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FIELD OF THE INVENTION
This invention relates to a device capable of suction-adhering to a wall
surface or the like by the pressure of an ambient fluid such as air or
water and moving therealong.
DESCRIPTION OF THE PRIOR ART
An example of a device capable of suction-adhering to an inclined or
substantially perpendicular wall surface in ships, buildings, etc. and
moving therealong is disclosed, for example, in U.S. Pat. No. 4,095,378.
Such a device comprises a main body, wheels as moving means mounted on the
main body, a partitioning member connected to the main body and having its
free end portion adapted to make contact with a wall surface, and vacuum
creating means for discharging a fluid from a pressure reduction space
defined by the main body, the wall surface and the partitioning member.
When the vacuum creating means is energized in this device, the fluid
within the pressure reduction space is discharged outside, and the
pressure of the fluid acting on the main body of the device owing to the
difference in fluid pressure between the inside and the outside of the
pressure reduction space is transmitted to the wall surface via the wheel,
and the fluid pressure causes the device to suction-adhere to the wall
surface. When in this suction-adhering state, the wheel is rotated by
driving means such as an electric motor, the action of the wheel causes
the device to move along the wall surface.
The conventional device described above, however, has the following
problems to be solved.
Firstly, the partitioning member in the conventional device is comprised of
a plate-like member and connected at its one end portion to the main body
of the device. Its other end portion is adapted to make contact with the
wall surface. When the partitioning member is formed of a relatively
flexible material, its free end portion can easily move toward and away
from the wall surface following the raised and depressed parts of the wall
surface. But when it gets on a relatively large protruding object on the
wall surface, it tends to turn over inwardly. If the partitioning member
is formed of a relatively rigid material, occurrence of its turn-over is
reduced. Its free end portion, however, cannot follow the raised and
depressed parts of the wall surface, and its ability to seal the space
between the partitioning member and the wall surface is reduced.
Secondly, in the conventional device, the ground-contacting pressure of the
partitioning member depends upon the difference in fluid pressure between
the inside and outside of the pressure reduction space, and increases as
the difference in fluid pressure between the inside and the outside of the
pressure reduction space increases. Larger ground-contacting pressures
result in higher friction force between the partitioning member and the
wall suface. This will consequently lead to the need for a larger driving
power for moving the main body of the device, and also quicken wearing of
the free end portion of the partitioning member (that portion which makes
contact with the wall surface).
Thirdly, in the conventional device, the moving direction of its main body
is changed by changing the rotating speed of a plurality of wheels (for
example, the rotating speeds of a wheel disposed at a right portion and a
wheel disposed at a left portion are varied from each other). Slippage
therefore occurs between the wheels and the wall surface at the time of
changing the moving direction, and will injure the wall surface.
SUMMARY OF THE INVENTION
It is a primary object of this invention to provide an excellent device in
which a partitioning member follows the raised and depressed parts of a
wall surface to give a sufficient sealing performance.
Another object of this invention is provide an excellent device in which
the ground-contacting pressure of a partitioning member can be adjusted to
a desired value substantially irrespective of the pressure of a pressure
reduction space.
Still another object of this invention is to provide an excellent device in
which the moving direction of its main body can be changed without causing
inconveniences such as injury to a wall surface.
