CA2095143A1

CA2095143A1 - Inner treatment process and device for inaccessible pipes

Info

Publication number: CA2095143A1
Application number: CA002095143A
Authority: CA
Inventors: Alfred Morgenegg
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-08-30
Filing date: 1992-08-28
Publication date: 1993-03-01
Also published as: CZ73893A3; EP0556358A1; AU2448892A; WO1993005334A1; JPH06501767A; NO931520D0; FI931922A0; HUT67874A; NO931520L; FI931922A7; BR9205435A; HU9301175D0

Abstract

ABSTRACT OF THE DISCLOSURE

The process uses a remote-control robot with a video-monitored working head. The part to be opened or repaired is cut out, or a pig is placed and inflated so as to be clamped in the pipe at the part to be sealed. The process is mainly characterized in that the desired cut-out part is sealed with a two-component epoxy resin. Both components are mixed in an opposite flow helical mixer just before reaching the working head, forming an intimate, curing epoxy resin mixture. The device had a front rotary disk wheel arranged on the robot, that carries a fork provided with an articulation. A
pivotable and retractable working head is mounted between the ends of the fork. The working head may be designed as a cutting unit, as an inflating unit for clamping pigs, as a pressing unit for pressing and smoothening epoxy resin, as a whirling unit for coating the inside of pipes or as a combination of such units.

Description

' Inner Treatment Process and Device for Inaccessible Pipes The present invention relates to a process and a device for working conduits, the interior of which is inaccessible to persons, such as sewers. In particular, the invention makes it possible to close or open lateral branches of such conduits and to l- perform repairs of damaged sections.
! For this, so-called conduit repair robots are so far known, t which comprise a small, elongated, self-propelled vehicle which can travel in the conduits and is embodied as a robot in that it has working tools, such as a cutter head as well as injectors and trowel devices. In addition, the robot vehicle is equipped with a - video camera and can therefore be operated by a supply and control , unit located above ground. In most cases the supply and control unit is permanently installed in a special vehicle, for example the body of a truck, the body of a trailer or an easily movable container. The cutter of the cutter head is movable. With its aid and by means of video monitoring it is possible to cut out a section to be repaired, after which filler material is injected into the cut-out section from a cartridge housed in the robot vehicle. Finally, the section is filled by means of an extruding shoe and smoothed.
Conventional robots have several disadvantages which limit their use or reduce their efficiency. For example, one such disadvantage is seen in that the cutter cannot operate forward but only laterally in respect to the elongated robot vehicle. Also, for technical reasons the cutters of conventional robots often have an insufficient output or rpm. Finally, in case of extended work phases it is necessary to remove the robot vehicle from the conduit for replacing the used-up cartridge by a fresh, full one.
Much valuable time is lost in this process during which the entire installation, which does represent a large investment, is shut down.
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., - It is the object of the present invention to remove these disadvantages and to provide a more technically advanced process and a device for its execution, which generally allow wider technical application possibilities with increased efficiency of their effects, and to realize improved technical solutions in many respects.
The object is attained by means of a process for the interior working of conduits which cannot be entered by persons, wherein a remote-controlled robot, having a video-monitored working head, is brought by an above ground supply and control unit into the conduit to be worked, cuts out the section to be opened or repaired or places a pig at the spot to be closed off - and braces it in the conduits by expanding it, wherein the process is distinguished by the characterizing features of claim 1.
Another aspect of the object to be achieved is attained by a process for the interior working of conduits which cannot be entered by persons in accordance with claim 1, wherein the cutting of the spot to be opened is performed in accordance with the characterizing process steps of claim 2.
Finally, the object is attained by a device for executing the process in accordance with claim 1 or 2, having a remote-controlled robot, which is to be brought into the conduit to be worked, with a video-monitored working head and an associated supply and control unit, wherein the device is distinguished by the characterizing features in accordance with claim 3.
The invention also permits frontal operations, i.e. at a dead end of a conduit or a blockage at the front. The robot is particularly efficient because of its special technical embodiment and operation is correspondingly efficient and versatile. Much time can be saved because mixing of the filler material takes place at the work face by means of a continuous supply of an appropriate epoxy resin. In addition, only as much filler ~J~

