The present disclosure relates to an apparatus configured to generate downforce, and a system including the apparatus and a remote base unit. In particular, but not exclusively, the present disclosure relates to a wall climbing apparatus.

Manually painting interior and exterior walls can be time consuming. Furthermore, to reach high inaccessible regions, ladders or scaffold is often required. This can further slow the process, and can also lead to increased risk of accidents.

An alternative is to use automated painting systems. Existing automated painting systems have a spray head mounted on a support, secured to a base. The system is positioned on a level floor near a wall, and the spray moves along the support to spray the wall. The support may enable both horizontal and vertical movement. These systems can be cumbersome to use, and require regular repositioning to paint along the length of a wall. Painting ceilings is also inconvenient.

A number of different wall climbing toys and robots are known. In general these use a curtain to enclose a volume between a chassis of the device, and the wall. Air is pumped from within the volume to form a vacuum, so that the device adheres to the wall.

However, these devices are very small and lightweight and do not create sufficient adherence to the wall to support the weight of a payload such as a spray head and other components. If such existing technology is scaled up, the device will become too heavy, and be unable to support its own weight, and the weight of a payload.

According to a first aspect of the invention, there is provided an apparatus configured to generate downforce, the apparatus having: a platform configured to move around a surface, the platform having a top face and a bottom face; a conduit extending through the platform and having an inlet and an outlet; and an impeller provided in the conduit and configured to draw air from the underside of the platform, through the inlet of the conduit to the outlet, to generate an area of low pressure beneath the platform, to generate downforce onto the surface. The conduit has a first diameter at a point proximal to the impeller, a second diameter at the inlet and a third diameter at the outlet. The second diameter and/or the third diameter is greater than the first diameter.

When the apparatus is in use on a surface, the top face of the platform is distal from the surface, and the bottom face of the platform is proximal to the surface.

If the second diameter is greater than the first diameter then the conduit has a diverging inlet. Such an arrangement results in a smoother transition of air from beneath the platform into the conduit, reducing turbulence beneath the platform and in the conduit.

If the third diameter is greater than the first diameter then the conduit has a diverging outlet. Such an arrangement results in a smoother transition of air from inside the conduit to above the platform, reducing turbulence in the conduit and above the platform.

The duct therefore houses the components which are necessary to generate airflow, whilst being shaped to most efficiently control that airflow. As a result, the apparatus creates strong downforce to adhere to walls, ceilings and non-horizontal surfaces where gravity cannot hold the apparatus in place. This may be useful for painting as well as other purposes where ladders or scaffold are often required, such as cleaning, inspection, and applying of other media such as protective coatings.

It may be that the conduit has a mid-portion between the inlet and the outlet.

It may be that the mid-portion of the conduit has a constant diameter.

In some embodiments the impeller is provided in the mid-portion of the conduit.

It may be that the second diameter is greater than the first diameter, and the third diameter is greater than the second diameter.

It may be that the platform is made of foam cored carbon fibre panels.

It may be that the platform is made of any material and composition of materials which is lightweight. In some embodiments, the diameter of the conduit transitions smoothly between the first diameter and the second diameter. In some embodiments, the diameter of the conduit transitions smoothly between the first diameter and the third diameter. Smooth transitions between the different conduit diameters ensure that turbulence inside the conduit is reduced.

It may be that an edge of the inlet is rounded. In such embodiments, the rounded inlet allows a smoother transition for the air from the underside of the platform to inside the conduit, reducing turbulence under the platform and in the conduit.

The conduit may be received within the platform, and may extend between the top face and bottom face such that the outlet of the conduit is adjacent to the top face of the platform and the inlet is adjacent to the bottom face of the platform.

The wall climbing apparatus may include a cover or housing which is supported from the platform. The cover or housing may enclose at least part of the platform and may extend away from the platform. The cover or housing may enclose a volume. The outlet of the conduit may open into the volume. The volume may include an opening to atmosphere.

It may be that the outlet of the conduit is flush with the top face of the platform, and/or that the inlet of the conduit is flush with the bottom face of the platform.

It may be that the outlet of the conduit is recessed into the top face of the platform and/or the inlet of the conduit is recessed into the bottom face of the platform.

It may be that the outlet of the conduit is protuberant from the top face of the platform and/or the inlet of the conduit is protuberant from the bottom face of the platform.

In this context, the term adjacent is intended to encompass any combination of flush, recessed, and/or protuberant conduit inlets and/or outlets.

It may be that a significant portion of the conduit is protuberant from the top face of the platform. In such an embodiment, the inlet of the conduit may be flush with the bottom face of the platform, the inlet may be recessed into the bottom face of the platform, or the inlet may be protuberant from the bottom face of the platform.