According to this invention, there is provided a device comprising a main
body, moving means mounted on the main body, a partitioning member mounted
on the main body and defining a pressure reduction space in cooperation
with the main body of the device and a wall surface, and vacuum creating
means for discharging a fluid from the pressure reduction space, said
device being adapted to suction-adhere to the wall surface by the pressure
of an ambient fluid acting on the main body of the device owing to the
difference in fluid pressure between the inside and outside of the
pressure reduction space and to move along the wall surface by the action
of the moving means; wherein
the partitioning member has an outside wall portion extending from one end
of said member connected to the main body of the device to a contacting
portion of said member which makes contact with the wall surface and an
inside wall portion located inwardly of the outside wall portion and
extending from said contacting portion to the other end of said member
connected to the main body of the device, and
a stretchable and contractible portion capable of stretching toward the
wall surface and contracting away from it is provided in at least one of
the outside wall portion and the inside wall portion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing one embodiment of the device in
accordance with this invention;
FIG. 2 is a top plan view of the device shown in FIG. 1;
FIG. 3 is a side view of the device shown in FIG. 1;
FIG. 4 is a side view showing the device of FIG. 1 in which at the time of
changing its moving direction, a pressure adjusting space is pressurized;
and
FIGS. 5-A, 5-B and 5-C are sectional views partly showing a first to a
third modified embodiment of the partitioning member in the device of this
invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The invention will be descried in detail with reference to the accompanying
drawings.
With reference to FIGS. 1 to 3, mainly FIG. 1, the illustrated device has a
main body shown generally at 2. The main body 2 is provided with a nearly
rectangular parallelpipedal housing 4 and a rotating member 6 mounted
rotatably on the housing 4. The left end portion in FIG. 1 of the housing
4 projects upwardly. The housing 4 is hollow, and communicates with a
pressure reduction space to be described. A circular opening is formed in
the upper wall 8 of the housing 4, and a supporting member 10 is fixed to
the opening by welding or like means. The supporting member 10 has a
disk-like main body portion 12 and a sleeve portion 14 projecting in
sleeve form from one surface of the main body portion 12. An electric
motor 16 constituting a driving source is secured to the outside surface
of the main body portion 12 by a plurality of screws 18. The output shaft
20 of the electric motor 16 projects into the sleeve portion 14 through
the opening formed in the main body portion 12 of the supporting member
10. Within the sleeve portion 14, a coupling member 24 having a receiving
portion 22 defined therein is rotatably supported via a bearing member 26.
The output shaft 20 projecting into the sleeve portion 14 is received in
the receiving portion 22 of the coupling member 24, and drivingly linked
to the coupling member 24 via a key member 26.
A circular opening is also formed nearly centrally in the lower wall 28 of
the housing 4, and the rotating member 6 is disposed in this opening. The
rotating member 6 is comprised of a circular plate 30 formed of a rigid or
semirigid material such as a steel sheet, and a circular opening is formed
in its central part. An annular flange 32 projecting toward the lower wall
28 of the housing 4 is provided in the inside edge portion of the circular
plate 30, and connected by a plurality of radially extending linking
portions 36 to an annular securing portion 34 disposed inwardly of the
annular flange 32. A plurality of radially extending reinforcing members
38 are provided on the upper surface of the circular plate 30 (see FIG. 2
also). The rotating member 6 is secured to the coupling member 24 by
mounting the annular securing portion 34 to the lower end portion of the
coupling member 24 and fixing a plate 42 to its end surface by means of a
screw 40. A key member 44 is interposed between the annular securing
portion 34 and the coupling member 24 to connect them drivingly to each
other. An annular spacer 46 is provided between the annular securing
portion 34 and the sleeve portion 14 of the supporting member 10. Thus,
when the electric motor 16 is energized, the rotating force of its output
shaft 20 is transmitted to the annular securing portion 34 of the rotating
member 6 via the key member 26, the coupling member 24 and the key member
44, whereby the rotating member 6 rotates relative to the housing 4.
A partitioning member 50 is attached to the outside edge portion of that
surface of the circular plate 30 which faces a wall surface 48. The
partitioning member 50 may be formed of a relatively flexible material
such as polyurethane rubber or synthetic resins. As shown in FIG. 1, the
partitioning member 50 has an outside wall portion 54 extending from its
one end portion connected to the peripheral edge part of the circular
plate 30 to its contacting portion 52 making contact with the wall surface
48 and an inside wall portion 56 inwardly of the outside wall portion 54
extending from the contacting portion 52 to its other end connected to the
circular plate 30. It will be seen from FIGS. 1 and 3 that the
partitioning member 50 is nearly annular in its entire shape, and its
outside wall portion 54 defines an outer circumferential surface while its
inside wall portion 56 defines an inner circumferential surface. In the
illustrated embodiment, annular flanges 58 and 60 extending radially
outwardly are provided integrally at the opposite ends of the partitioning
member 50. The outside flange 58 is held between the circular plate 30 and
an annular plate 64 by securing a plurality of bolts 62 to a fixing
annular plate 64 through the circular plate 30 and the annular flange 58.