material as is actually needed is prepared at any time and no unnecessary waste is produced, which is unavoidable when using cartridges the contents of which are often only partially used up in a work phase.
The device of the invention will be described below by means of drawings of an exemplary embodiment and the function of the individual components will be described so that the process of the invention and its specific features and advantages also become clear.
Shown are in:
Fig. 1: a composite train consisting of a locomotive, control valve unit and robot;
Fig. 2: the working head, embodied as a cutter head in this case and pivotably seated between the fork tips, viewed from above;
Fig. 3: the cutter head with cutter and the video camera, pivotably seated in the also pivotable fork, viewed from the side;
Fig. 4: the cutter head in cross section viewed from the side;
Fig. 5: the cutter head between the fork tips, viewed from the front, with the friction shafts which make it possible to extend the cutter head;
Fig. 6: the extrusion unit mounted on the cutter head;
Fig. 7: the opposite flow helical mixer, partially in section, viewed from the side;
Fig. 8: the synchronous drive of the locomotive with toothed wheels.
All essential components of the device of the invention are shown in a total view in Fig. 1. The device forms a composite train of a locomotive 8, control valve unit 14 and the actual robot 1. These individual composite elements 1, 8 and 14 are connected with each other via pivot hinges 15, 16. The elements h i~
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1, 8 and 14 can thus be pivoted up and down as well as sideways in respect to each other. The entire composite train is very flexible on account of these pivot hinges 15, 16 and it is even possible ~o travel through curves with the smallest radii possibly occurring in sewers. The locomotive 8 is responsible for i displacing the entire composite train. For this purpose it must ; ~ be able to exert as large as possible a pulling or pushing power.
~ To do this, it is equipped with a synchronous all-wheel drive i~ acting via four wheels 12 with special cleated tires 2~ which assure good adhesion on the mostly wet and slippery inner walls of the conduits. Propulsion is obtained via a single electric motor housed in the locomotive 8 and will be described in detail later on. The supply and control lines 3, which can be approximately i` 200 m long, extend through the locomotive 8 and must be pulled by the locomotive 8 from the access shaft from which the composite is inserted into the conduit to be worked. These are three lines with different functions, namely an electric control and supply line 33 for the electric supply of the electric motor as well as the control and measuring signals, furthermore a pneumatic supply line 34 and supply lines for the epoxy resin to be used, namely two lines 35 for the two components of the epoxy resin. The lines 33, 34 and 35 extend through the locomotive 8 into the next element towards the front, the valve control unit 14. An opposite flow helical mixer is housed in this valve control unit 14, by means of which the two components of the epoxy resin are intimately mixed with each other during their passage. The construction and disposition of this helical mixer will be described in detail later on. It can be seen from the drawings that two lines 35 for the two components of the epoxy resin enter the valve control unit 14, but only one line 35 leaves it, because - when leaving the valve control unit 14, the epoxy resin is already ready-mixed for use. Starting at the valve control unit 14, the ~J ~J ~ ~J ~

