DEVICE FOR USE IN REPLACING SEWAGE PIPING

Abstract: The invention relates to a device for use in replacing particularly sewage piping by using a forced inserting method, the device comprising an impact member (3) provided with a drawing tip (2), and a reamer (12) breaking the pipe (1) to be replaced, the rear portion of the reamer comprising means for fastening the pipe (4) to be inserted, the supply hoses (5) for the driving medium of the impact member (3) being conducted through the pipe (4) to be inserted. To increase the possibilities of using forced inserting, the device according to the invention is characterized in that at least one other tip (7) is attached to the reamer (12) by means of an arm (6) projecting sideways from the reamer for laying another pipe (8).

Description: Device for use in replacing sewage piping The invention relates to a device for use in replacing particularly sewage piping by using a forced inserting method, the device comprising an impact member provided with a drawing tip, and a reamer breaking the pipe to be replaced, the rear portion of the reamer comprising means for fastening the pipe to be inserted, the supply hoses for the driving medium of the impact member being conducted through the pipe to be inserted. In connection with renovating piping, a forced inserting method refers to a method where an existing pipe, such as a water, sewage or gas pipe is replaced with a new pipe, which is drawn into the old pipeline by means of a suitable device. If the diameter of the pipeline is to remain unchanged, the drawing device comprises a reamer, which expands the hole, while advancing in the pipe, to such an extent that the device can draw behind it a pipe which has an internal diameter equal to or greater than the internal diameter of the old pipe. Conventionally, a cable wire is first drawn through the old pipe, and the device is attached from its drawing tip to this cable wire. The purpose of the cable wire is to cause the device to move in the right direction and to a certain extent to help it advance. The movement of the device inside the old pipe is provided substantially by an impact member or "mole" included in the device. These impact moles are conventionally pneumatically driven. For example European Published Application 0,086,567 and British Published Application 2,113,795 disclose such pneumatic devices. The object of the present invention is to provide a new type of device for use in replacing particularly sewage piping by using a forced inserting method. By means of this device, a water pipe or a rainwater sewer can be renovated simultaneously with the sewage pipe. This is achieved by means of the device according to the invention, which is characterized in that at least one other tip is attached to the reamer by means of an arm projecting sideways from the reamer for laying another pipe. According to a preferred embodiment of the invention, the second tip comprises a front portion cutting the soil in a plough-like manner and a tubular rear portion for feeding the second pipe conducted through the pipe to be inserted to replace the old pipe and through the tubular rear portion of the second tip. In this embodiment, the second pipe is thus conducted first through the pipe to be inserted to replace the old pipe, and then it is turned back to the direction it arrived from by means of the second tip, and it remains there in the groove cut in a plough-like manner by the second tip. Thus, the second pipe does not have to slide in the groove cut for it when the drawing continues. Since the direction of the second pipe has to be changed in a relatively small space and thus with quite a small radius of curvature, the second pipe has to be naturally rather flexible. Pipes with a corrugated outer surface suitable for this purpose have recently come onto the market. Such a pipe is very well applicable as a sewage or protective pipe. In another embodiment of the invention, the rear portion of the second tip comprises means for fastening the second pipe. Thus the second pipe, which can be for example a water pipe or a rainwater pipe, can be drawn simultaneously with the sewage pipe. Thus the second pipe is drawn into the soil surrounding the pipe to be renovated by means of the second tip, and it has to slide in relation to the soil as the drawing continues. The drawing may be realized solely by means of energy from an impact member operating inside the sewage pipe to be renovated, but it is possible that the second tip comprises its own impact member, the supply hose or hoses for the driving medium of this impact member being conducted through the pipe to be inserted to replace the old pipe. Alternatively, the second tip comprises a hydraulic drilling tip, the supply hoses for the driving medium of this tip being conducted through the pipe to be inserted to replace the old pipe. To prevent the second pipe from twisting too much around the centre line of the sewage pipe to be replaced, the second tip comprises hydraulic guides, the supply hoses for the driving medium of the guides being conducted through the pipe to be inserted to replace the old pipe. To make it possible to control the guides, i.e. to obtain information about the possible twisting of the second pipe around the sewer line to be renovated, the pipe to be inserted to replace the old pipe comprises a device, which indicates if the pipe to be inserted twists around its axial centre line. Since the pipe to be inserted is so rigid that it cannot