DE8716205U1 - Plastic protective pipe for trenchless laying of supply lines - Google Patents

Description

G. A. Pfleiderer GmbH & Co KG

Plastic protection pipe for trenchless
Laying supply lines

The invention relates to a plastic protective pipe for trenchless laying of supply lines, in particular for the renovation of gas and water pipes, with the aid of a soil displacement hammer with a rear mounting device for the protective pipe to be pulled in consisting of pipe sections joined together into which the supply line is subsequently inserted.

Usually, trenchless laying of supply lines is carried out using soil displacement hammers in such a way that the actual supply pipe is attached directly to the soil displacement hammer. The soil displacement hammer either works its way through the subsoil on its own or it is - particularly when renovating old pipes - additionally pulled by a winch using a pull rope. This procedure has the consequence - because the pipeline must be made up of individual sections - that the laying work always has to be interrupted for longer periods of time until the rear end of the pipe to be pulled in is reached.

ti «<

t * t *

&bull; t · ·

a new shot is welded on. Since the weld in this case not only has to withstand the mechanical tensile stress, but an absolutely tight weld is required, the effort is correspondingly high and, consequently, the downtime during which the entire team stands still with the expensive soil displacement hammer is correspondingly long.

This difficulty also exists with the modified method described at the beginning, in which a protective pipe is first pulled in with the soil displacement hammer, into which the actual supply line is subsequently inserted. Continuous operation with the soil displacement hammer is only possible if the protective pipe is so small in diameter that it can be unwound from a roll, i.e. is available as a virtually endless pipe. In most cases in which the protective pipe has to be assembled from individual sections, however, the previously known methods (see, for example, the magazine gwf-gas/erdgas 127 (1986) issue 10/11, page 434) require the individual sections or rods to be joined together using butt welds and E-fitting connections. The problem of welding them together is presented here as - at best slightly simplified compared to the production of the weld seam of the actual supply line

just as with small extensions grs-uerx!LoS3ri Laying method without using a protective pipe.

The connection of the individual pipe sections using socket connections is not permitted, on the one hand, because it hinders the tightening of the plastic pipe, which should ideally have a completely smooth outer surface

IiIIIl I · · « ·

Il Il I I < I · « ·

If, on the other hand, the channel is widened in diameter, only a smaller plastic protective pipe and thus smaller supply lines could be pulled through the rim of the diameter of the sleeves. However, the arrangement of the individual sections in such a way that they _are only pushed together by the pulling rope does not provide sufficient - tightness in the rough conditions that occur. In addition ^, the pipes ^- G ■- - could become jammed and not only endanger the pulling in process as a whole, but dirt could also penetrate the pipe, which would then hinder the subsequent insertion of the actual supply line.

1:5 . &Iacgr;

The invention is therefore based on the object*

Plastic protective pipe made from individual pipe sections eh zn ' ■- I

,schaffenj which is very easy to manufacture and with the help of \

of the soil displacement hammer.

■ . ;

To solve this problem, the invention provides that each pipe section is provided at one end with an inner sleeve, preferably made of plastic, which is inserted at both ends at an acute angle.

_t : chamfered.

The inner sleeve according to the invention already suffices

_ ^l the pipes are put together and held together by the pull rope that runs through the entire protective pipe string to ensure sufficient tightness on the one hand and to prevent the risk of the pipe sections moving sideways against each other. At the same time, the outer surface is completely smooth, so that the remnants of the old pipe are not unnecessarily hindered when they are pulled into the widened floor channel.

« 4 e »

I I ·

I I ·

ti I ·

I I 4

I I ·

Of particular importance in this context is the chamfering of both ends of the inner sleeve, which is preferably glued into the pipe, as this way there are no joints that could hinder the later insertion of the actual supply line.

In addition to the already mentioned assembly of the individual sections, whereby the inner sleeve is preferably arranged at the trailing end of the section, so that the new protective pipe section to be attached is attached with its end not having ^an inner sleeve to the inner sleeve of the protective pipe which has already been largely retracted, it can also be provided for special applications that the newly attached pipe section is glued to the inner sleeve of the leading section.

Further advantages, features and details of the invention emerge from the following description of an embodiment and from the drawing. ¹ In which:

Fig* 1 a schematic view of the insertion

a plastic protective tube according to the invention
&igr; in the course of a gas or water pipe renovation And

Fig. 2 an enlarged section of the ends two
pipe sections to be joined together.

In Fig. 1, 1 indicates an old gas or water pipe that is to be repaired using a so-called soil displacement device 2. For this purpose, shafts are dug into the ground at intervals to expose the old pipe. In one shaft 3, a pulling device (not shown) is installed.

A cable winch is set up to pull the soil displacement hammer 2 with the ripper links S arranged on its head through the old pipe with the help of a pull rope 4. The leaking or simply too small pipe is removed by these ripper links S.

,, &igr;, -,ne old pipe 1 is torn open and pressed outwards over the conical head ,, and the adjoining cylinder from the section of _the soil displacement hammer, whereby a larger channel cross-section is created _overall than that of the original pipe 1. At the end of the soil displacement hammer 2, a plastic

I-I

protective pipe 6, which is made up of individual sections 6 ¹ or 6 ¹ '. At the trailing end of each such section 6' or 6 ^1? there is a glued-in inner sleeve 7, which is bevelled at an acute angle at both ends. The inclined surfaces 8 and 9 formed in this way prevent the actual new supply line from hitting the edges of the inner sleeve when it is later pulled in, which could endanger the pulling in process. The bevelling at both ends enables the new supply line to be pulled in at an acute angle. easy to attach the sections to the soil displacement hammer 2 with either a leading or trailing inner sleeve. Preferably, an additional traction cable (not shown in the drawings) is provided on the soil displacement hammer, which passes through the pipe sections of the plastic protective pipe 6 and is supported at the rear end, ie in the spaced-apart pit (not shown) in which the new sections are attached to the plastic protective pipe 6, by means of a crosspiece on the front face, so that the individual sections are pressed together under tension. If necessary, however, this traction cable could also be omitted and the pipe sections could be attached to the outer surfaces of the plastic sleeve.

Glue the counter pipe sections so that a strand is formed that absorbs the tensile forces and is also denser

l* <»»· I I. ta Il <>><

« &igr;&igr;■#&igr; i · « &igr; *

Claims (3)

Protection claims 1. Plastic protective pipe for trenchless laying of supply lines, in particular for the renovation of gas and water lines, with the aid of a soil displacement hammer with a rear holding device for the protective pipe to be pulled in, consisting of pipe sections joined together, into which the supply line is subsequently introduced, characterized in that each pipe section ( ^6f , 6'') is provided at one end with an inner sleeve (7), preferably made of plastic, which is chamfered at both ends at an acute angle. 2. Plastic protective pipe according to claim 1, characterized in that the inner sleeve is glued into the respective pipe section (6 ^? , 6''). 3. Plastic protective tube according to claim 1 or 2, characterized in that the inner sleeve, preferably arranged at the trailing end of the protective tube (6), is glued into the plugged-on end of an adjacent protective tube section.