Sealing means between two interengaging concrete pre-casts.

The invention relates to a seal between two prefabricated concrete parts fittable together and to a method for producing such a seal.

Interlock together precast concrete products such as concrete pipes according to DIN 4032 and 4035 are generally sealed with elastomeric seals, which can be designed as a rolling rings or sliding seals. In the latter, it is known (DE-OS 29 00 437) to use a sealing ring for sealing the space between two substantially concentric sealing surfaces, consisting of two sealing portions each having a sliding surface, the sealing portions touch each other at the sliding surfaces and are so formed that they remain upon insertion of one of the sealing surfaces of the other seal surface is substantially in the same place, bear against a sealing surface to each other and slide along the sliding surfaces. The sealing ring can be provided with a lubricant or lubricants. A disadvantage of this known embodiment, the sealing ring is the fact that the lubricant dry up over time or may harden, whereby the seal can no longer effectively slide on the associated precast concrete.

When installed precast concrete parts, in particular pipes, relative displacements of parts occur between them, particularly for subsidence as they occur frequently in mining areas. The seals known operability after a few years of installation is impaired when it comes to such relative displacements of the precast elements comes up to today.

The invention has for its object to provide a seal for precast concrete products that reliably performs its sealing function even after many years, even when it comes to relative displacements of the precast concrete parts to each other.

This object is achieved in that the first precast concrete a standard compression and / or lip seal is fixed while adheres an annular liner on the second precast concrete, wherein the compression and / or lip seal in the assembled state of precast concrete rests on the liner.

In the preferred embodiment, the lining consists of a tube with eingefülltem lubricant. The lubricant is protected in the hose against drying and hardening. Also noteworthy is the fact that the seal and the lubricant are separated from each other.

Further details of the invention will be described with reference to the drawing. In which:<ul><li>Fig. 1 shows a cross section through a tubing string in the first embodiment of the seal,</li><li>FIG. 2 shows an enlarged detail, namely a container filled with lubricant rubber hose,</li><li>Fig. 3 shows the manufacture of a concrete pipe with a second embodiment of the seal,</li><li>Fig. 4 shows the assembly of two concrete pipes and</li><li>Fig. 5 shows the seal in the operative state.</li></ul>

In Fig. 1, the socket end 1 and the spigot end 2 of two adjacent, of stacked concrete pipes are shown, which are separated by a ring gap 3. In the region of the annular gap a permanently installed seal 5 is the socket end 1 is provided which can be designed as a compression and / or lip seal, said commercially available seals can be used. On the spigot end 2 a squashed rubber tube 10 is mounted, which lines the spigot. 2 To 5 arrive at a safe overlap of the seal with the rubber tube 10, the width of the plastic tube 10 should be about two-thirds the length of the spigot. 2 The gap-shaped interior of the hose 10 is filled with a lubricant or lubricant 15, as shown in FIG. 2. On flattened rubber tube 10 has a radially outer wall 11 and a radially inner wall 12 can be distinguished, which can easily be moved as a result of the lubricant 15 against each other, of course, hiking portions of the outer wall to the inner wall and vice versa. The rubber hose 10 may be provided on the outside with corrugations 13, ie, along the large diameter of the hose, running in the circumferential direction. It can be provided on the inside 14 of the tube 10 to avoid the collision gluing of the walls 11 and 12 also corrugations.

The filled in the tube 10 sealant 15 has a relatively low viscosity, and the amount used is small because it is only important that the two walls 11, 12 of the tube can slide against each other.

As is apparent from Fig. 1, contacts the radially inner end 6 of the seal 5, the outer surface of the wall 11 of the rubber hose 10 and engages in particular between the corrugations of a thirteenth When dragging the concrete pipes in the direction of the arrows 7, 8 against each other, so taking the top 6 of the gasket 5, the radially outer wall 11 of the rubber hose 10 with itself, so that the tip 6 never scrapes along rough concrete. Since the lubricant is 15 well closed, it is not subject to the influence of the flowing or conveyed through the tubes medium so that the lubricity of the lubricant remains long. It is therefore expected that the sealing function of the compound represented remains long, even when the concrete pipes concerned are subject to frequent shifts.

While the arrangement shown of the rubber hose 10 at the pointed end 2 and the built-seal 5 is easiest to implement the socket end 1, the reverse arrangement with rubber hose on the socket end and seal the spigot is conceivable. In this case, one could let the rubber tube slightly protrude from the front end 1a of the bell-shaped socket 1, in which case the line on the spigot seal the rubber tube pulls into the gap 3 when the precast concrete parts are plugged into each other.

Except rubber as the material of the tube 10 are also other plastics into consideration that do not age and are compatible with lubricants. The material used for the tube 10 and in particular, the corrugations 13 should also have a certain elasticity to sealing engage blowholes of the concrete and also to compensate for the roughness of the concrete. This prevents that the sealing effect can be to a certain extent undermined on the tube base.

FIGS. 3 to 5 show a second embodiment of the invention. Corresponding components are assigned the same reference numerals as in the first embodiment. Instead of closed rubber hose foil fold 20 is used, which consists of a material that is extremely easy to today slidably. The film has 20 fold (from the component 1) an inner foil part 21 and an outer film part 22nd On film portion 21 breakable holding projections 24 are attached to hold the film fold at the bell end 1 temporarily. As in the case of the use of a rubber hose 10, the outer side of the film 20 may be provided with corrugations 23 which facilitate the entrainment effect by the spigot end 2nd

Fig. 3 shows the manufacture of a concrete pipe in the socket end 1 by means of a mold, which consists of an annular base ring 31 and an inner formwork and outer tube 32 and 33. In the bottom pallet 31, the sheet fold 20, the seal 5 and a support body 34 are inserted from foamed plastic, whereafter the mold is 31, 32, 33 is filled with concrete. The extensions 24 of the film fold 20 are enclosed in which hardening concrete, so that the film fold 20 is not lost on the prepared concrete box 1, when the mold is disassembled. The supporting body 34 normally remains to protect the seal 5 in the bell-shaped socket 1 until just prior to their assembly with a spigot end 2, as shown in FIG. 4 and 5.

FIGS. 4 and 5 show the socket end and the spigot end of the concrete pipe during assembly and in the assembled state, namely lying, because this is the usual manner of use of concrete pipes. When the spigot end 2 is pushed into the socket end 1, it impinges on the outer foil part 22 and pulls it with due to its roughness, so that the inner sheet member 21 is radially outwardly also taken at the transition 26 to the outer film part and demolish the extensions 24 in succession. The film fold 20 is pulled so inwardly across the seal 5, and at the same time an annular lining of the spigot end 2 is provided which ensures that the tip 6 of the gasket 5 no scrapes on rough concrete of the spigot. 2 It is therefore a long-lasting, good sealing achieved, even if the two concrete pipes should move against each other in the direction of the arrows. 7 and 8

In order to increase the slidability between the film members 21 and 22, lubricant may be filled in the film crease. It is also possible, with a simple film composed it were only from the film portion 21 to manage. The extensions 24 must be sufficiently weak in this case, so that they tear on the film and its entrainment when hitting the spigot. 2 The film is carried along during the further displacement of the spigot end 2, slides over the seal 5 and forms an annular liner on the spigot end 2. Alternatively, the simple film are shrunk onto the spigot. 2 Also in this case it is ensured that the tip 6 of the seal never scrapes on rough ground.