GB2426534A

GB2426534A - Device for the overdrilling of underground lines

Info

Publication number: GB2426534A
Application number: GB0610309A
Authority: GB
Inventors: Dieter Wurm
Original assignee: Tracto Technik GmbH and Co KG
Current assignee: Tracto Technik GmbH and Co KG
Priority date: 2005-05-25
Filing date: 2006-05-24
Publication date: 2006-11-29
Anticipated expiration: 2026-05-24
Also published as: GB2426534B; DE102005024572A1; US20070023205A1; GB0610309D0

Abstract

An apparatus for overdrilling underground lines, comprising a rotary driven push and/or pull linkage 1, the tip 6 of which is connected to a cylindrical scavenging head 4 equipped with nozzles (fig.2, 10, 12) and engaging around the line 5 to be overdrilled, wherein at least one nozzle has an outlet axis at an angle to the plane of the longitudinal axis of the scavenging head 4. The orifices of the angled nozzles (fig.2, 12), which optionally also point opposite to the direction of advance (fig.3, 11), are directed onto the line 5 to assist with freeing up and cleaning the line 5, and also improving the discharge of the released earth.

Description

2426534

."Device for the overdrillinq of underground lines"

The invention relates to a device for the overdrilling of underground lines, with a rotary-driven push and/or pull linkage, the front end of which is connected to an annular hollow-cylindrical scavenging head equipped with nozzles.

Devices of this type serve for exposing underground cables and pipelines (lines hereafter) without excavation and then for renovating them. This takes place in that, with the aid of a scavenging fluid and, if appropriate, with the assistance of cutting and broaching tools, an annular duct surrounding the line is produced, which makes it possible to pull out or press out the old line with a low degree of friction and to pull in or press in a new line.

A device suitable for this purpose is described in DE 195 04 484 CI. This device possesses a linkage, at the front end of which is arranged an annular over-drilling head engaging around the old line and having nozzles for a scavenging fluid which point in the direction of advance. The wall of the annular over-drilling head possesses, approximately by half, an approximately sickle-shaped cross section, on which the linkage running laterally next to the old line engages. The scavenging fluid arrives via the linkage at the nozzles which are arranged in the form of a ring in an irregular distribution and the longitudinal or jet axes of which run parallel to the longitudinal axis of the overdrilling head. Insofar as the nature of the ground allows, the nozzle jets scavenge the line free and at the same time produce an annular duct which is intended to allow low-friction line exchange. However, this is often achieved only incompletely, because the fluid jets of the nozzles arranged in the form of a ring at a distance from the old line cannot reach the line

surface, at least not to the extent and with the intensity required for the removal of encrustations, because their axes run parallel to the longitudinal axis of the line or of the overdrilling head.

This is also the case in a device known from DE 100 65 523 CI because the nozzles are arranged in the same way in the form of a ring in the overdrilling or scavenging head. In this device, admittedly, a nozzle ring connected to a rotary drive is equipped with cutting tools for releasing relatively hard soil constituents. However, the tools naturally do not reach the line surface; they would otherwise even damage the line mechanically.

In a further device for the exposure of underground lines which is known from DE 102 11 833 B4, in addition to the overdrilling head, the linkage tip is also provided with a rotary-driven tool which, however, serves essentially only for cutting free for the linkage a duct which laterally accompanies the annular space. This device is intended to avoid free scavenging and therefore operates purely mechanically.

Against this background, the problem on which the invention is based is, in the exposure of an underground line without excavation, not only to produce the customary annular space, but at the same time also to free the surface of the line from accretions.

This takes place, according to the invention, with the aid of a scavenging head which on the end face possesses at least one nozzle inclined in the direction of the line. The jets from the respective nozzles accordingly impinge onto the line surface and scrape off accretions located there, while other nozzles can be directed in the conventional way parallel to the scavenging head axis or line axis. The cutting head may

be provided not only with inclined nozzles arranged on the end face of the scavenging head, but also with nozzles which point in the opposite direction and are inclined at least partially in the direction of the old line and which not only continue to clean the old line, but also improve the discharge of the released earth by means of the scavenging fluid.

So that the device can be operated with different or differently inclined nozzles according to the situation, the device may have a nozzle ring arranged in a scavenging head carrier. In this way, nozzle rings equipped very differently with nozzles and/or tools can be used on the nozzle carrier by simple exchange or worn nozzle rings can be replaced.

Moreover, the nozzle ring may be mounted rotatably and be connected to a rotary drive which preferably possesses two directions of action. Preferably, however, the linkage is connected to a rotary drive which possesses two directions of action and thus allows a rotating to-and-fro movement, so that each nozzle is moved on a part circle.

In order also to provide in the earth a free space required for the advance of the linkage, the front end of the linkage and/or the scavenging head carrier may be additionally equipped with nozzles.

