Process and device for inspecting just as servicing and repairing subsidiary canals branching off from a main drain

The invention relates to a method and a device for channel examinations with a camera end.

In the examination of sewer ducts and the like, it is known to introduce a television camera mounted on a self-propelled car or on a push rod into the duct so that the wall of the sewer pipe can be inspected by means of the television camera. For this purpose the TV camera is connected by a cable to a monitor installed outside the channel.

On the other hand, for removing clogging or cleaning channels, it is known to introduce a flushing lance with nozzle fixtures into the channel and to clean the channel pipes with water jets which are discharged at high pressure from the flushing lance.

In the investigation of canal systems, there is occasionally the need not only to inspect the main canal, but also to penetrate into the secondary canals, which branch off from the main canal, with a narrower cross-section.

For this purpose, it is known to mount the camera on a steerable carriage, which can also be deflected into the secondary channels. However, this is only possible for secondary channels branching laterally from the main channel. Secondary channels which extend upwards or obliquely upwards from the main channel can not be achieved in this way. A further disadvantage is that the frictional resistance of the cable retracted by the camera carriage at the kinking points is considerably increased, so that the pulling force of the relatively small and light camera cars is not sufficient to penetrate deep into the secondary channels. In addition, the camera cart can easily get stuck on obstacles.

In another known system, a drivable drum is installed on the channel carriage which can be moved in the main channel, on which a semi-rigid push rod is wound, with which a small camera end can be advanced into the secondary channels. In this method, too, however, only relatively small penetration depths are achieved because, due to the flexibility of the push rod, no large penetration resistors can be overcome.

DE 38 03 274 A1 and DE 91 05 211 U1 disclose methods and devices for the investigation of secondary channels according to the preamble of claim 1 or of the first device claim 3 in which a conventional camera car is provided with a deflecting frame with deflecting and driving rollers, With which the camera, which is arranged at the front end of a flexible shaft or a semi-rigid camera cable and whose objective is normally directed forward in the direction of the axis of the main channel tube, pivots into a branching secondary channel and can then be pushed into the subchannel at the camera cable or the shaft . In this method, however, the above-mentioned problems also occur. So that you can only enter the side canal for a limited distance.

In DE 38 77 721 T2, a jet nozzle is described with which a camera car serving for examining canal pipes can be driven by the recoil principle. However, this recoil-driven camera car is not suitable for use in secondary ducts, since it is not manoeuvrable enough and can not be directed into branching secondary ducts, in particular if the secondary ducts emerge obliquely upward from the main duct.

The invention is based on the object of providing a method and a device which allow the camera end to penetrate more deeply into the secondary channels branching off from the main channel and to overcome any obstacles.

This object is achieved with the features specified in claims 1 and 4.

According to the invention, the camera end is provided with recoil nozzles and is connected to a hose for supplying a pressure medium to the recirculation nozzles. Due to the propulsion of the camera end in accordance with the rebound principle, a high drive force can be generated with little structural complexity and with extremely small dimensions so that the camera end penetrates easily into narrow secondary channels and overcomes also large gradients and the camera cable and the hose for the printing medium Over long lengths. Unlike camera cars with driven wheels or caterpillars, the propulsion force is not affected by slippery dirt on the channel walls. Since, on the other hand, the propulsive force is generated directly at the camera end, the danger that the probe is caught by projections or offsets in the channel wall is considerably smaller than in systems in which the probe is advanced with a push rod.

Both compressed air and water can be used as the pressure medium for producing the necessary recoil. Particularly when using water, cleaning of the pipe walls is achieved at the same time. It is therefore possible, for example, to clean the pipe wall when the camera end is retracted, and then to inspect the pipe wall freed from dirt encrustations when the probe is withdrawn, so that it is easier to detect damage points.

Advantageous further developments and refinements of the invention are given in the subclaims.

