Apparatus for use in renovation of tube systems, in particular sewer tube systems

An apparatus for use in renovating tube systems, in particular, sewer tubes of a circular cross section. The apparatus includes a frame on wheel, with the frame being arranged so as to be moved inside a tube in such a manner that a position of the apparatus in the tube is determined. A motor-driven tool is arranged for cutting away items extending or protruding into the tube and/or for forming side openings in the tube wall or in a tube lining. The motor driven tool is mounted on a carrier arm extending beyond an end part of a rotatable portion of the apparatus. The carrier arm is pivotally connected, opposite the tool, to the rotatable portion at a distance from the end part thereof. An inflatable lifting member is arranged inside the rotatable portion between the end part of the rotatable portion and the pivot axis of the carrier arm. The lifting member is interposed between the rotatable portion and the carrier arm in such a manner that the tool can be moved diametrically within the tube. A turning motor is interposed between the frame and the rotatable portion.

FIELD OF THE INVENTION 
The present invention relates to an apparatus for use in renovating tube 
systems, and, in particular, sewer tube systems. 
BACKGROUND OF THE INVENTION 
In the renovation of sewer tube systems it was previously necessary to 
exchange damaged sewer tubes with entirely new sewer tubes, which 
encompassed major costs and possibly troublesome digging work which 
additionally disturbs the surroundings. Today a newer method of renovation 
is applied more and more, provided that damaged sewer tubes have the 
required capacity, wherein the existing sewer tubes are provided in situ 
with a tube lining comprising a plastics lining which is, for example, 
formed from a plastics strip which is wound up and assembled inside the 
sewer tube by special methods and apparatus. It should be remarked that a 
plurality of accepted methods are known for renovating sewer tube systems 
by means of an inner lining. 
A mandatory prerequisite for applying the new renovation method as 
mentioned is, at least if sewer systems are concerned which do not allow 
personal access, the development of small mobile TV cameras such that one 
may part inspect, prepare and measure up the existing sewer system 
precisely and part reestablish the positions, precisely as well, at which 
side openings must be formed again in the plastics lining. 
More specifically the invention relates to an apparatus which is primarily 
developed for use in renovation of sewer tubes, for example, according to 
the method as mentioned above wherein a plastics liner is formed by 
winding up inside an existing sewer tube. Admittedly, apparatus are known 
which are meant to serve the same purpose; but to some extent these known 
apparatus are very clumsy and complicated in their construction and, 
consequently, they are rather costly. Furthermore the known apparatus for 
the purpose mentioned are so large that in practice they can only be used 
in relatively large sewer tubes. 
EP-A-0 084 427 discloses an apparatus for use in renovating sewer tubes and 
comprising a cylindrical apparatus body adapted to be moved inside a tube 
in such a way that the position of the apparatus in the tube is known, and 
a motor-driven tool wherein the motor-driven tool is mounted on a carrier 
member which protrudes from an end portion of the apparatus body and is 
journaled so as to be rotatable with respect to the apparatus body around 
a longitudinal axis. Opposite the apparatus body, the carrier member 
comprises a lifting mechanism which is interposed between a free end of 
the carrier member and the tool in such a way that the tool on the latter 
can be moved diametrally within the tube. Furthermore this known apparatus 
comprises a turning motor which is interposed between the apparatus body 
and the rotatable carrier member. 
SUMMARY OF THE INVENTION 
It is a purpose of the invention to provide an apparatus of the initially 
mentioned type and which, despite of the fact that it utilizes simple 
means and a simple and economical construction, may lead to an improved 
precision and efficiency, for example, in the method of renovation. 
The apparatus according to the invention is distinctive in that the carrier 
member includes a carrier arm made of springy material, for example, 
spring steel, and is pivotably connected, opposite the tool, to the 
rotatable portion at a distance from the end part thereof, and that the 
lifting member is interposed between the end part of the rotatable portion 
and the pivot axis of the carrier arm, with the pivot axis being 
perpendicular to the longitudinal rotation axis of the rotatable portion. 
Thus, an efficient and easily operated apparatus is attained by simple 
means, which can be used in a safe and precise way, utilizing the tool, 
for working in principle on any part of the wall of a sewer tube or a tube 
lining, depending on the type of tool which is arranged at the extreme end 
of the carrier arm. The latter can itself be moved diametrically within 
the tube but, as the carrier arm is furthermore arranged to extend from 
the portion which with respect in relation to the frame, the tool on the 
carrier arm can also be moved around along the periphery of, for example, 
the lining wall, by turning the rotatable portion in relation to the 
frame. 
