TECHNICAL FIELD The present invention relates to a wall transition coupling device for pipes, particularly pipes for a water supply system, said device being of the type comprising a clamping sleeve coupling known per se, and a wall plate, wherein the clamping sleeve coupling includes a first coupiing part projecting from the wall plate, and a second coupling part being shaped to cooperate with the first coupling part.

BACKGROUND AND PROBLEM Wall plates with clamping sleeve couplings, of a type known per se, are used for transit and joining of pipes, particularly water supply pipes, through walls for example in connection with faucets and radiators in bathrooms or other spaces. In a villa, for example, the water supply pipes are drawn on the inside of the wall up to the room, for example a bathroom, in which the water shall be used. The water will then be led on to for example a blender on a wash basin or similar, and it is in the transition between the hidden pipe extension in the wall and the visible pipe extension on the outside of the wall that wall plates with clamping sleeve couplings are used. This is made in order to join the pipes in the wall with the pipes in the room in a neat and reliable way, since these pipes are seldom of the same kind due to both practical and esthetical reasons.

The pipes in the wall are often made of copper or plastic and the pipes in the room are often made of stainless steel or chromed copper.

Generally, a device according to the above may be described as a wall plate which is normally fixedly attached to a first coupling part such as for example a nut having been riveted or upset in a hole through the plate made for this purpose. This nut and plate is applied on the pipe in the wall, which pipe is usually cut 20-30 mm from the wall and has been fixed to the wall by means of sealing putty or a fixture. A clamping sleeve of a known type is then applied on the pipe end as well as a second coupling part, such as for example a nipple, a wall valve or a pipe angle being adapted to be screwed into the first coupling part in a known manner. The first and the second coupling parts are usually provided with internal conical surfaces which make the clamping sleeve deform on the pipe as the second coupling part is screwed into the first coupling part, which enables a sealing attachment of the pipe in the coupling.

Currently available wall plates with clamping sleeve couplings are, however, subjected to several problems, the largest problem relating to the need for disassembling the wall plate from the wall. Upon larger repairs or exchange of wall panels, from for example a

wet room carpet to a tile wall, it is often necessary to dissemble the wall plate.

Furthermore, a assembly may be necessitated by a faulty installation of the wall plate.

Many current wall plates are provided with leak indication, allowing the water to trickle out on the front side of the wall, upon a leakage, through a drainage hole in the wall plate and thus become visible, instead of gathering within the wall where it cannot be detected, and may lead to severe water damage before eventual detection. The drainage holes, that communicate with channels from the coupling extending in a sealing layer on the back of the plate, are often only provided in one end of the plate.

Thus, the installator must very carefully ensure that the plate is orientated in such a way that a drainage hole will face the floor. Otherwise, water will build up within the plate and flow into the wall in the case of a leakage, which means that it is necessary to disassemble the plate again should the installator have turned the plate in the wrong way. The design of the current leak indication may thus hose a problem, since it is dependent on in which way the plate has been turned.

Unfortunately, disassembly of current wall plates is easier said than done. Once the deformation of the clamping sleeve has taken place on the pipe, the nut may of course not be drawn over the same again, and consequently the wall plate cannot be disassembled with lesser means than removal of the clamping sleeve from the pipe, or alternatively, the pipe can be cut inside of the clamping sleeve, which means removal of the clamping sleeve by cutting away the pipe end to which the sleeve is attached.

However, none of these methods are preferable. In the first case, the clamping sleeve is drawn off the pipe with some kind of tooi and since the sleeve is a very tight fit on the pipe, deformations on the pipe are formed, primarily in the shape of longitudinal scratches. These scratches reduce the sealing capability of the coupling and may lead to leakage as a new clamping sleeve is then attached and the coupling is reassembled. In the other case, the pipe remains undamaged (since the coupling takes place on a"new" piece of pipe), but in many cases, this method is not practically feasible at all since the piece of pipe which project from the wall is to short to be cut and then be maintained in a new coupling.

Additionally, in most cases, it is desirable to temporarily plug the pipe during the course of the work at larger repairs or for example an exchange of wall panels, as one does not want to cut water supply since such a measure would cause disturbances for people, particularly since an entire villa or several apartments may be affected. Such a plugging is carried out with the same type of clamping sleeve coupling which, in turn, after the work is finished, has to be disassembled-with the above mentioned problem. Similar plugging procedure must also be carried out at new building sites, where the system, in accordance with governmental regulations, must be test-pressurized with water or air

before pipes to for example wash basin blenders and radiators may be attached and finished.

