FIELD OF THE INVENTION AND PRIOR ART

The present invention relates to a device according to the preamble of the appended claim 1.

Such devices may be used in all conceivable arrangements, in which there is a desire to achieve a lead-through sealed with re¬ spect to an outer impermeable wall layer through an insulating wall for connection of air conducting members to the room inside the wall. Devices which are used for achieving an air intake and/or air outlet of so called insulated fans will be described so as to illus¬ trate the invention, but this is not at all to be interpreted as any re¬ striction of the field of use of the invention. These so called insu¬ lated fans are formed by a fan, which is surrounded by a house having a wall of the type meantioned above for obtaining an insulat¬ ing for primarily fire and noise reason, but also against condensa¬ tion. Such insulated fans are in some situations an obligation, for instance when air is transported from a plurality of apartments in a building. It is then usually a question of so called channel fans, i.e. fans being arranged in long air channels, where it is difficult to oth¬ erwise obtain a satisfying air flow.

The walls of the insulated fan houses have a considerable thick¬ ness for making it possible for the insulating layer to well fulfil its function, and it is absolutely necessary that sealed lead-throughs are created at the inlet into and the outlet from the impermeable house wall layer through the wall of the fan house and so that means are provided externally of the fan house for a tight external connection of air conducting members such as an air conducting channel to the house.

A device already known for achieving such a lead-through has a first tube having a circular cross-section, which is arranged outside the house for providing said connection means and has been pro¬ vided with a flange folded radially outwardly, which has been led inside the impermeable house-wall layer, between this and the in¬ sulating layer, and which has through a surrounding point-welding in this way been secured to the house wall layer. The outer part of the lead-through has been formed in this way and the tightness with respect to the impermeable house wall layer has been established. Furthermore, this device already known comprises a second tube having a circular cross-section, which is arranged to extend from the interior of the house through an opening in the insulating layer and the outer house wall layer and a distance into the first tube. The second tube may then be internally secured to said first tube.

Although this device already known functions well, the present in¬ ventor has understood that it should be possible to save costs by modifying this construction and accordingly that the construction of this device already known would be too labour and material de- manding and the device will by that be unnecessarily expensive to produce.

Another device already known for achieving a lead-through of the type discussed here has besides a very complicated and by that labour and material demanding construction also turned out to have a defective function, since it does not enable any sound insulating. This has been the case in known so called insulated fans having a lead-through with a rectangular cross-section for connection of air conducting channels having a rectangular cross-section to the fan. These insulated fans have been constructed by an inner metal case being opened at the opposite ends, in which a fan is arranged, and an outer metal casing, which has walls with an outer imperme¬ able metal wall layer and an insulating layer located inside thereof. This outer casing, which is delimited by walls coated by metal and through which the one open end of the inner metal casing is in¬ tended to project so as to form the lead-through and through the

ends thereof provide means for an external connection of an air conducting channel thereto. Thus, the fan is here in practise lo¬ cated in an air conducting channel, which is surrounded by double houses with an insulation therebetween, so that no real sound insu¬ lating is achieved. Furthermore, this device requires unnecessarily much material as a consequence of the arrangement of double houses and therefore become unnecessarily expensive.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a device of the type defined in the introduction, which primarily may be produced in big series to a lower cost than the known devices described.

This object is according to the invention obtained by arranging the tube in a device of the type defined in the introduction to project freely outside the house wall and provide said means for external connection and create a surrounding sealing of the tube with re¬ spect to the outer impermeable house wall layer. Thus, a single tube is in this way utilised instead of two or instead of an inner house for creating the lead-through having the features desired, which primarily in big series means a considerable saving of money with respect to the devices of this type already known. Accordingly, one single tube forms both a short lead-through channel through the insulation and by the projection in the wall the means for exter¬ nal connection of an air conducting member - at the same time as a sealing is established between the impermeable house wall layer and the tube.

According to an advantageous embodiment of the invention said ceiling means comprises a collar formed by the impermeable wall layer, folded outwardly from the rest thereof and surrounding said opening, which collar is adapted to externally bear against portions of the tube for sealing with respect thereto. By the creation of such a collar by the wall layer already there a sealing may in a simple

way be established between the wall layer and the tube penetrating through the opening from the room inside the wall.

According to a still further advantageous embodiment of the inven- tion said tube portions define a part of the extension of the tube having a larger cross-section than the part of the tube arranged to project to the exterior past the collar, and the collar has an inside cross-section substantially corresponding to said larger outside cross-section of the tube. The tube may by that on the application thereof comfortably be pushed from the interior through the opening with the outer portion freely passing said collar, at the same time as the collar still may be used for achieving an adequate sealing with respect to the tube portions having the larger cross-section.

According to an other advantageous embodiment of the invention the tube is adapted to be mounted in said opening by being pushed therethrough from the interior of the house, the collar is provided with stop members adapted to allow the passage of said tube part on such pushing through and be hit by said tube portions or tube regions adjacent therethrough for forming obstacles against further pushing through of the tube, and the collar is at a free extremity thereof folded inwardly so as to form said stop members and give them a lip-like character. Thanks to this construction of the collar it will be possible to by simple means define the position of the tube when it is pushed through the wall and also obtain a sealing of the outer wall layer with respect to the tube also in the axial direction.