The inside annular flange 60 is held between the circular plate 30 and an
annular plate 68 by projecting a plurality of bolts 66 through the annular
plate 68, the annular flange 60 and the circular plate 30 and securing
nuts 70 to the projecting end portions of the bolts 66.
It is critical that in the device of this invention, a strechable and
contractible portion should be provided in at least one of the outside
wall portion 54 and the inside wall portion 56 of the partitioning member
50. In the illustrated embodiment, the outside wall portion 54 extends
inwardly from its one end connected to the circular plate 30 in a straight
line in a direction approaching the wall surface 48. The inside wall
portion 56 has a first inclined portion 56a extending inwardly in a
straight line from the contacting portion 52 in a direction away from the
wall surface 48 and a second inclined portion 56b extending outwardly from
the first inclined portion 56a in a straight line in a direction away from
the wall surface 48. The first and second inclined portions 56a and 56b
constitute a bellows portion. In the illustrated embodiment, one flexed
part exists between the first inclined portion 56a and the second inclined
portion 56b. To increase the amount of stretching or contracting, two or
more such flexed parts may be provided.
The partitioning member 50 defines a pressure reduction space 72 in
cooperation with the main body 2 of the device (particularly, the rotating
member 6) and the wall surface 48. The pressure reduction space 72
communicates with the housing 4 through the opening formed in the circular
plate 30 and the opening defined by the annular flange 32, the annular
securing portion 34 and the linking portion 36. A connecting tube portion
76 is provided in the left end wall in FIG. 1 of the housing 4 and
connected to vacuum creating means 78 such as a vacuum pump via a flexible
hose (not shown), for example. When the vacuum creating means 78 is
energized, a fluid such as air in the pressure reduction space 72 is
discharged outside through the housing 4 and the aforesaid hose (not
shown) to reduce the pressure of the pressure reduction space 72. In the
illustrated embodiment, an annular seal member 80 is disposed in order to
prevent entry of the fluid through the opening formed in the lower wall 28
of the housing 4. The outer circumferential edge of the seal member 80 is
held between the lower wall 28 and the annular plate 84 by securing a
plurality of bolts 82 to a fixing annular plate 84. Its inner
circumferential edge portion is kept in contact with the peripheral
surface of the annular flange 32.