pneumatic supply line 34, although combined in a tube enclosure, is branched when entering the actual robot 1, in which the compressed air is required for diverse functions. The robot 1 consists of a cylinder-shaped drive and control part 36. Here, it is provided with runners 37 or wheels on the exterior, on which it glides or rolls in the conduit without sustaining damage. This cylinder-shaped drive and control part 36 is built relatively heavy, because it must absorb the reaction forces during working and lend the required stability to the entire robot 1. A disk wheel 9 is seated like a closing lid at the front of the cylinder-shaped drive and control part 36. This disk wheel 9 can be rotated by a compressed air motor via a toothed wheel drive around the long axis of the robot 1, in fact up to 420. A fork 10 which has a pivot hinge 13 is mounted on this disk wheel 9. The actual working head 2 is disposed pivotable by a motor between the fork ends or fork tips 11. ~he working head 2 can be a cutting unit 4 for cutting out sections of the conduit, or it can be embodied as a blower unit for bracing pigs, as an extruding unit 23 (Fig. 6) for extruding and smoothing epoxy resin, as a spinning unit for the interior coating of conduits, or as a combination of such units 4, 23. In the illustrated example, the working head 2 is a cutting unit 4 with a cutter 5. Behind the working head 2, a video camera 7 with a halogen lamp 21 is mounted in the fork 10 and is pivotable there and can be arrested in any position. In actuality, the composite train of locomotive 8, control valve unit 14 and robot 1 is most frequently manually pushed from a shaft into a conduit which is to be worked. The setting of the pivot angle of the fork 10 at the fork hinge 13 is adapted to the diameter of the conduit to be worked. Thanks to this hinge 13, around which the fork can be swiveled over approximately 60, it is possible to work conduits up to an internal diameter of approximately 850 mm. After inserting the composite train into i the conduit, the locomotive 8 pushes the robot 1 and the valve control unit 14 as far as the desired work place, which is monitored by video from the supply and control unit, i.e. from above ground. Advantageously the supply and control unit is housed in a truck body, the body of a trailer or an easily movable container. Further operation can take place exclusively from the control console of this supply and control unit. When pushing the robot 1 in, the locomotive 8 must pull the supply and control lines 3, 33 to 35 behind it, for which reason a strong propulsion unit for the locomotive 8 is imperative.
The detailed arrangement of the working head 2, in this case the cutting unit 4, is shown in Fig. 2 in a top view. This cutting unit 4 is pivotably disposed between the fork ends 11.
The drive for its motor-driven pivoting can be seen on one side of the cutting unit 4. This is a toothed wheel 39 which is engaged by a worm 41 driven pneumatically, i.e. by a compressed air motor, from the drive and control part 36 of the robot 1. Power transfer can take place via universal shafts with universal joints or via a wire. Thus the cutting unit 4 can be driven into the desired pivoted position while being monitored by video, and self-locking of the worm drive assures good stability, so that the cutting unit 4 can easily absorb the reaction forces of the work in the set pivoted position. The back of the cutting unit 4 is rounded corresponding to the pivot radius, so that during pivoting by the motor it does not possibly get caught anywhere.
The fork 10 with the cutting unit 4 disposed in it is shown in a lateral view in Fig. 3. The fork 10 is mounted on the disk wheel 9, which can be rotated over 420 via a toothed wheel drive by means of a compressed air motor. The fork 10 and the working head 2, in this case the cutting unit 4, disposed between its ends turns along with the disk wheel 9. The fork 10 has a hinge 13, around which the front part of the fork lO is upwardly pivotable !