be twisted, the twisting of this pipe also indicates, in a reliable manner, the possible movement of the second pipe either upwards or downwards in relation to the sewer line to be renovated. It is possible to diminish the inclination of the second tip to pull the drawing tip off its course towards the second tip by means of an arrangement where the axial centre line of the second tip is arranged to intersect the axial centre line of the drawing tip in front of the drawing tip. Thus, the second tip is arranged to be in a "toe-in" in relation to the drawing tip. The arrangement according to the invention provides the considerable advantage that the second pipe may be closed at least from the end attached to the second tip, so it is not necessary to wash the pipe before it is used for example as a water pipe. The same concerns also an embodiment where the second pipe is conducted through the pipe to be inserted to replace the old pipe to the second tip and from there into the soil. In addition to the second tip, the device according to the invention may comprise a third tip, which is situated most preferably diametrically in relation to the second tip. In the following, the device according to the invention will be described in greater detail with reference to the accompanying drawing, in which the figure shows a partial cross-section of an exemplary embodiment of the device according to the invention. The device shown in the figure comprises a reamer 12 provided with a drawing tip 2, the rear portion of the reamer comprising conventional means for fastening the pipe 4 to be inserted. The reamer 12 and the drawing tip 2 are mutually separate parts, which are supported against each other by means of a conical surface. Thus the reamer 12 may be changed to fit the diameter of each pipe to be renovated, whereas an impact member or mole 3 with its drawing tip 2 may remain substantially the same regardless of the diameter of the pipe. Thus the reamer may also have a smaller diameter than the pipe to be renovated, and thus it does not actually expand the pipeline to be renovated, even though it breaks it in the case according to the invention. However, in practice the drawing tip 2 and the reamer 12 with the pipe 4 attached thereto operate as a nearly integrated whole, since a draw wire 10 is attached to the drawing tip 2 to direct a relatively great tractive force at the drawing tip 2 and via the conical surface of the tip also at the reamer 12 and the pipe 4 added thereto. When a jointless pipe is being drawn, i.e. during so-called extended drawing, when for example sewage pipes are renovated, a weldable PEH pipe is conventionally used as the pipe. According to the invention, an arm 6 projecting sideways from the reamer 12 is also attached to the reamer 12, the pipe 4 to be inserted being attached to the rear portion of the reamer. A second tip 7 is attached to the outer end of this arm, and a second pipe 8 in turn is attached to the rear portion of the second tip. The arm 6 is designed so that it is very firm and it can effectively penetrate through the pipe 1 to be renovated and through the surrounding soil. The second tip 7 is also designed in such a way that it effectively penetrates into the soil, thus displacing it and making it possible to draw the pipe 8 with it. As the figure shows, the arm 6 guarantees that the second tip travels at a constant distance in relation to the drawing tip 2. In this way, the second pipe 8 is made to follow the pipe 4 at a constant distance. Furthermore, it is also necessary to insure, however, that the pipe 4 cannot twist around its longitudinal axis while it is being drawn, since in such a case the pipe 8 might even try to twist spirally around the pipe 4, whereupon it naturally could not be drawn. In practice, it is relatively easy to control this correct position of the pipe 8. Since in practice the pipe 4 cannot twist, it is possible to monitor the twisting position of the pipe 4 and thus the actual position of the pipe 8 next to the pipe 4, by means of, for example, a marking on the surface of the pipe 4 or a mark attached to its rear end. If the pipe 8 and the tip drawing it try to twist around the pipe 4, the tip 7 can be directed upwards or downwards by means of hydraulic guides 9 provided in the tip. These guides may be in practice flaps hinged to the tip 7 from their front ends, i.e. from the side of the front of the tip 7. These flaps are positioned on the upper and lower surface of the tip 7 and they can be pushed outwards, if necessary, from their rear ends by means of hydraulic cylinders. If the pipe 8 has a small diameter, it is probable that the impact mole 3 can also provide enough impact force to make the tip 7 penetrate the soil and draw the pipe 8 with it. However, if the soil or the diameter of the pipe 8 necessitate the use of extra force, the tip 7 may be equipped with its own impact mole driven either hydraulically or pneumatically. Supply hoses 5 required for such impact moles are conducted through the pipeline 4 intended as a sewer. Thus it is not necessary to draw any pipes or the like through the pipe 8. In fact, the pipe 8 can be closed from the end nearer to the tip 7 as tightly as possible, so after the pipe 8 is installed it is immediately ready for use for example as a water pipe. The pipe 8 is thus exactly in the same condition as when it was delivered from the factory, i.e. in practice it is clean. Instead of the impact mole, the tip 7 may also be equipped with a