In embodiments, the platform may have a substantially rectangular footprint with a cut-out at each corner. Such an arrangement may increase the surface area of the platform, thus increasing the volume beneath the platform and hence increasing the downforce.

In some embodiments, the apparatus may have a second conduit and a second impeller, said second conduit extending through the platform and having an inlet and an outlet; and said second impeller provided in the second conduit and configured to draw air from the underside of the platform, through the inlet of the second conduit to the outlet of the second conduit. The second conduit may have a first diameter at a point proximal to the second impeller, a second diameter at the inlet and a third diameter at the outlet. The second diameter and/or the third diameter may be greater than the fourth diameter.

In some embodiments the apparatus may have three or more conduits, and three or more impellers, each conduit extending through the platform and having an inlet and an outlet; each impeller provided in a respective conduit and configured to draw air from the underside of the platform, through a respective inlet to a respective outlet. Each conduit may have a first diameter at a point proximal to the impeller, a second diameter at the inlet and a third diameter at the outlet. The second diameter and/or the third diameter may be greater than the first diameter.

It may be that at least a portion of the perimeter edge of the bottom face of the platform has a curtain fixed thereto. The curtain may reduce airflow from the surrounding area to beneath the platform, resulting in a stronger area of low pressure beneath the platform, sucking the platform onto the surface. In some embodiments a single edge of the platform may not be provided with a curtain. In such embodiments, that edge may be the forward or the rearward edge of the platform with respect to the platform’s direction of travel. The forward and rearward edge of the platform may be considered to be at a first end of the platform and a second end of the platform respectively. In an alternative embodiment, only the sides of the bottom face with respect to the direction of travel are provided with curtains. In a further alternative embodiment, the entire perimeter of the bottom face may be provided with a curtain.

In some embodiments, the apparatus includes a power cable for connecting the platform to a power supply on a remote base unit in order to provide power for the one or more impellers.

It may be that the apparatus includes a step-down voltage transformer mounted on the platform. By mounting a step-down voltage transformer on the platform, the voltage in the power cable can be higher. This higher voltage means that a lower current can be used to provide the same amount of power to the platform. This in turn has the effect that the power cable can be of smaller gauge whilst still reducing losses due to cable resistance. This is a desirable trait since when the platform is on a non-horizontal surface, the power cable will act to pull the platform away from the surface. Reducing this weight ensures that the platform is more firmly held on the surface by the downforce generated by the impeller(s) and conduit(s).

It may be that a media delivery system is provided on the platform, said media delivery system arranged to deliver a media onto the surface. In embodiments, the media comprises paint. It may be that the media delivery system is arranged to deliver the media behind the platform, in a direction of travel, in use.

It may be that the media delivery system includes a known spray gun held in a support mounted at the second end of the platform.

A trigger of the spray gun may be actuated by an actuation member which may be controlled by a servo motor. A nozzle may deliver media from the spray gun to the first end of the platform where it is applied to the surface.

The apparatus may comprise support members configured to support the platform on the surface. The support members may be rotary support members such as wheels, continuous tracks, rollers, or other suitable rotary support members. The support members may be static support members, such as skids, skis, feet, or other suitable static support members. The apparatus may have mixed support members, such as, for example, wheels at one end of the platform, and skis at the other end of the platform. Any combination of the support members mentioned above is envisaged.

The support members may comprise wheels affixed to the platform, wherein the wheels contact the surface in use.

The apparatus may be configured to move around the surface on the support members. In embodiments, one or more of the rotational support members may be driven, for example by one or more electric drive motors.

According to a second aspect of the invention, there is provided a system comprising: an apparatus according to the first aspect of the invention; and a remote base unit, said remote base unit comprising a power supply.

The power supply may be provided by mains electricity, alternatively it may be battery powered or a generator running on alternative fuel such as diesel, petroleum, or bio-fuels may be provided.

In some embodiments, the remote base unit comprises a reservoir for holding media and the system comprises a hose connecting the reservoir to the media delivery system.

The system may further comprise a controller arranged to control movement of the platform. The controller may be further arranged to control delivery of the media.

According to a third aspect of the invention, there is provided an apparatus configured to climb a vertical or near vertical surface, the apparatus having: a platform configured to move around on the surface, a power cable for connecting the platform to a power supply on a base unit, and a step-down voltage transformer.

The voltage transformer may be mounted on the platform.

By mounting a step-down voltage transformer on the platform, the voltage in the power cable can be higher. This higher voltage means that a lower current can be used to provide the same amount of power to the platform. This in turn has the effect that the power cable can be thinner whilst still reducing losses due to cable resistance. This is a desirable trait since the weight of the power cable will act to pull the platform away from the vertical or near vertical surface.

Features discussed in relation to one aspect may be applied to any other aspect, unless mutually exclusive.