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by approximately 60. Thus, in combination with the turning of the disk wheel g, the result is a wide working range for the working head or the cutting unit 4 which, with the rotation of the disk wheel 9, describes a correspondingly large circle. A compact special video camera 7 with a halogen lamp 21 is disposed approximately in the center of the extent of the fork 10, the pivot axis of which is fixed in such a way, that the lens 30 is directed approximately in the direction of the working point. To keep the lens 30 clean during cutting operations, a water jet is directed toward the lens 30, via which it is sprayed with high pressure when required. The cutting unit 4 with the cutter 5 is seated in the front between the fork ends 11, where it can be pivoted in the way indicated by the arrows via the described worm drive by a motor. So that the video camera 7 itself can also be pivoted under remote control, it can be placed directly on the working head 2. Then it is possible to position it more exactly for viewing the interior conduit walls, in particular the interior conduit walls of joining conduits.
In Fig. 4 the cutting unit 4 is shown in cross section. It consists of a housing 18, in which the actual cutting head 17 is housed so it is translatorily displaceable. The cutter 5 is pneumatically driven via a turbine 40. A hollow shaft 6 extends axially along the cutter shaft, through which cooling water can be pumped, which can cool the actual cutter 5 from the inside and which then exits laterally. The displacement of the cutting head 17 in the housing 18 takes place pneumatically in both directions.
Maintaining the cutting head 17 in a desired extended position is accomplished in accordance with the invention by means of pneumatically operated oil brake cylinders. The oil circulation supplying the said oil brake cylinders with hydraulic oil is in a closed loop within the cutting unit 4. In this way it becomes possible to generate a very high braking force in spite of the ~ c3~ 3 cutting unit 4 being only supplied with air, so that the cutting head 17 extended in the housing 18 can absorb large reaction forces during cutting.
The cutting unit 4 seated between the fork ends 11 of the fork 10 is shown in a front view in Fig. 5, in which the fork 10 is in an extended position. As shown in this drawing figure, the fork 10 is rounded on its outside, so that the fork 10 cannot catch someplace with an edge when the disk wheel 9 rotates inside a narrow conduit. Also visible is the worm drive for pivoting the working head 2, in this case the cutting unit 4. The latter includes the worm 41 driven from the robot housing and the toothed wheel 39, which is fixedly connected with the pivot shaft of the housing 18. In accordance with the invention, the cutting head 17 is seated inside the housing 18 by means of two oppositely located friction shafts of hardened bar steel. Respectively two hardened, parallel disposed bar steel pieces 19 are fixed on the cutting head 17 on two sides of the cutting head 17 located opposite each other. Respectively one single hardened bar steel piece 20 is disposed on the oppositely located insides of the housing 18 and rests against the cutting head 17 along respectively one line in the center between the adjoining bar steel pairs 19. The play of the friction bearing formed in this manner can be adjusted by means of the screws 2~ on the housing 18, which prestress the bar steel pieces 20 and in this way determine their pressing force.
In addition to the pneumatic cylinder 42, the oil brake cylinder 43 is visible. If an extruding shoe is attached to the cutting head 17, the epoxy resin line is connected at the point 48 in Fig.
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The working head can also be a separate blower unit without a cutting device, having a compressed air nipple for attaching the inflating hose of a pig equipped with a one-way valve. The pig is placed in the conduit or an opening to be closed by means of the L 4 t~

robot 1 and is subsequently inflated by means of compressed air, so that it is braced in the respective inner conduit. Afterwards the lateral recesses around the entire pig can be filled with extruded epoxy resin. The working head can also be a spinning unit, which essentially has a pneumatically operated spinning disk, onto which a coating material or paint in liquid form can he sprayed by a jet on the working head aimed at the spinning disk.
It is possible by means of such a spinning unit to apply interior coatings to conduits, which are distinguished by a very homogeneous distribution of the coating material.
The control valve unit 14 contains the electrically actuated pneumatic valves for controlling the robot 1. All drives of the robot 1 are operated pneumatically or pneumatically-mechanically. The disk wheel 9, for one, is turned via the toothed wheel gear which itself is driven by a compressed air motor, the working head 2 or the cutting unit 4, on the other hand, are pivoted by means of the mechanical worm gear where again the worm is driven by a compressed air motor. In addition, the cutting head 17 is extended and retracted pneumatically and is arrested in any desired position by means of pneumatically driven oil brake cylinders. Finally, the actual cutter drive is pneumatic, in that a turbine 40 in the interior of the cutting unit 4 is supplied with compressed air. This drive permits cutter rpm up to approximately 45,000 rpm and correspondingly high cutting output. All these functions are controlled via the electrically actuable air valves in the control valve unit 14.
The opposite flow helical mixer is disposed underneath the control valve unit 14. Suitably the robot unit 36 contains in its interior a cross profile extending along its long axis, so that four recesses are formed which are V-shaped in cross section. The first compressed air motor is housed in a first recess, the supply lines for the compressed air and the electrical control lines in a , .

