The object of this invention is a conduit collar and a method for installing a conduit collar into a hole made into a concrete or stone structure.

In industrial construction work it is at times necessary to insert pipes, hoses, conductors, etc. , through structures. The normal procedure is to use a diamond drill to bore a hole in the desired spot for passing through the pipes, etc. As the items to be passed through must not come into contact with the surrounding structure, it is necessary to provide the hole with a protective collar to prevent the entry of water and falling material. As the conduit collar it may be used a pipe with a flange welded threto for its fastening and sealing. Often it is also necessary to have the concrete structure around the hole pick dressed to accommodate the flange prior to the final mounting of the collar. Using wedge anchors, the collar pipe is then fastened by its flange to the concrete structure. This is followed by conc¬ rete being cast over the flange to provide well sealed fastening. The resulting surface may require finishing.

Another way of installing a conduit in a concrete structure is to weld starter bars onto the conduit collar sheath. The collar is then inserted in the hole. The gap between the collar pipe and the hole periphery is then boarded up from below and concrete is poured into the said gap to fuse the collar with the concrete structure.' The formwork boards are dismantled once the concrete has set.

Yet another way to execute a conduit is to use two pipes, one inside the other and both tapering in the same directi¬ on. Here too, the external pipe has to be provided with a flange for the pipe to stay in the hole. Sealing compound is also often needed between the pipe sheaths. Another pre¬ caution is to bolt the flange of the other pipe to the floor.

The disadvantages of the above methods include time consu¬ ming installation, the labour input of several persons, and several work stages (pick dressing, casting of concrete, welding and formwork) . The f stening of the boarding under¬ neath the hole is difficult because high elevations or cramped spaces necessitate different scaffolding for the assembling and dismantling of the formwork. The latter method necessitates the use of two pipes.

The conduit collar and the method for installing it in accordance with the invention are decisive improvements on the above shortcomings. For the realization of these impro¬ vements, the method in accordance with the invention is characterized by what is presented in the characterization part of claim 1, and the collar is further characterized by what is presented in the characterization part of claim 5.

The foremost advantage of the invention may be considered to be in that the collar and method in accordance with the invention facilitate speedy installation as well as a well sealed and ready-to-use structure. Most advantageously, the collar comprises two ribs inserted into the hole wherein they result in a stable structure within the hole and the resultant sealing effect is superior to that achievable if only one rib is employed. Additionally, it is advantageous that the rib near the mouth of the hole seals the mouth and thereby prevents water from flowing into the gap between the hole and the collar sheath. If the collar comprises three or more ribs inserted into the hole, the resultant friction between the hole and the rib may become quite considerable. Due to the above reasons, the most advantageous form of implementation of the invention will comprise two insertable ribs.

In the following, the invention is described in detail by referring to the appended drawings.

Figure 1 depicts the conduit collar in accordance with the invention.

Figure 2 depicts the insertion into a hole made into a concrete structure of a conduit collar in accordance with the invention.

Figure 3 depicts the fastening into a hole of a conduit collar in accordance with the invention.

The conduit collar depicted in Fig. 1 comprises ribs 1 and 2 and a tube 3 with an outside diameter of di . Ribs 1 and 2 are advantageously essentially wedge-like or segment shaped in cross section.

In Fig. 2, sealing compound 4 has been spread in between rib 1 and upper rib 2. Fig. 2 depicts the insertion of conduit collar 3 into a hole 5 with a diameter of d ₃ bored into the concrete or stone structure 6.

Figure 3 depicts the installation of collar 3 into hole 5. The result is a well sealed structure that prevents splash water from flowing into the gap between the outer sheath and the hole.

Prior to inserting ribs 1 and 2 into the hole, sealing com¬ pound 4 may be spread onto the area between the said ribs. Since those conduit collar ribs that are inserted into the hole 5 are slightly larger than the diameter of hole 5, the conduit collar has to be forced into hole Once the con¬ duit collar is in the hole, the rib with the largest diame¬ ter will become tightly wedged to the mouth of the conduit hole.

As an example, the plate thickness of a collar in accordance with the invention made of acid-proof stainless steel mate¬ rial might be 1.5 mm. The diameter of a rib to be inserted advantageously inside the hole would in such a case be, at

its widest point, 2 mm larger the diameter of the hole while the outside diameter of the collar conduit would be c. 2 mm smaller than the diameter of the hole. The outside diameter of the rib positioned advantageously at the mouth of the hole is greater than the diameter of the rib inserted into the hole. In addition, it is necessary to point out that the combined arc widths of the ribs inserted advantageously into the hole are less than half of the length of the hole.

Various known devices for and means of inserting the collar can be used. For example, one may use a draw-in device comp¬ rising a grooved installation plate the grooves of which are such that they fit onto the end of the collar. At the other end there is the tool's counter piece. The said counter piece and the tightening nut on top of the installation plate are joined by a tie bolt. On the nut being tightened, the counter piece becomes supported by the base of the concrete structure and the installation plate is drawn steadily downward. The nut is tightened until the upper rib is level with the mouth of the hole.

It should be noted that in the above the invention has been described with reference being made to only one of its implementation examples. In no way is this intended to confine the invention to apply to only this example. On the contrary, many variations, such as the number and shape of the ribs, the material used to make the conduit collar, are possible within the framework of the inventive idea as defined in the following patent claims.