Embodiments of the invention will now be described, by way of example only, with reference to the drawings, in which:

Figure 1 illustrates a perspective view of an example wall climbing apparatus with media spraying apparatus affixed thereto;

Figure 2 illustrates a perspective view of an example wall climbing apparatus;

Figure 3 illustrates a side profile view of the wall climbing apparatus of Figure 2;

Figure 4 illustrates an end profile view of the wall climbing apparatus of Figure 2;

Figure 5 illustrates a profile view of the underside of the wall climbing apparatus of Figure 2;

Figure 6 illustrates a perspective view of an example conduit;

Figure 7 illustrates a cross sectional view of the conduit of Figure 6;

Figure 8 illustrates a perspective view of a further example wall climbing apparatus;

Figure 9 illustrates a profile view of the underside of a further example wall climbing apparatus;

Figure 10 illustrates a side profile view of a further example wall climbing apparatus;

Figure 11 illustrates a system including an example wall climbing apparatus and an example base unit;

Figure 12 schematically illustrates a controller for controlling the wall climbing apparatus of Figure 1 ; and

Figure 13 illustrate a cross sectional view of an alternative embodiment of the wall climbing apparatus with two conduits.

Figures 1 to 5 schematically illustrate a wall climbing apparatus 1 according to an embodiment of the invention. The apparatus 1 comprises a platform 3 having a top surface 3a and a bottom surface 3b parallel to and spaced from the top surface 3a. The platform 3 is formed of carbon fibre. Carbon fibre is an advantageous material because of its low mass, and high strength and stiffness. It is envisaged that other materials with similar properties may be used. To further enhance the stiffness of the platform 3, the platform 3 may comprise stiffening members, such as stiffening rods. The stiffening rods may be affixed to the platform 3, or they may be integrally formed with the platform 3.

The platform 3 has a conduit 5 extending there through, between the top surface 3a and the bottom surface 3b. The outlet 7 of the conduit 5 is adjacent to the top surface 3a of the platform 3, and the inlet 9 of the conduit 5 is adjacent to the bottom surface 3b of the platform 3 such that the conduit 5 is received within the depth of the platform 3. In the illustrated embodiment, the outlet 7 of the conduit 5 is flush with the top surface 3a of the platform 3, and the inlet 9 of the conduit 5 is flush with the bottom surface 3b of the platform 3. The conduit 5 is discussed in detail below in relation to Figures 6 and 7.

The conduit 5 extends generally along axial direction A, where axial direction A is perpendicular to the plane defined by the top surface 3a of the platform 3.

Above, below, top, and bottom are discussed with reference to the platform 3, where, when the apparatus is in use on a surface, the top face 3a of the platform 3 is distal from (facing away from) the surface, and the bottom face 3b of the platform 3 is proximal to (facing towards) the surface. The top face 3a is above the bottom face 3b, and the bottom face 3b is below the top face 3a.

The conduit 5 houses an impeller 11 which is configured to rotate around the axial direction A, in order to draw air from beneath the platform 3 into the inlet 9 of the conduit 5 and then expel it from the outlet 7 of the conduit 5. This action creates an area of low pressure beneath the platform 3, creating a downforce holding the wall climbing apparatus 1 to the surface, which may be a wall 101. The impeller 11 includes a central hub 10 and blades 14 extending radially outwards from the central hub 10. The impeller 11 is powered by an electric motor 12. In the illustrated embodiment, a 1500W motor is used, operating at 21000RPM, although any suitable motor may be used. In the illustrated embodiment, four wheels 17 are mounted on the platform. A first pair of wheels 17 are mounted on opposite sides of the platform 3 and are arranged to rotate about a first axis which is perpendicular to axial direction A. A second pair of wheels 17 are mounted on opposite sides of the platform 3 and are arranged to rotate about a second axis which is also perpendicular to axial direction A. The first axis and the second axis are parallel to each other.

The wall climbing apparatus 1 is configured to have a single axis of travel. The platform 3 has a first end and a second end which are discussed in relation to this single axis of travel. Side edges extended parallel to and spaced from each other, between the ends.

When the wall climbing apparatus 1 is in use on a vertical surface such as wall 101, the first end of the platform 3 is the uppermost end of the platform 3 whilst the second end is the end which is closer to the ground. The first pair of wheels 17 are mounted proximal to the first end of the platform 3. The second pair of wheels 17 are mounted proximal to the second end of the platform 3. The first and second axes about which the first and second pair of wheels 17 rotate are both perpendicular to the single axis of travel.

One or more of the wheels 17 may be driven in a known manner, for example using one or more electric drive motors 16. In the illustrated embodiment two electric motors 16 are used. Each motor 16 drives both wheels 17 on a single side (i.e. one wheel from each pair). Differential drive speeds on each side of the platform 3 can be used to steer the wall climbing apparatus 1 in a known manner.