In order to solve the above described problem with clamping sleeves that have to be cut away, or alternatively has to be drawn off with tools, coupling designs have been presented, in which the clamping sleeve is slotted. The clamping sleeve may then be dissembled by carefully prying it apart with a tool. Unfortunately, a coupling design has then been achieved, in which the function of the clamping sleeve has been reduced to maintaining the pipe in the coupling and wherein the sealing, which is of at least the same importance for the function of the coupling, must be provided with a conventional sealing ring. This is undesirable, since it is well known that sealing rings of a conventional type tend to age, whereby the sealing effect is reduced accordingly.

Additionally, sealing rings may settle and it is difficult to make them follow the movements subjected to the coupling upon temperature variations and vibrations. A clamping sleeve with a sealing ring also means a risk of a faulty assembly, since it is very important that the clamping sleeve is turned in such a way that the sealing ring is facing in the right direction. Furthermore, a slotted clamping sleeve also damages the pipe, which results in a risk at reassembly.

The Swedish patent document SE 462 504 describes a known wall plate with coupling nuts. Each coupling nut hereby exhibits a flange with a lesser diameter than the rest of the coupling nut, said flange being adapted to be led through a hole in the wall plate upon assembly of the coupling nut. The coupling nut is then fixed to the wail piate by moving a locking member in the shape of a brass ring over the flange and into engagement with a groove in the flange on the back of the wall plate, by means of plastic deformation directed radially inwards. After the assembly, the coupling nut can no longer be disassembled from the wall plate, whereby said disassembly problem remains.

Accept for the substantiall problems upon disassembly and assembly of current wall plates and couplings, there are further problems.

Many of the current designs are relatively expensive to manufacture, for example an extra work moment is required upsetting sleeve.

Further, man y designs are formed to exclusively be combined with special coupling parts and not with the conventional clamping sleeve couplings available on the market and that are commonly used in the visible pipe fittings. These disassembly-enabling designs are also requiring the use of special tools for assembly and disassembly, which

is undesirable for the instailator, for example, or perhaps primarily for the repair man, who consequently, in many cases, must be equipped with a number of special tools and special coupling parts in order to be able to serve all types of wall transitions.

SUMMARY OF THE INVENTION As described above, previously known wall transition coupling devices for pipes, particularly pipes for a water supply system, suffer from a number of problems and the purpose of the present invention is therefore to solve these problems by providing a device which: has a design which allows disassembly of the wall plate without causing damage to the pipe, i. e. without having to remove the clamping sleeve from the pipe or having to cut the pipe in order to get rid of the clamping sleeve ; may allow plugging of the coupling by means of the existant first coupling part so that the water supply system may be test- pressurized after assembly and may be operational during repairs or an exchange of wall panels; provides a reliable leak indication independent of which way the wall plate was turned upon assembly; provides a very simple assembly and disassembly which, for example, does not require the use of special tools ; is cheaper to manufacture than earlier designs; may be combined with the standard coupling parts of the Vatettes-system ; may be used for all kinds of pipes, for example both for pipes of copper or stainless steel, and for pipes of plastic, for example PEX-pipes, Alupex-pipes, Presol-pipes and PB-pipes.

These objects have been achieved by a device according to claim 1, and a preferred embodiment is described in the appended dependent claims.

SHORT DESCRIPTION OF THE DRAWINGS The invention will now be described in greater detail with reference to the appended drawings, in which: Fig. 1 shows a diagrammatic, partially cross-sectional side-view of a preferred embodiment of the invention and a partial enlargement of the same; Fig. 2 shows a diagrammatic, perspective explosion view of the following parts: washer, first coupling part, wall plate and locking ring; Fig. 3 shows a diagrammatic side-view of the first coupling part;

Fig. 4a shows a diagrammatic view, in perspective, of the locking ring in a"assembled" position; Fig. 4b shows a diagrammatic view, in perspective, of the locking ring in a "disassembled"position ; and Fig. 4c shows a diagrammatic view of a cross-section through the locking ring in an "assembled"position.

DESCRIPTION OF AN EMBODIMENT The invention relates to a wall transition coupling device for pipes, particularly pipes for a water supply system, said device being of the type comprising a clamping sleeve coupling known per se, and a wall plate. As described above, the device is particularly applicable to pipes for a water supply system, which water supply system may for example be placed in a villa or in any other kind of building. As also described above, the term wall transition usually refers to the transition, or pipe joint, between the often hidden pipe extension within the wall and the often visible pipe extension on the outside of the wall.

