Device capable of adhering to a wall surface by suction and treating it

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BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a device capable of suction-adhering to a wall surface by the pressure of an ambient fluid such as air or water and treating the wall surface. More specifically, it relates, although not exclusively, to a device capable of suction-adhering to a wall surface of a ship or a building and cleaning or otherwise treating the wall surface.

2. Description of the Prior Art

A device for performing work such as cleaning of an outside wall surface of a ship, an outside wall surface of an oil reservoir tank, an outside surface of a tall building, etc. is proposed in U.S. Pat. No. 4,095,378 to F. Urakami which comprises a pressure receiver housing, a plurality of wheels provided in the pressure receiver housing for contact with the wall surface, a partition having one end connected to the pressure receiver housing and adapted to define a substantially fluid-tight pressure reduction zone in cooperation with the pressure receiver housing and the wall surface upon partial contact with the wall surface, means for discharging fluid from the pressure reduction zone to create a vacuum within the pressure reduction zone, and working means provided in the pressure receiver housing.

In this conventional device, a vacuum is formed within the pressure reduction zone by vacuum-producing means, and a part of the partition is contacted fluid-tight with the wall surface by the fluid pressure acting on the partition owing to a difference in fluid pressure between the inside and outside of the pressure reduction zone. In the meanwhile, the fluid pressure acting on the pressure receiver housing owing to a difference in pressure reduction zone is transmitted to the wall surface via the wheels. As a result, the device is caused to adhere by suction to the wall surface. The device suction-adhering to the wall surface is adapted to move along the wall surface by driving the wheels. Hence, the above-described device can adhere to the wall surface by suction and can move along it. By the working means provided in it, it can perform the desired work such as cleaning of the wall surface.

In the known device, means for causing the device to adhere by suction to the wall surface and move along it and treating means for performing treatments such as cleaning of the wall surface are constructed independently from each other. This structure increases the size and weight of the entire device and leads to a high cost of production.

SUMMARY OF THE INVENTION

It is an object of this invention to provide a novel and excellent device which can surely adhere to a wall surface by suction and treat the wall surface in a required manner by a simple construction, and which is conductive to a reduction in size and the cost of production.

Another object of this invention is to provide a novel and excellent device capable of suction-adhering to a wall surface and uniformly treating the wall surface while moving along it.

Other objects of this invention will become apparent from the following description.

According to this invention, there is provided a device capable of adhering to a wall surface by suction by the pressure of an ambient fluid and treating the wall surface, said device comprising

a pressure receiver member made of a rigid or semirigid material,

a partition provided on that side of the pressure receiver member which faces the wall surface, the partition being movable relative to the pressure receiver member, and a part of the partition being adapted to make contact with the wall surface to define a pressure reduction zone in cooperation with the pressure receiver member and the wall surface,

means for creating a vacuum within the pressure reduction zone by discharging the fluid from the pressure reduction zone, and

a driving source mounted on the pressure receiver member for moving the partition with respect to the pressure receiver member;

wherein the device is caused to adhere to the wall surface by suction owing to a difference in fluid pressure between the inside and outside of the pressure reduction zone, and the wall surface is treated by moving the partition by the driving source.

According to another aspect of this invention, there is provided a device capable of adhering to a wall surface by suction by the pressure of an ambient fluid and treating the wall surface, said device comprising

a main body,

a pressure receiver member made of a rigid or semirigid material and mounted on the main body for free relative movement with respect to the main body,

a partition provided on that side of the pressure receiver member which faces the wall surface, one end portion of the partition being connected to the pressure receiver member, and a part of the partition being adapted to make contact with the wall surface to define a pressure reduction zone in cooperation with the pressure receiver member and the wall surface,

means for creating a vacuum within the pressure reduction zone by discharging the fluid from the pressure reduction zone, and

a driving source mounted on the main body for moving the pressure receiver member with respect to the main body;

wherein the device is caused to adhere to the wall surface by suction owing to a difference in fluid pressure between the inside and outside of the pressure reduction zone, and the wall surface is treated by moving the partition by the driving source.

