 |
Claims  |
|
|
I claim:
1. A traveling device having frame means, and moving means mounted on the frame means and moving on a travel surface, the moving means comprising a plurality of wheels, or a plurality of
endless tracks each including a plurality of belt pulleys, wherein
the frame means includes a main frame, a pair of oscillating frames arranged on both sides of the main frame, and a connecting frame disposed on one end portion side of the main frame; a central portion of the connecting frame is coupled to the
one end portion side of the main frame via monoaxially oscillating joint means; both end portions of the connecting frame are coupled to .one end portion of each of the oscillating frames via omniaxially oscillating joint means; the other end portion
of each of the oscillating frames is coupled to both side portions of the other end portion of the main frame via biaxially oscillating joint means; each of the biaxially oscillating joint means has an oscillating longitudinal shaft having an
oscillating plane substantially parallel to the travel surface, and an oscillating transverse shaft having an oscillating plane substantially perpendicularly intersecting the travel surface; and the monoaxially oscillating joint means has an oscillating
transverse shaft having an oscillating plane substantially perpendicularly intersecting the travel surface and also substantially perpendicularly intersecting the oscillating plane of the oscillating transverse shaft of each of the biaxially oscillating
joint means.
2. The traveling device of claim 1 wherein the connecting frame is slidable along the oscillating transverse shaft of the monoaxially oscillating joint means.
3. The traveling device of claim 1 wherein the wheels or endless tracks are mounted on each of the oscillating frames.
4. The traveling device of claim 1, which includes a pressure reduction housing mounted on the main frame, suction-adhering sealing means mounted on the pressure reduction housing and defining a pressure reduction space in cooperation with the
pressure reduction housing and the travel surface, and pressure reducing means for discharging a fluid from the pressure reduction space to the outside, and which is caused to suction-adhere to the travel surface by the pressure of an ambient fluid
acting on the pressure reduction housing owing to the difference in fluid pressure between the inside and the outside of the pressure reduction space.
5. The traveling device of claim 1 wherein the rotating shafts of the respective wheels, or the rotating shafts of the plurality of belt pulleys included in the respective endless tracks, are not arranged on the same plane orthogonal to the
direction of travel of the traveling device and perpendicularly intersecting the travel surface, but are arranged on different such planes.
6. The traveling device of claim 4, which has the pressure reduction housing provided with an annular mounting portion, the suction-adhering sealing means having a space portion toroidal in shape and opened on one end side thereof, and sealing
function compensating means for compensating the sealing function of the suction-adhering sealing means, and in which the space portion of the suction-adhering sealing means is substantially sealed by mounting the one end side of the suction-adhering
sealing means on the mounting portion of the pressure reduction housing; and the sealing function compensating equipment has pressure detecting means for detecting the pressure inside the pressure reduction space, pressure fluid feeding means for
feeding a pressure fluid to the space portion to inflate the suction-adhering sealing means, and controlling means that, when the degree of vacuum of the pressure reduction space has lowered to less than a predetermined degree of vacuum, actuates the
pressure fluid feeding means based on an input signal from the pressure detecting means to feed a pressure fluid to the space portion.
7. A traveling device having frame means, and moving means mounted on the frame means and moving on a travel surface, the moving means comprising a plurality of wheels, or a plurality of endless tracks each including a plurality of belt pulleys,
wherein
the frame means includes a main frame, a pair of oscillating frames arranged on both sides of the main frame, and a connecting frame disposed on one end portion side of the main frame; a central portion of the connecting frame is coupled to the
one end portion side of the main frame via monoaxially oscillating joint means; both end portions of the connecting frame are coupled to one end portion of each of the oscillating frames via omniaxially oscillating joint means; the other end portion of
each of the oscillating frames is coupled to both side portions of the other end portion of the main frame via monoaxially oscillating joint means; the monoaxially oscillating joint means in each of the oscillating frames has an oscillating transverse
shaft having an oscillating plane substantially perpendicularly intersecting the travel surface; and the monoaxially oscillating joint means in the connecting frame has an oscillating transverse shaft having an oscillating plane substantially
perpendicularly intersecting the travel surface and also substantially perpendicularly intersecting the oscillating plane of the oscillating transverse shaft of the monoaxially oscillating joint means in each of the oscillating frames.
8. The traveling device of claim 7 wherein each of the oscillating frames is constructed such that the one end portion thereof can deflect toward the main frame on a plane parallel to the travel surface.
