Sewer pipe inspection system and guide unit for sewer pipe inspection system

Abstract

Sewer pipe inspection system (1) comprising: a frame (2), a basket (3) rotatably mounted on the frame (2), which has a receiving section (4), wherein the receiving section (4) is configured to receive a flexible sliding rod (5) which tends to assume a straight path in an unwound state, and a guide unit (10) with a guide channel (11) for guiding the flexible push rod (5) during the winding and unwinding of the push rod (5) from the receiving section (4), wherein the guide unit (10) has an insertion opening (12) laterally connected to the guide channel (11) for inserting the push rod (5) into the guide channel (11), and wherein the insertion opening (12) has a shape that differs from the guide channel (11) in its longitudinal extent.

Description

[0001] The present invention relates to a sewer pipe inspection system and a guide unit for such a sewer pipe inspection system.

[0002] Sewer pipe inspection systems are used, for example, to inspect sewer pipes in wastewater systems. A typical sewer pipe inspection system comprises a frame and a basket rotatably mounted on the frame, containing a receiving section onto which a flexible push rod can be wound and unwound. The push rod is either detachably or permanently connected to a camera. The camera is inserted into the sewer pipe to be inspected using the push rod, allowing the camera to locate damage or obstructions within the pipe and display them on a suitable monitor. When unwound, the push rod tends to assume a substantially straight path. As a result of this tendency, i.e., due to a constraint imposed by being wound up in the receiving section of the basket, the push rod is located in its wound or unwound state.partially wound up in a pre-tensioned state, which is why the basket is designed to be braked in order to prevent the push rod from unwinding completely on its own as a result of the pre-tension.

[0003] Typically, two rotating guide rollers, mounted one above the other on the frame, are used to guide the push rod during winding and unwinding. A problem has been found in that, due to the tendency of the push rod to assume a largely straight position when unwound (i.e., due to the preload described above), it can jump sideways out between the two guide rollers during winding and unwinding and, in the worst case, jam. Furthermore, such guide rollers are subject to high wear because the push rod is often contaminated after the camera is inserted into the sewer pipe, and this contaminant is at least partially deposited on the guide rollers when the push rod is wound up after use.

[0004] Alternatively, frustoconical guide funnels are used, which radially enclose the sliding rod during operation, thus preventing it from jumping out of the funnel. However, a problem has been found in that the guide funnels often have openings that are too large. While the sliding rod, including the camera connection or camera, can be pushed through these openings, the funnel then guides the rod into the recording section with insufficient precision, and consequently, the rod cannot be wound up neatly. Often, the guide funnel has smaller openings through which the sliding rod can be guided into the recording section with sufficient precision, but then mounting the sliding rod, including the camera connection or camera, to the basket through the guide funnel is very difficult, and sections of the sliding rod, including the camera connection, are left unwound.The camera of the sewer pipe inspection system must be stored outside the recording section, unnecessarily increasing the dimensions of the sewer pipe inspection system, which can negatively affect, for example, the transport of the sewer pipe inspection system.

[0005] Furthermore, the German patent application DE 299 13 517 U1 describes an inspection device for cavities, in particular for pipelines, comprising a video camera, a signal cable, and a frame for support on a surface, on which a reel for the signal cable and a braking device are arranged. A guide and braking device is also arranged on the frame, through which the signal cable can be inserted into and withdrawn from the reel in a substantially tangential direction.

[0006] The object of the present invention is therefore to provide a sewer pipe inspection system and a guide unit for such a sewer pipe inspection system which solve the aforementioned problems.

[0007] This task is solved by a sewer pipe inspection system and a control unit for such a sewer pipe inspection system according to the independent and dependent claims, respectively. Preferred embodiments and further developments are specified in the dependent claims.

[0008] According to a first aspect of the present invention, a sewer pipe inspection system comprises a frame and a basket rotatably mounted on the frame, the basket having a receiving section, wherein the receiving section is configured to receive a flexible push rod which tends to assume a straight path in an unwound state. Furthermore, the sewer pipe inspection system has a guide unit with a guide channel for guiding the flexible push rod when the push rod is wound up or unwound from or into the receiving section, the guide unit comprising an insertion opening laterally connected to the guide channel for inserting the push rod into the guide channel.