At the transition, a previously known clamping sleeve coupling is used as described above, in conjunction with a wail plate. The function of the wall plate is known per se, and generally consists in positioning the coupling and covering the pipe transition, wherein said covering fulfils two functions: partly to provide it with a nice appearance and partly to prevent for example water from finding its way into the wall at the pipes.

The latter function is primarily important in wet room spaces, where the walls are often sprayed with water in conjunction with showers and cleaning. The function of the clamping sleeve coupling, which is also previously known, is to hold the pipe projecting from the wall and to provide a sealed joint.

There are many types of clamping sleeve couplings, only one of which is shown in the embodiment soon to be described, but is should be realized that the invention is applicable on a whole range of other types of clamping sleeve couplings. Thus, the coupling as such will not be described in great detail. Furthermore, many different types of wall plates are previously known, for instance of various sizes, for various numbers of pipes and pipes provided with different types of washers. Neither these, will be described in great detail. Finally, one should be aware of that there are a number of different variations of how the pipes are protected in the wall by means of protective pipes etc, and this will only briefly be described with reference to the embodiments.

The invention will now be described by way of a preferred embodiment with reference to Fig. 1-4, wherein the device is used for a normal wall transition of a so called PEX-pipes in a wall.

In the drawings, reference numeral 10 denotes a wall plate known per see. The wall plate 10 of the type used upon transition and joining of two pipes 12, and consists of a thin, substantially rectangular plate, for example made of stainless steel, having a front side referred as its first side 14, and a back side referred to its second side 16, and which is provided, along its outer periphery, with a continually extending edge which extends in the direction towards the second side 16 and which is shaped so as to form a gap between the plate 10 and a wall 18 as the plate 10 is held with the second side 16 against the wall 18. This gap is filled up in a known manner by means of a washer 20 normally consisting of a slab of cell plastic, for example cell-polyethylene. The washer 20 may, for example be seen in Fig. 2. Furthermore, the wall plate 10 is provided with recesses for screws, by means of which the wall plate 10 is attached to the wall. In the shown example, the wall plate 10 is also provided with two substantially circular holes 22, placed at the transition of the pipes. In an alternative, not shown embodiment, the holes 22 may exhibit other shapes than circular, such as for example rectangular or polygonal shapes. In this way, a first coupling part, denoted 24, is arranged in each respective hole 22, for coupling the respective pipes, projecting from the wall 18. At least one of the holes 22 has a diameter exceeding the diameter of the first coupling part 22 so that a gap is formed between the hole 22 and the first coupling part 24. In a known manner, the gap is meant to make the coupling part 24 somewhat dispiaceable in the hole 22 in order to compensate for any eventual fitting errors that may arise when the distance between the holes 22 does not coincide with the distance between the pipes 12 (that have been fixed to the wall 18, in a known manner, by means of a sealing putty or a fixture). Preferably, the diameter of the hole 22 is 1 mm larger than the diameter of the coupling part 24 in the portion of the coupling part 24 which extends through the hole 22. This results in a total tolerance of +/-2 mm if both holes 22 has the larger diameter.

In the example, the pipes 12 are shown placed in a vertical line and the wall plate 10 is orientated accordingly, even if it shall be noted that the wall plate 10 may of course also be applied for an assembly where the pipes 12 are placed in a horizontal line.

As previously mentioned, the device also includes a first coupling part 24, which may be seen for example in Fig. 1 and 3, said first coupling part 24 being arranged to project from the wall plate 10 in an assembled condition and which also forms a part of a clamping sleeve coupling known per see. The clamping sleeve coupling further includes

a second coupling part (not shown) which is adapted to cooperate with the first coupling part and a first clamping sleeve (not shown). The clamping sleeve coupling may briefly be described by saying that the first coupling apart 24 is provided with an internal thread 26 (which will be further described below) and an internal conical surface 28.

The other coupling part, which may for example consist of a nipple, a ball valve or an angle pipe, may be screwed into the first coupling part 24 and is thus provided with a thread corresponding to the thread 26 in the first coupling part. The second coupling part is also provided with a conical surface. Upon screwing in the second coupling part in the first coupling part, the conical surface in each part will, in a known manner, cooperate with the outer peripheral surface of the clamping sleeve and will thereby press the ring hard enough against the pipe 12, so that the ring is fixed to the pipe 12 and deforms the pipe a bit.