9. The traveling device of claim 7 wherein the connecting frame is slidable along the oscillating transverse shaft of the monoaxially oscillating joint means in the connecting frame.
10. The traveling device of claim 7 wherein the connecting frame is fixed so as not to be slidable along the oscillating transverse shaft of the monoaxially oscillating joint means in the connecting frame, and is constructed such that said both
end portions of the connecting frame can deflect toward the main frame on a plane parallel to the travel surface.
11. A traveling device having frame means; moving means mounted on the frame means and moving on a travel surface, the moving means comprising a plurality of wheels, or a plurality of endless tracks each including a plurality of belt pulleys;
a pressure reduction housing mounted on a main frame; suction-adhering sealing means mounted on the pressure reduction housing and defining a pressure reduction space in cooperation with the pressure reduction housing and the travel surface; and
pressure reducing means for discharging a fluid from the pressure reduction space to the outside; the traveling device being capable of suction-adhering to the travel surface by the pressure of an ambient fluid acting on the pressure reduction housing
owing to the difference in fluid pressure between the inside and the outside of the pressure reduction space, and being capable of moving along the travel surface; wherein
the frame means includes the main frame, a pair of oscillating frames arranged on both sides of the main frame, and a connecting frame disposed on one end portion side of the main frame; a central portion of the connecting frame is coupled to
the one end portion side of the main frame via monoaxially oscillating joint means; both end portions of the connecting frame are coupled to one end portion of each of the oscillating frames via omniaxially oscillating joint means; the other end
portion of each of the oscillating frames is coupled to both side portions of the other end portion of the main frame via biaxially oscillating joint means; each of the biaxially oscillating joint means has an oscillating longitudinal shaft having an
oscillating plane substantially parallel to the travel surface, and an oscillating transverse shaft having an oscillating plane substantially perpendicularly intersecting the travel surface; and the monoaxially oscillating joint means has an oscillating
transverse shaft having an oscillating plane substantially perpendicularly intersecting the travel surface and also substantially perpendicularly intersecting the oscillating plane of the oscillating transverse shaft of each of the biaxially oscillating
joint means.
12. A traveling device having frame means; moving means mounted on the frame means and moving on a travel surface, the moving means comprising a plurality of wheels, or a plurality of endless tracks each including a plurality of belt pulleys;
a pressure reduction housing mounted on a main frame; suction-adhering sealing means mounted on the pressure reduction housing and defining a pressure reduction space in cooperation with the pressure reduction housing and the travel surface; and
pressure reducing means for discharging a fluid from the pressure reduction space to the outside; the traveling device suction-adhering to the travel surface by the pressure of an ambient fluid acting on the pressure reduction housing owing to the
difference in fluid pressure between the inside and the outside of the pressure reduction space, and moving along the travel surface; wherein
rotating shafts of the plural wheels, or rotating shafts of the plural belt pulleys included in the respective endless tracks, are not arranged on the same plane orthogonal to the direction of travel of the traveling device and perpendicularly
intersecting the travel surface, but are arranged on different such planes.
13. The traveling device of claim 12, which has the pressure reduction housing provided with an annular mounting portion, the suction-adhering sealing means having a space portion toroidal in shape and opened on one end side thereof, and sealing
function compensating means for compensating the sealing function of the suction-adhering sealing means, and in which the space portion of the suction-adhering sealing means is substantially sealed by mounting the one end side of the suction-adhering
sealing means on the mounting portion of the pressure reduction housing; and the sealing function compensating equipment has pressure detecting means for detecting the pressure inside the pressure reduction space, pressure fluid feeding means for
feeding a pressure fluid to the space portion to inflate the suction-adhering sealing means, and controlling means that, when the degree of vacuum of the pressure reduction space has lowered to less than a predetermined degree of vacuum, actuates the
pressure fluid feeding means based on an input signal from the pressure detecting means to feed a pressure fluid to the space portion.