Preferably, the recoil nozzles are arranged on a rim which surrounds the water-tight housing of a conventional camera end at its periphery at a small distance from the front end, and the nozzle openings are directed obliquely rearward on the pipe wall. This construction ensures that the camera end is kept at a distance from the tube wall by the nozzle jets so that projections and bumps of the tube wall can be more easily overcome and the camera lens is less easily soiled. In addition, an approximate self-centering of the camera end on the crude axis is also achieved in channel tubes whose inner diameter is significantly greater than the diameter of the camera end, so that the tube wall can be equally well inspected on its entire circumference.

In addition, it is advantageous to integrate the camera cable directly into the hose for the printing medium so that only a single supply strand needs to be pulled by the probe. For example, the camera cable can extend through the interior of the hose, or the wires of the camera cable can be integrated into the pressure-resistant jacket of the hose.

On the other hand, it is conceivable to connect several hoses with a correspondingly smaller cross-section to the camera end so that individual recoil nozzles or groups of recoil nozzles can be controlled separately. This achieves a controllability of the camera end so that the probe can be positioned in the secondary channels. The same effect can also be achieved by the fact that one or more valves electrically, hydraulically or by cable pull are arranged in the camera end for controlling the recoil nozzles, or that pivotable recoil nozzles are provided.

A further possibility, which is currently regarded as particularly advantageous, of directing the camera end into the secondary channel branching off from the main channel is that a deflection rack which guides the camera into the secondary channel is fixed in the main channel at the branch point of the secondary channel.

In the simplest case, the deflecting frame consists of a cylindrical block, the cross-section of which approximately corresponds to the cross-section of the main channel and is chamfered at its rear end, so that it forms a guide surface for the camera end. The block is inserted into the main channel by means of an eccentrically arranged push rod before the camera end is inserted into the main channel. If, with the aid of the camera end, a branch is discovered on the main channel, the block is held on the push rod and rotated so that its guide surface is directed towards the branching secondary channel. Subsequently, the camera hose is let down so that the camera end penetrates into the side channel.

In another embodiment, the deflecting rack is mounted on a conventional camera carriage for the main channel. In this case, the camera hose for the camera end to be introduced into the secondary channel can be unwound from a drum mounted on the camera carriage, or, if the hose is fed from the shaft, be pulled from the camera carriage by means of a pinch roller drive or the like. The recoil nozzles at the camera end then only have to overcome the frictional resistance of the hose section running through the secondary channel.

In this case, however, the driving drive of the main channel camera car must have a good traction, since, in addition to the cable of the main channel camera, the hose and possibly the separate cable for the subchannel camera end must also be pulled through the main channel Additional tensile forces are applied to the camera wagon. It is therefore expedient to clamp the camera carriage with claws or roller feet which can be spread in the main channel as a function of the tensile force.

According to a particularly advantageous embodiment of the method according to the invention, a locating device is installed on the camera end provided with recoil nozzles, the locating signals of which can be measured overground and thus indicate the position of the probe inserted into the channel. In this way, the position of the damage points fixed with the aid of the camera can be precisely measured. If a combination of the camera and the locating device is used, the channel can also be precisely and detailed in one operation, simultaneously with the examination of the state of the channels. This considerably simplifies the planning of restoration work for a reconstruction requirement determined by the channel underfloor. The measured data obtained with the aid of the location device can be processed electronically in a CAD system for the generation of the location plans, and the data obtained in this way can be entered into an electronic channel sensor so that precise information on the position and position of the main channels recorded in the cadastre can be obtained The state of the secondary channels can be called up.

In the following, preferred embodiments of the invention are explained in more detail with reference to the drawings.

Show it:<dl id="dl0001"><dt>FIG</dt><dd>An exemplary embodiment of the device according to the invention in a main channel from which a secondary channel branches off,</dd><dt>FIG</dt><dd>A schematic front view of the main channel camera cart;</dd><dt>FIG</dt><dd>3 is a partial longitudinal section of the camera carriage;</dd><dt>FIG</dt><dd>5 shows a side view of a device according to a further exemplary embodiment;</dd><dt>FIG</dt><dd>4 is a front view of the device according to FIG. 4;</dd><dt>FIG</dt><dd>4 shows a section through a mount for a camera end in the device according to FIG. 4; </dd><dt>FIG</dt><dd>A section through a pipe branch with a deflection block for a camera end;</dd><dt>FIG</dt><dd>A drag nozzle arranged in a hose of the camera end;</dd><dt>FIG</dt><dd>An axial section through a camera end with locating device;</dd><dt>FIG</dt><dd>A front view of the camera end according to FIG. 9; and</dd><dt>FIG</dt><dd>2 shows a section through a camera end with locating device according to a modified exemplary embodiment.</dd></dl>

