GB2103162A

GB2103162A - Apparatus moving on wall

Info

Publication number: GB2103162A
Application number: GB08219831A
Authority: GB
Inventors: Shirou Shimatani; Hitoshi Okamoto; Ryoji Orita
Original assignee: Mitsui Engineering and Shipbuilding Co Ltd
Current assignee: Mitsui Engineering and Shipbuilding Co Ltd
Priority date: 1981-07-17
Filing date: 1982-07-08
Publication date: 1983-02-16
Also published as: NO822477L; JPS5812075U; GB2103162B; DE3226291A1; ES514031A0; ES8402213A1

Abstract

Apparatus capable of moving on a wall while adhering thereto by magnet means comprises six endless track crawlers 2 each mounted on two spaced wheels 21 which are rotatably mounted on an arm 5 which is seesawably mounted on the body of the apparatus, whereby if one of the crawlers is in part caused to leave the wail surface, the apparatus as a whole is kept in contact with the wall surface. The six crawlers are driven through chains by electric motors supplied from a battery. An engine 6 drives a generator 7 supplying electricity to the battery. The apparatus can be used for painting, film thickness or surface roughness measurement, grinding or cleaning. The apparatus particularly described carries an eddy-current type film thickness measurement device. <IMAGE>

Description

SPECIFICATION Apparatus moving on wall The present invention relates to an apparatus moving on the wall for automatically performing in a remote control manner such operations as coating, measurement of film thickness, surface roughness measurement, grinding/cleaning operation, painting, cargo work, communication operation and the like on the side wall or the ceiling of a marine structure such as a vessel or an ordinary steel structure.

In recent years, for example, with the need for economy in fuel cost, it has been more frequent to paint vessels with a rust proof coating, an antifouling coating and the like, and also there has been an increasing demand for such operations as the measurement of the film thickness and the surface roughness of such coatings at the request of shipowners.

It is, however, apt to become difficult or even impossible to perform such measuring operations because they often have to be effected at places where scaffolding has already been removed or there is no lifting equipment. Therefore, it has been highly needed to cope with such problems considering the increasing necessity for the operations at such places.

There are, however, a few apparatus which automatically travel on a steel wall without any suspension equipment. Although some apparatus have been developed, such as a magnetic attraction moving apparatus utilizing the attraction force of a magnet, or a moving apparatus adapted to move in a measuring wormlike manner through the combination of an electromagnet and a stretchable frame, they are all unstable in magnetic adhesion to the wall, so that they easily fall off and are poor in steerability.

Therefore, they cannot be put to practical use.

The above mentioned magnetic attraction moving apparatus, for example, is apt to fall off when running onto an obstacle and when the non magnetic-adhesion portion spreads, because the attraction force of the magnet on the apparatus is small as compared with the apparatus's own weight, while the abovementioned measuring worm-like moving apparatus is difficult to turn, so that it is impossible to obtain a sufficient moving performance.

On the other hand, a moving apparatus having a crawler equipped with a magnet has been devised. When riding across such an obstacle as a curved surface or a projection, however, the apparatus falls off in a loop-the-loop manner when separation, which starts from the front end of the crawler, becomes large.

In addition, the abovementioned separation becomes more apt to occur when the tension of the crawler is increased in order to bear the load in the vertical direction.

It is, therefore, an object of the present invention to provide a moving apparatus on the wall which never falls off from the wall when riding across such an obstacle as a curved surface or a projection.

To this end, according to the invention, there is provided an apparatus moving on the wall capable of moving on a wall while adhering thereto by means of a magnet provided to an endless driving means or a crawler, characterized in that two wheels stretching the crawler are rotatably mounted on an arm, which is seesawably mounted on the body of the apparatus moving on the wall.

Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings.

Fig. 1 is a side view of an apparatus moving on the wall according to the present invention; Fig. 2 is a plan view of the apparatus moving on the wall according to the present invention; Fig. 3 (A) through Fig. 3 (D) are side views of the apparatus moving on the wall according to the present invention, particularly showing it riding across an obstacle; and Fig. 4 is a side view of a hull, particularly showing it being measured in coating film thickness by means of the apparatus moving on the wall according to the present invention.

As shown in Fig. 1 and Fig. 2, an apparatus moving on the wall 1 is provided with three driving shafts 30a, 30b and 30c on each of its right and left sides, and an arm 5 is seesawably mounted on each of these driving shafts 30a, 30b and 30c.

Each of the arms 5 is provided with a shaft 31 at each of its ends, and a wheel 21 is rotatably mounted at the outer end portion of each of the shafts 31. Then, an endless driving means or a crawler 2 is stretched between the two wheels 21 mounted on each of the arms 5, and a permanent magnet (not shown) is attached to the outside portion of each of the crawlers 2 so as to enable the apparaus moving on the wall 1 to adhere to a steel structure such as a hull.

A gear 3a is secured to one of the two shafts 21 mounted on each of the abovementioned arms 5, and gears 3b engaging with the gears 3a respectively are secured to the abovementioned driving shafts 30a, 30b and 30c respectively.