[0009] In the context of the present invention, the term "unwound state" of the sliding rod means that the sliding rod is fully or partially unwound from the basket. Thus, both the fully unwound and the partially unwound sliding rod tend to assume a straight path.

[0010] The guide channel can, in principle, have any shape. For example, the guide channel can be completely straight along one longitudinal direction of the guide unit, hereinafter also referred to as the X-direction. The guide channel can also have at least a partial or complete arc-shaped profile along its longitudinal direction. For instance, the guide channel can have a substantially rectangular or square cross-section with rounded corners. The cross-section can also be substantially round or oval. The cross-section of the guide channel can also have a constant shape along its longitudinal direction. However, it is also conceivable that the guide channel has slightly different cross-sectional shapes along the X-direction. To wind or unwind the push rod, the push rod can be moved within the guide channel essentially along the longitudinal direction of the guide unit.

[0011] The insertion opening essentially corresponds entirely to the length of the guide channel. The insertion opening can, for example, extend to the left or right of the guide channel in the longitudinal direction of the guide unit. To insert the push rod into the guide channel, the push rod can be moved through the insertion opening essentially transversely to the longitudinal direction of the guide unit.

[0012] The sewer pipe inspection system according to the first aspect of the present invention offers the advantage that, on the one hand, the guide channel is designed such that it can guide the push rod with sufficient accuracy into and out of the receiving section during winding and unwinding, without the push rod becoming jammed or protruding from the insertion opening. On the other hand, it is ensured that the push rod can be completely stored in the receiving section after use of the sewer pipe inspection system, since the push rod can be easily removed from the guide unit.

[0013] In a preferred embodiment of the sewer pipe inspection system according to the first aspect of the present invention, the guide channel is arc-shaped.

[0014] This offers the advantage that the guide channel can guide the push rod into or out of the receiving section of the basket at a predetermined angle, making it easier to wind the push rod into or out of the receiving section.

[0015] The insertion opening has a shape that differs from the guide channel along its length. Alternatively or additionally, the guide channel and the insertion opening can run at least partially at an angle to each other.

[0016] This results in the following: although the guide channel does not completely surround the sliding rod on the side where the insertion opening is located, inner surfaces of the guide channel extend even on this side in such a way that the sliding rod can be guided particularly securely in the predetermined shape of the guide channel without being able to jump out of the guide channel.

[0017] Preferably, the insertion opening can also be designed in an arc shape along its longitudinal extent.

[0018] Since the sliding rod tends to assume a substantially straight path when unwound, the arc-shaped design of the insertion opening along its length prevents the sliding rod from slipping out of the guide channel during winding and unwinding simply by its tendency to do so. Therefore, it is securely guided within the guide channel. In other words, in order to spring out of the guide channel through the insertion opening, the sliding rod would have to assume an arc-shaped form, which it would not naturally assume because it tends to follow a straight path. Consequently, this design securely guides the sliding rod within the guide channel and prevents it from springing out of the insertion opening.

[0019] In a further preferred embodiment of the sewer pipe inspection system according to the first aspect of the present invention, the insertion opening can be designed such that the push rod can be inserted into the guide channel through the insertion opening in a predetermined curvature, wherein the guide channel can be designed such that the push rod inserted into the guide channel assumes a curvature that deviates from the predetermined curvature of the insertion opening.

[0020] The specified curvature of the insertion opening can be greater or smaller than the curvature of the sliding rod that it assumes in the guide channel.

[0021] In other words, the push rod, which tends to assume a straight path when unwound, must be bent by an operator of the sewer pipe inspection system in such a way that it can be inserted through the opening into the guide channel. The guide channel may have a greater or lesser curvature than the opening. In any case, the push rod is held securely in the guide channel during winding and unwinding because, due to its tendency to assume a straight path, it conforms to the shape of the guide channel and exhibits a bend or curvature that prevents it from springing out of the guide channel through the opening.