A particularly stable structure is obtained when the front end of the linkage engages into an approximately U-shaped recess in the casing of a hollow-cylindrical scavenging head carrier which likewise engages around the old line. The casing of the scavenging head carrier in this case engages around the appliance tip in an approximately horseshoe-shaped manner.

The invention is explained in more detail below with reference to an exemplary embodiment illustrated in the drawing in which:

fig. 1 shows the front part of a linkage with a scavenging head according to the invention,

fig. 2 shows a front view of the illustration in fig. 1 in a section perpendicular to the longitudinal axes of the linkage and line,

fig. 3 shows a perspective illustration of a nozzle ring, and fig. 4 shows a perspective illustration of the linkage with a scavenging head carrier without a scavenging head and old line.

The device according to the invention consists essentially of a linkage 1 which is provided with a rotary-driven push and/or pull drive, not illustrated, and of which in each case only the front part is illustrated.

The linkage engages with its front end into an approximately U-shaped recess 2 in the casing 3 of a scavenging head carrier 4 which engages around an old line 5 extending approximately parallel to the linkage 1 and the rear end of which is beveled. The bevel 14 reduces the amount of friction between the line 5 and the casing of the scavenging head 4 and the risk of blockages in the annular space between the old line 5 and the scavenging head casing to a minimum. The linkage tip 6 is provided with a nozzle 7 and laterally adjoins the scavenging head casing which at the same time engages with its U-shaped recess 2 around the front part of the linkage 1 in an approximately horseshoe-shaped manner. This results in an extremely

stable, in particular flexion-resistant connection between the scavenging head carrier 4 and the linkage 1 or the linkage tip 6.

The scavenging head carrier 4 serves for receiving a nozzle ring 8 which is rounded on the end face to avoid line damage and which is provided with cutting and broaching tools 9 and nozzles 10, 12 and a plurality of nozzles 11 pointing in the opposite direction. It may be arranged rotatably on the nozzle carrier 8 and be connected to a specific rotary drive, not illustrated. The outlet direction of the nozzle group 10 runs parallel to the longitudinal axes of the old line 5 and of the nozzle ring 8, while the nozzles in the nozzle groups 11, 12 are inclined such that the emerging jets impinge at least for a substantial part onto the line 5.

The cutting and broaching tools 9 for cutting free more stable or harder earth constituents are arranged in each case between the front-side nozzles 10, 12.

The nozzles 10, 11, 12, encircling the old line 5 over a part-circular arc as a result of the rotating pendulum movement of the linkage, not only produce the necessary free space for pulling out or pressing out the old line 5, but also largely expose the line surface, so that a low-friction removal of the old line from the earth is possible. Moreover, the nozzle 7 in the linkage tip 6 ensures a low-friction advance of the linkage during the exposure of the old line and during a return movement of the linkage when a line section running between a starting excavation and a target excavation is exposed and the linkage is then pulled back into the starting excavation. The linkage or the scavenging head carrier may in this case be connected to an exchange line.

Claims

- 6 - Patent claims

1. A device for the overdrilling of underground lines (5), with a rotary-driven push and/or pull linkage (1), the front end of which is connected to a hollow-cylindrical scavenging head (4, 8) equipped with nozzles, wherein the outlet axis of at least one nozzle (10, 11, 12) runs at an inclination in the direction of the line in a plane of the longitudinal axis of the scavenging head.

2. The device as claimed in claim 1, wherein the outlet axis for at least one nozzle (10) points parallel to the longitudinal axis of the scavenging head (4, 8) .

3. The device as claimed in claim 1 or 2, wherein the nozzles (10, 11, 12) point partly in the direction of advance and partly in the opposite direction.

4. The device as claimed in one of claims 1 to 3, wherein the nozzles (10, 11, 12) are arranged at least partially in a nozzle ring (8) connected to a scavenging head carrier (4) .

5. The device as claimed in one of claims 1 to 4, wherein the nozzle ring (8) is connected to a rotary drive.

6. The device as claimed in claim 5, wherein the rotary drive possesses two directions of action.

7. The device as claimed in claim 4 or 6, wherein the nozzle ring (8) is equipped with cutting and/or broaching tools (9).

8. The device as claimed in one of claims 1 to 7, wherein the end face of the nozzle ring (8) is rounded.

9. The device as claimed in one of claims 1 to 8, wherein the linkage tip (6) and/or the scavenging head carrier (4) are/is provided with at least one nozzle (7) .

10. The device as claimed in one of claims 1 to 9, wherein the front end of the linkage is arranged in a recess (2) in the casing (3) of the scavenging head carrier (4) .

11. The device as claimed in one of claims 1 to 10, wherein the rear side (14) of the scavenging head carrier (4) is beveled.

12. The use of a nozzle ring as claimed in one of claims 4 to 8 for equipping a scavenging head carrier (4).