The wheels 17 have a large diameter and width with respect to the dimensions of the platform 3. This size helps the wheels 17 to move over rough surfaces. The curved surface of the wheels is formed from high friction silicon. In the illustrated embodiment, the wheels 17 are provided with a tread pattern 18 to help the wheels 17 grip the surface, but this is entirely optional.

As can be best seen in Figures 3 and 4, curtains 13 are provided at the side edges of the bottom surface 3b, and at the first end of the bottom surface 3b. The curtains 13 partially enclose a volume 15 below the platform 3, helping to maintain and enhance the area of low pressure beneath the platform 3, and hence increasing the force holding the wall climbing apparatus 1 on to the surface. In the illustrated embodiment, the bottom surface 3b of the platform is about 10mm from the surface such that the volume 15 is about 10mm high. The curtains 13 are formed of a hard-wearing but flexible material, for example hard rubber.

The wheels 17 extend further below the bottom surface of the platform 3 than the curtains 13 extend. This has the result that the bottoms of the curtains 13 are spaced from the surface, when the wheels 17 are in contact with the surface. This clearance in turn alleviates the risk of the curtains 13 becoming stuck on rough surfaces. The degree of spacing is optimally large enough to sufficiently reduce the risk of the curtains 13 becoming stuck on rough surfaces, but not so large as to significantly reduce the curtain’s ability to enclose a sufficient volume 15 to help generate an area of low pressure. In a preferred embodiment, this spacing is 2-3mm.

The wall climbing apparatus 1 is provided with a power cable 19 for providing power to the motor 12 driving the impeller 11. The power cable 19 is made from silicon coated copper cable. The power cable 19 may also provide power to a propulsion system, such as one or more electric drive motors 16 for the wheels 17. The power cable 19 may also provide power to a guidance system, such as a LIDAR guidance system. In the illustrated embodiment, a step-down voltage transformer 20 is also provided on the wall climbing apparatus 1. In an alternative embodiment, the wall climbing apparatus 1 may be battery powered, and as such, the power cable 19 may be omitted.

Figure 1 shows the wall climbing apparatus 1 with a media delivery system 21 attached. The media delivery system 21 includes a spray nozzle 22 for delivering media such as paint as a spray. In the illustrated embodiment, the media delivery system 21 is mounted on the top face 3a of the platform 3, proximal to the second end of the platform 3 for ease of connection to a media supply on the ground. The spray nozzle 22 passes over the platform 3, with an outlet proximal to the first end of the platform 3, such that the media is delivered at the first end of the platform 3. In use, the wall climbing apparatus 1 starts at the top of an area to be painted and travels down the surface, spraying the media onto the surface behind the platform 3 with respect to the current direction of travel of the wall climbing apparatus 1. In such an embodiment, delivery of media may be actuated by a servo motor. Media is supplied to the spray head 21 via a supply hose 23. The supply hose 23 is constructed of flexible tubing.

Figure 6 shows a perspective view of the conduit 5. The electric motor 12 is mounted along the central axis A of the conduit above the impeller 11. Both the motor 12 and impeller 11 are mounted on a mounting portion 26 which is received within the conduit 5. The mounting portion 26 is a cylindrical member extending along the direction of the conduit 5 and having a central passage which receives part of the motor 12 and impeller 11. The mounting portion only extends along a portion of the length of the conduit 5. The axial position of the mounting portion 26 is biased towards the upper end of the conduit 5 such that electric motor 12 projects from the upper end of the conduit 5.

The cylindrical member is spaced from the inner surface 29 of the conduit 5, so that an annular space is formed between the mounting portion 26 and the inner surface 29 of the conduit 5. The mounting portion 26 is held in place by support arms 25 which are fixed to the inner surface 29 of the conduit 5.

The support arms 25 are shaped to promote airflow. The leading edge of each support arm 25, which is the upstream edge, closer to the impeller 11, is thinner than the trailing edge. The support arms 25 are also slightly curved around axes which are perpendicular or substantially perpendicular to the central axis A. Such curving ensures that the support arms 25 are less obstructive to the airflow from the impeller 11.

The embodiment shown by Figure 6 is only by way of example, and does not restrict the wall-climbing apparatus to the four support arms shown. Alternative embodiments may have two support arms.

The support arms may not be solid as shown and may be of any shape and configuration found to promote airflow. The conduit 5 may be manufactured as a unitary component which can be fitted into a hole provided in the platform 3.

Figure 7 shows a cross sectional view of the conduit assembly 27, including the conduit 5, the impeller 1 1, and the electric motor 12. The cross section is taken along the central axis A of the conduit. The cross section taken perpendicular to the central axis of the conduit 5 is circular at all points along the central axis A of the conduit 5.