[0022] Preferably, the guide channel and the insertion opening can be designed such that the diameter of the sliding rod is smaller than the height of the guide channel but larger than the height of the insertion opening.

[0023] Within the scope of the present invention, the height of the insertion opening is defined as the greatest vertical distance in the Z-direction between two opposing wall surfaces of the guide unit that define the insertion opening. Furthermore, within the scope of the present invention, the height of the guide channel is defined as the greatest vertical distance in the Z-direction between two opposing wall surfaces of the guide unit that define the guide channel.

[0024] When inserting the sliding rod into the guide channel, it must therefore be pressed through the insertion opening. Consequently, there is preferably an interference fit between the sliding rod and the insertion opening. This can be achieved, for example, by the sliding rod having a compressible coating which compresses when the sliding rod is pressed through the insertion opening and then expands back to its original state within the guide channel.

[0025] The diameter of the sliding rod can, for example, range from 5 mm to 15 mm. The height of the insertion opening can, for example, be 0.5 mm to 2.5 mm smaller than the diameter of the sliding rod. The height of the guide channel can, for example, be 5 mm to 75 mm larger than the diameter of the sliding rod.

[0026] It is also conceivable that the wall surfaces of the guide unit, which define the insertion opening, could alternatively or additionally be made of or covered with a compressible material, such as a rubber like polyurethane. It is also conceivable that the insertion opening could alternatively or additionally taper conically from the outside in, so that an increasing force is required when pressing the push rod into the insertion opening from the outside in. This offers the advantage that, although the push rod is more difficult to remove from the guide channel through the insertion opening, it also reliably prevents the push rod from unintentionally protruding from the insertion opening.It has been found that a conical taper of the insertion opening from the outside to the inside, especially with a gradient of 1% to 5%, yields particularly good results, in which the push rod is particularly securely protected against jumping out of the insertion opening during winding and unwinding, and the push rod can still be removed from the guide channel through the insertion opening with comparatively user-friendly effort.

[0027] In a further preferred embodiment of the sewer pipe inspection system according to the first aspect, the guide channel can be funnel-shaped in the longitudinal direction of the guide unit.

[0028] The guide unit can be designed such that the first opening of the guide channel, which the push rod passes through first as it unwinds in the direction of movement, is smaller than the second opening of the guide channel, which the push rod passes through after the first opening. This offers the advantage that the push rod can be wound more precisely into and out of the receiving section. However, the first opening can also be larger than the second opening.

[0029] Preferably, the guide unit is a cast part or a 3D printed component.

[0030] This makes it possible to manufacture the guide unit in one piece with particular ease.

[0031] In a further preferred embodiment of the duct pipe inspection system according to the first aspect of the present invention, the guide channel can have a first curvature at a first opening section and a second curvature at a second opening section, wherein the first curvature and the second curvature are curved differently.

[0032] For example, the first opening section and the second opening section can be located at the first opening of the guide channel, with the first opening section being arranged on one of the two wall surfaces that define the height of the guide channel and the second opening section on the other of the two wall surfaces that define the height of the guide channel. In other words, the first opening section and the second opening section can be arranged one above the other at the same opening of the guide channel. However, it is also conceivable that the first opening section is located at the first opening of the guide channel and the second opening section at the second opening of the guide channel, or both opening sections at the second opening.

[0033] If the first and second opening sections are located at the opening that the sliding rod first passes through when unwinding in the direction of its movement, the first opening section can be positioned below the second opening section. This means the first opening section can be located closer to the pivot axis of the basket than the second opening section. In other words, the first opening section can be located on an inward-facing inner wall surface of the guide channel, and the second opening section on an outward-facing inner wall surface of the guide channel. It can be particularly advantageous if the first opening section has a greater curvature than the second. In this case, the first opening section has a more arcuate shape along the longitudinal length of the guide channel compared to the second opening section.Consequently, the first opening section corresponds more closely to a circular arc section than the second opening section.