1 shows a longitudinal section through a main duct pipe 10, from which a secondary duct pipe 12 branches off upwards. A camera carriage 14, whose construction is fundamentally known, is displaceable in the main channel tube 10, and therefore only the rear part of the drawing is shown in the drawing. A main channel camera, not shown, is mounted on the front end of the camera carriage 14 for inspection of the main channel tube 10. From the camera carriage 14, a cable (not shown) passes through the main canal tube 10 to a shaft from which the camera car 14 has been started. This cable is used to power the camera car's drive, and the signals from the main channel camera, as well as control signals for the operation of the camera and camera carriage 14, are transmitted through this cable.

A shaft 16 is mounted at the rear end of the camera carriage 14 and is rotatable about its axis extending parallel to the axis of the main channel tube 10 by means of an electric or hydraulic motor 18. The shaft 16 is flattened at its rear end, forming a platform 20 on which is mounted a deflection frame 22 for a camera end 24 for inspection of the secondary channel tube 12.

The deflecting rack 22 is essentially constituted by a tubular mount 26, which is pivotally connected to the shaft 16 by a hinge 28. The pivoting movement of the mount 26 is controlled by an air cylinder or hydraulic cylinder 30.

The camera end 24 has a watertight housing of known design which receives a television camera (not shown) in such a way that a region located in front of the end face of the camera end, at the upper right in FIG. 1, is detected by the camera with a relatively wide opening angle. In the state shown in FIG. 1, the mouth of the secondary channel tube 12 thus lies in the field of view of the camera in the camera end 24.

The housing of the camera end 24 is surrounded by a nozzle ring 32, which has a number of nozzle openings 34 directed obliquely outwards and rearwards with respect to the axis of the camera end 24. The nozzle ring 32 is connected at the rear end of the camera end 24 to a high-pressure-resistant hose 36, via which a pressure medium, for example water, is supplied under high pressure so that it emits jet-like out of the nozzle openings 34, . A camera cable 40 for the power supply of the camera end 24 and the transmission of the camera signals is integrated into the tube 36. At the lower end of the mount 26, two guide rollers 42 are arranged which receive the hose 36 between them. The hose 36 is held clamped between two drive rollers 44 which are mounted on the platform 20 and can be mutually driven by means of a motor (not shown) accommodated in the shaft 16, as well as a gear 46 indicated only in dashed lines in the drawing.

Two further drive rollers 48 with an associated transmission 50 are arranged offset on the platform 20, offset upwards, relative to the drive rollers 44 and receive a rinsing hose 52 between them. The flushing hose 52 runs into the secondary channel tube 12 by way of a guide channel 54 externally mounted on the mount 26 and carries at its free end a purge nozzle (not shown) for cleaning the secondary channel tube.

The deflecting rack 22 as a whole is designed and arranged in such a way that, even in the case of different pivoting positions of the mount 24, it finds place in a main duct tube 10 with a relatively narrow cross-section. If, in narrow channels, the camera carriage 14 itself does not leave enough space for the attachment of the deflecting frame, the deflecting frame can also be designed as a type of trailer to the camera car.

The mode of operation of the device described above is to be explained below.

The autonomous camera car 14 drives remote controlled into the main canal tube 10 until the main canal camera mounted at the front end of the camera cart engages the branch of the secondary canal tube 12. On the basis of the camera image on the monitor, the operator controls the motor 18 such that the shaft 16 is rotated so that the azimuth of the mount 26 coincides with the azimuth of the mouth of the subchannel tube 12. Subsequently, the camera carriage 14 is advanced further, while the image provided by the camera end 24 is observed until the camera carriage reaches the position shown in FIG. 1 and the mouth of the secondary channel 12 appears on the screen connected to the camera end 24. With the aid of the hydraulic cylinder 30, the mount 26 is then pivoted such that its axis runs approximately parallel to the axis of the secondary channel 12.