In these devices of the invention, a part of the partition is adapted to make contact with the wall surface to define the pressure reduction zone in cooperation with the pressure receiver member and the wall surface, and the partition or the pressure receiver member to which the partition is connected is mounted movably with respect to the pressure receiver member or the main body of the device. Accordingly, the partition has a sealing function of preventing an outside fluid from flowing in a large amount into the pressure reduction zone and a treating function of treating the wall surface in a desired manner by being moved with respect to the pressure receiver member or the main body of the device. The devices, therefore, do not separately require means for treating the wall surface, and can be simplified and reduced in size.

According to still another aspect of the invention, there is provided a device capable of adhering to a wall surface by suction by the pressure of an ambient fluid and treating the wall surface, said device comprising

a pressure receiver member made of a rigid or a semirigid material,

a partition provided on that side of the pressure receiver member which faces the wall surface, the partition being rotatable with respect to the pressure receiver member about an axis of rotation slightly inclined to an axis substantially perpendicular to the wall surface, and a part of the partition being adapted to make contact with the wall surface to define a pressure reduction zone in cooperation with the pressure receiver member and the wall surface, means for creating a vacuum within the pressure reduction zone by discharging the fluid from the pressure reduction zone, and

a driving source mounted on the pressure receiver member for rotating the partition with respect to the pressure receiver member;

wherein the device is caused to adhere to the wall surface by suction owing to a difference in fluid pressure between the inside and outside of the pressure reduction zone, and the device is moved by rotating the partition by the driving source.

According to yet another aspect of the invention, there is provided a device capable of adhering to a wall surface by suction by the pressure of an ambient fluid and treating the wall surface, said device comprising

a main body,

a pressure receiver member made of a rigid or semirigid material and mounted on the main body for free movement about an axis of rotation slightly inclined to an axis substantially perpendicular to the wall surface,

a partition provided on that side of the pressure receiver member which faces the wall surface, one end portion of the partition being connected to the pressure receiver member, and a part of the partition being adapted to make contact with the wall surface to define a pressure reduction zone in cooperation with the pressure receiver member and the wall surface, means for creating a vacuum within the pressure reduction zone by discharging the fluid from the pressure reduction zone, and

a driving source mounted on the main body for rotating the pressure receiver member with respect to the main body;

wherein the device is caused to adhere by suction to the wall surface owing to a difference in fluid pressure between the inside and outside of the pressure reduction zone, and the device is moved by rotating the partition by the driving source.

In these devices of the invention, a part of the partition is adapted to make contact with the wall surface to define the pressure reduction zone in cooperation with the pressure receiver member and the wall surface. The partition or the pressure receiver member to which the partition is connected is mounted rotatably about an axis of rotation slightly inclined to an axis substantially perpendicular to the wall surface with respect to the pressure receiver member or the main body of the device. Accordingly, the partition has a sealing function of preventing an outside fluid from flowing in a large amount into the pressure reduction zone, and a travelling function of moving the device by being rotated with respect to the pressure receiver member or the main body of the device. The partition can therefore serve also as part of travelling means for moving the device, and the simplification and size reduction in the device can be achieved.

In embodiments of these devices, the partition has a treating function of treating the wall surface in addition to the sealing function and the travelling function. As a result, the device do not separately require means for treating the wall surface. Thus, the present invention achieves further simplification and size reduction in devices capable of moving along a wall surface and treating it.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view showing a first embodiment of the device constructed in accordance with this invention;

FIG. 2 is a side elevation of the device shown in FIG. 1;

FIG. 3 is a sectional view taken along line III--III of FIG. 1;

FIG. 4 is a rough view showing the state in which a job of a wall surface is done by using the device of FIG. 1;

FIG. 5A is a sectional view showing the peripheral edge portion of a pressure receiver member in the device of FIG. 1 on an enlarged scale;