The pressure of the pressure reduction space 72 can be adjusted by pressure
adjusting means 86 comprising a valve body 88, a biasing spring 90 for
elastically biasing the valve body 88 toward a closing position and an
adjusting screw 92 for adjusting a preload on the biasing spring 90. A
circular opening is formed in the left end portion of the lower wall 28 of
the housing 4. A valve seat member 94 having a plurality of fan-like
openings formed in the circumferential direction is secured to the
circular opening. A guide shaft 98 is mounted on the central part of the
valve seat member 94 by means of a bolt 96. The guide shaft 98 extends
toward the upper wall 8 within the housing 4. A receiving portion 100 is
defined in the valve body 88, and by positioning the guide shaft 98 within
the receiving portion 100, the valve body 88 is mounted so as to be free
to move toward and away from the valve seat member 84. A rubber material
102 is bonded to that surface of the valve body 88 which makes contact
with the valve seat member 94 in order to increase sealability. A
rectangular opening is formed in the left end portion of the upper wall 8
of the housing 4, and a rectangular cover 106 is attached to the opening
by means of a plurality of screws 104. Preferably, a seal member 108 is
provided between the upper wall 8 and the cover 106. A screw fitting
member 110 having an internally threaded hole is fixed to the central part
of the cover 106, and the adjusting screw 92 is put on the screw fitting
member 110. One end portion of the adjusting screw 92 projects into the
housing 2 through the opening formed in the upper wall 8. A spring
receiving member 114 is secured to the projecting end portion of the screw
92 by means of a nut 112. The biasing spring 90 is interposed between the
spring receiving member 114 and a spring receiving portion 116 defined in
the valve body 88. A compression load is exerted in advance on the biasing
spring 90. Hence, this biasing spring 90 elastically biases the valve body
88 toward a closing position shown in FIG. 1 (at which the valve body 88
seats on the valve member 94). When the pressure of the pressure reduction
space 72 abnormally decreases, the pressure of a fluid such as atmospheric
air outside pushes the valve body 88 of the pressure adjusting means 86
upwardly in FIG. 1 against the force of the biasing spring 90, and the
outside fluid flows into the housing 4 through the space between the valve
body 88 and the valve seat member 94, thus preventing the abnormal
reduction of the pressure of the pressure reduction space 72.
Incidentally, when the adjusting screw 92 is turned in a predetermined
direction (or a direction opposite to it) by loosening a lock nut 118, the
spring receiving member 114 is moved downwardly (or upwardly) in FIG. 1
and accordingly, the pre-load on the biasing spring 90 becomes high(or
low), and the pressure of the pressure reduction space 72 can be set at a
lower (or higher) value.
A pressure adjusting space 120 is defined between the outside wall portion
54 and the inside wall portion 56 of the partitioning member 50. In the
illustrated embodiment, the pressure adjusting space 120 is defined by the
outside wall portion 54, the inside wall portion 56 and the peripheral
edge of the circular plate 30, and connected to variable pressure setting
means 122 via an opening 124 formed in the circular plate 30, a flow
passage 128 defined by the circular plate 30 and a member 126, a
through-hole 130 formed in the annular securing portion 34 of the rotating
member 6, holes 132 and 134 formed in the coupling member 24, a space
between the coupling member 24 and the supporting member 14, a hole 136
formed in the supporting member 14, flow passage 140 defined by a tube
member 138 fixed to the supporting member 14, a flow passage defined by a
connecting member 142 fastened to the supporting member 14 and a flow
passage defined by a hose (not shown) connected to the connecting member
142. The variable pressure setting means 122 is comprised of a combination
of vacuum creating means 144 such as a vacuum pump for discharging a fluid
such as air from the pressure adjusting space 120, a pressurized fluid
supply source 146 such as a compressor for supplying a pressurized fluid
such as compressed air to the pressure adjusting space 120, and a switch
valve 148 for connecting the vacuum creating means 144 or the pressurized
fluid supply source 146 to the pressure adjusting space 120. When the
switch valve 148 is held at a first position, the vacuum creating means
144 communicates with the pressure adjusting space 120. When it is held at
a second position, the pressurized fluid supply source communicates with
the pressure adjusting space 120.
With reference to FIGS. 2 and 3, a pair of auxiliary frames 150a and a pair
of auxiliary frames 150b are fixed respectively to both side walls of the
housing 4. A right frame 154a is mounted between the auxiliary frames 150a
by means of a bolt 152, and a left frame 154b if mounted between the
auxiliary frame 150b by means of a bolt 152. An electric motor 156
constituting driving source is mounted on one end portion of each of the
right frame 154a and the left frame 154b. A wheel 158 and a sprocket 160
are mounted on the output shaft of the motor 156 so as to rotate as a
unit. A rotating shaft 162 is rotatably mounted on the other end portion
of each of the frames 154a and 154b via a bearing member (not shown), and
a wheel 164 and a sprocket 166 are mounted on the rotating shaft 162 so as
to rotate as a unit. The sprocket 160 and the sprocket 166 are drivingly
connected via a chain 168. Hence, when each electric motor 156 is
energized, the wheel 158 is rotated in a predetermined direction, and its
rotating force is transmitted to the other wheel 164 via the sprocket 160,
the chain 168 and the sprocket 166. Desirably, the electric motor 156 can
be rotated both in a normal direction and in a reverse direction.
