuity in I on the surface being traversed or past a discontinuity between otherwise planar surfaces.48. Apparatus and method of generating a vortex as described in and by the above statement with reference to the accompanying drawings.49. Apparatus and method of accessing horizontal, sloping, vertical or inverted surfaces and the capability of undertaking operations there, as described in and by the above statement with reference to the accompanying drawings.