The rinse hose 52 is then extended with the aid of the drive rollers 48, so that the rinsing nozzle attached thereto is guided into the secondary channel tube 12 through the guide channel 54. The correct introduction of the flushing hose 52 into the secondary channel pipe 12 can be monitored with the aid of the camera end 24. Then, the secondary channel tube 12 is purged with the aid of the flushing hose 52. If the secondary channel tube runs upwards, as shown in FIG. 1, it is expedient to advance the camera carriage beforehand (to the right in FIG. 1) so that the camera end 24 does not pass through The rinsing water emerging from the secondary channel tube 12 is polluted. The forward movement of the flushing hose 52 in the secondary channel tube 12 is effected in part by the drive rollers 48 and additionally by the recoil of the flushing nozzle (not shown). After the secondary channel pipe 12 has been cleaned, the flushing hose 52 is withdrawn until the end provided with the flushing nozzle is located in the guide channel 54. The camera carriage 14 is positioned such that the mouth of the tubular carriage 26 is directed precisely to the axis of the secondary channel tube 12.

When the pressurized water supply is then switched on via the hose 36, the camera end 24 penetrates the secondary channel tube 12 due to the rebound generated by the nozzle jets 38, and the previously cleaned tube wall can be inspected with the aid of the camera. During propulsion of the camera end 24, the hose 36 is pulled by means of the drive rollers 44, so that the driving force generated by means of the recoil nozzles 34 is required only for the portion of the hose 36 located between the camera end 24 and the drive rollers 44. The guide rollers 42 ensure that the hose 36 is not damaged at the edge of the mount 26.

In the manner described above, secondary channel tubes can be inspected to a great depth by means of the device according to the invention, whereby the device can be adapted to the desired outlet directions of the secondary channel tube by rotation of the shaft 16 and pivoting of the mount 26. When examination of a secondary channel is completed, the camera end 24 is retracted back to the position shown in FIG. 1, and the camera carriage 14 travels to the branch of the next sub-channel tube, where the same examination procedure is repeated. The drive roller pairs 44 and 48 can be fixed, for example, by using self-supporting drive motors or by means of suitable couplings or locking devices such that the hoses 36 and 52 are retained and retracted during the forward movement of the camera carriage 14.

Since, in addition to the two hoses 36 and 52, the supply cable (not shown) must also be retracted for the camera carriage 14 during the forward movement of the camera carriage 14, relatively high tensile forces can occur in the case of longer main channel sections, so that the camera carriage 14 must have a correspondingly good traction. In addition, when propelling the tubes 36, 52 with the aid of the drive roller pairs 44 and 48, it can also be necessary to fix the camera carriage 14 firmly in the main channel tube 10 in order to absorb the occurring reaction forces. For this purpose, the construction of the camera carriage 14 shown schematically in FIGS. 2 and 3 is suitable.

2, the camera carriage 14 has a cylindrical housing 56 from the circumference of which at least three roller feet 58 arranged at regular angular intervals extend in the radial direction. Each roller foot 58 carries, at the free end, two roller sets 60 arranged one behind the other in the axial direction of the housing 56, each with two rollers 62 which roll on the inner surface of the main channel tube. The housing 56 is thus held coaxially in the main channel tube. The roller feet 58 are preferably longitudinally adjustable or telescopic and biased outwardly so that the channel carriage 14 can be adapted to different pipe diameters.

Each roller set 60 has at least one driven roller 62 in order to ensure uniform advancement of the camera carriage 14 even if one of the roller sets 60 temporarily loses contact with the inner wall of the pipe, for example when a branch is passed over. The distance between the roller sets 60 of each roller foot is preferably greater than the diameter of the secondary channel tubes branching off from the main channel tube. Optionally, each roller set 60 can also consist of several pairs of rollers which are offset in the longitudinal direction of the main channel tube. A frame 64 connecting the roller sets 60 is preferably pivotally mounted on the shank of the roller base 58 so that the rollers 62 are better able to roll over obstacles such as encrustations on the pipe wall or offsets on sleeve connections.