[0034] This offers the advantage that, during winding, the push rod is guided along the first opening section of the inwardly directed inner wall surface of the guide channel in such a way that the push rod experiences a directional constraint, which has a positive effect on the circular winding in the receiving section.

[0035] Since the second opening section with the second curvature in this case corresponds more closely to a straight course than the first opening section with the first curvature, the sliding rod, due to its tendency to have a straight, stretched course in the unwound state, is guided during unwinding along the second opening section of the outwardly directed inner wall surface of the guide channel in such a way that the sliding rod experiences a directional constraint which has a positive effect on the unwinding from the receiving section.

[0036] According to a second aspect of the present invention, a sewer pipe inspection system comprises a frame, a basket rotatably mounted on the frame, which has a receiving section, wherein the receiving section is configured to receive a flexible push rod which tends to assume a straight path in an unwound state, and a guide unit with an arc-shaped guide channel for guiding the flexible push rod when the push rod is wound up or unwound from the receiving section.

[0037] This offers the advantage that the guide channel can guide the push rod into or out of the receiving section of the basket at a predetermined angle, making it easier to wind the push rod into or out of the receiving section.

[0038] It is understood that the sewer pipe inspection system according to the second aspect of the present invention can also be combined with one or more embodiments of the sewer pipe inspection system according to the first aspect of the present invention.

[0039] According to a third aspect of the present invention, a guide unit comprises a guide channel, wherein the guide unit is configured to accommodate a flexible push rod which can be wound up or unwound into a receiving section of a basket of a sewer pipe inspection system, and which strives to have a straight course in an unwound state, and to guide the push rod in two different predetermined directions when wound up or unwound by means of the guide channel, wherein the guide unit has an insertion opening laterally connected to the guide channel for inserting the push rod into the guide channel.

[0040] The guide unit according to the third aspect of the present invention offers the advantage that, on the one hand, the guide channel is designed such that it can guide the push rod with sufficient precision into and out of the receiving section during winding and unwinding, without the push rod becoming jammed or protruding from the insertion opening. On the other hand, it ensures that the push rod can be completely stored in the receiving section after use of the sewer pipe inspection system, since the push rod can be easily and completely removed from the guide unit.

[0041] According to a fourth aspect of the present invention, a guide unit comprises an arc-shaped guide channel, wherein the guide unit is configured to guide a flexible push rod, which can be wound up or unwound into a receiving section of a basket of a sewer pipe inspection system, and which strives to have a straight course in an unwound state, in two different predetermined directions when winding up and unwinding the push rod by means of the arc-shaped guide channel.

[0042] The guide unit according to the fourth aspect of the present invention therefore offers the advantage that the push rod can be wound up or unwound into or out of the receiving section with particular precision.

[0043] The guide units described according to the third and fourth aspects of the present invention can be used in a sewer pipe inspection system. The guide units according to the third and fourth aspects of the present invention can, of course, also be configured according to one or more of the preferred embodiments mentioned in the first aspect of the present invention.

[0044] The invention is described in more detail below by way of example with reference to the accompanying drawings.

[0045] They show: Fig. 1 a perspective view of a sewer pipe inspection system according to a first embodiment according to the invention, Fig. 2 another perspective view of the sewer pipe inspection system according to the first embodiment, Fig. 3 a perspective view of a guide unit of the sewer pipe inspection system according to the first embodiment according to the invention, Fig. 4 a perspective view of a sewer pipe inspection system according to a second embodiment according to the invention, Fig. 5 a perspective view of a guide unit of the sewer pipe inspection system according to the second embodiment and Fig. 6 another perspective view of the inventive guide unit of the sewer pipe inspection system according to the second embodiment.