14. A traveling device having frame means; moving means mounted on the frame means and moving on a travel surface, the moving means comprising a plurality of wheels, or a plurality of endless tracks each including a plurality of belt pulleys;
a pressure reduction housing mounted a main frame; suction-adhering sealing means mounted on the pressure reduction housing and defining a pressure reduction space in cooperation with the pressure reduction housing and the travel surface; and pressure
reducing means for discharging a fluid from the pressure reduction space to the outside; the traveling device suction-adhering to the travel surface by the pressure of an ambient fluid acting on the pressure reduction housing owing to the difference in
fluid pressure between the inside and the outside of the pressure reduction space, and moving along the travel surface; wherein
traveling device has the pressure reduction housing provided with an annular mounting portion, the suction-adhering sealing means having a space portion toroidal in shape and opened on one end side thereof, and sealing function compensating means
for compensating the sealing function of the suction-adhering sealing means,
the space portion of the suction-adhering sealing means is substantially sealed by mounting the one end side of the suction-adhering sealing means on the mounting portion of the pressure reduction housing, and
the sealing function compensating equipment has pressure detecting means for detecting the pressure inside the pressure reduction space, pressure fluid feeding means for feeding a pressure fluid to the space portion to inflate the
suction-adhering sealing means, and controlling means that, when the degree of vacuum of the pressure reduction space has lowered to less than a predetermined degree of vacuum, actuates the pressure fluid feeding means based on an input signal from the
pressure detecting means to feed a pressure fluid to the space portion. |
|
 |
|
 |
Claims |
|
|
|
Description |
|
|
TECHNICAL FIELD
This invention relates to a traveling device capable of moving on the surface of an object having curved faces (hereinafter referred to as a travel surface), such as the inside or outside surface of a pipe or the surface of a ship hull, by means
of a plurality of wheels as moving means, or a plurality of endless tracks, including a plurality of belt pulleys, as moving means, while performing work such as sandblasting.
The invention also relates to a traveling device capable of suction-adhering to a travel surface having curved faces, such as the inside or outside surface of a pipe or the surface of a ship hull, by the pressure of an ambient fluid such as air
or water, and capable of moving along the travel surface by means of a plurality of wheels as moving means, or a plurality of endless tracks, including a plurality of belt pulleys, as moving means, while performing work such as sandblasting.
BACKGROUND ART
A typical example of a traveling device capable of suction-adhering to a travel surface having curved faces, such as the inside or outside surface of a pipe or the surface of a ship hull, by the pressure of an ambient fluid such as air or water,
and of moving along the travel surface, while performing work such as sandblasting, is the device disclosed in the specification and drawings of U.S. Pat. No. 4,095,378. The device has a pressure reduction housing mounted on a frame, a moving means
mounted on the frame, a suction-adhering seal mounted on the pressure reduction housing and defining a pressure reduction space in cooperation with the pressure reduction housing and the travel surface, and a pressure reducing means for discharging a
fluid from the pressure reduction space to decrease the pressure inside the pressure reduction space. The moving means is composed of a plurality of wheels (e.g. 4 wheels), or a plurality of endless tracks including a plurality of belt pulleys (e.g. 2
endless tracks each with 2 belt pulleys). The traveling device is equipped with a working unit such as sandblasting equipment which directs a jet of a polishing and cleaning material at the transfer surface.
In the above-described conventional traveling device, when the pressure reducing means is actuated, fluid inside the pressure reduction space is discharged to the outside. Owing to the difference in fluid pressure between the inside and outside
of the pressure reduction space, the fluid pressure acts on the pressure reduction housing, and is then transmitted to the travel surface via the wheels or belt pulleys. Under this fluid pressure, the device is caused to suction-adhere to the travel
surface. In this state of suction-adhesion, when the wheels or belt pulleys are driven by a driving means such as an electric motor, the device moves along the travel surface by the action of the wheels or endless tracks.
In the foregoing traveling device which suction-adheres to a travel surface having curved faces, such as the inside or outside surface of a pipe or the surface of a ship hull, by the pressure of an ambient fluid, and moves along the travel
surface, while performing work such as sandblasting, the frame on which the moving means is mounted has a rigid structure whose shape substantially does not change flexibly. Therefore, in the traveling device equipped with, say, 4 wheels as the moving
means, i.e., the traveling device having 2 wheels on each side of the frame, one of the four wheels separates from the travel surface. More specifically, if the device sits on the outside surface of, say, a cylindrical pipe, and if the central axis in
the traveling direction of the device is on a plane obliquely intersecting the central axis of the pipe, one of the four wheels departs from the travel surface. Owing to this departure, the posture of the device is always unstable. Not all of the four
wheels being in contact with the travel surface results in an insufficient driving force. Such technical problems exist also with a conventional traveling device which moves while performing work such as sandblasting, but which lacks means for
suction-adhering to the travel surface by the pressure of an ambient fluid. Furthermore, in the aforementioned traveling device which suction-adheres to a travel surface by the pressure of an ambient fluid, and moves along it, the sealing function of
the suction-adhering seal may be hampered, owing to the separation of one of the four wheels from the travel surface. One could easily understand that these problems occur for the same reasons as stated earlier, in connection with the aforementioned
traveling device equipped with two endless tracks including a total of 4 belt pulleys as moving means.