The impeller 1 1 is provided in a mid-portion 8 of the conduit 5. The mid-portion 8 of the conduit 5 is between the inlet 9 and outlet 7 along the central axis A. This midportion 8 has a constant diameter. The conduit 5 widens from the mid-portion 8 to the outlet 7. Therefore, the diameter at the outlet 7 of the conduit 5 is greater than the diameter at the mid-portion 8 of the conduit 5. The interior wall 29 of the conduit 5 transitions smoothly from the diameter of the mid-portion 8 to the diameter of the outlet 7. The interior wall 29 of the conduit 5 is convex such that the portion of the conduit 5 between the mid-portion 8 and the outlet 7 is formed as a flared cylinder.

The conduit also widens from the mid-portion 8 to the inlet 9. The diameter at the inlet 9 of the conduit 5 is greater than the diameter at the mid-portion 8 of the conduit 5. The diameter at the inlet 9 is smaller than the diameter at the outlet 7. The interior wall 29 of the conduit 5 transitions smoothly from the diameter of the mid-portion 8 to the diameter of the inlet 9. The transition from the diameter of the mid-portion 8 to the diameter of the inlet 9 is less gradual than the transition from the diameter of the mid-portion 8 to the diameter of the outlet 7.

As can be seen from Figure 7, the widening from the mid-portion 8 to the outlet 7 extends over a greater axial portion of the conduit 5 than the widening from the midportion 8 to the inlet 9. The gradient of widening is sharper at the inlet 9 than at the outlet 7. Furthermore, the diameter at the outlet 7 is larger than the diameter of the inlet 9.

A nose cone 28 is mounted on the mounting assembly 27 upstream of the impeller 1 1. The nose cone 28 guides airflow away from the central axis A and into the path of the impeller blades. Figure 8 shows an alternative embodiment of the wall climbing apparatus 1. The embodiment shown in Figure 8 is the same as the embodiment described above, unless explicitly stated otherwise. The wall climbing apparatus 1 shown in Figure 8 has two conduit assemblies 27. Each of the conduits 5 is generally as described above. In one example, the two conduits 5 may be identical. In other examples, one of the conduits 5may be larger than the other, and/or the inlet/outlet may widen in different ways. Such an embodiment may provide a more uniform area of low pressure beneath the platform 3.

In the illustrated embodiment, the two conduits 5 both lie on the central axis of the platform 3 which is parallel to the axis of travel. In the example shown the conduits 5 are located along this axis in positions such that the distance along the axis from the first end of the platform 3 to the central axis of the first conduit 5 is equal to the distance from the second end of the platform 3 to the central axis of the second conduit 5. It will be appreciated that the conduits 5 may be arranged in any suitable way.

Figure 9 shows an alternative embodiment of the wall climbing apparatus 1. The embodiment shown in Figure 9 is the same as described above, unless explicitly stated otherwise. In the embodiment shown in Figure 9, the platform 3 has a substantially rectangular footprint, but has cut-outs at each corner for the wheels 17, such that side pods are formed between the two wheels 17 on each side. In the specific embodiment shown in Figure 9, two conduits 5 are provided.

This platform shape increases surface area by taking advantage of the space between the wheels 17 to increase the volume 15 and hence increase the suction force. In the same way as embodiments with a cuboidal platform, the rectangular with corner cutout platform embodiment may be provided with a single conduit 5 or two or more conduits 5 respectively housing impellers 11. Further, the specific embodiment of Figure 9 is shown with skirts 13, but these skirts 13 may be omitted in embodiments.

In the embodiments discussed, the platform length is around 400mm to 700mm. Figure 10 schematically illustrates an embodiment of the invention in which the media delivery system includes a known spray gun 30 held in a support 33 mounted at the second end of the platform 3. The embodiment shown in Figure 10 is the same as the embodiment described above in relation to Figure 1, unless explicitly stated otherwise. The trigger 32 of the spray gun 30 is actuated by an actuation member 31 controlled by a servo motor. The nozzle 22 delivers media from the spray gun 30 to the first end of the platform 3 where it is applied to the surface.

Figure 11 schematically illustrates a system 100 comprising a wall climbing apparatus 1, a base unit 102, and a controller 104. The base unit 102 comprises a power supply 106 and a media reservoir 108. The power cable 19 is connected to the power supply and supplies power to the wall climbing apparatus 1. The supply hose is connected to the media reservoir 108 to supply media te the media delivery system 21.

The controller 104 controls the movement of the wall climbing apparatus 1. In the illustrated embodiment, this is done by controlling the electric drive motors 16 which drive the wheels 17. The controller 104 also controls the delivery of media onto the wall 101.