Since the channel carriage 14 can be firmly clamped in the main channel tube with the construction shown in FIG. 2, relatively high tensile forces can be absorbed.

FIG. 3 shows a mechanism by which the pressing force of the roller sets 60 against the raw wall can be increased as a function of the tensile force. The roller foot 58 has an outer tube 66 in which a pressure rod 68 connected to the frame 64 is slidably guided. The pressure rod 68 extends into the interior of the housing 56 and rests there with an inclined surface 70 on a cone 72. The cone 72 is held coaxially in the housing 56 and is movable in the axial direction and likewise supports the pressure rods of the two remaining roller feet 58 in the same way.

The tensile forces acting on the camera carriage 14, ie, the pulling force of the supply cable and the tensile forces of the hoses 36 and 52 acting on the drive rollers 44 and 48 in FIG. 1, act via a tension spring 74 on the tapered end of the cone 72 Pull force to an axial movement of the cone 72 and thus to a radial outward movement of the pressure rods 68 so that the roller sets 60 are tightened more firmly against the pipe wall. Instead of a mechanical spreading mechanism with the cone 72, a hydraulic spreading mechanism can also be provided, which has a pressure generating cylinder, the piston of which is subjected to the tensile force, and spreading cylinders connected to the pressure generating cylinder for extending the roller feet.

FIGS. 4 to 6 show a deflection frame 76, which can be used independently of a camera car. The deflection frame 76 has a basket-like cylindrical housing 78, the largest diameter of which is somewhat smaller than the inner diameter of the main channel tube and which can be slidably mounted on sleds 80 in the main channel tube. The drive is, for example, effected via a push rod, which can be coupled to a sleeve 82 at the left end of the housing 78 in FIG. Optionally, motor driven drive wheels can also be arranged on the runners 80.

At the end of the housing opposite the sleeve 82, the tubular mount 26 for the camera end 24 (FIG. 6) is pivoted via a hinge 84. A pull cable 86, which runs through eyes 88 on one of the runners 80, serves to pivot the mount 26 about the axis of the hinge 84.

In the exemplary embodiment shown in FIG. 6 of the camera end 24, the recoil nozzles are not arranged on the circumference of the housing 92 of the camera end but in a separate nozzle head 90 at the rear end of the housing 92. In operation, the nozzle head 90 thus slides the camera-accommodating housing 92 forward, and the housing 92 slides through the sub-channel tube. Optionally, the housing 92 may be provided with runners of slidable material or wheels to more easily slide over unevenness on the inner surface of the subchannel tube.

In the exemplary embodiment according to FIG. 6, the guide rollers 42 are not mounted on the mount 26 but rather directly on a sleeve 94 belonging to the housing 78.

FIG. 7 shows an exemplary embodiment of a deflection frame 96, which is distinguished by a simple design. This deflection frame is formed by a solid cylindrical block 98 which is adapted to the inner cross-section of the main duct pipe and can be introduced into the main duct pipe by means of a push rod 100. At the rear, the block 98 is beveled, and the beveled end face forms a deflection surface 102, through which the camera end, not shown in FIG. 7, is deflected into the branching secondary channel tube 12. In the exemplary embodiment shown, the deflection surface 102 is formed by a shallow cavity which is open on the side of the secondary duct pipe 12 towards the circumference of the block 98 and runs flat on the side of the pushing rod 100. When the camera end runs on the deflection surface 102, the block 98 is held by means of the push rod 100. In addition, the push rod 100 serves to rotate the block 98 about the longitudinal axis thereof so that the deflection surface 102 is directed toward the branching secondary channel tube 12.