FIG. 5-B is a sectional view showing the peripheral edge portion of a pressure receiving member in the device equipped with a modified partition on an enlarged scale;

FIG. 6 is a sectional view showing the peripheral edge portion of a pressure receiving member in the device equipped with another modified partition on an enlarged scale;

FIG. 7 is a top plan view of a second embodiment of the device constructed in accordance with this invention;

FIG. 8 is a sectional view taken along line VIII--VIII of FIG. 7;

FIG. 9 is a sectional view showing a third embodiment of the device constructed in accordance with this invention;

FIG. 10 is a top plan view showing a fourth embodiment of the device constructed in accordance with this invention;

FIG. 11 is a side elevation of the device shown in FIG. 10;

FIG. 12 is a sectional view taken along line XII--XII of FIG. 10;

FIGS. 13-A and 13-B are simplified views for illustrating the travelling directions of the device shown in FIG. 10;

FIG. 14 is a sectional view showing a fifth embodiment of the device constructed in accordance with this invention; and

FIG. 15 is a sectional view showing a sixth embodiment of the device constructed in accordance with this invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred embodiments of the device constructed in accordance with this invention will be described in detail with reference to the accompanying drawings.

With reference mainly to FIGS. 1 to 3, a first embodiment of the device of this invention will be described.

The apparatus of the first embodiment shown in FIGS. 1 to 3 includes a pressure receiver member 2 made of a rigid or semirigid material such as a steel plate. The pressure receiver member 2 may be of any suitable shape which defines a pressure reduction zone 6 in cooperation with a partition and a wall surface to which the device adheres by suction. In the illustrated embodiment, the pressure receiver member 2 is of a generally circular shape. A shaft member 8 is fixed to a central part of the outside surface of the pressure receiver member 2 (that surface of the pressure receiver member 2 which is opposite to the surface facing the wall surface 4). It has a large-diameter portion 8a extending substantially perpendicularly outwardly and a small-diameter portion 8b extending further outwardly from the large-diameter portion. The large-diameter portion 8a and the small-diameter portion 8b of the shaft member 8 are each rotatably mounted on a main body 12 of the device through bearings 10. Specifically, the large-diameter portion 8a is rotatably supported on a cylindrical wall 14 of the main body 12 through the bearing 10, and the small-diameter portion 8b is rotatably supported on a cylindrical projecting wall 18 extending outwardly from an upper wall 16 of the main body 12 through the bearing 10. It will be understood from FIG. 3 that the bearings 10 used are those for thrust loads and radial loads. The free end of the shaft member 8 projects outwardly through the cylindrical projecting wall 18, and a pulley 20 having two V-shaped grooves is mounted on the free projecting end of the shaft member 8. A driving source 22 such as an electric motor is mounted on the main body 12 of the device. A pulley 24 having two V-shaped grooves is mounted on the output terminal of the driving source 22 as in the shaft member 8. Two belts 26 are wrapped between the pulleys 20 and 24. Hence, when the driving source 22 is rotated, the shaft member 8 is rotated in a direction of an arrow 26 (FIG. 1) via the belts 26, and the pressure receiver member 2, in turn, is rotated about the central axis of the shaft member 8, i.e. an axis of rotation extending substantially perpendicularly to the wall surface 4.

A rigid frame member 28 is fixed to the main body 12 of the device, and wheels 32a, 32b, 32c and 32d are rotatably mounted respectively on four leg portions 30a, 30b, 30c and 30d of the frame member 28 (FIG. 1). As will be described in detail hereinafter, in this embodiment, the wheels 32a, 32b, 32c and 32d are urged against, and kept in contact with, the wall surface 4 by the pressure of an ambient fluid acting on the pressure receiver member 2. Two electric motors 34a and 34b constituting a driving source are attached to the frame member 28. Preferably, the electric motors 34a and 34b can rotate in two directions. The electric motor 34a is drivingly connected to the wheels 32a and 32b via a suitable power transmission means such as a chain 36 and a sprocket to rotate the wheels 32a and 32b. Likewise, the electric motor 34b is drivingly connected to the wheels 32c and 32d via a suitable power transmission means such as a chain 38 and a sprocket to rotate the wheels 32c and 32d. In the illustrated embodiment, four wheels are used. Alternatively, three or five or more wheels may be used. Furthermore, instead of the wheels, two or more endless tracks known per se may be used.