[0046] As from the Fig. 1 and Fig. As can be seen in Figure 2, the sewer pipe inspection system 1 according to the first embodiment comprises a frame 2 and a basket 3 mounted on the frame 2, which is rotatable about its axis of rotation A. The basket 3 has a receiving section 4 onto which a flexible push rod 5 is wound. The push rod 5 can, in particular, be wound in circular paths through the receiving section 4. The push rod 5 tends to assume a straight path when unwound. Therefore, when wound up, the push rod 5 tends to assume the largest possible winding diameter in the cylindrical receiving section 4, i.e., to expand. The basket 3 can be rotatable manually or, as in this case, by means of an electric motor, which winds and unwinds the push rod 5 connected to the basket 3.The sewer pipe inspection system 1 according to the first embodiment according to the invention also has a guide unit 10 arranged externally on the frame 2, which is described below by means of . Fig. 3 is described in more detail.

[0047] As in Fig. As shown in Figure 3, the command unit 10 has a command channel 11, which is configured to connect to the Fig. 1 and Fig. The guide channel 11 is designed to guide the sliding rod 5, as shown in Figure 2, during its winding and unwinding from the receiving section 4. It is funnel-shaped in the X-direction and comprises a first opening 11a and a second opening 11b. The first opening 11a, which the sliding rod 5 passes through first when unwinding in the direction of its movement, is larger than the second opening 11b, which the sliding rod passes through after the first opening. The guide channel 11 can be arc-shaped or, as shown in Figure 2, curved. Fig. 3 shown, just designed.

[0048] The guide unit 10 also includes a laterally arranged insertion opening 12, through which the sliding rod 5 can be inserted laterally into or removed from the guide channel 11. The insertion opening 12 has a straight course in the X direction with a constant height h.E The funnel-shaped guide channel 11 has a height h at its first opening. F , which is greater than the height h E the insertion opening 12, where the height h F of the guide channel 11 in the direction of the second opening 11b is reduced, but at the second opening 11b it is still greater than the height h E the insertion opening 12. For the sake of clarity, in Fig. 3. The sliding rod 5 (not shown) comprises a compressible casing. Furthermore, in the uncompressed state of the casing, the sliding rod 5 has a diameter that is greater than its height h. E the insertion opening 12, however, is smaller than the height h Fof the guide channel 11. This ensures that the push rod 5 can be inserted into or removed from the guide channel 12 as needed, but that the push rod 5 cannot slip out of the guide channel 11 during winding or unwinding, but is securely guided within the guide channel 11. Furthermore, the second opening 11b, which is smaller than the first opening 11a, allows for more precise directional control of the push rod 5 when winding it into the receiving section 4, thus facilitating better winding of the push rod 5 within the receiving section 4. After operation of the channel inspection system 1, the push rod 5 can be removed from the guide unit 10 through the insertion opening 12 and stored completely in the receiving section 4 or in the basket 3. In particular, a camera connected to the push rod 5 (not shown in the figures) can also be removed and stored in the receiving section 4 or in the basket 3.This reduces the dimensions of the channel inspection system 1 according to the invention during transport and better protects the camera from damage in the recording section 4 or in the basket 3 during transport.

[0049] In Fig. Figure 4 shows a sewer pipe inspection system 1 according to a second embodiment, wherein the sewer pipe inspection system 1 according to the second embodiment is essentially identical to the sewer pipe inspection system 1 according to the first embodiment, except for the guide unit 10.

[0050] The sewer pipe inspection system 1 according to the second embodiment also comprises a frame 2 and a basket 3 rotatably mounted on the frame 2, which is rotatable about its axis of rotation A. The basket 3 includes a cylindrical receiving section 4. A flexible push rod 5 is wound up in the receiving section 4, which tends to assume a straight path when unwound. The guide unit 10 of the sewer pipe inspection system 1 according to the second embodiment is mounted internally in a lower area of ​​the frame 2.

[0051] As in the Fig. 5 and Fig. As shown in Figure 6, the guide unit 10 comprises an arc-shaped guide channel 11 for guiding the Fig. Figure 4 shows the flexible sliding rod 5 during the winding and unwinding of the sliding rod 5 from the receiving section 4. The guide unit 10 also includes an internal insertion opening 12, laterally connected to the guide channel 11, through which the sliding rod 5 can be inserted into or removed from the guide channel 11. The insertion opening 12 is arc-shaped in its longitudinal extent, i.e., in the X-direction, and has a different shape compared to the guide channel 12.