The first coupling part 24, which in the example consists of a nut, has a substantially circular cross-section in the shown example, and is divided in at least three portions I, II, III along its axial extension as shown in roman digits in Fig. 1 and Fig. 3. In alternative not shown embodiments, the first coupling part 24 may also exhibit other cross-sections then a circular one, such as for example rectangular or other polygonal cross-sections. The first portion I consists of a flange 30 which radially extends a bit outside of the two other portions II, III. Next portion, the second portion II, forms a radial groove 32 where the first portion I, i. e. the flange 30, forms a first axial end of the groove 32 and where the third portion III forms the second axial end of the groove 32. The third portion III thus has a larger cross-sectionai dimension than the second portion II, but small enough to allow the hole 32 of the wall plate 10 to be withdrawn over the third portion III of the first coupling part 24 upon disassembly. At a small distance from the end of the groove 32, the outer peripheral surface of the third portion has been provided with a tool interface 34, for example in the shape of an hexagon or a similar known interface for a spanner or other tool key. No special tools will thus be required for assembly and disassembly.

The flange 30 is provided with at least one jolt 36, and preferably several jolts 36, that will result in that the axial surfaces of the flange 30 will not be plain, but will instead more or less undulating depending on the number of jolts 36. In the example, the flange 30 has been provided with four jolts 36 equally distributed over the flange 30, se Fig. 2 and 3. It should, however, be noted that this is not necessarily the most suitable number in all designs. Later, the function of these jolts 36 will be described and it will then also be clear that the assembly is facilitated if the specific number of jolts 36 has been equally distributed around the flange 30.

The first coupling part 24 is, as previously described, also provided with an internal through-hole provided with a thread 26. This threaded hole is adapted in size, type and dimension to fit the standard set by the applicants Vatettes-system. It is therefore possible to combine the device with a great number of existent coupling fitting.

As opposed to previously known wall plates with clamping sleeve couplings, the first coupling part 24 in the present invention is separate from the wall plate 10 and not fixedly attached to the wall plate 10. It is, however adapted fixedly attached to the wall plate 10 by means of a locking member 31.

How this is achieved will be described in detail later. First, a described of the locking member 38 in the preferred embodiment will follow.

The purpose of the locking member 38 is to fix the first coupling part 24 to the wall plate 10 and thud, its shape is dependent of the shape of these parts. In the example, the locking member 38 is preferably formed as a locking ring, and this ring 38, may for example be seen in Fig. 4a-4c. The locking ring 38 is preferably with a radio slot 40.

Furthermore the axial sides of the ring 38 exhibits a parallel-conical shape, in such a wall, that if one studies a cross-section of the rich 38, one can see that the shape is substantially a parallelogram, see Fig. 1. One may also say that the ring has a concave surface 42 and a convex surface 44.

With reference now to Fig. 4a-Fig. 4c, the slot 40 is preferably chamfered and the chamfer 46 has been made in the edge between the concave surface 42 of the ring 38 and the respective surfaces formed by the opposing surfaces of the slots 40. The chamfer 46 thus extends between the outer periphery of the ring 38 and its inner periphery and a radial cross-section of the slot 40 exhibits a V-shape 48 where the opening in the V-shape 48 is thus directed towards the concave surface 42 of the ring 38.

The material of the locking ring 38 should be flexible and preferably, for example, of a type of polymer material or a stainless spring materiat. Furthermore, the locking ring 38 should be preferably be manufacturing with a small pre-tensioning, so that the locking ring 38, when it is not assembled, i. e. in an unloaded condition, will reduce its diameter by letting the free ends at the slots 40 over lap each other, see Fig. 4b. In an assembled condition, the ring 38 should have such a diameter, that the ends of the slot 40 such meet and thereby encloses the tip of the V-shape 48, see Fig. 4a.

In the following, assembly, and then disassembly of the present invention will be described in great detail.

The pipes 12, which normally are allowed to project about 120-30 m from the wall 18, depending of a choice of coupling, is fixed in the outer panel of the wall 18, which may for example be made of plaster, in a fixture or by means of a sealing putty (not shown) at a distance from each other essentially corresponding to the distance between the holes 22 in the wall plate 10. The pipes 12 may, within the wall 18, be covered with a known flexible protective pipe 50, which at the wall 18 is provided with a known protective pipe fastening sleeve 52. These parts may be seen in Fig. 1.

Hereinafter only one pipe 12 will be described, but it should be noted that in a two-pipe transition, to first coupling parts 24, two locking rings 27 are used.