Optionally, a spreading mechanism can be provided at the block 98, which can be actuated by a second push rod and serves to clamp the block 98 in the main channel tube 10. Rollers can be provided on the spreading claws of the spreading mechanism which roll circumferentially against the inner surface of the main channel tube 10 and are driven, for example, by rotation of the push rod so that the block 98 can be rotated simply and precisely about its longitudinal axis.

Finally, the block 98 may auc be mounted in a sleeve not shown h rotate, which in turn can be moved axially in the Hauptkanalrohrl0. The guide sleeve can be provided on its circumference with skids or rollers, which are supported on the tube wall.

When the camera end has to travel a very wide distance in the main channel tube 10 before it reaches the branch of the secondary channel tube 12, the arrangement shown in FIG. 8 can also be used to overcome the then very great frictional resistance of the tube instead of the drive rollers 44 from FIG. In this arrangement, the rear end of the hose 36 of the camera end 24 is connected to a drag nozzle 104, which in turn is connected to a hose 106 with a larger cross-section. The printing medium is fed via the hose 106. The drag nozzle 104 includes a valve (not shown) which is responsive to a certain minimum pressure so that a portion of the pressure medium is discharged from the drag nozzle 104 in the form of rearward beams 108, while another portion of the pressure medium is supplied to the recirculation nozzles via the hose 36 34 of the Cameroonian.

First of all, the camera end 24 is driven forward with the aid of the recoil nozzles 34 in the main channel tube, pulling the hose 36 back. The pressure of the pressure medium is thereby smaller than the opening pressure of the valve. After the camera end has been introduced into a secondary channel, for example with the deflection frame shown in FIG. 4 or in FIG. 7, the pressure of the pressure medium is increased, so that the hose 106 is pulled by the recoil of the drag nozzle 104 in the main channel tube. In this way, a high advance force can be generated with the aid of the drag nozzle 104, while the more flexible hose 36 is used in the secondary channel.

In the following, exemplary embodiments are described in which a locating device is integrated into the camera end.

A conventional camera end typically includes a substantially cylindrical camera housing terminated at one axial end by the camera lens and optionally an additional protection disc. Inside the cylindrical housing is the actual camera module with the camera electronics. This module is usually constructed on a circuit board and accordingly has the shape of a flat plate whose width corresponds to the internal diameter of the camera housing. According to one embodiment of the invention, the locating device is accommodated in one of the two segment-shaped cavities which are formed in the cylindrical camera housing on the one hand by the camera module.

In another embodiment, the locating device is housed in an annular housing which surrounds a portion of the housing of the actual camera end or the cable emerging from the housing at the rear end.

Frequently, the camera user has a camera slit, which takes up the actual camera housing and serves to guide the camera in the channel tube. In this case, the locating device can be mounted on or in the camera carriage.

A particularly compact design can be achieved by the fact that the locating device is directly connected to the power supply of the camera so that bulky batteries can not be used for the power supply of the locating device. For this purpose, the locating device is designed to operate with the operating voltage of the camera of, for example, 12 volts, or a small-sized electronic voltage converter is provided which converts the operating voltage of the camera to the voltage required for the locating device.

This solution also has the advantage that, in the case of lengthy investigations, no interruptions are necessary to replace the batteries for the locating device.

If the camera end has an electrically driven camera car, the drive of the camera car can also be connected to the common voltage supply for the camera and the locating device. In addition, the operating voltage for the drive of the camera car is simultaneously tapped from the camera head directly connected to the camera cable via the plug-in coupling. In such camera heads, the locating device can be inserted with a corresponding plug-in coupling between the camera head and the camera carriage. Conversely, it is also possible to couple the locating device separately from the camera to the camera car so that the locating device receives the operating voltage from the camera car, which in turn is supplied with the operating voltage via the camera head. Preferably, the electrical plug-in couplings are adapted to one another on the camera head, the locating device and the camera car so that the locating device can optionally also be coupled directly to the camera head. There is then the possibility of using the camera head with a location device without a camera cart and, for example, by means of a flexible rod, to feed in the channel tube.