In the case of the aforesaid traveling device which suction-adheres to a travel surface by the pressure of an ambient fluid, and moves along it, and which has 4 wheels as the moving means, namely, a traveling device of the type having 2 wheels on
each side of the frame, the following phenomenon may arise: During the upward movement of the device on a vertical travel surface such as the wall surface of a ship hull, if a projection extending in a horizontal direction, such as a different-level weld
line formed by a laminate of welded steel plates, exists on the travel surface, the device has no sufficient driving force to pass over the projection, with the result that the wheels may rotate at the projection, without imparting a forward movement.
Especially when a coating with a small coefficient of friction is present on the travel surface, making the wheels easily slip there, the ascent of the device is impeded at the projection, causing the wheels to run idly. The reason is as follows: In the
aforesaid traveling device, the rotating shafts of the four wheels are arranged on the same plane which is at right angles to the traveling direction of the device and which perpendicularly intersects the travel surface. Hence, as the device moves
upwards on the vertical travel surface in the vertical direction, 2 of the wheels of the device simultaneously encounter the projection. Thus, the driving force necessary for the device to pass across the projection is twice the driving force required
when each one of the four wheels passes over the projection. It will be easily understandable that this problem occurs for the same reason, in regard to the aforementioned traveling device provided with two endless tracks including, say, four belt
pulleys, as the moving means. Such a technical problem is also posed with a conventional traveling device which moves while performing work such as sandblasting, but which lacks means for suction-adhering to the travel surface by the pressure of an
ambient fluid.
The conventional traveling device, which suction-adheres to the travel surface by the pressure of an ambient fluid and moves along it, may face the following situation: When the device moves while suction-adhering to the travel surface having
curved faces, such as the inside and outside surfaces of pipes or those of a ship hull, it may encounter a travel surface having a great curvature in excess of a critical curvature within which travel with suction-adhesion remains possible. In this
case, the suction-adhering seal of the device reaches its limit of flexible deformation according to the curvature of the travel surface. This may destroy the sealing function of the suction-adhering seal. Thus, the degree of vacuum of the pressure
reduction region of the device may rapidly fall, causing the device to separate from the travel surface abruptly.
DISCLOSURE OF THE INVENTION
An object of the present invention, therefore, is to provide a traveling device which can travel on a travel surface having curved faces with a stable posture, and which has a sufficient driving force.
Another object of the invention is to provide a traveling device which can travel on a travel surface having curved faces with a stable posture, has a sufficient driving force, can suction-adhere to the travel surface by the pressure of an
ambient fluid such as air or water, and is able to move along it.
Still another object of the invention is to provide a traveling device which has a sufficient driving force to pass over a projection extending in a horizontal direction, such as a weld line present on a vertical travel surface, can
suction-adhere to the travel surface by the pressure of an ambient fluid such as air or water, and is able to move along it.
A further object of the invention is to provide a traveling device which can prevent its separation from the travel surface due to the decline in the sealing function of the suction-adhering sealing means, suction-adhere to the travel surface by
the pressure of an ambient fluid such as air or water, and move along it.
Other objects of the invention will become apparent from the following description presented in detail by reference to the appended drawings in connection with embodiments of the traveling device constructed in accordance with the invention.