The first coupling part 24 with its flange 30 directed towards the wall 18, is attached to the pipes 12. It is then time to attach the clamping sleeve (not shows). Upon a new installation, one may choose to screw in the second coupling part and to finish the coupling in order to then plug the free end of the second coupling part, once this is done, one may perform a test-pressurization of the system, i. e. one starts the water- flow during a shorter time period in order to see that everything is in order before one proceeds with coupling to faucets and radiators. This is also the principle for maintaining the water supply system in operation during an ongoing work, for example in a bathroom, when one desires to have water connected to the rest of the building. Test- pressurization and plugging are temporarily measures and they do not need to carry our with the second part which will then be used. Test-pressurization and plugging does not have to been performed with, for example: the T-pipe 1 then intends to used for the final fitting, but a nipple or similar may advantageously be used.

After test-pressurization, or when repair work has been completed, and when it is thus time for the final installation, the temporary second coupling part is removed and it is time to assemble the wall plate 10, or alternatively the chosen second coupling part to be used further on depending on if the wall plate 10 can be withdrawn over this or not.

If, for example, a T-pipe is used as a second coupling part, the wall plate 10 must be assembled first. The same applies for the case where one has not made a test- pressurization or plugging or where the clamping sleeve is still not deformed on the pipe 12.

The second side 16 of the wall plate 10, the back side, which is to be facing the wall plate 18, is provided with a washer 20 of a known type, by means of glue or other

adhesive. The washer 20, naturally has two holes corresponding to the position of the holes 22 in the plate 10. However, these holes must be larger than the holes in the piate 10, namely equal to or larger than the diameter of the flange 30 on the coupling part.

The wall plate 10 is then drawn over an eventual second coupling part and then over the third portion, i. e. the tool interface 34, of the first coupling part 24 and is placed in the second portion, i. e. the groove 32. The flange 30 will then abut the second side 16 of the wall plate 10.

After this, the wall plate 10 is fixed by screws into the wall 18 and it becomes time to fix the first coupling part 24 on the wall plate 10 by means of the locking ring 38.

The locking ring 38 is expanded and drawn over the first coupling part 24 with the concave side 42 of the locking ring 38 facing the first side 14 of the wall plate 10, and is then released into the groove 32 which forms its second portion. The parallel-conical shape of the locking ring 38 means that the inner periphery of the locking ring 38 will abut one end of the groove 32 in the first coupling part 24 and that the outer periphery of the locking ring 38 will abut the first side 14 of the wall plate 10. Thus, both an axial and an radial pre-tensioning of the first coupling part 24 against the wall plate 10 is achieved, resulting in a good sealing against water spray, i. e. water being sprayed over the device and which holds the locking ring 38 and the coupling part 24 in place relative to each other. When the ring 38 is in place, it is turned so that the siot 40 is placed in a direction down towards the floor. The reason for doing this has to do with the leak indication of the device, and will be described further on.

Once the first coupling part 24 is fixed in the wall plate 10, the second coupling part is finally screwed on (if it is not already in place). In the second coupling part, one may then attach the pipe which is to be conducted on the outside of the wall to for example a radiator or a wash basin.

Upon new installations, one normally does not want the wall plate 10 with its washer 20, the locking ring 38 and the first coupling part 24 in parts. Advantageously, the assembly of these parts into a unit, may then take place already at the manufacturing plant, so that the installation out at the end consumer may be speeded up.

As described initially, the main advantage of the invention is the facilitated disassembly, which makes it possible to disassemble the wall transition without damaging the pipe 12, i. e. without having to remove the clamping sleeve from the pipe 12 or without

having to cut the pipe 12 in order to get rid of the clamping sleeves. As mentioned, there are a number of instances, where there is a need to be able to disassemble the wall plate and/or coupling: at repairs or an exchange of wall panels, at test- pressurization and at plugging in order to maintain the water supply system in operation during longer work periods.

By using the present invention, the assembly is very simple, since the wall plate 10 may be withdrawn over the first coupling part 22 and since the clamping sleeve thereby does not to be damaged.

Disassembly is more particularly made in such a way that the second coupling part is screwed out of the first coupling part 24 so that the pipe end 12 and the clamping sleeve (not shown) is exposed. The slotted locking ring 38 is then pryed up with example a screw driver and removed from the first coupling part 24. The first coupling part 24 is then no longer fixed to the wall plate 10 and since the hole 22 in the wall plate 10 is larger than the portions in the first coupling part 24, that the wall plate 10 must be drawn over in order to be released, the wall plate 10 may be screwed out of the wall 18 and drawn past the first coupling part 24 which is then left on the pipe 12 together with the clamping sleeve (not shown).