A partition 40 is disposed on the peripheral edge portion of the inside surface of the pressure receiver member 2 (that surface of the pressure receiver member 2 which faces the wall surface 4). As can be easily seen from FIG. 3, one end of the partition 40 is connected to the pressure receiver member 2, and a part of the partition 40 makes contact with the wall surface 4. In cooperation with the pressure receiver member 2 and the wall surface 4, the partition 40 defines the pressure reduction zone 6. Preferably, at least that part of the partition 40 which makes contact with the wall surface 4 can be displaced by a relatively small force toward and away from the wall surface 4 with respect to the pressure receiver member 2. Accordingly, in the first embodiment, the partition 40 is constructed of a relatively thin plate-like annular member 42 and a relatively thick annular member 44 fixed to the peripheral part of the annular member 42, as shown in FIG. 3. One end portion of the partition 40, i.e., the inner circumferential portion of the annular member 42, is connected to the peripheral edge part of the inner surface of the pressure receiver member 2 by a suitable means such as a bolt 46, and the inner circumferential part of the annular member 42 is pressed against the pressure receiver member 2 by a pressing plate 47. The annular member 42 is formed preferably of a flexible material such as a polyurethane rubber. This enables the inner circumferential portion of the annular member 42, i.e., that portion of the annular member 42 which is connected to the pressure receiver member 2, to be displaced by a relatively small force toward and away from the wall surface 4. In the illustrated embodiment, the annular member 44 is also made of a flexible material such as a polyurethane rubber.

The pressure reduction zone 6 defined by the pressure receiver member 2, the partition 40 and the wall surface 4 is caused to communicate with means for forming a vacuum within the pressure reduction zone 6, such as a vacuum pump or a liquid pump. With reference to FIGS. 3 and 4, an axially extending hollow portion 48 is formed in the large-diameter portion 8a of the shaft member 8. The hollow portion 48 is caused to communicate with the pressure reduction zone 6 through an opening formed in the pressure receiver member 2. A stepped portion 8c is formed in the large-diameter portion 8a of the shaft member 8 (more specifically between the small diameter portion 8b and that part of the large-diameter portion 8a which is supported on the bearing 10). An annular space 50 is defined between the peripheral surface of the stepped portion 8c and the inner circumferential surface of the cylindrical wall 14 of the main body 12 of the device. The hollow portion 48 communicates with the annular space 50 through a plurality of holes 52 formed in a stepped portion 8c. A connecting portion 54 is formed in the cylindrical wall 14 as an integral unit. One end portion of a flexible hose 56 is connected to the connecting portion 54, and its other end is connected to an exhaust means such as a vacuum pump 58 via a separator 57. The vacuum pump 58 is operated, for example, by an engine 60. Desirably, a vacuum breaker (not shown) is provided in order prevent the vacuum produced within the pressure reduction zone 6 from attaining a degree of vacuum above a certain limit.

The device described above can be applied, for example, to a job of treating the outside wall surface 4 of an oil reservoir tank 62 as shown in FIG. 4. In FIG. 4, the illustrated device can be operated by a remote control method, and the driving source 22 and the electric motors 34a and 34b provided in the device can be operated and controlled when the operator manipulates a control box 65 connected to the device through a cable 63. A rope 64 is stretched alongside the wall surface and a known fall-preventing member 66 is secured to the rope 64. The fall-preventing member 66 is equipped with a wind-up drum (not shown), and an output end of the rope 68 wound upon the wind-up drum is connected to the frame member 28, for example, of the illustrated device. On the other hand, the separator 57, the vacuum pump 58 and the engine 60 are secured to a track 70 movable over the ground.