[0052] This results in the following: although the guide channel 11 does not completely surround the push rod 5 on the side facing the basket, where the insertion opening 12 is located, inner surfaces of the guide channel 11 extend even on this side in such a way that the push rod 5 can be guided particularly securely in the predetermined shape of the guide channel 11, without the push rod 5 being able to jump out of the guide channel 12.

[0053] The guide channel 11 comprises a second opening 11b, which the sliding rod 5 first passes through when unwinding it in the direction of movement, and a first opening 11a, which the sliding rod 5 passes through after the second opening 11b when unwinding it in the direction of movement. The guide channel 11 has a substantially rectangular cross-section with rounded corner sections. The arcuate guide channel 11 reaches its greatest height h at the second opening 11b. F The height of the guide channel 11 varies from the second opening 11b to the first opening 11a in such a way that the height in longitudinal extent, i.e. in the X direction, of the guide channel 11 assumes the smallest value approximately in the middle of the guide channel 11 and increases again further towards the first opening 11a.

[0054] In contrast, the insertion opening 12 has a height h Eon, which has a substantially constant value in the longitudinal extent of the insertion opening 12. The in Fig. The sliding rod 5 shown in Figure 4 comprises a compressible casing, wherein the sliding rod 5 has a diameter in the uncompressed state which is greater than the height h. E the insertion opening is smaller than the height h F of the guide channel 11. This ensures with particular certainty that the push rod 5 does not jump out of the guide channel 11 during winding or unwinding.

[0055] In this case, the second opening 11b comprises a first opening section 11b1 and a second opening section 11b2, wherein the first opening section 11b1 is arranged above the second opening section 11b2, i.e., the first opening section 11b1 is located closer to the axis of rotation A of the basket 3 than the second opening section 11b2. In other words, the first opening section 11b1 is located on an inwardly facing inner wall surface of the guide channel 11, and the second opening section 11b2 is located on an outwardly facing inner wall surface of the guide channel 11. The first opening section 11b1 has a first curvature k1 that is greater than a second curvature k2 of the second opening section 11b2. The first opening section 11b1 is therefore more arc-shaped in the longitudinal extent of the guide channel 11 compared to the second opening section 11b2 in the longitudinal extent of the guide channel 11.

[0056] This offers the advantage that the push rod 5 is guided during winding at the first opening section 11b1 of the inwardly directed inner wall surface of the guide channel 11 in such a way that the push rod 5 experiences a directional constraint which has a positive effect on the circular winding in the receiving section 4.

[0057] Since the second opening section 11b2 with the second curvature k2 is smaller than the first curvature k1, the sliding rod 5, due to its tendency to have a straight, stretched course in the unwound state, is guided during unwinding at the second opening section 11b2 of the outwardly directed inner wall surface of the guide channel 11 in such a way that the sliding rod 5 experiences a directional constraint which has a positive effect on the unwinding from the receiving section 4.

[0058] It is understood that the described features of the various aspects of the present invention and of the explained embodiments can be combined with each other to form new embodiments. Reference symbol list 1 Sewer pipe inspection system 2 frames 3 basket 4 Recording section 5 sliding rod 10 Command Unit 11 Guide channel 11a first opening guide channel 11b second opening guide channel 11b1 first opening section 11b2 second opening section 12 Insertion opening h F Height of guide channel h E Height of insertion opening k1 first curvature k2 second curvature