If the work is scheduled to stretch over a longer period of time, and one wishes to maintain the water supply system in operation during this time, a second coupling part (not shown) is screwed with a plug into the first coupling part 24. It is then simple to remove again when it is time to reassemble the system and reposition the wall plate 10.

Finally, it shall be shown how the device, by means of its design, provides a reliable leak indication. If there is a leak in the coupling or something has happened to the pipe in the wall 18, the water shall be able to exit on the front of the wall 18 so that people living in the building become aware of the fact that something is wrong. This is suitably achieved with some kind of drainage channel which extends from the back side 16 of the wall plate 10 and outwards. When designing the drainage channel one is, however, faced with the problem that-at the same time as water shall be able to find its way out of the wall plate 10-the water shall be prevented from entering inside of the wall plate 10 upon an external spraying.

The device according to the present invention solves this problem. As described above, the flange 30 is provided with at least one jolt 36, and in the example, four jolts 36 are equally distributed around the flange 30. Each jolt 36 is shaped to form a radio channel 54 together with the wall plate 10 when the flange 30 abut the wall plate 10, said

channel 54 extending along essentially the entire radio extension of the flange 30, and thus being in communication with the hole 22 of the wall plate 10. Since the hole 22 is larger than the periphery of the first coupling part 24, the water can flow through the hole 22 to the groove 32 in the first coupling part 24. Water may thus flow from the inside of the wall plate 10 through are formed between the flange 30 and the wall plate 10, and exit on the from side on the wall plate 10 in the groove 32 where the locking ring 38 is positioned. It should thus be noted that several jolts 36 on the fiange 30, in equal distribution around the same, is preferable to only one jolt, since the water will then very likely find a channel 54 regardless of how it flows.

As mentioned above, water flows to the groove 32 where the conically shaped locking ring 38 is situated. The locking ring 38 delimit a cross-sectionally substantially triangular area, see Fig. 1, which forms a radial and tangential drainage gap 56. The water then flows in the gap 56 to the slot 40, which preferably is orientated in the floor, where it, by means of the chamfers 46, is allowed to flow out on the front side 14 on the wall plate 10 where it becomes visible. This design effectively prevents water being sprayed water over the front side of the wall plate 10 from finding its way into the wall plate 10, since the slot 40 of the locking ring 38, on the convex side 44, i. e. the side facing out towards the room, is closed. Additionally, the ring 38 is tightly pre-tensioned both radially and axially, in such a way that the only place where water possibly may find its way in is in the radially directed chamfer 46 if the slot 40, in a less favourable way has been placed in a direction towards the roof. This faulty assembly may, however, be easily corrected by turning the locking ring 38, which does not cause any damage to the first coupling part 24 or the wall plate 10.

It should be noted that the invention is not limited to the shown embodiment, but that a number of variations and modifications are conceivable within the scope of the appended claims. For example, the first coupling part 24 does not have to consists of threaded nut. The important thing is that can be made to cooperate with the second coupling part (not shown), for example by means of threads, snap joints, screw joints, friction or similar. Furthermore, the first coupling 24 is not limited to a circular or substantially circular cross-section, but may as previously mentioned, alternatively have a cross-section with the shape of a rectangle square or other polygon. The same applies, as previously mentioned also to the holes 22 in the wall plate 10.

Further, the locking member 38 is not limited to being a locking ring as in the example, but may, for example, be of another type such as a threaded ring, an elastic ring of the 0-ring type or other types of members that locks the first coupling part 24 to the wall plate 10 by means of snap joints, wedge joints, cone joints or screw joints.

Also, it should be noted that the wall plate 10 is of course not limited to having a rectangular shape, but may have other shapes. Furthermore, the invention is not limited to a wall transition for two pipes, but the number of pipes may vary. In normal case, the number of pipes are 1-3, but more pipes are of course also conceivable.

LIST OF REFERENCE NUMERALS 10 wall pipe 12 pipe 14 first side of wall plate 16 second side of wall plate 18 wall 20 washer 22 hole in wall plate 24 first coupling part 26 thread 28 conical surface 30 flange 32 groove 34 tool interface 36 jolt 39 locking member 40 slot 42 concave surface/side 44 convex surface/side 46 chamfer 48 V-shape 50 protective pipe 52 protective pipe fastening sleeve 54 channel 56 drainage gap