The camera end 210 shown in FIG. 9 has a cup-shaped housing 212, which is terminated at the front end by a frustoconical end piece 214. At the rear end of the housing 212, a screw connection 216 is provided for a pressure hose (not shown). In the wall of the housing 212, an annular chamber 218 is formed, which is connected at the rear end to the screw connection 216 and is connected at the front end to obliquely outwardly and rearwardly directed recoil nozzles 220. If water is supplied under suitable pressure via the pressure hose, the water is emitted in a jet-like manner through the recirculation nozzles 220, and the propulsion of the camera end 210 and the centering of the camera end in the sewer pipe is thereby effected.

In the front part of the housing 212 and the end piece 214, a cylindrical camera housing 222 is housed, which is closed at the front end by a protective disc 224. The camera lens 226 is mounted directly behind the protective screen 224. A camera module 228, which contains electrooptical sensors (not shown) and the camera electronics, is in the form of a flat plate-shaped component and is mounted in the camera housing 222 in such a way that it lies in a diameter plane of the camera housing, as can be seen in FIG. The camera module 228 thus defines two cavities 230, 22 with a circular segment-shaped cross-section in the camera housing 222.

In the exemplary embodiment shown, a locating device 234 is accommodated in the cavity 230. Alternatively, however, the locating device can also be divided into two assemblies, one of which is accommodated in one of the cavities 230 and 232. In this way, the locating device 234 can be accommodated in a space-saving manner in the camera housing 222.

A camera cable 236, which is connected to the camera module 228, is guided in a liquid-tight manner in the illustrated example through the end wall of the housing 212 and runs through the interior of the screw connection 216 and the pressure tube (not shown). This camera cable 236 serves, in turn, for forwarding the camera signal to a monitor (not shown) and, on the other hand, for the voltage supply of the camera module 228 and the locating device 234.

The locating device 234 is, for example, a long-wave transmitter. However, the locating device can also be formed by a transmitter for electromagnetic waves in a different frequency range or else by an ultrasonic transducer or the like. The electronics of the locating device, which are not shown in detail, are designed in such a way that they can be operated with the same voltage as the camera module 228, that is, for example, with a DC voltage of 12 volts.

Alternatively, however, the locating device 234 can also operate as conventional locating devices with an operating voltage of 1.5 to 1.7 volts. In this case, the operating voltage can be supplied by a battery accommodated in the cavity 232.

In the illustrated example, the cylindrical cavity in the housing 212 and end piece 214, which is available for accommodating the camera housing 222, has a length of approximately 100 mm and a diameter of approximately 40 mm. A positioning device with a length of approximately 50 mm and a height of approximately 10 mm can therefore be easily accommodated in each of the circular segment-shaped cavities 230,

FIG. 11 shows a modified embodiment of the camera end 210, in which a tubular shank 238 is formed between the screw connection 16 and the end wall of the housing 212. The locating device 234, which in this case has an annular housing, rests on this shaft. The annular housing of the locating device 234 has in the example shown an inner diameter which corresponds to the outer diameter of the shaft 238 and an outer diameter which corresponds to the outer diameter of the housing 212.

In this embodiment as well, the voltage supply of the locating device 234 can optionally take place via a battery which is integrated into the housing of the locating device or via the voltage supply of the camera module. In the latter case, a connecting terminal 240, which is connected to the camera cable and is connected to the locating device 234 via a line 242, is arranged between the camera housing 222 and the end wall of the housing 212. The conduit 242 extends, for example, through radial webs 244 formed in the annular chamber of the housing 212 and is thus protected against water flow.

The problem of introducing a probe into the secondary channel branching off from the main channel is not only found in the detection of damage points during a channel inspection, but also in the subsequent repair of such damage sites. Various working tools are known which are to be introduced into a sewer pipe in order to perform appropriate repair work. These devices include, in particular, gripping, cutting or milling tools for removing foreign bodies such as waxy roots and the like, as well as devices for repairing damage points in the channel wall, for example for filling cracks or holes with a filling compound or for lining or ejecting the inner surface of the Channel wall with a coating compound. A modified embodiment of the device according to the invention makes it possible also to carry out such work in the secondary channel tube. For this purpose, the required working tool is attached to the reed-driven probe.