The operation and effect of the device described above will now be
described in detail.
Energization of the vacuum creating means 78 discharges a fluid such as air
in the pressure reduction space 72 outside through the housing 4 and the
hose (not shown), and the pressure reduction space 72 is reduced in
pressure. When the pressure of the pressure reduction space 72 decreases
abnormally, the valve body 88 is opened to permit the outside fluid such
as air to flow into the housing 4 through the valve seat member 94 and the
valve body 88, and consequently, the pressure of the pressure reduction
space 72 is maintained at a predetermined pressure set by the pressure
adjusting means 86. When the pressure of the pressure reduction space 72
thus decreases, the pressure of an ambient fluid such as atmospheric air
which acts on the main body 2 of the device (especially the rotating
member 6 acting as a pressure receiving member) owing to the difference in
fluid pressure between the inside and outside of the pressure reduction
space 72 is transmitted to the wall surface 48 via the right frame 154a,
the left frame 154b and the wheels 158 and 164. As a result, the main body
2 of the device suction-adheres to the wall surface 48 by the ambient
fluid pressure.
When the vacuum creating means 144 in the variable pressure setting means
122 is energized and the switch valve 148 is held at the first position,
the pressure adjusting space 120 of the partitioning member 50
communicates with the vacuum creating means 144 via the switch valve 148
and a fluid such as air in the pressure adjusting space 120 is discharged
outside to reduce the pressure of the pressure adjusting space 120 to a
desired value. The pressure of the pressure adjusting space 120 which
greatly affects the ground-contacting pressure of the partitioning member
50 can be set as follows. When the pressure Pa of the pressure adjusting
space 120 is set at a value lower than the outside pressure Po and higher
than the pressure Pb of the pressure adjusting space 72 (Po<Pa<Pb), the
fluid pressure of the pressure adjusting space 120 acting on the inside
wall portion 56 of the partitioning member 50 owing to the difference in
fluid pressure between the pressure adjusting space 120 and the pressure
reduction space 72 produces a force tending toward the wall surface 48
which acts on the contacting portion 52. Furthermore, the outside fluid
pressure acting on the outside wall portion 54 of the partitioning member
50 owing to the difference in fluid pressure between the outside and the
pressure adjusting means 120 produces a force in a direction away from the
wall surface 48 which acts on the contacting portion 52. Hence, the
contacting portion 52 of the partitioning member 50 is pressed against the
wall surface 48 by the difference between the force in a direction
approaching the wall surface 48 and the force in a direction away from the
wall surface 48. Thus, even when the fluid pressure of the pressure
reduction space 72 is set at a relatively low value, the ground-contacting
pressure of the contacting portion 52 can be lowered. In order to keep the
contacting portion 52 of the partitioning member 50 from substantially
leaving the wall surface 48, it is necessary to make the force in a
direction approaching the wall surface 48 larger than the force in a
direction away from the wall surface 48. It will be seen from the
foregoing statement that while the pressure of the pressure reduction
space 72 is maintained constant, the ground-contacting pressure of the
contacting portion 52 of the partitioning member 50 can be adjusted by
changing the pressure of the pressure adjusting space 120. When the
pressure of the pressure adjusting space 120 is made close to the pressure
of an outside fluid such as atmospheric air, the force in a direction away
from the wall surface 48 decreases and the ground-contacting pressure of
the contacting portion 52 becomes higher. On the other hand, when the
pressure of the pressure adjusting space 120 is made close to the pressure
of the reduction space 72, the force in a direction approaching the wall
surface 48 is lowered and the ground-contacting pressure of the contacting
portion 52 becomes lower.