According to an aspect of the present invention, there is provided a traveling device having a frame means, and a moving means mounted on the frame means and moving on a travel surface, the moving means comprising a plurality of wheels, or a
plurality of endless tracks each including a plurality of belt pulleys, wherein the frame means includes a main frame, a pair of oscillating frames arranged on both sides of the main frame, and a connecting frame disposed on one end portion side of the
main frame; a central portion of the connecting frame is coupled to the one end portion side of the main frame via a monoaxially oscillating joint means; both end portions of the connecting frame are coupled to one end portion of each of the oscillating
frames via an omniaxially oscillating joint means; the other end portion of each of the oscillating frames is coupled to both side portions of the other end portion of the main frame via a biaxially oscillating joint means; each of the biaxially
oscillating joint means has an oscillating longitudinal shaft having an oscillating plane substantially parallel to the travel surface, and an oscillating transverse shaft having an oscillating plane substantially perpendicularly intersecting the travel
surface; and the monoaxially oscillating joint means has an oscillating transverse shaft having an oscillating plane substantially perpendicularly intersecting the travel surface and also substantially perpendicularly intersecting the oscillating plane
of the oscillating transverse shaft of each of the biaxially oscillating joint means.
According to another aspect of the present invention, there is provided a traveling device having a frame means, and a moving means mounted on the frame means and moving on a travel surface, the moving means comprising a plurality of wheels, or a
plurality of endless tracks each including a plurality of belt pulleys, wherein the frame means includes a main frame, a pair of oscillating frames arranged on both sides of the main frame, and a connecting frame disposed on one end portion side of the
main frame; a central portion of the connecting frame is coupled to the one end portion side of the main frame via a monoaxially oscillating joint means; both end portions of the connecting frame are coupled to one end portion of each of the oscillating
frames via an omniaxially oscillating joint means; the other end portion of each of the oscillating frames is coupled to both side portions of the other end portion of the main frame via a monoaxially oscillating joint means; the monoaxially oscillating
joint means in each of the oscillating frames has an oscillating transverse shaft having an oscillating plane substantially perpendicularly intersecting the travel surface; and the monoaxially oscillating joint means in the connecting frame has an
oscillating transverse shaft having an oscillating plane substantially perpendicularly intersecting the travel surface and also substantially perpendicularly intersecting the oscillating plane of the oscillating transverse shaft of the monoaxially
oscillating joint means in each of the oscillating frames.
According to still another aspect of the present invention, there is provided a traveling device having a frame means; a moving means mounted on the frame means and moving on a travel surface, the moving means comprising a plurality of wheels, or
a plurality of endless tracks each including a plurality of belt pulleys; a pressure reduction housing mounted on the main frame; a suction-adhering sealing means mounted on the pressure reduction housing and defining a pressure reduction space in
cooperation with the pressure reduction housing and the travel surface; and a pressure reducing means for discharging a fluid from the pressure reduction space to the outside; the traveling device being capable of suction-adhering to the travel surface
by the pressure of an ambient fluid acting on the pressure reduction housing owing to the difference in fluid pressure between the inside and the outside of the pressure reduction space, and being capable of moving along the travel surface; wherein the
frame means includes a main frame, a pair of oscillating frames arranged on both sides of the main frame, and a connecting frame disposed on one end portion side of the main frame; a central portion of the connecting frame is coupled to the one end
portion side of the main frame via a monoaxially oscillating joint means; both end portions of the connecting frame are coupled to one end portion of each of the oscillating frames via an omniaxially oscillating joint means; the other end portion of each
of the oscillating frames is connected to both side portions of the other end portion of the main frame via a biaxially oscillating joint means; each of the biaxially oscillating joint means has an oscillating longitudinal shaft having an oscillating
plane substantially parallel to the travel surface, and an oscillating transverse shaft having an oscillating plane substantially perpendicularly intersecting the travel surface; and the monoaxially oscillating joint means has an oscillating transverse
shaft having an oscillating plane substantially perpendicularly intersecting the travel surface and also substantially perpendicularly intersecting the oscillating plane of the oscillating transverse shaft of each of the biaxially oscillating joint
means.
According a further aspect of the present invention, there is provided a traveling device having a frame means; a moving means mounted on the frame means and moving on a travel surface, the moving means comprising a plurality of wheels, or a
plurality of endless tracks each including a plurality of belt pulleys; a pressure reduction housing mounted on the main frame; a suction-adhering sealing means mounted on the pressure reduction housing and defining a pressure reduction space in
cooperation with the pressure reduction housing and the travel surface; and a pressure reducing means for discharging a fluid from the pressure reduction space to the outside; the traveling device being capable of suction-adhering to the travel surface
by the pressure of an ambient fluid acting on the pressure reduction housing owing to the difference in fluid pressure between the inside and the outside of the pressure reduction space, and being capable of moving along the travel surface; wherein the
rotating shafts of the plural wheels, or the rotating shafts of the plural belt pulleys included in the respective endless tracks, are not arranged on the same plane orthogonal to the direction of travel of the traveling device and perpendicularly
intersecting the travel surface, but are arranged on different such planes.