J ~ c~ . 1, .~ . ) second and fourth recess The second compressed air motor for the drives is housed in a third recess. The individual mQvements of the robot 1 and the work performed by it can be continuously monitored by the video camera 8 seated in the fork 10 and can be controlled via the camera image by the supply and control unit disposed above ground, which is equipped with an appropriate monitor. The control unit even permits automatic cutting of programmable cutting curves, which is of particular advantage when cutting lateral junctions which are to be opened. If it is intended to cut such a junction for the first time, or if one that was closed is to be opened again, it is necessary that the conduit wall of the conduit in which the robot 1 is located is cut as exactly as possible along the inner contour of the joining conduit. It is first necessary to locate the place to be cut.
This can take place visually, in cases where a previously closed spot is to be reopened, by traveling along the estimated area of the juncture and scanning it with the video camera. The previously closed place can usually be recognized visually. In those cases where the previously closed place cannot be found visually, or in all those cases where a conduit is to join for the first time, an ultrasound sensor is employed, which is mounted on the cutting head. The reflected ultrasound signals are different when they strike a conduit wall behind which a hollow place is located, for example the interior of a joining conduit. Once this spot has been found, it is drilled by the cutter 5 while being monitored by the video. Then the cutter 5 is moved, starting at the drilled hole, along two intersecting directions as far as the respective stop. The cutting paths can be detected via potentiometers. The control unit is equipped with an electronic device which makes it possible to calculate the center and the dimensions of the joining conduit on the basis of the cutting paths traveled and detected by the potentiometers in the form of .'..~
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~J iJ~j~j3~ 3 electrical signals, and to store them as data material. On the basis of these data the electronic device can calculate a circular cutting curve and subsequently can control the cutter electronically in such a way that lt travels exactly along the calculated cutting curve, because of which the said place is cleanly opened.
An extruding unit 23, which can be installed between the fork ends 11 in place of the cutting unit, performs the extrusion of epoxy resin for the purpose of repairing or closing off a place in the conduit at the end of the cutting work or after the insertion of a pig has been terminated. However, the extrusion unit 23 is advantageously embodied as an add-on piece which can be placed directed on the cutting head 17 and fastened there by screws, as can be seen in Fig. 6. The extrusion unit 23 consists of a shoe 24, the shape of which is a section of a hollow cylinder. Runners 25 are mounted on the rounded long edges of the extrusion shoe 24. During working, these runners 25 rest on the intact conduit wall on both sides of the place to be worked and in this way act as spacers. The rear end edge of the extrusion shoe 24 is embodied as a special smoothing edge 26 which acts as a smoothing trowel. The outlet opening 48 for the epoxy resin to be extruded is located approximately in the center of the extrusion shoe 24. On the back of the extrusion shoe 24 a nipple is disposed around the outlet opening, on which the hose for the epoxy resin is mounted. In use, the extrusion shoe 24, while being monitored by video, is taken to the place to be repaired or closed off and is then pressed against this place by extending the cutting head 17. In the course of this the lateral runners 25 are placed on an intact area around the place to be filled by extrusion and define the position of the extrusion shoe 24. Now the two components of the epoxy resin are pushed forward from the supply unit by means of a pump located there, and are mixed ~ u ~

directly prior to use and in place, so to speak, in an opposite flow helical mixer 46, as will be described later. Once it has - been determined through video monitoring that the injected epoxy resin has sufficiently filled the place, the extrusion shoe 24 is pivoted along its runners 25 approximately around its radius of curvature by pivoting the cutting unit 4 or by rotating the fork 10 by means of the disk wheel 9. In the course of this the smoothing edge 26 passes across the place filled with extruded epoxy resin on the exact level of the runners 25 and thus on the level of the surrounding area of the inner wall and cleanly smooths out the epoxy resin.
An opposite flow helical mixer is illustrated in Fig. 7 in a lateral view with a partially cut wall. This is a plastic pipe 46 with a diameter which slightly tapers toward the front. In the interior of the plastic pipe 46 a row of rectangles 47, respectively twisted by 180, is disposed so they adjoin each other, so that their long edges respectively form a helical shape.
The individual twisted rectangles 47 or twisting elements 47 are lined up with each other in such a way that the straight ends or broad sides of the respective twisted rectangles adjoin each other at right angles. The two components of the epoxy resin pushed through the opposite flow helical mixer are turned by 180 by each twisting element 47, and then each component is cut in two by the front edge of the next twisting element 46 and brought tosether - with half of the other component. Thus, on both sides of each twisting element 47 two fresh portions arriving from the previous twisting element 47 are freshly mixed. This process extends over approximately ten twisting elements 47, because of which very intimate mixing of the two original components is achieved. This opposite flow helical mixer is disposed underneath the valve , control unit 14. Thus, the finished epoxy resin mixture exits the ~' supply line 35 there and reaches the extrusion unit 23, by means ,",:
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~ ~ Y ;3 1 ~L 3 of which the epoxy resin is applied~ to the place in the conduit to be repaired or closed off.
The embodiment of the synchronous drive of the locomotive 8 is illustrated in Fig. 8. A row of toothed wheels of equal size and in an uneven number, which transfer the driving force from the drive shaft 44 to the other one, 45, is disposed between the front and rear drive wheels 12, which are respectively connected with each other via a rigid axle. By means of this type of power transfer, absolutely synchronous running of the four drive wheels 12 of the locomotive 8 is assured without play and with the least space required and most effective power transfer. Each of these toothed wheels 29 is disposed on a separate plate 38 which, in turn, is sealingly bolted to the housing 27. The entire gas-tight housing of the locomotive 8 is filled with nitrogen at an overpressure of approximately 0.2 bar in respect to the environment in order to prevent any entry of moisture or water.
This overpressure can be regularly checked and replenished, if needed, through a valve provided for this purpose on the locomotive housing 27. The electric motor inside the locomotive housing has a rated motor voltage of 60 V at 5 A current intensity, for example. It is equipped with a tachometer generator, which is coupled with a transformer and amplifier in the supply and control unit. A voltage reduction because of an rpm reduction of the electric motor is automatically compensated for by the supply and control unit via the transformer and amplifier with an increased current intensity in accordance with an optimized characteristic curve based on the motor type. The four specially developed solid rubber cleated tires 28, which are provided with many rubber cleats all around the visible tire cross section, assure the optimal power transfer of the locomotive 8 so as to obtain as great as possible an adhesion to the curved inner wall of the conduit through which it travels.