Figure 12 illustrates the controller 104 for operating the wall climbing apparatus 1. The controller includes a processing unit 216 (for example an Intel® X86 processor such as an 15, 17 processor or the like) a memory 202, a communications interface 218 system drivers 220, and a system interface 226, connected to each other via a system bus 224. The memory 202 is subdivided into program storage 204 and data storage 206.

It will be appreciated that although reference is made to a memory 202 it is possible that the memory 202 could be provided by a variety of devices. For example, the memory may be provided by a cache memory, a RAM memory, a local mass storage device such as the hard disk, any of these connected to the processing circuitry 104 over a network connection. However, the processing unit 216 can access the memory 202 via the system bus 224 and, if necessary, communications interface 218, to access program code to instruct it what steps to perform and also to access data to be processed. The processing unit 216 is arranged to process the data as outlined by the program code. The program code may be delivered to memory 202 in any suitable manner. For example, the program code may be installed on the device from a CDROM; a DVD ROM / RAM (including -R/-RW or +R/+RW); a separate hard drive; a memory (including a USB drive; an SD card; a compact flash card or the like); a transmitted signal (including an Internet download, ftp file transfer of the like); a wire; etc.

In the illustrated embodiment, the controller 104 is shown as a separate unit. It is envisaged that the controller 104 may be provided on the wall climbing apparatus 1, the base unit 102, in a separate location (for example a user’s computer or mobile phone or the like), or distributed between two or more of these. Where the controller 104 is not provided on the wall climbing apparatus 1, the controller 104 may communicate with the remote unit by wired communications, or wireless communications using electromagnetic radiation in a known manner, such as via radio waves, or via infrared radiation.

In order to apply media to a surface, the wall climbing apparatus 1 requires a path. The data storage portion 206 of the memory includes path data 212 that provides details of the path for the wall climbing apparatus 1 to follow. This includes the physical path the wall climbing apparatus 1 should cover on the surface.

The data storage 206 also includes calibration data 214 that maps input levels (e.g. voltages/currents) to the drive motors 16 on the wall climbing apparatus 1. Based on the path data 212 and calibration data 214, a wall climbing apparatus control module 210, provided in the program storage portion 204 of the memory 202, operates the drive motors 16 through the system drivers 220.

A valve and possibly pump (not shown) may be provided to control delivery of media from the media delivery system 21. The valve may be provided in the media delivery system 21, in the reservoir 108 or any point between. In such an embodiment, the controller 104 also controls the valve to control delivery of media. For example, the path data 212 may also include details of when the valve should be opened, as a function of the wall climbing apparatus’ 1 position on the surface. In one example, the media valve may be always open whilst the wall climbing apparatus 1 is moving, and the speed of the wall climbing apparatus 1 may be varied to ensure even coverage of media, for example, when the wall climbing apparatus 1 is turning. In other examples, the valve may be opened and closed, or the pressure from the media delivery system 21 varied, as the wall climbing apparatus 1 moves.

In some examples, the media delivery system 21 may include a motor (not shown) to rotate the position of the nozzle 22, to control the direction media is dispensed in. In such an embodiment, this motor is also controlled by the controller 104 based on path data 212.

In one example, the wall climbing apparatus 1 may include sensors 222 such as proximity/radar sensors, image sensors and the like. This allows for obstacles and the like to be detected and avoided as the wall climbing apparatus 1 is moving.

Furthermore, in some examples, the sensors 222 may enable the controller 104 to analyse the surface, and determine a path for the wall climbing apparatus 1, using path determination module 208 and calibration data 214.

In other examples, a user may determine a path and input this through the system i/o 226. The path may be entered through wired or wireless communications, for example from a computer, keyboard, mouse, or other device. Alternatively, the path may be entered through controls (not shown) provided on the wall climbing apparatus 1 or base unit 102.

It will be appreciated that, if used for the application of media, the wall climbing apparatus 1 should be controlled such that, where media such as paint is deposited, the wall climbing apparatus 1 does not move over previously deposited media before it is dry/set. This may be by, for example, correct selection of the path and/or correctly controlling the media delivery system 21.

As discussed above, the conduit 5 widens at the outlet 7 such that the diameter is greater at the outlet 7 than at the mid-portion 8 of the conduit 5. This diverging outlet allows the air which has been accelerated through the conduit by the impeller 11 to transition back to atmospheric pressure more smoothly. This reduces the turbulence which is present in the air leaving the conduit 5. Less turbulent air allows the impeller 11 and conduit 5 to work more effectively, resulting in an increase of downforce. Furthermore, the air around the platform is less disturbed. In embodiments of the invention which are used for applying media to a surface, disturbed air will affect the quality and consistency of the spray pattern, and so reducing atmospheric disturbance around the platform is advantageous.