According a still further aspect of the present invention, there is provided a traveling device having a frame means; a moving means mounted on the frame means and moving on a travel surface, the moving means comprising a plurality of wheels, or
a plurality of endless tracks each including a plurality of belt pulleys; a pressure reduction housing mounted on the main frame; a suction-adhering sealing means mounted on the pressure reduction housing and defining a pressure reduction space in
cooperation with the pressure reduction housing and the travel surface; and a pressure reducing means for discharging a fluid from the pressure reduction space to the outside; the traveling device suction-adhering to the travel surface by the pressure of
an ambient fluid acting on the pressure reduction housing owing to the difference in fluid pressure between the inside and the outside of the pressure reduction space, and moving along the travel surface; wherein the device has the pressure reduction
housing provided with an annular mounting portion, the suction-adhering sealing means having a space portion toroidal in shape and opened on one end side thereof, and a sealing function compensating means for compensating the sealing function of the
suction-adhering sealing means; the space portion of the suction-adhering sealing means is substantially sealed by mounting the one end side of the suction-adhering sealing means on the mounting portion of the pressure reduction housing; and the sealing
function compensating equipment has a pressure detecting means for detecting the pressure inside the pressure reduction space, a pressure fluid feeding means for feeding a pressure fluid to the space portion to inflate the suction-adhering sealing means,
and a controlling means which, when the degree of vacuum of the pressure reduction space has lowered to less than a predetermined degree of vacuum, actuates the pressure fluid feeding means based on an input signal from the pressure detecting means to
feed a pressure fluid to the space portion.
First, the actions of the traveling device constructed according to one aspect of the present invention will be described. For convenience of explanation, an explanation will be offered for the actions of the traveling device having 2 wheels
mounted on each of a pair of oscillating frames as a moving means. In this device, a central portion of a connecting frame and one end portion side of a main frame are coupled by a monoaxially oscillating joint means, both end portions of the connecting
frame and one end portion of each oscillating frame are coupled by an omniaxial joint means, and the other end portion of each oscillating frame is coupled to both side portions on the other end portion side of the main frame via a biaxially oscillating
joint means. If the device lies on the outside surface of, say, a cylindrical pipe, and if the central axis in the traveling direction of the device is on a plane obliquely intersecting the central axis of the pipe, the pair of oscillating frames
oscillate with respect to the main frame, and the connecting frame pivots about the main frame, so that the frames as a whole deform following the travel surface. As a result, the four wheels all contact the travel surface. Thus, this device can travel
on the travel surface with a stable posture and show a sufficient driving force. On such traveling device is generally mounted working equipment such as a sandblaster for directing a jet of an abrasive material at the travel surface. When the traveling
device is equipped with, say, a sandblaster, it can reliably perform sandblasting on the travel surface having curved faces, similarly to a flat travel surface.
When the entire frame deforms, the relative positions of the main frame and each oscillating frame change freely with each biaxially oscillating joint means as the center of revolution. Also, the relative positions of the main frame and the
connecting frame change freely with the oscillating transverse shaft of the monoaxially oscillating joint means as the center of revolution. The contents of these changes in the relative positions will be described in greater detail. On the plane
perpendicularly intersecting the oscillating transverse shaft of each of the biaxially oscillating joint means, the relative angles of the main frame to each of the oscillating frames vary. Also on the plane perpendicularly intersecting the oscillating
longitudinal shaft of each of the biaxially oscillating joint means, the relative angles of the main frame to each of the oscillating frames vary. However, the relative angles of the main frame to each of the oscillating frames do not vary on the plane
bearing each oscillating transverse shaft and perpendicularly intersecting the travel surface. On the other hand, the relative angle between the main frame and the connecting frame varies on the plane perpendicularly intersecting the oscillating
transverse shaft of the monoaxially oscillating joint means. The above-described relative changes in the positions of the connecting frame and each oscillating frame with respect to the main frame can be made by the omniaxially oscillating joint means
connecting both end portions of the connecting frame to the one end portion of each oscillating frame.