When the electric motor 16 is energized in this suction-adhering state, the
rotating member 6 is rotated relative to the housing 4 because the
frictional force between the wall surface 48 and the wheels 158 and 164 is
large. Thus, the contacting portion 52 of the partitioning member 50
rotates while being in contact with the wall surface 48, and the wall
surface is cleaned by the action of the contacting portion 52. When the
electric motor 156 is energized and rotated in a normal (or reverse)
direction, the wheels 158 and 164 are rotated in a predetermined direction
(or in a direction opposite to it). The main body 2 of the device cleans
the wall surface 48 while moving to the left (or to the right) in FIG. 1
along the wall surface 48. When the main body 32 of the device so moves
and the partitioning member 50 passes over a protruding object (or a
depressed part) on the wall surface 48, the first inclined portion 56a and
the second inclined portion 56b constituting the stretchable and
contractible portion come closer to each other (or move apart from each
other) and the inside wall portion contracts (or stretches) in a direction
substantially perpendicular to the wall surface. Hence, the seal between
the contacting portion 52 and the wall surface 48 does not break.
Furthermore, since the inside wall portion 56 and the outside wall portion
54 are connected to the circular plate 30, the partitioning member 50 does
not turn over inwardly even when it comes into contact with a relatively
large protruding object on the wall surface. The partitioning member 50
can easily ride over the protruding object. Furthermore, since the
stretchable and contractible portion is provided in the inside wall
portion 56, the contacting portion 52 of the partitioning member 50 is
displaced relatively greatly in a direction toward and away from the wall
surface 48.
Surface treating means for blast cleaning, coating, sweeping, etc. of a
wall surface in a ship, etc. may be separately provided instead of
utilizing the partitioning member 50 as surface-treating means. In this
alternative, too, it is preferred to rotate the partitioning member 50 as
above during the movement of the main body 2 of the device. By so doing,
the frictional force between the contacting portion 52 of the partitioning
member 50 and the wall surface 48 can be decreased.
When it is desired to change the moving direction of the main body 2 of the
device, the electric motor 16 is deenergized, and then the pressurized
fluid supply source 146 in the variable pressure setting means 122 is
energized and at the same time, the switch valve 148 is held at the second
position. As a result, the pressure adjusting space 120 of the
partitioning member 50 communicates with the pressurized fluid supply
source 146 via the switch valve 148 and a pressurized fluid such as
compressed air is supplied to the pressure adjusting space 120 from the
pressurized fluid supply source 146. It is possible to energize the vacuum
creating means 144 and the pressurized fluid supply means 146 during the
operation of the device, and to reduce or elevate the pressure of the
pressure adjusting space 120 by operating the switch valve 148. When the
pressurized fluid is supplied to the pressure adjusting space 120, the
first inclined portion 56a and the second inclined portion 56b move apart
from each other by the action of the pressurized fluid and the inside wall
portion 56 stretches in a direction substantially perpendicular to the
wall surface 48. As a result, the above stretching of the inside wall
portion 56 pushes the rotating member 6 (as a unit with this, the housing
4, the right frame 154a and the left frame 154b) upwardly in a direction
away from the wall surface 48 and the wheels 158 and 164 are moved away
from the wall surface 48, as can be easily understood from a comparison of
FIGS. 3 and 4. Thereafter, the electric motor 16 is slightly revolved.
Since the partitioning member 50 is in contact with the wall surface 48,
and the relative rotation of it is hampered, the housing 4, the right
frame 154b, the left frame 154b and the wheels 158 and 164 are rotated,
and the moving direction of the main body 2 of the device can be changed.
Accordingly, the moving direction of the main body 2 of the device is
changed by the rotation of the housing 4 (and the wheels 158 and 164
mounted on it) to the relative to the partitioning member 50. Hence, no
inconvenience such as injury to the wall surface 48 occurs at the time of
changing the moving direction of the device. After the moving direction is
changed, the switch valve 148 is held at the first position, the pressure
of the pressure adjusting space 120 is reduced to a desired pressure, and
the rotating member 6 is rotated by energizing the electric motor 16.