The inlet 9 of the conduit 5 also has a larger diameter than the mid-portion 8 of the conduit 5. This rounded inlet 9 allows air which is beneath the platform 3 in volume 15 to transition more smoothly into the high pressure area inside the conduit 5. This reduces the turbulence which is present in the air inside the conduit 5. This allows the impeller 11 and conduit 5 to work more effectively, resulting in an increase in downforce.

It has been found that the rounded inlet 9 results in the generation of 5-8% more downforce when compared with a straight conduit.

It has further been found that the combination of the rounded inlet 9 and the diverging outlet 7 results in the generation of 15-20% more downforce when compared with a straight conduit.

In the embodiment described above in relation to Figure 9, the wall climbing apparatus 1 has a mass of around 10 to 15 kg and is capable of supporting a further payload having a mass of around 15 to 25 kg. It will, however, be appreciated that this is by way of example only.

The impeller 11 is provided in the mid portion 8 of the conduit 5, where the diameter of the conduit is narrowest. The mid-portion 8 of the conduit 5 continues after the impeller 11 (in the direction of air flow).

In the illustrated embodiment, curtains 13 are provided on both side edges of the bottom face 3b of the platform 3, and on the first end of the bottom face of the platform 3. These curtains 13 act to partially enclose an area 15 which helps to maintain an area of low pressure beneath the platform 3, increasing the downforce generated. In the illustrated embodiment, the curtain is omitted at the second end of the platform 3. Surrounding air will be pulled into the area of low pressure beneath the platform. In embodiments where the wall climbing apparatus 1 is provided with a media delivery system 21 at the first end of the platform 3 configured to spray media onto the surface behind the platform 3, this movement of air (from the surrounding area into the area 15 beneath the platform) will interfere with the spraying of media. By omitting the curtain at the opposite end, the path of least resistance for air to flow into the low pressure area 15 is through the gap in the curtain at the second end of the platform. The majority of the airflow from the surrounding area to beneath the platform will therefore be close to the second end of the platform, and hence distant from the spray of media at the first end of the platform.

A step-down voltage transformer 20 is provided on the wall climbing apparatus 1. This has the advantage that power can be supplied to the apparatus 1 at high voltage, allowing the power cable 19 to be thinner and therefore lighter whilst still reducing losses in the power cable 19. When the wall climbing apparatus 1 is on a vertical, or near vertical surface, such as wall 101, the weight of the power cable 19 acts to pull the wall climbing apparatus 1 away from the surface and as such, it is advantageous to reduce the weight of the power cable.

In the illustrated embodiment, the platform 3 is parallel to the surface. In use on a vertical or near vertical surface, the platform will squat under its own weight as a result of a moment force, resulting in the second end of the platform (the end closer to the ground) being closer to the surface than the first end. To counteract this, the wall climbing apparatus 1 may be set up such that there is a relative displacement between the axes of rotation of the two pairs of wheels 17, so that when the climbing apparatus is on a horizontal surface, the first end is closer to the surface than the second end. In this way, when the platform squats when on a vertical surface, the offset is overcome and the platform becomes parallel to the surface along its entire length.

In one embodiment, the axis of the first pair of wheels 17 may be more distal from the bottom face 3b of the platform, and closer to the top face 3a of the platform than the axis of the second pair of wheels 17, such that the first end of the bottom face 3b is closer to a horizontal surface than the second end of the bottom face. In the illustrated embodiment, the platform 3 is cuboidal. Figure 9 shows an alternative embodiment in which the platform 3 has a rectangular footprint with cutouts at each corner for the wheel, forming side pods between the wheels. However, in other embodiments, the platform 3 could be any suitable shape.

In the illustrated embodiment, the conduit inlet 9 and outlet 7 are flush with the bottom surface 3b and top surface 3a respectively. It is envisaged that the inlet 9 and/or outlet 7 may instead be recessed into the respective platform face, or protuberant from the respective platform face.

Figure 13 shows a cross-sectional view of an alternative embodiment of the wall climbing apparatus 1. The embodiment shown in Figure 13 is the same as that described above, except in that two conduits are used and that the cross-sectional profile of the conduits is more accentuated and more pronounced. In the embodiment described, the conduit interior wall 29 curves outwards at the outlet 7, the curvature provided on a longer axial path than that described in Figure 7. The section between the mid-portion 8 and the end of the conduit is thus longer in the axial direction in the described embodiment compared to that described in the alternative embodiment shown in Figure 7.

Each of the conduit assembly 27 is provided with an impeller at the mid portion 8, where the diameter of the conduit is at its narrowest. The diameter of the conduit is larger at the inlet 9 compared to the mid portion 8, and it is larger yet at the outlet 7 to promote airflow.

The embodiment shown in Figure 13 has two support arms 25.