As the relative angle between the main frame and the oscillating frame on the plane perpendicularly intersecting the oscillating transverse shaft (this angle is 0 degree on the flat travel surface) becomes larger, the relative angle between the
connecting frame and the main frame (0 degree on the flat travel surface) also increases. Thus, that distance between one end portion and the other end portion of the connecting frame which is on the plane perpendicularly intersecting the oscillating
longitudinal shaft of each biaxially oscillating joint means becomes smaller. Consequently, the relative angle between the main frame and the oscillating frame on the plane perpendicularly intersecting each oscillating longitudinal shaft (this angle is
90 degrees on the flat travel surface) becomes smaller than 90 degrees. On this occasion, that distance between the central portion of the connecting frame and the oscillating transverse shaft of each biaxially oscillating joint means which is on the
plane perpendicularly intersecting the oscillating longitudinal shaft of each biaxially oscillating joint means is reduced. As a result, a force heading for the main frame on the oscillating transverse shaft of the monoaxially oscillating joint means
acts on the central portion of the connecting frame. To absorb this force, the connecting frame is preferably constructed so as to be slidable along the oscillating transverse shaft of the monoaxially oscillating joint means. This construction permits
a smooth deformation without deflection occurring in the pair of oscillating frames and without a strain acting on the frames as a whole. If the connecting frame cannot slide toward the main frame along the oscillating transverse shaft of the
monoaxially oscillating joint means, the structure or material of the connecting frame needs to be specified so that the connecting frame can deflect toward the main frame. As an example, the connecting frame may be composed of a steel plate shaped like
a belt. If the connecting frame can neither slide along the oscillating transverse shaft of the monoaxially oscillating joint means nor defect toward the main frame, the omniaxial joint means connecting both end portions of the connecting frame to one
end portion of each oscillating frame needs to be mounted so as to be movable toward the main frame.
In the above-mentioned traveling device, 2 wheels are mounted on each of the pair of oscillating frames as a moving means, but it is possible to mount one wheel on each of the pair of oscillating frames and two wheels on the main frame. The
total number of the wheels to be mounted on the device is not restricted as long as it is 4 or more. Nor is there any restriction on the place where the wheels are mounted. As the moving means, there may be mounted an endless track on each of the pair
of oscillating frames. The total number of the endless tracks to be mounted on the device is not restricted as long as it is 2 or more. Nor is there any restriction on the place where the endless tracks are mounted. If, for example, two endless tracks
each including two belt pulleys are mounted as moving means, a total of 4 belt pulleys are grounded on the travel surface. The mounting of the wheels or endless tracks on each oscillating frame improves the stability of travel.
Next, the actions of the traveling device constructed according to another aspect of the present invention will be described. For convenience of explanation, an explanation will be offered for the actions of the traveling device having 2 wheels
mounted on each of a pair of oscillating frames as a moving means. In this device, a central portion of a connecting frame and one end portion side of a main frame are coupled by a monoaxially oscillating joint means, both end portions of the connecting
frame and one end portion of each oscillating frame are coupled by an omniaxial joint means, and the other end portion of each oscillating frame is connected to both side portions on the other end portion side of the main frame via a monoaxially
oscillating joint means. If the device lies on the outside surface of, say, a cylindrical pipe, and if the central axis in the traveling direction of the device is on a plane obliquely intersecting the central axis of the pipe, the pair of oscillating
frames oscillate with respect to the main frame, and the connecting frame pivots about the main frame, so that the frames as a whole deform following the travel surface. As a result, the four wheels all contact the travel surface. Thus, this device can
also travel on the travel surface with a stable posture and show a sufficient driving force. When the traveling device is equipped with, say, a sandblaster, it can reliably perform sandblasting on the travel surface having curved faces, similarly to a
flat travel surface.
When the entire frame deforms, the relative positions of the main frame and each oscillating frame change freely with the oscillating transverse shaft of each monoaxially oscillating joint means as the center of revolution. Also, the relative
positions of the main frame and the connecting frame change freely, with the oscillating transverse shaft of the monoaxially oscillating joint means, which connects these frames together, as the center of revolution. The contents of these changes in the
relative positions will be described in greater detail. On the plane perpendicularly intersecting the oscillating transverse shaft of each of the monoaxially oscillating joint means connecting the main frame and each oscillating frame, the relative
angles of the main frame to each of the oscillating frames vary. Also on the plane parallel to the travel surface, the relative angles of the main frame to each of the oscillating frames vary. In this case, stress occurring at each junction of each
os | | |