Thus, the operation of cleaning the wall surface 48 is resumed.
It will be easily seen that the device described above may be used broadly
not only in a gas such as atmospheric air but also in a liquid such as
water or sea water.
In the illustrated embodiment, the stretchable and contractible portion is
provided in the inside wall portion of the partitioning member.
Alternatively, it may be provided in the outside wall portion.
Furthermore, as shown in FIGS. 5-A to 5-C, the stretchable and
contractible portion may be provided both in the inside and outside wall
portions.
In FIG. 5-A showing part of a first modified embodiment of the partitioning
member, the illustrated partitioning member 202 which may be formed of,
for example, polyurethane rubber has an outside wall portion 210 extending
from its one end connected to the peripheral edge of a circular plate 204
to a contacting portion 208 contacting a wall surface 206 and an inside
wall portion 214 located inwardly of the outside wall portion 210 and
extending from the contacting portion 208 to its other end connected to
the circular plate 204, and a pressure adjusting space 216 is defined
between the outside wall portion 210 and the inside wall portion 214. The
outside portion 210 has a first curved portion 210a projecting in
semicircular form in a direction approaching the wall surface 206 and a
second curved portion 210b following the first curved portion 210a and
projecting in semicircular form in a direction away from the wall surface
206. The first curved portion 210a and the second curved portion 210b
constitute a bellows portion functioning as a stretchable and contractible
portion. The inside wall portion 214 has a first inclined portion 214a
extending inwardly in a direction away from the wall surface 206, a second
inclined portion 214b following the first inclined portion 214a and
extending inclinedly outwardly in a direction away from the wall surface
206, and a third inclined portion 214c following the second inclined
portion 214b and extending inclinedly inwardly in a direction away from
the wall surface 206. The first to third inclined portions 214a, 214b and
214c constitute a bellows portion functioning as a stretchable and
contractible portion. A groove 220 for communication between the outside
and the pressure reduction space 218 is formed in the contacting portion
208 of the partitioning member 202. A plurality of such grooves 220 may be
provided in circumferentially spaced relationship on that surface of the
contacting portion 208 which makes contact with the wall surface 206.
Since the bellows portion as the strechable and contractible portion is
provided both in the outside wall portion 210 and the inside wall portion
214 in this first modified embodiment of the partitioning member, this
partitioning member 202 can move while following the raised and depressed
portions of the wall surface 206 more than the partitioning member
depicted in FIGS. 1 to 3. The grooves 220 formed in the contacting portion
208 act effectively on the wall surface 206 during the rotation of the
partitioning member 50 and increase the cleaning effect of the wall
surface 206. Since the fluid always flows through the grooves 220 when the
device is suction-adhering to the wall surface 206, dust, dirt, etc.
occurring during the cleaning operation are carried on the flow of the
fluid and collected in the pressure reduction space 222. Hence, scattering
of the dust, dirt, etc. outside may be eliminated.
FIG. 5-B shows a second modified embodiment of the partitioning member. The
illustrated partitioning member 320 has an outside wall portion 310
extending from its one end connected to the peripheral edge of a circular
plate 304 to a contacting portion 308 contacting a wall surface 306 and an
inside wall portion 312 located inwardly of the outside wall portion 310
and extending from the contacting portion 308 to its other end connected
to the circular plate 304, and a pressure adjusting space 314 is defined
between the outside wall portion 310 and the inside wall portion 312. The
outside wall portion 310 includes a first and a second curved portion 310a
and 310b projecting in a relatively small curvature toward the wall
surface 306 and a third curved portion 310c projecting at a relatively
large curvature in a direction away from the wall surface 306. The third
curved portion 310c existing between the first and second curved portions
310a and 310b mainly constitutes a bellows portion functioning as a
stretchable and contractible portion. The inside wall portion 312 has a
first curved portion 312a and a second curved portion 312b curving at a
relatively small curvature and a third curved portion 312c and a fourth
curved portion 312d curving at a relatively large curvature. The fourth
curved portion 312d projecting inwardly in nearly semicircular form mainly
constitutes a bellows portion functioning as a stretchable and
contractible portion. Furthermore, a plurality of circumferentially spaced
grooves 318 (only one of which is shown in FIG. 5-B) for communication
between the outside and the pressure reduction space 316 are formed in the
contacting portion 308 of the partitioning member 302.