In a preferred embodiment, the apparatus according to the invention is 
expediently arranged such that the rotatable, portion includes a mainly 
horizontally positioned cylindrical hollow part formed with an elongated 
upper opening, with the carrier arm extending above and along the opening 
from the pivot axis at an end of the opening and further on beyond the end 
part of the cylindrical part. The lifting member includes an inflatable, 
elastic body which is arranged inside the cylindrical part, and cooperates 
with the carrier arm via the elongated opening for swinging the former 
outwardly by inflation of the elastic body. For swinging the carrier arm 
back by withdrawal of air from the inflatable body, the carrier arm is 
preferably springloaded towards the inflatable body. 
With a view to guiding the radial or diametrical movement of the tool more 
easily and to be able to more easily monitor the engagement area of the 
tool and its working operation at the extreme end of the carrier arm, the 
latter may be advantageously curved or bent into such a shape that the 
tool at an extreme end of the carrier arm may be placed on a level with or 
below the upper opening of the rotatable portion.

DETAILED DESCRIPTION 
The renovating apparatus generally designated by the reference numeral 2 as 
shown has a frame 4 which comprises a solid steel rod so as to form a 
stable base with a low center of gravity, and which is provided with 
wheels 6 on exchangeable wheel bogies 8. Thus, the apparatus 2 may, in a 
simple way, be equipped for use in renovating sewer tubes with diameters 
from 170 mm-1000 mm, inasmuch as a longitudinal axis of rotation 10 of the 
apparatus 2 may be placed substantially level with the longitudinal axis 
of the sewer tube by exchanging the wheel bogies 8 and/or the wheels 6. 
The frame 4 has a foremost upright bearing console 12 for a rotatably 
suspended portion 14 which comprises a cylindrical tube body 16, and which 
is nonrotatably connect opposite of the bearing console 12 to a motor 
shaft 18 of a turning motor 20 which is fixed to the frame 4 by an upright 
bracket 22. The turning motor 20 preferably comprises a watertight, 
reversible low-voltage motor, for example, of the same type as a known 
turning motor for turning a TV antenna by slow rotation of the vertical 
carrier tube. The turning motor 20 is controlled by a special 
potentiometer with a so-called slave scale, that is, the turning motor 
runs until the TV antenna has the same direction as the setting on the 
controlling scale. 
Approximately level with the axis of rotation 10 the cylindrical tube body 
16 is formed with an upper, elongated opening 24. Adjacent the back end of 
the opening 24, a carrier arm 28 is pivotably journaled on a transverse 
pivot axis 26, with the arm 28 extending above and along the opening 24 
and onward a distance forward in front of the apparatus 2. As shown the 
carrier arm 28 is angularly bent downward at about the end of the 
rotatable cylindrical body 16, such that a motor-driven, preferably, 
pneumatically driven tool 30 at the extreme end of the carrier arm 28 can 
be moved diametrically within the sewer tube, by swinging the former in 
relation to the tube body 16, from a position in front of the apparatus 2 
to a position at a wall part of the sewer tube. 
Inside the tube body 16 an inflatable elastic body 32 is arranged which 
preferably includes a sturdy inflatable cylinder device which is normally 
used for temporary end closure of conduit tubes, that is, a cylindrical 
elastic body which can be jammed like a cork in an end of a tube by means 
of inflation with air. During inflation of the elastic body 32 a side part 
of it cooperates via the opening 24 with the lower side of the carrier arm 
28 such that the latter is swung outward relative to the tube body 16 and 
swung in towards the upper side of the tube body 16 when the elastic body 
32 is deflated. 
A bracket 34 for a TV camera is provided at the upper side of the body 
behind the pivot axle 26 of the carrier arm 28. The TV, mounted camera in 
front of the apparatus 2 monitors the inside of the sewer tube for 
controlling the movement of the carrier arm 28 and the tool 30. The 
bracket 34 is provided with an indicator arrangement 36 with a pendulum 
indicator 38 which is rotatably mounted in front of a center axis of the 
TV camera, such that a given angular position of the rotatable portion 14 
can be read off an angle scale along the periphery of the camera lens as 
the pendulum indicator 38 will remain vertical when the rotatable portion 
14 is rotated around the axis of rotation 10. 
The apparatus 2 may be intended to be moved along the sewer tube by a 
separate wire pulling system with a measuring tape for determining the 
exact position of the apparatus along the tube; but the apparatus 2 may 
also, cf. FIG. 2 and 3, be provided with a driving motor 40 with a 
frictional drive wheel 42 which can be pressed against the sewer tube wall 
opposite the wheels 6 by a preferably pneumatic cylinder 44, whereby the 
exact position of the apparatus 2 along the tube may still be determined a 
measuring tape. 