The operation and advantages of the illustrated device will be described mainly with reference to FIG. 3. For example, when the vacuum pump 58 is operated in the state shown in FIG. 4, a fluid (air when the device is used in the open atmosphere as in FIG. 4) within the pressure reduction zone 6 is discharged out of the zone 6 via the hollow portion 48 of the shaft member 8, the holes 52 formed in the shaft member 8, the annular space 50 and the flexible hose 56, whereby a vacuum is created within the pressure reduction zone 6. Preferably, at this time, a seal member 71 is mounted, for example, as shown in FIG. 3 in order to prevent the inflow of a fluid from outside into the annular space 50.

One end portion of the partition 40 is connected to the pressure receiver member 2 so that it can be displaced toward and away from the wall surface 4 by a relatively small force. On the other hand, the wheels 32a, 32b, 32c and 32d are provided in the pressure receiver member 2 through the rigid frame 28 substantially all. When a vacuum is created within the pressure reduction zone 6, substantially all the pressure of an ambient fluid acting on the pressure receiver member 2 owing to a difference in fluid pressure between the inside and outside of the pressure reduction zone 6 is transmitted to the wheels 32a, 32b, 32c and 32d from the pressure receiver member 2 via the bearings 10, the main body 12 of the device and the rigid frame 28, and further transmitted to the wall surface via these wheels, as can be easily seen from FIG. 3. As a result, the device is caused to adhere to the wall surface 4 by suction.

On the other hand, the pressure of an ambient fluid acting on the partition 40, particularly on the annular member 42, owing to a difference in fluid pressure between the inside and outside of the pressure reduction zone 6 acts so as to bias the partition 40, i.e. the annular member 42 and the annular member 44, toward the wall surface 4 and contact the annular member 44 with the wall surface 4, as shown by a broken arrow in FIG. 5-A. Consequently, the partition 40 (the annular member 44 in the embodiment) makes contact with the wall surface 4, and the contacting pressure makes possible a job of treating the wall surface 4. The pressure reduction zone 6 defined by the partition 40 is substantially fluid tight, or may have some air permeability.

When the driving source 22 is energized while the device adheres to the wall surface 4 in this way, the pressure receiver member 2 is rotated in the direction of arrow 26 (FIG. 1) via the pulley 24, the belts 26, the pulley 20 and the shaft member 8. As a result, the partition 40 is also rotated in the direction of arrow 26 as a unit with the pressure receiver member 2, and by the rotation of the partition 40, the wall surface 4 can be cleaned. In the suction-adhering state, a part of the partition 40, i.e. the annular member 44, is kept in contact with the wall surface 4. Thus, when the partition 40 is rotated by the energization of the driving source 22, the annular member 44 moves while acting on the wall surface 4 and thereby cleans the surface 4. In the illustrated embodiment, the one end portion of the partition 40 is connected to the pressure receiver member 2, so that it can be displaced toward and away from the wall surface 4 by a relatively small force, and the partition 40 is brought into contact with the wall surface 4 by the pressure of an ambient fluid acting on it. Hence, the pressure of contact between the partition 40 and the wall surface 4, namely the pressure of the cleaning operation, can be maintained constant and the wall surface can be cleaned substantially uniformly. The pressure of contact between the partition 40 and the wall surface 4 is affected by the pressure of the fluid acting on the partition 40 substantially irrespective of the fluid pressure acting on the pressure receiver member 2 owing to a difference in fluid pressure between the inside and outside of the pressure reduction zone 6, and can be easily changed by changing the pressure receiving area of the partition 40. In this regard, a suction force required for the adherence of the device to the wall surface 4 can be obtained by prescribing the pressure-receiving area of the pressure receiver member 2 at a suitable value.

