The object of this invention is a pipe duct for the installation of risers for HEPAC or other comparable pipes in high-rise buildings, comprising a framework dimensioned to floor-to-floor height, into which pipes in floor-to-floor lengths are installed.

FI Printed Patent Publication no 75634 includes the above-type duct element. In this duct element, the required HEPAC pipes are installed inside a shaft, cast of polyurethane. This compacted shaft makes later changes, such as pipe branching, difficult and also the replacing the pipes themselves will require the replacement of the entire element. The most prominent problem in this existing ductwork is, however, that the pipes in it are in totally fixed positions. The floor slab through holes should therefore be extremely accurate in order to make the connection of the pipes, installed between the different floors, possible. This connection must in addition be carried out in rather close quarters and the floor slab through holes cannot be sufficiently insulated to eliminate noise and smell problems.

The aim of the present invention is to introduce a pipe duct, where the said problems are successfully eliminated. It is characteristic for this pipe duct invention, that the framework has a solid upper level, where the pipes are supported to at least the said upper level and the pipe fittings allow a lateral

moving of their lower ends. The advantage is that the pipes are fitted to the upper level by through bushings.

In the pipe duct, in accordance with the invention, the upper level of the framework acts as a casting bed, facilitating the grouting of the duct opening in the floor slab to an even level with the rest of the surface. When this grouting is done, the pipes penetrate the floor slab only by their lead-through elements, which guarantee an air-tight and fire-proof lead-through. The through elements in FI patent applications 871234 and 874992 can economically be used for this purpose. On the other hand, as the pipes are primarily fixed to the framework by their upper ends with these lead-through elements, and are not necessarily fixed to any other part of the frame¬ work, their lower ends can easily be moved laterally to the extent that they can be quickly and easily aligned and connected with the top ends of pipes in a comparable duct element, penetrating through the floor slab below. An exact top alignment of the duct elements, located between the different floors, will thus become unnecessary.

The following is a more detailed description of the pipe duct, according to the invention with references to the enclosed drawing, which illustrates a sample implementation of the pipe duct, according to the invention, leaving out unessential structural details, for the sake of clarity.

The pipe duct, shown in the drawing, comprises the framework 1, which is assembled with sheet metal profiles, joined together at the seams by either riveting, sheet metal screws, bolts or other comparable conventional methods, generally in the shape of a rectangular frame. This frame is naturally dimensioned and shaped according to each need, i.e. its dimensions and form are, on one hand, determined by the number and dimensions of the pipes to be installed inside and, on the other hand, by the position of the pipe duct in the room space. It is essential that the pipes can be fitted compactly in the duct element. The solid upper level 6 (for frame¬ work 1 ) is formed of e.g. metal sheeting and so is the solid intermediate level 11. The bottom end of the framework 1 is left open, instead, and the vertical profiles 12. Exactly dimensioned holes are cut in both the top level 6 and the intermediate level ll for pipes 2, 3, 4 and 5, to be installed in the framework 1. In the example, shown in the drawing, pipe 2 is an air conditioning duct, pipe 3 a sewer pipe and pipes 4 and 5 are water pipes. After cutting the holes, the lead-through elements 7, 8, 9 and 10 for the pipes are fitted to upper level 6. These lead- through elements have an external casing, which may be of e.g. plastic or metal, and inserted sleevelike gaskets of e.g. synthetic rubber, where the central hole is dimensioned according to the pipes to be installed in them. These through sleeves 7, 8, 9 and 10 are then mounted on the upper level by a conven¬ tional method such as by a support flange 13, as shown in lead-throughs 9 and 10. Reference to these

lead-through elements and their supports is found in the above-mentioned FI patent applications 871234 and 874992.

Pipes 2 and 3, which are the said air-conditioning and sewer pipes, are not supported on the intermediate level 11, sufficiently large lead-through holes have instead been cut for them on this level 11. Water pipes 4 and 5 are instead supported on this inter¬ mediate level 11 by through elements 9 and 10, corresponding to elements 14 and 15. This support of the water pipes 4 and 5 to the intermediate level 11 is done because this is a way to prevent potential vibratory noise coming from the pipes, which is caused by the use of the water supply. Single handle taps, in particular, have a tendency to cause this type of vibration. The supporting of water pipes on the intermediate level 11 is also possible, because these pipes are of copper and thus rather flexible, and will not hamper the lateral moving of their lower ends.

