GB2203108A

GB2203108A - Endless track vehicle for verticle and like surfaces

Info

Publication number: GB2203108A
Application number: GB08808166A
Authority: GB
Inventors: John Edward Chapman
Original assignee: Babcock Energy Ltd
Current assignee: Doosan Babcock Ltd
Priority date: 1987-04-07
Filing date: 1988-04-07
Publication date: 1988-10-12
Also published as: GB8808166D0; GB8708235D0

Abstract

The vehicle 1 is provided along each side with an endless track 9. The track 9 carries transverse, similarly orientated magnets so by which the vehicle may cling to a surface of magnetic material. At their ends, the tracks pass over pinion wheels 10. The teeth of the trailing sprocket wheels 10, at least, are also provided with magnets 21 but of opposite polarity to the magnets 20. The effect of the magnets 21 is to counter the attraction exerted by the magnets 20 and so tend to release them from the surface along which the vehicle is travelling. In a modification shown in Figure 4 the magnetism is provided by electromagnets 30 that are energized whilst passing from the leading sprocket wheel 10a to the trailing sprocket wheel 10 by contact 37 sliding along busbars 40 and 41. The electromagnets will have ceased to be energized whilst they pass on to, and over, the trailing sprocket wheel. <IMAGE>

Description

"Improvements in or relating to Vehicles" DESCRIPTION This invention developed from the fact that it is frequently desirable to inspect the submerged hull of a ship by the use of instruments with, or without, the accompaniment of a diver.

According to the present invention there is provided a vehicle having an endless drive track at each side and magnetic means distributed along, and moving with, each track so that the vehicle can cling to a magnetic surface from which it would fall were the magnetisation of the magnetic means absent. The vehicle may carry, say, an ultrasonic probe and a television camera may be mounted in a superstructure. By the magnetic means, the vehicle can cling to the iron plates of a ship and the magnetic means may be of such strength that the vehicle may cling upsidedown to the hull of the ship.

By way of example, embodiments of the invention will now be described in which Figure 1 shows in side view a vehicle embodying the invention; Figure 2 shows a view, from below, and with the casing removed, of Figure 1: Figure 3 shows a partial view , from the bottom of Figure 2, and the right way up; Figure 4 shows a detail of a different vehicle embodying the invention, being a detail of a side view, similar to the view that is shown in Figure 3; and Figure 5 is a plan view of what is shown in Figure 4.

The vehicle that is denoted by 1 in Figure 1 is intended to facilitate the under-water inspection of, say, the hull of a ship and may carry apparatus such as an ultrasonic probe or a television camera. Such apparatus is indicated generally at 1 in Figure 2 and may be arranged to be effective through the forward-facing windows 2 of the aluminium casing 3. The rear of the casing 3 is provided with a tether attachment 4 and a nozzle 5 through which electrical cables may enter the vehicle.

Each side of the vehicle 1 is provided with an endless track 9. At each end of each side, there is provided a pinion wheel 10, mounted for rotation in a stub 11, over which a track 9 passes. Each of the leading wheels 10a is provided with a driving motor 12.

Each track 9 comprises a succession of pairs of links 14 connected together by transverse pins 15 which permit successive links to oscillate relatively to each other as they pass over the wheels 10. To drive the tracks, the pins 15 engage'successively between the teeth of the pinion wheels 10a.

Extending across each pair of links 14 is a bar magnetic 20. All the magnets 20 are similar and of similar polarity and the magnets 20 that lie at any stage at the bottom (as shown in Figure 1) of the vehicle, between pinion wheels 10, can exert an attraction or any magnetic surface with which they are in contact. It is envisaged that the attraction will be such as to enable the vehicle to hang upside-down from the iron plates of a ship's hull. For instance, the weight of the vehicle may be in the order of 75kg and the force exerted by the magnets may be in the order of 100kg, and this could be increased by longer and wider tracks. The cuter surface of each magnet 20 may be faced with anti-skid material, such as rubber, to mitigate any tendency of the magnets to slide on the surface with which they co-operate.