Since in the cleaning operation, some gap exists between the partition 40 and the wall surface 4 by the rough nature of the wall surface 4, the fluid from outside flows at high speed into the pressure reduction zone 6 via the gap between the partition 40 and the wall surface 4. As a result, dust and dirt generated during cleaning are carried to the inside of the pressure reduction zone 6 on the high-speed fluid and is therefore prevented from scattering out of the device. The dust and dirt carried into the pressure reduction zone 6 is transferred to the separator 57 through the flexible hose 56 together with the fluid within the pressure reduction zone 6 by the action of the vacuum pump 58 and thus recovered by the separator 57.

The partition 40 may be formed of, for example, a brush-like member or a porous material. Alternatively, a plurality of small protrusions may be provided on that surface of the partition 40 which makes contact with the wall surface 4, and this can also increase the cleaning efficiency during the cleaning operation.

When the wall surface is to be cleaned, a partition 72 illustrated in FIG. 5-B may be conveniently used instead of the partition 40 shown in FIGS. 1 to 4 and 5-A.

In FIG. 5-B showing the peripheral edge portion of the pressure receiver member 2, the partition 72 is formed of an annular member made of a flexible material such as a polyurethane rubber. As is clear from FIG. 5-B, the partition 72 includes a main portion 78 extending outwardly toward the wall surface 4 from its one end connected to the peripheral edge portion of the pressure receiver member 2 by a suitable means such as a bolt 74 and having a free end portion 76 adapted to make contact with the wall surface 4, and an extension 80 extending outwardly from the free end portion 76 away from the wall surface 4. Since the partition 72 itself is formed of a flexible material, the free end 76 of the main portion 78 can be displaced toward and away from the wall surface 4 by a relatively small force because of the flexibility of the main portion 78.

Accordingly, when the partition 72 shown in FIG. 5-B partly on an enlarged scale is used instead of the partition 40 shown in FIG. 5-A partly on an enlarged scale, a similar effect can be produced because that portion of the partition 72 which makes contact with the wall surface 4 (i.e., the free end 76 of the main portion 78) can be displaced toward and away from the wall surface 4 by a relatively small force. Specifically, by the fluid pressure acting on the partition 72 owing to a difference in fluid pressure between the inside and outside of the pressure reduction zone 6, the free end portion 76 of the main portion 78 is brought into contact with the wall surface 4. In the meantime, the fluid pressure acting on the pressure receiver member 2 owing to a difference in fluid pressure between the inside and outside of the pressure reduction zone 6 is transmitted to the wheels 32a, 32b, 32c and 32d via the main body 12 of the device and the frame member 28 and further to the wall surface 4 via these wheels 32a to 32d. As a result, the device is caused to adhere to the wall surface 4 by suction.

Since the partition 72 has the extension 80 extending outwardly from the free end portion 76 to be contacted with the wall surface 4 and in a direction away from the wall surface 4, the use of the partition 72 has the advantage that even when protrusions exist on the wall surface 4, the partition 72 does not warp inwardly during the travelling of the device to be described, and can easily ride over the protrusions by the action of the extension 80.

When it is desired to remove solid matter adhering to the wall surface 4, a blade 82 may be attached as shown in FIG. 6 to the partition 72 shown in FIG. 5-B. In FIG. 6, the blade 82 which can be formed from a metallic material is attached to the partition 72, more specifically to that surface of the extension 80 which faces the wall surface 4, by a suitable means such as a bolt 84. Accordingly, the blade 82 rotates as a unit with the partition 72.

When the partition 72 equipped with the blade 82 is used, the rotating blade 82 acts on the solid matter adhering to the wall surface 4, and during the cleaning of the wall surface 4 by the partition 72, the solid matter can be surely removed by the blade 82.

The partition 72 shown in FIG. 6 can be conveniently used for cleaning the outside wall surface of a ship, and solid matter such as barnacles adhering to the outside wall surface of the ship can be easily removed by the action of the rotating blade 82.