~Y~ LLl3 So that the device can also be employed in conduits of considerably larger diameter than those the inner wall of which the robot, resting on the conduit floor, can reach, instead of the runners the robot l can be equipped at two places additionally with traveling gear legs which can be radially extended away from it. These traveling gear legs can be extended pneumatically, for example and can be arrested in any extended position by means of pneumatically operated oil brake cylinders. In an advantageous manner the traveling gear legs are equipped with free-wheeling wheels in such a way that the robot 1 can be stabilized around its long axis for work in the center of large diameter conduits and still remains movable by means of the locomotive 8.

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A process for the interior working of conduits which cannot be entered by persons, wherein a remote-controlled robot (1), having a video-monitored working head (2), is brought by a supply and control unit above ground into the conduit to be worked, cuts out the section to be opened or repaired or places a pig at the spot to be closed off and braces it in the conduits by expanding it, characterized in that a. in case of cutting, this is performed by means of a pneumatically operated cutter (5) at an rpm of more than 35,000 rpm;
b. for repairs, two components of a two-component epoxy resin are pushed via two separate hose lines (35) from the supply and control unit to the robot (1);
c. the two components are mixed in a opposite flow helical mixer (46) into an intimate, hardening epoxy resin mixture immediately prior to reaching the working head (2);
d. the mixed, hardening epoxy resin is extruded into the cut-out spot or the area ahead of the braced pig and is smoothed.

2. The process in accordance with claim 1, wherein cutting of the spot to be opened takes place in that a. the spot to be opened is reached with the aid of the video camera (7) or is detected by means of ultrasound detectors, b. the spot to be opened is drilled, c. starting at the bore, cutting is sequentially performed in two crossing directions back and forth as far as the stop, in the course of which the cutting paths are electronically measured and the center and the dimensions of the joining conduit and the associated cutting curve are calculated therefrom and stored, d. the electronically stored cutting curve is travelled, because of which the spot is opened as desired.

3. A device for executing the process in accordance with claim 1 or 2, with a remote-controlled robot (1), which can be inserted into the conduit to be worked, with a video-monitored working head (2) and an associated supply and control unit disposed above ground, characterized in that at the front of the robot (1) a disk wheel (9), which is rotatable around its long axis over more then 360°, is disposed, which supports a fork (10) provided with a hinge (13), between the fork ends (11) of which a working head (2) is seated pivotably and extendible, which is embodied as a cutting unit (14) for cutting out spots, as a blower unit for bracing pigs, as an extrusion unit (23) for extruding and smoothing epoxy resin, as a spinning unit for the interior coating of conduits, or as a combination of such units (4, 23).