In the illustrated embodiment, the or each conduit 5 houses a single impeller 11. It is envisaged that two or more impellers 11 may be provided inside the or each conduit 5.

In the illustrated embodiment, each impeller is driven by an individual electric motor 12 provided inside the conduit 5. It is envisaged that where multiple conduits 5 and/or multiple impellers 11 are provided, they may be powered by a number of electric motors 12 not equal to the number of impellers 11, for example by using gearing. In one embodiment, a single electric motor 11 may drive multiple impellers 11.

In the illustrated embodiment, four wheels 17 are mounted on the platform, which allow the platform 3 to move around the surface. Any suitable number of wheels may be used. It is further envisaged that wheels may be replaced with other elements, for example caterpillar tracks. The wheels 17 of the illustrated embodiment each rotate around axes which extend through the platform 3 between the top face 3a and the bottom face 3b. It is envisaged that the axes of rotation of the wheels may be below the bottom surface 3b or above the top surface 3a such that the wheels 17 may be mounted below or above the platform 3 respectively.

In the illustrated embodiment, a single electric motor drives both wheels on a single side of the platform. It is envisaged that the wheels may be driven by electric drive motors 16 in any suitable arrangement. For example, a separate electric drive motor 16 may be provided for each wheel.

In the illustrated embodiment, differential steering is used to direct the wall climbing apparatus 1. Other suitable steering arrangements are envisaged. For example, a conventional rack and pinion system may be used to steer the first pair of wheels 17 and/or the second pair of wheels 17.

In the illustrated embodiment, the wall climbing apparatus 1 has a single direction of travel. It is envisaged that the wall climbing apparatus may be able to travel in more than one direction. For example, the wall climbing apparatus 1 may be able to travel in forward and reverse directions.

In the illustrated embodiment, curtains 13 are spaced from the surface. It is envisaged that the curtains may be in contact with the surface to better enclose volume 15. It is further envisaged that the height of the curtains 13 may be adjustable to allow the curtains 13 to be configured for different surfaces. For example, on rough surfaces the spacing between the curtains 13 and the surface may be increased. In the illustrated embodiment, both a power cable 19 and a supply hose 23 are provided. These may be grouped together, or provided separately. Furthermore, the cables, tubes and the like may be housed in a separate outer tube, sheath or jacket.

The controller 104 discussed above is given by way of example only. Any suitable controller may be used to control the operation of the wall climbing apparatus 1. Furthermore, the sensors are optional and need not be provided.

In the above examples, the movement of the wall climbing apparatus 1 is managed based on path data 212 stored in the data storage 206 of the memory 202. In other examples, this may not be the case. For example, the controller 104 may be a remote control which allows a user to input commands to control the movement of wall climbing apparatus 1 in real time.

In other examples, the program storage may include an automated control module (not shown), to allow the wall climbing apparatus 1 to control its own movement based on sensor inputs. For example, proximity sensors may be used to steer, and image/colour or other sensors used to judge when to apply media such as paint.

In the illustrated embodiment, the base unit 102 is stationary. In other embodiments, the base unit 102 may be mobile. For example, in use, the base unit 102 may move to a first position and stop. From this position, the wall climbing apparatus 1 may move over an area accessible to it with the base unit 102 in the current position. When that span of movement is completed, the base unit 102 moves to a second position.

It will be appreciated that the base unit 102 may be controlled by a separate controller (not shown) to the wall climbing apparatus 1, constructed in the same way as the controller 104. Alternatively, movement of the base unit 102 may be by hand. To facilitate movement of the base unit 102, the base unit may be provided with wheels or caterpillar tracks.

The wall climbing apparatus 1 discussed above may be used in any system required to climb walls, other vertical or inclined surfaces, or pass across ceilings upside down. For example, the remote unit may be used for any of the following: Painting of a building exterior, a building interior, a ship or any other structure;

Window cleaning or cleaning of a building exterior, a building interior, a ship or any other structure (in which case the media is cleaning fluid);

Surveying of any inaccessible structure; and/or Remedial works on buildings.

In embodiments of the wall climbing apparatus 1 discussed above, media is applied to the surface as a spray by a media delivery system 21. In any of the above mentioned applications where media is applied to a surface, it is envisaged that media may be applied to the surface by other methods. Any suitable dispenser may be used. In addition, any appropriate tool may be provided, depending on the media deposited. For example, the tool may tread, treat, apply or remove the media where appropriate. For example, the tool may include a scraper, a cutter, a blade, or a source of radiation such as UV radiation. In further examples, such as surveying applications, no media may be deposited, and the tool may be provided for measurement or analysis of the surface. Such tools may be provided on any appropriate position on the platform 3.

It will be understood that the invention is not limited to the embodiments abovedescribed and various modifications and improvements can be made without departing from the concepts herein.