By turning the rotatable portion 14 around the axis of rotation 10, as 
shown in FIG. 3, the tool 30 of the apparatus can be used for working on 
the tube wall or the inside of the sewer tube along an angular sector of 
about 300.degree. which is limited only by the front wheels 6 and wheel 
bogie 8. In practice, however, the carrier arm 28 will be able to serve 
the remaining lower 60.degree. of the sewer tube wall as well, by 
preventing the carrier arm 28 to engage, as shown in FIG. 2, an inlet tube 
46 while the turning motor 20 is activated so that the entire apparatus 2 
is moved sideways on the lower portion of the tube wall while it is 
supported on the wheels 6. In this slightly inclined position the 
frictional drive roller 42 may assist in maintaining the apparatus 2 in 
position inside the tube, and generally it may be an advantage if the 
apparatus comprises support rollers proper which permanently abut the 
"ceiling" of the sewer tube. 
Besides the tool 30 as shown, which consists of a grinding cone of plastics 
material (technical grade nylon), the apparatus 2 may operate with a 
common flat cutting or sanding disc 303 (FIG. 1A) and possibly with a 
reciprocating sawblade 30b (FIG. 1B) which runs in extension of the 
carrier arm 28, and with other appropriate tools. 
If, according to its primary purpose, the apparatus according to the 
invention is used for renovation of sewer tubes to be provided with a 
plastics lining wound up on location, the existing sewer tube is measured 
and prepared by the apparatus 2. The latter is first moved through the 
sewer tube to cut away possible roots and other inwardly protruding parts, 
for example tubing stubs of branching tubes, and the same time, a precise 
measurement and registration of all branching connections both their 
position along the tube and their angular position is made by recording a 
video tape which is used later on, that is, when the plastics lining is 
fitted along the inner wall of the sewer tube, for reestablishing the 
connections with the registered branching tubes by means of suitable 
tools, for example, the cutting cone 30. 
In a further embodiment of the present invention, as shown in FIGS. 4 and 
5, a sewer robot apparatus 50 may be dimensioned in size to work in very 
narrow surroundings, for example, sewer tubes with an inner diameter down 
to as low as about 100 mm, with the sewer apparatus comprising a frame 4 
which is provided with wheels 6 and with an inside ballast 52 and turning 
motor 20 (FIG. 5). The turning motor 20 actuates a rotatably suspended 
cylindrical portion 14 which is connected to the frame 4 by a special 
rotational link 54 with ring-shaped connecting spaces 56 and 58 through 
which a portion of pressurized air is supplied to the tool 30 on the 
carrier arm 28 and a portion to the inflatable body 32 which is placed 
inside the portion 14. The inflatable body 32 actuates the carrier arm 28 
via a special actuator part 60 with a compression spring 62. The carrier 
arm 28 is hollow so as to allow running a supply line 64 for the tool 30 
from the pivot axis 26 to an outer connecting stub 66 in protection within 
the carrier arm 28. For an easy exchange of the carrier arm 28 with the 
tool 30, a free end of the supply line 64 may be connected with the 
ring-shaped connecting space 56 by tucking it into a connector fitting 68. 
A similar tuck-in fitting 70, connected with the ring-shaped connecting 
space 58, may be provided for a supply line 72 to the inflatable body 32 
so that the latter is likewise easy to exchange. The rotational link 54 
enables the apparatus 50 to execute continuous rotations of the 
cylindrical portion 14, that is, the tool 30 can operate on the entire 
inner wall of the 360.degree. of a sewer tube. 
Opposite the rotatable cylindrical portion 14, the frame 4 is provided with 
a pipe connector 74 for a flexible supply pipe 76 through which air pipes 
78 and possibly electric supply lines can be led to the hollow of the 
frame. The apparatus 50 is not provided with an independent driving motor; 
instead the apparatus 50 is intended to be coupled to a camera trolley, 
placed in front of the tool 30, which can be provided with a driving 
motor, and which can be used as a tractor for the apparatus 50. Otherwise 
the latter can be pulled along the sewer tube by a pulling wire or 
possibly the apparatus 50 can be pushed forward within the sewer tube by 
the supply pipe 76. Furthermore the frame 4 is provided with a holding 
cylinder with a telescopic piston 80 for fixing the apparatus 50 against 
the "ceiling" of the sewer tube in the work position. 
The inflatable body 32 may be exchanged for an actuator cylinder positioned 
like the actuator part 60, so that the overall length of the apparatus 50 
is reduced enough to enable the apparatus to operate in curved sewer tube 
sections.