4. A device in accordance with claim 3, characterized in that the robot (1) is an element of a composite train consisting of a locomotive (8), control valve unit (14) and the robot (1), wherein these three elements (1, 8, 14) are connected with each other via pivot hinges (15, 16) which are pivotable to all sides, but are not rotatable in respect to each other, that the robot (1) is maintained secure against relative rotation in the conduit interior without any further bracing means, and that electronic measuring devices are provided, by means of which all movements of the composite train, namely horizontal travel of the locomotive (8), rotation of the fork (10) as well as pivoting and extension of the working head (2), can be detected and controlled.

5. A device in accordance with one of claims 3 or 4, characterized in that the working head has a blower and cutting unit (4) with a pneumatically extensible cutting head (17), which can be arrested in any extended position by means of pneumatically actuable, hydraulic oil brake cylinders, the oil circulation of which is in a closed loop within the cutting unit (4).

6. A device in accordance with one of claims 3 to 5, characterized in that the blower and cutting unit (4) has a housing (18), from which the cutting head (17), seated on a friction bearing, can be extended, wherein the friction bearings are formed on the one hand at the cutting head (17) on two sides of the cutting head (17) by respectively two hardened, parallel disposed bar steel pieces (19), and on the other hand by respectively one single hardened bar steel piece (20) on the oppositely located insides of the housing (18) in such a way, that the individual bar steel pieces (20) rest along one line in the center between the bar steel pairs (19), wherein the play of these friction bearings can be adjusted by means of setting the pressure with screws (22) on the housing (18), which prestress the hardened bar steel pieces (20) on the housing (18).

7. A device in accordance with one of claims 3 to 6, characterized in that the working head (2) can be brought into its pivoted position pneumatically-mechanically by means of a worm drive and can be arrested there because of self-locking of the worm gear and that, if the working head (2) is embodied as a blower and cutting unit (4), the cutter (5) can be pneumatically driven via a turbine (40), wherein a hollow shaft (6) is provided, through which the cutter (5) can be water-cooled on the inside in that water can be conducted from the interior of the cutter (7) to the outside.

8. A device in accordance with one of claims 3 to 7, characterized in that the working head (2) is embodied as an extrusion unit (23), wherein, ahead of the working head (2) in the valve control unit (14), an opposite flow helical mixer (46) is housed, by means of which the epoxy resin components can be intimately mixed immediately prior to being pushed into the working head (2), and that the extrusion unit (23) has a rounded extrusion shoe (24) with runners (25) on both sides and a smoothing edge (26), by means of which the mixed epoxy resin mixture can be extruded on the surface to be worked and smoothed there.

9. A device in accordance with one of claims 3 to 8, characterized in that the locomotive (8) has a one-piece housing (27), sealed gas-tight under N2-overpressure, and is driven by four wheels (12) equipped with cleated tires (28), which are collectively driven synchronously via a row of toothed wheels (29) by a single electric motor equipped with a tachometer generator, so that a voltage reduction because of an rpm reduction of the electric motor is automatically compensated for by the supply and control unit via the transformer and amplifier with an increased current intensity in accordance with an optimized characteristic curve based on the motor type.

10. A device in accordance with one of claims 3 to 9, characterized in that the video camera (7) is disposed directly on the working head (2) and its lens (30) is directed on the working point at an angle of approximately 45° in respect to the cutter axis.

11. A device in accordance with one of claims 3 to 10, characterized in that the extrusion unit (23) can be mounted directly on the cutting head (17).

12. A device in accordance with one of claims 3 to 11, characterized in that the robot (1) can be equipped at two places with traveling gear legs which can be radially extended away from it, can be extended pneumatically and arrested by means of pneumatically operated oil brake cylinders and are equipped with free-wheeling wheels in such a way that it can be stabilized around its long axis for work in the center of large diameter conduits.

13. A device in accordance with one of claims 3 to 12, characterized in that a spinning unit is inserted between the fork ends (11), by means of which the inner surface of the conduit to be worked can be coated.