Moreover, chain wheels 32a, 22b and 32c are secured to the driving shafts 30a, 30b and 30c respectively, and a chain 4a is stretched between the chain wheels 32a and 32b while a chain 4b is stretched between the chain wheels 32b and 32c.

Then, the rotation of the driving shaft 30a is transmitted to the driving shaft 30b through the chain 4a and further transmitted to the driving shaft 30c through both the chains 4a and 4b.

As shown in Fig 2, the abovementioned apparatus 1 is provided with a generator 7 driven by a gasoline engine 6, and the electricity generated by the generator 7 is once stored in a battery 11. Morever, the apparatus 1 is provided with electric motors 8 rotated by means of the electricity from the battery 11, and the rotational forces of the motors 8 are transmitted to the abovementioned driving shafts 30a through reduction gears 9 respectively.

In addition, the electric motors 8 are controlled from a remote place as shown in Fig. 4 by means of a radio controller 17 with an antenna 1 4c so as to operate in the forward and reverse directions by means of resistors attached to servomotors 10, respectively, controlled by means of a radio controller receiver 16 with an antenna 14a mounted on the apparatus 1.

In measuring the coating film thickness, instructions are given through the radio controller 1 7 so that an eddy-current type film thickness measuring sensor 1 5 is pressed against a wall 25 of a hull 40 by means of the servomotors 10 controlled through the radio controller receiver 1 6 mounted on the apparaus 1.

The measured current value is passed through an A/D converter 13 and a telemeter 12 and sent from an antenna 1 4b to a telemeter 20 at a remote place, where the value is converted into a film thickness value and displayed on a film thickness meter 1 9 as well as recorded in a data printer 18, the telemeter 20 having an antenna 14d.

The operation of the apparatus moving on the wall will be described herein under with reference to Fig. 3 (A) through Fig. 3 (D). For easier understanding, the crawlers 2 are denoted by the first crawler 2a, the second crawler 2b and the third crawler 2c from the front end toward the rear end of the apparatus moving on the wall.

As shown in Fig. 3 (A), when the apparatus, moving along the wall 25 of the hull in the direction of an arrow A, rides across an obstacle 26, the first crawler 2a runs thereonto from its front end and substantially loses its magnetic adhesion, but a magnetic adhesion needed for attaching the apparatus to the wall can be maintained by both the second and third crawlers 2b and 2c.

When the apparatus further moves forward and the obstacle 26 is located at the substantially central portion of the first crawler 2a as shown in Fig. 3 (B), the obstacle 26 tries to lift the apparatus from the wall, but the apparatus is pressed against the wall by the strong magnetic adhesion forces of the second and third crawlers 2b and 2c.

When the apparatus furthermore moves forward and the obstacle 26 is located at the rear end of the first crawler 2a as shown in Fig. 3 (C), the obstacle 26 lifts the rear portion of the first crawler 2a from the wall, allowing the magnetic adhesion of the front end of the first crawler 2a to be recovered.

Even under this condition, both the second and third crawlers 2b and 2c maintain their strong magnetic adhesion forces to press the apparatus against the wall.

When the apparatus furthermore moves forward and the obstacle 26 is located between the first and second crawlers 2a and 2b as shown in Fig. 3 (D), the first, second and third crawlers 2a, 2b and 2c all magnetically adhere to the wall 25.

While allowing the second and third crawlers 2b and 2c to successively operate similarly to the first crawler 2a, the apparatus can further move on the steelplate wall 25 with the obstacle 26 without falling off.

As mentioned above, because in the apparatus moving on the wall according to the present invention, two wheels stretching each crawler adapted to be adherable to the wall by means of a magnet are supported by the arm and because the arm is seesawably mounted on the body of the apparatus moving on the wall, the aforementioned crawlers seesaw about the aforementioned shafts respectively.

Accordingly, if a part of the crawlers is separated from the wall when the apparatus rides across an obstacle such as a projection, the separated part magnetically adheres to the wall again, so that the apparatus can move at will without falling off from a steel-plate wall.

As a result, by the application of the present invention, it is possible to safely and highly accurately perform various operations such as film thickness measurement, surface roughness measurement, grinding/cleaning operation, painting and the like on the outside wall of a hull and the wall, ceiling and horizontal portions of other steel structures.

Claims

1. An apparatus moving on the wall capable of moving on a wall while adhereing thereto by means of a magnet provided to an endless driving means or a crawler, wherein two wheels stretching the crawler are rotatably mounted on an arm, which is seesawably mounted on the body of the apparatus moving on the wall.

2. An apparatus moving on the wall as defined in claim 1, wherein said arm is mounted on the apparatus moving on the wall so as to seesaw about the central part of said arm.

3. An apparatus moving on the wall as defined in claim 1 or 2, wherein said arm is seesawably mounted on a driving shaft.

4. An apparatus moving on the wall as defined in claim 1, having a plurality of endless driving means on end of its sides.

5. An apparatus moving on the wall as defined in claim 1 or 4, having three endless driving means on each of its sides.

6. Apparatus substantially as hereinbefore described with reference to and as shown in the accompanying drawings.