hydraulically driven drilling tip which helps the tip move forward in the soil. As it is possible to conclude from the aforementioned, the pneumatic air to the impact mole 3 is also brought by means of the hoses 5 through the pipe 4. The pneumatic air can thus be released directly into the pipe 4. Several advantages are achieved by means of the device according to the invention as compared with a conventional arrangement where the sewage pipe is first renovated by inserting, and then a water pipe, denoted in the figure by reference numeral 11, is renovated separately. These advantages include saving time when both pipes are renovated simultaneously. It is also unnecessary to organize a temporary water supply, since the old water pipe can be used during the whole drawing operation. Furthermore, the new water pipe is clean after it is installed, since no hydraulic hoses or pneumatic air have been conducted through it, as would be the case if the water pipe were renovated alone by inserting. Thus it is not necessary to clean the water pipe at all or treat it with bactericides after the installation when a device according to the invention is used. Another advantage is that it is also possible now to renovate water pipes which cannot be renovated by forced inserting, i.e. the material of the pipes cannot be broken by means of forced inserting. Such a renovation by means of inserting is suitable for grey cast iron, but unsuitable for S6 casting or steel pipe. It is also an advantage that there is no old broken water pipe around the new water pipe 8. As noted above, the device according to the invention also has an embodiment where the pipe drawn by the second tip does not have to slide in relation to the soil, but it is directed in its place through the pipe to be inserted to replace the old pipe and through the second tip. This embodiment, which comprises all the advantages described above, is especially preferable when the soil where the second pipe is to be drawn is solid or rocky, whereupon the soil would resist excessively the drawing of the pipe. If a pipe drawn in this way is not applicable for example as a water pipe due to its material, it can be used in any case as a protective pipe inside which the water pipe will be drawn later. Thus an effective mechanical protection is also provided for the water pipe. The device according to the invention is described above by means of only two exemplary embodiments where the second pipe is in particular a water pipe. It must be understood, however, that the second pipe could also be a gas pipe, a rainwater sewer or some other pipe of this type. Naturally the pipe 8 may also be a protective pipe inside which the actual material pipe is later drawn. Similarly, in addition to the second tip, the device may also comprise a third tip or possibly several tips for the simultaneous drawing of several pipes. It must be understood thus that the device according to the invention may be modified, when necessary, without imparting however from the scope of the appended claims.

Claims: 6 11 AMENDED CLAIMS [received by the International Bureau on 19 June 1995 (19.06.95); original claims 1-10 replaced by new claims 1-6 (2 pages)] 1. A device for use in replacing particula ly sewage piping by using a forced inserting method, the device comprising an impact member (3) provided with a drawing tip (2), a reamer (12) breaking the pipe (1) to be replaced, the rear portion of the reamer comprising means for fastening the pipe (4) to be inserted, the supply hoses (5) for the driving medium of the impact member (3) being conducted through the pipe (4) to be inserted, and at least one other tip (7) attached to the reamer (12) by means of an arm (6) projecting sideways from the reamer for laying another pipe (8), c h a r ¬ a c t e r i z e d in that the second tip (7) comprises a front portion cutting the soil in a plough-like manner and a tubular rear portion for feeding the second pipe (8) conducted through the pipe (4) to be inserted to replace the old pipe and through the tubular rear portion of the second tip. 2. A device according to claim 1, c h a r a c t e r i z e d in that the second tip comprises its own impact member, the supply hose or hoses (5) for the driving medium of the impact member being conducted through the pipe (4) to be inserted to replace the old pipe. 3. A device according to claim 1, c h a r a c t e r i z e d in that the second tip comprises a hydraulically driven drilling tip, the supply hoses (5) for the driving medium of the tip being conducted through the pipe (4) to be inserted to replace the old pipe. 4. A device according to any of the claims 1 to 3, c h a r a c t e r i z e d in that the second tip comprises hydraulically driven guides, the supply hoses (5) for the driving medium of the guides being conducted through the pipe (4) to be inserted to replace the old pipe. 5. A device according to any of the claims 1 to 4, c h a r a c t e r i z e d in that the pipe (4) to be inserted to replace the old pipe comprises a device, which indicates the twisting of the pipe to be inserted around its axial centre line. 6. A device according to any of the claims 1 to 5, c h a r a c t e r i z e d in that in addition to the second tip (7), it comprises a third tip positioned diametrically in relation to the second tip.

Inventors: PAJUNEN PERTTI, PAJUNEN, PERTTI
Applicants: AINEKO AB OY, PAJUNEN PERTTI, OY AINEKO AB, PAJUNEN, PERTTI
Application year: 1995
Main classification: F16L55
IPC codes: E21B7, F16L55