Again with reference to FIGS. 1 to 3, the illustrated device can be caused to travel in a required manner while adhering to the wall surface by operating the electric motors 34a and 34b. For example, when the wheels 32a and 32b and the wheels 32c and 32d are rotated in the same direction by operating the electric motors 34a and 34b the device advances straight along the wall surface 4. When the wheels 32a and 32b and the wheels 32c and 32d are rotated in an opposite direction by operating the electric motors 34a and 34b, the device moves while rotating about its axis and is directed in the desired direction.

In the first embodiment shown in FIGS. 1 to 4, means for creating a vacuum in the pressure reduction zone is not directly mounted on the pressure receiver member, but is attached to a track movable over the ground. Instead of this arrangement, such means may be directly provided in the pressure receiver member as shown in FIGS. 7 and 8.

FIGS. 7 and 8 shown a second embodiment of the device in accordance with this invention. The device in the second embodiment has a pressure receiver member 102 which can be formed of a rigid or semirigid material. In the second embodiment, too, the pressure receiver member 102 is nearly circular as a whole. One end portion of a shaft member 104 is threadedly secured to a central portion of the pressure receiver member 102, and the other end of the shaft member 104 extends outwardly from the outside surface of the pressure receiver member 102 (that surface which is opposite to the surface facing a wall surface 106) in a direction substantially perpendicular to the pressure receiver member 102. The shaft member 104 is rotatably supported on the main body 110 of the device through bearings 108, and its other end is drivingly connected to the output shaft of a driving source 114 such as an electric motor mounted on the main body 110 of the device via a connecting means 112. The bearings 108 used are those for thrust loads and for radial loads. Hence, when the driving source 114 is rotated, the pressure receiver member 102 is rotated via the shaft member 104 about the central axis of the shaft member 104, namely about an axis of rotation extending substantially perpendicularly to the wall surface 106.

In the second embodiment, means for creating a vacuum within a pressure reduction zone 118 defined by the pressure receiver member 102, a partition 116 attached to the pressure receiver member 102 and the wall surface 106 is mounted on the pressure receiver member 102. Such means is comprised of a plurality of vanes 120. More specifically, an annular opening is formed in the pressure receiver member 102, and the plurality of (eight in the illustrated embodiment) vanes 120 are disposed within the annular opening 122 at predetermined intervals. The vanes 120 may be detachably mounted on the pressure receiver member 102, or as shown in the illustrated embodiment, may be formed as a integral unit with the pressure receiver member 102. These vanes 120 may be of any shape which permits a fluid within the pressure reduction zone 118 to be discharged outside through the annular opening 122 when the pressure receiver member 102 is rotated by the driving source 114.

The remainder of the device in the second embodiment is of substantially the same structure as the first embodiment. Specifically, a rigid frame member 124 is fixed to the main body 110 of the device, and wheels 128a, 128b, 128c and 128d are rotatably mounted on four leg portions 126a, 126b, 126c and 126d of the frame member 124. Two electric motors 130a and 130b constituting a driving source for travelling are provided in the frame member 124. To the peripheral portion of the pressure receiver member 102 is connected by a suitable means such as a bolt 132 a partition 116 having substantially the same structure as the partition 42 illustrated in FIGS. 1 to 4 and 5-A. Alternatively, the partition 72 illustrated in FIGS. 5-B or 6 may be used instead of the partition 116.

When the driving source 114 is operated in the second embodiment, the pressure receiver member 102 is rotated in a predetermined direction via the shaft member 104. As a result, the vanes 120 provided in the pressure receiver member 102 rotate as a unit with the pressure receiver member, and a fluid (for example, sea water when the device is used in the sea) within the pressure reduction zone 118 is discharged outside through the annular opening 122 to thereby create a vacuum within the pressure reduction zone 118 (in other words, to maintain the pressure reduction zone at a low pressure). Since the partition 116 has substantially the same structure as the first embodiment and is connected to the pressure receiver member 102, the fluid pressure acting on the pressure receiver member 102 owing to a difference in fluid pressure between the inside and outside of the pressure reduction zone 118 is transmitted to the wheels 128a, 128b, 128c and 128d through the shaft member 104, the bearings 108, the main body 110 of the device and the frame member 124, and further to the wall surface 106 via these wheels 128a to 128d to thereby cause the device to adhere to the wall surface 106 by suction. In the meanwhile, the fluid pressure acting on the partition 116, particularly an annular member 134, owing to a difference in fluid pressure between the inside and outside of the pressure reduction zone 118 biases the partition 116, that is the annular member 134 and an annular member 136, toward the wall surface 106. As a result, the annular member 136 is brought into contact with the wall surface 106. Furthermore, the partition 116 is rotated as a unit with the pressure receiver member 102, and the wall surface 106 is consequently cleaned.