On engagement with the trailing pinion wheels 10, the magnets 20 will be pulled away from the magnetic surfaces with which they co-operate. To facilitate the separation, additional magnets 21 are fixed to the teeth of the pinion wheels 10, parallel to the axis of the wheel. The magnetism of the magnets 21 act in opposition to the magnets 20. For ease of manufacture, leading pionion wheels 10 are similar to the trailing pinion wheels 10. The magnets 21 that are associated with the leading pinion wheels also facilitate the motion of the vehicle in reverse.

As is illustrated at 25 in Figure 3, a spring jockey roller of known form is provided to put the return run of the tracks under tension so that the active run is not flabby.

In the embodiment illustrated in Figures 4 and 5, the magnetism by which the vehicle can be supported is provided by electromagnets 30. Each electromagnet 30 is disposed in a box 31 that extends for the width of the track and the boxes are provided with leading and trailing lugs 32 and 33 that are each connected to the next by pins 15a. The pins 15a are comparable to the pins 15 and similarly engaged between the teeth of the sprocket wheels.

Each box 31 is closed by a bottom wall 34 of magnetically insulating material having a co-efficient of friction of approximately 0.5. The core 35 of each electromagnet 30 is C-shaped and its ends fill openings in the wall 34, ending flush with the outer surface of the wall 34. They act as poles and face outwardly of the track. Between its ends, the core 35 is surrounded by a winding 36, the ends of which terminate in busbar contact 37 at one end and another busbar contact (not shown) at the other end. On a fillet 39, fixed relatively to the vehicle, are conducting strips 40 and 41 held at opposite polarities.

During the passage of the boxes 31 from the leading sprockets lOa to the trailing sprockets 10, the hussar contacts 37 slide along the strips 40 whilst the other contacts slide along the strips 41. The coils are thus energized and create the magnetic force by which the vehicle can be held to a support of magnetic material.

Claims

CLAIMS:

1. A vehicle having an endless drive track at each side and magnetic means distributed along, and moving with,the track so that the vehicle can cling to, whilst moving along, a magnetic surface from which it would fall were the magnetisation of the magnetic means absent.

2. A vehicle as claimed in claim 1 in which each track passes over two rollers and means is provided by which the force exerted by the magnetic means during the passage of the track from the leading roller to the trailing roller is greater than the force exerted as the track passes over the trailing roller.

3. A vehicle as claimed in claim 2 in which each track comprises a succession of links pivotally connected together by transverse pins, each roller is in the form of a sprocket wheel and the track is driven by engagement of the pins between the teeth of a sprocket wheel that can be rotated, each link carries a transversely extending bar magnet lying between the pins by which each link is connected to the next, the bar magnets are disposed with their polarities all similarly orientated and each tooth of the trailing sprocket wheel is provided with a transversley extending bar magnet, the polarities of the magnets with which the sprocket wheel is provided all having their polarities similarly orientated and being opposed to those of the magnets carried by the links.

4. A vehicle as claimed in claim 2 in which each track comprises a succession of similar electromagnet devices each providing a pole facing outwardly of the track, each device is pivotally connected to the next by a transverse pin, each roller is in the form of a sprocket wheel and the track is driven by engagement of the pins between the teeth of a sprocket wheel that can be rotated, the coil of each electromagnet device is provided with two busbar contacts, and the vehicle is provided with two busbars of opposite polarity so arranged that during the passage of each electromagnet device between the rollers the busbar contacts of the device slide along the busbars.

5. A vehicle as claimed in claim 4 in which the busbars are such that the contacts slide along them throughout substantially the entire movement of the device between the sprocket wheels.

6 A vehicle as claimed in either of claims 4 and 5 in which each electromagnet device has a core that is generally C-shaped, the core extends generally transversely of the track, and each end of the core acts as a pole facing outwardly of the track.

7. A vehicle substantially as described with reference to, and as illustrated by, Figures 1 to 3 of the accompanying drawing or these Figures modified as shown in Figures 4 and 5.