Claims

[1] Sewer pipe inspection system (1) comprising: a frame (2), a basket (3) rotatably mounted on the frame (2), which has a receiving section (4), wherein the receiving section (4) is configured to receive a flexible sliding rod (5) which tends to assume a straight path in an unwound state, and a guide unit (10) with a guide channel (11) for guiding the flexible push rod (5) during the winding and unwinding of the push rod (5) from the receiving section (4), wherein the guide unit (10) has an insertion opening (12) laterally connected to the guide channel (11) for inserting the push rod (5) into the guide channel (11), and wherein the insertion opening (12) has a shape that differs from the guide channel (11) in its longitudinal extent. [2] Sewer pipe inspection system (1) according to claim 1, wherein the guide channel (11) is curved. [3] Sewer pipe inspection system (1) according to claim 1 or 2, wherein the insertion opening (12) and the guide channel (11) run at least partially obliquely to each other in their respective course. [4] Sewer pipe inspection system (1) according to one of claims 1 to 3, wherein the insertion opening (12) is designed in an arc shape in the longitudinal extent of the insertion opening (12). [5] Sewer pipe inspection system (1) according to one of claims 1 to 4, wherein the insertion opening (12) is designed such that the push rod (5) can be inserted into the guide channel (11) through the insertion opening (12) in a predetermined curvature, and the guide channel (11) is designed such that the push rod (5) inserted into the guide channel (11) can assume a curvature that deviates from the predetermined curvature of the insertion opening (12). [6] Sewer pipe inspection system (1) according to one of claims 1 to 5, wherein the guide channel (11) and the insertion opening (12) are designed such that a diameter of the push rod (5) is smaller than a height of the guide channel (h F ) however, greater than the height of the insertion opening (h E ) is. [7] Sewer pipe inspection system (1) according to one of claims 1 to 6, wherein the guide channel (11) is funnel-shaped in the longitudinal direction (X) of the guide unit (10). [8] Sewer pipe inspection system (1) according to any one of claims 1 to 7, wherein the guide unit (10) is a cast part or a 3D printed part. [9] Sewer pipe inspection system (1) according to any one of claims 1 to 8, wherein the guide channel (11) has a first curvature (k1) at a first opening section (11b1) and a second curvature (k2) at a second opening section (11b2), wherein the first curvature (k1) and the second curvature (k2) are different. [10] Sewer pipe inspection system (1) comprising: a frame (2), a basket (3) rotatably mounted on the frame (2), which has a receiving section (4), wherein the receiving section (4) is configured to receive a flexible sliding rod (5) which tends to assume a straight path in an unwound state, and a guide unit (10) with an arc-shaped guide channel (11) for guiding the flexible push rod (5) when winding and unwinding the push rod (5) from the receiving section (4), wherein the guide unit (10) has an insertion opening (12) laterally connected to the guide channel (11) for inserting the push rod (5) into the guide channel (11), and wherein the insertion opening (12) and the guide channel (11) run at least partially obliquely to each other in their respective course. [11] Control unit (10) with a control channel (11), wherein the guide unit (10) is configured to guide a flexible push rod (5), which can be wound up and unwound into a receiving section (4) of a basket (3) of a sewer pipe inspection system (1), and which tends to have a straight course in an unwound state, in two different predetermined directions by means of the guide channel (11) when winding up and unwinding the push rod (5), wherein the guide unit (10) has an insertion opening (12) laterally connected to the guide channel (11) for inserting the push rod (5) into the guide channel (11), and wherein the insertion opening (12) has a shape that differs from the guide channel (11) in its longitudinal extent. [12] Guide unit (10) with an arc-shaped guide channel (11), wherein the guide unit (10) is configured to guide a flexible push rod (5), which can be wound up and unwound into a receiving section (4) of a basket (3) of a sewer pipe inspection system (1), and which tends to have a straight course in an unwound state, in two different predetermined directions when winding up and unwinding the push rod (5) by means of the arc-shaped guide channel (11), wherein the guide unit (10) has an insertion opening (12) laterally connected to the guide channel (11) for inserting the push rod (5) into the guide channel (11), and wherein the insertion opening (12) and the guide channel (11) run at least partially obliquely to each other in their respective course. [13] Use of a guide unit (10) according to claim 11 or 12 in a sewer pipe inspection system (1).

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