Accordingly, the second embodiment also achieves the same result as the first embodiment. Furthermore, the device of the second embodiment can be made more simplified and reduced in size because the driving source 114 can be utilized not only to rotate the partition 116 (in other words, to cause it to act for treating the wall surface 106) but also to rotate the vanes 120 (in other words, to cause it to act for pressure reduction in the pressure reduction zone 118).

If desired, an ejector may be provided directly in the pressure receiver member instead of providing the vanes.

In the first and second embodiments described above, the pressure receiver member and the partition are moved with respect to the main body of the device. Instead of this construction, the device may also be constructed such that the partition is moved with respect to the pressure receiver member as shown, for example, in FIG. 9.

FIG. 9 shows a third embodiment of this invention. The illustrated device includes a pressure receiver member 202 which may be formed of a rigid or semirigid material. In the third embodiment, the pressure receiver member 202 is of a nearly cylindrical box-like shape and is opened at that side which faces a wall surface 204.

A nearly circular rotating plate 208, which may be formed of, for example, a steel plate is disposed on that side of an opening 206 in the pressure receiver member 202 which faces the wall surface 204. A driving source 210 is mounted on the top wall of the pressure receiver member 202, and the output side of the driving source 210 extends through the pressure receiver member 202 and projects from the opening 206 toward the wall surface 204. To the projecting output end of the driving source 210 is fixed a central portion of the rotating plate 208 by a suitable means such as a bolt 212.

A partition 214 is attached to the peripheral edge portion of the rotating plate 208. The illustrated partition 214 is of substantially the same structure as the partition 72 shown in FIG. 5-B, and includes a main portion 218 extending outwardly toward the wall surface 204 from its one end connected to the rotating plate 208 by a suitable means such as a bolt and having a free end portion 216 to be contacted with the wall surface 204, and an extension 220 extending outwardly from the main portion 218 in a direction away from the wall surface 204. As can be clearly seen from FIG. 9, the partition 214 defines a pressure reduction zone 222 in cooperation with the pressure receiver member 202 and the wall surface 204. The rotating plate 208 has formed therein a plurality of holes 224 for communication between a first zone of the pressure reduction zone 222 defined by the rotating plate 208, the partition 214 and the wall surface 204 and a second zone of the pressure reduction zone 222 defined by the rotating plate 208 and the pressure receiver member 202. Instead of the partition 214, the partition shown in FIGS. 1 to 4 and 5-A and the partition shown in FIG. 6 may be used.

Preferably, an annular seal member 226 is provided between the pressure receiver member 202 and the rotating plate 208 as shown in FIG. 9. The seal member 226 is connected at one end portion to the periphery portion of the opening 206 of the pressure receiver member 202 by a suitable means, and extends outwardly from this end portion toward the rotating plate 208. The other end portion of the seal member 226 is thus kept in contact with the rotating plate 208. Desirably, the seal member 226 is formed of a non-permeable and flexible material such as a rubber. Because of the above-mentioned structure, when the driving source 210 is rotated, the rotating plate 208 and the partition 214 are rotated as a unit in a predetermined direction about the central axis of the output portion of the driving source 210, i.e. an axis of rotation extending substantially perpendicularly to the wall surface 204, with respect to the pressure receiver member 202 and the seal member 226.

The remainder of the device in the third embodiment has nearly the same