The partitioning member 302 in the second modified embodiment may be used
in place of the partitioning member shown in FIGS. 1 to 3. It achieves
substantially the same effect as the partitioning member of the first
modified embodiment shown in FIG. 5-A although there is some difference in
shape.
In the modified embodiments shown in FIGS. 5-A and 5-B, grooves are formed
in the contacting portion of the partitioning member. Instead of providing
grooves, it is possible to attach an abrasive member having an abrasive
disposed on its surface to the contacting portion. In this arrangement,
the abrasive acts on the wall surface to clean it efficiently.
Furthermore, since the outside fluid flows into the pressure reduction
space through the spaces among the abrasive particles, the dust, dirt,
etc. occurring at the time of cleaning can be collected in the pressure
reduction space by the flow of the fluid.
FIG. 5-C shows a third modified embodiment of the partitioning member. In
the third modified embodiment, a lip portion is provided in the contacting
portion of the partitioning member.
In FIG. 5-C, an outwardly extending lip portion 322' is provided in the
contacting portion 308' of the partitioning member 302' which may be
formed of, for example, polyurethane rubber. The lip portion 322' may be
provided on substantially the entire circumference of the contacting
portion 308'. As shown, it may be formed integrally in the contacting
portion 308'. Alternatively, it may be formed as a separate piece and
attached to the contacting portion 308'. The lip portion 222' has a main
portion 324' extending outwardly from the contacting portion 308' along
the wall surface 306' and an extension 326' extending further outwardly
from the main portion 324' in a direction away from the wall surface 306'.
Otherwise, the structure of the partitioning member 302 in the third
modified embodiment is substantially the same as that shown in FIG. 5-B
excepting the grooves.
The basic form of the third modified embodiment is substantially the same
as the second modified embodiment shown in FIG. 5-B. Hence, the outside
wall portion 310' and the inside wall portion 312' stretch and contract in
a direction toward and away from the wall surface 306', and the contacting
portion 308' of the partitioning member 302' moves following the raised
and depressed parts of the wall surface 306'. In addition, since the lip
portion 322' (especially, the main portion 324') is provided in the
contacting portion 308', the lip portion 322' also moves toward and away
from the wall surface 306' while following the raised and depressed parts
of the wall surface 306'. Hence, sealability between the partitioning
member 302' and the wall surface 306' is further enhanced. Furthermore,
since the extension 326' is provided following the main portion 324', the
lip portion 322' can easily ride over raised and depressed parts of the
wall surface 306'.
In the third modified embodiment, too, grooves may be formed, or an
abrasive material may be attached, in order to increase the cleaning
effect of the wall surface. In this case, it is preferred to provide the
grooves or the abrasive material in an area ranging from the contacting
portion of the partitioning member to the main portion of the lip portion.
While the present invention has been described with reference to one
specific embodiment of the device constructed in accordance with this
invention, it should be understood that the invention is not limited to
this specific embodiment, and various changes and modifications are
possible without departing from the scope of the invention described and
claimed herein.
For example, in the illustrated embodiment, the ground-contacting pressure
of the partitioning member is reduced by setting the pressure of the
pressure adjusting space defined in the partitioning member at a value
lower than the outside pressure. As required, the ground-contacting
pressure of the partitioning member may be increased by making the
pressure of the pressure adjusting space higher than the outside pressure.
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