This would be the case with the air-conditioning duct and sewer pipes 2 and 3, which is why they have not been supported on this intermediate level. This way, the lateral mobility of the lower ends of all the pipes 2, 3, 4 and 5, remains good and the duct elements to be installed on the different floors can now be easily connected to each other, even when not fully aligned between the floors.

This connection of the pipes can in practice be carried out one by one and not even a plumber is necessarily needed. The connection of the sewer pipe 3 can for example be done by using a so-called expansion joint unit (not shown) at the lower end of the pipe in the element. This expansion joint unit allows the axial moving of the unit in question without its loosing its air tightness. The sewer pipe can thus be extended simply by moving the bottom end of this expansion unit to the sewer pipe and pressing it down until its lower end is inserted in the connecting sleeve of the top end of the sewer pipe in the duct element below. No other connections are needed. The connection of the air-conditioning duct can be done by a comparable method by using a long extension (not shown) . Water pipes are instead connected by a conventional method, e.g. by soldering.

One of the characteristics of the duct element, in accordance with the invention, to be mentioned, is that the pipes can be preinsulated prior to delivery to the work site. Furthermore, since the pipes are already fitted to their framework, installa¬ tion at worksite will be essentially simpler. Of course the needed branch joints for the pipe are built-in, they are, however, not shown in the drawing for the sake of clarity. Branch joints for water pipes are thus most often connected to the lower end of the framework, where they can be supported either by vertical or horizontal profile 12. A branch of the air-conditioning duct 2 is most often connected to its upper end, i.e. immediately below the top level. The simplest way to connect the sewer pipe junction is to do it immediately above the lead-through element.

The most practical joint here would be a T pipe, including a connecting sleeve for the connection of the following duct element. During the delivery of a duct element of the type in the drawing and its installation, the pipes 2, 3, 4 and 5 are supported to framework 1 by lead-through elements 7, 8, 9 and 10 and possibly also by lead-through elements 14 and 15. There is sufficient friction between these lead- through elements in practice to hold the pipes in place. This friction can easily be increased by for¬ ming a suitable, ring-type protrusion or edge on the external surface of the part inserted in the lead- through elements. On the water pipes, this edge can be made by compressing a metal ring around the pipes and for the air-conditioning ducts and the plastic sewer pipes, in particular, this can be made with e.g. a glued-on rubber or plastic ring. This type of an exten¬ sion on the surface of the pipe will, on one hand, increase friction between the pipe and the through element and, on the other hand, guarantee that it will stay in place during delivery and installment of the duct element and it will also improve the air tightness of the lead-through element.

When a lead-through element, in accordance with the invention, is delivered to the installation place, it is directly connected e.g. through a part of the framework or an attached metal connector to either the wall structure or the floor slab above by either plugging or by shot steel nails. The installation of the duct element can be carried out either before the installation of floor slabs, such as hollow-core

slabs, or after this by lowering it to the hole reserved for it prior to the casting of the slab. During the casting of the slab, the through hole, reserved for the duct element, is also filled, whereby the top level 6 acts as the casting bed. It should be mentioned that the installation of this duct element or the casting of the floor slab on top of it do not require the actual connection of pipes, instead, the pipe connections can be made afterwards, when so desired. The open structure of the framework and particularly the lateral mobility of the lower ends of the pipes, provide a good opportunity for this.

The duct element, in accordance with the invention, was in the above presented with a single implementation example and it should be understood that this can be modified in several ways, however, within the limits set by the patent claim. Therefore, the total shape, number and location of the pipes in the element can be changed, when needed. It is essential that the element have a solid upper level, which can be used as a bed for casting and that the lower ends of the pipes can be laterally moved during their possible connection into continuing risers, regardless of any mistakes in alignment in the duct elements between the different floors.