According to still another advantageous embodiment of the inven¬ tion the opening of the wall and the tube have substantially rectan- gular cross-sections, that part of the longitudinal extension of the tube which is arranged to extend through the wall has a first outside cross-section substantially corresponding to the cross-section of the wall opening, and the collar is arranged to be folded so that the inside cross-section delimited thereby along the extension of the collar from the wall substantially corresponds to a second outside cross-section of that part of the longitudinal extension of the tube

which is adapted to project out of the wall. In this way it is possible at a given cross-section of the opening of the wall enable a con¬ nection of air conducting members having different cross-section dimensions to the connection means of the tube since the part of the tube projecting out of the wall may be designed in such a way that it is terminated by a desired cross-section and still a good sealing with respect to the outer wall layer is ensured by an adap¬ tion of the folding of the collar to the extension of the tube.

Further advantages as well as advantageous characteristics of the invention will appear from the following description and the other dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the appended drawings, below follows a descrip¬ tion of two devices according to two preferred embodiments of the invention cited as examples.

In the drawings:

Fig. 1 is a partially sectioned lateral view of a fan having an insu¬ lated fan house, in which two devices according to a first embodiment of the invention are applied for the inlet and the outlet, respectively,

Fig. 2 is an enlarged view of one of the inventional devices shown in Fig. 1 ,

Fig. 3 is a sectioned view enlarged with respect to Fig. 2 of a part of the device according to the invention,

Fig. 4 is a perspective view of the device according to a second preferred embodiment of the invention, which is arranged in connection with a house for an insulated fan, some parts of the house having been broken away and the insulating

layer of the wall having been omitted for the sake of clear¬ ness,

Fig. 5 is a partially sectioned view of the device according to Fig. 4 from above, some parts being broken away for better il¬ lustrating the construction of the device, and

Fig. 6 and 7 are two enlarged detail views illustrating alternative embodiments of the tube of the embodiment of the inven- tion illustrated in Fig. 4 and 5.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

An example of an insulated fan, to which the device according to the invention has been applied, is illustrated in Fig. 1. Such an in¬ sulated fan has a house 1 , in the interior of which a fan member 2, here a radial fan, is arranged in the form of an impeller or fan wheel 4 rotatable through a motor 3. The impeller 4 is surrounded by an inner fan house 5 for conducting air to the inside from the right in Fig. 1 from below to the impeller 4 and conducting air to the outside to the left in Fig. 1 on the level of the impeller. The components 2-5 are surrounded by a thick house wall 6, which is formed by an in¬ ner, comparatively thick layer 7 of insulating material and an exter- nal impermeable layer 8 located outside thereof. The insulating layer 7 is made of a material most suitable for the intended use of the fan, so as to for example be most suited for silencing of noise and fire protection. The outer layer 8 is made of a rigid material, usually galvanised metal sheet. Typical thickness of the insulating layer 7 and the outer layer 8 is 50 mm and 0,7 mm, respectively, but any arbitrary thicknesses are of course conceivable. The house wall 6 is arranged to form a completely air-tight surrounding of the very fan, apart from the openings 9 for the air intake and the air ex¬ haust through the outer impermeable house wall layer 8. The house wall 6 also comprises a lid 10 air-tightly connectable to the rest of

the house wall 6 and removable for offering access to the interior of the house for repair and maintenance purposes.

A fan with such a house is used on such places or under such op- eration conditions that require protection against for example con¬ densation, fire and noise. When the fan is arranged for example close to a work place in a room, it may be a great need to apply sound insulation thereon by providing it with a suitable insulating layer 7. When the fan is arranged in a cold environment, where for example an outdoor temperature prevails and it conveys warmer air, it is important to protect it by such an insulating layer against condensation, which would seriously disturb the function of the fan and reduce the capacity thereof. The fire protection aspect has al¬ ready been penetrated.

Furthermore, means 11 in the form of conventional tube sockets are arranged for tight external connection of the interior of the house to air conducting members, such as ventilating pipes. It is extremely important that these connection means 11 are applied while forming a tight connection to the outer impermeable house wall layer 8, so that air may only pass from the inside of the house and outwardly or in the opposite direction through the respective tube 12, which provides the connection means 1 1.

The construction of the device according to the invention for achieving such a lead-through is illustrated in Fig. 2 and will now be explained with reference made also to Fig. 1 and 3. The device has one single tube 12, which is adapted to be mounted in the opening 9 in the insulating layer 7 and the impermeable wall layer 8 by being pushed through the opening from the interior of the house. The tube 12 has a length exceeding the thickness of the house wall, so that the tube 12, when it has been pushed through the opening 9 so far that it will bear against the inner side of the wall through a rear flange 13, projects sufficiently far out of the house for forming a tube socket for a tight connection of an air con¬ ducting member thereto. The tube length exceeding the thickness

of the house wall by 40 mm may be suitable when the wall thick¬ ness is 50 mm and the tube diameter is 125 mm, but this dimension information is only given by way of an example.

The outer impermeable house wall layer 8 is in the region of the opening 9 folded outwardly through a suitable shaping method for forming a collar 14 surrounding said opening. This collar 14 is at its free extremity folded inwardly while forming a surrounding lip 15.

The tube 12 has tube portions 16 extending over a part of the ex¬ tension of the tube and having a larger outside diameter than that part 17 which is arranged to project towards the exterior past the collar 14. The collar 14 has in its turn an inside diameter substan¬ tially corresponding to said larger outside diameter of the tube, so that the tube 12 may be pushed from the inside through the opening 9 while letting the tube part 17 go free from the lip 15 of the collar to the position shown in Fig. 2 and 3, i.e. until the front edge of the tube portions 16 hits the lip 15 of the collar. Thus, the lip 15 func¬ tions as a position defining stop member and the tube 15 is in this position secured to the collar 14 and by that to the house wall layer 8 surroundingly, for instance by point-welding or by accommodating deformation of tube portion regions in the edge region and/or con¬ versely according to for example the so called Tog-L-Loc®-method. The lip 15 is also designed to form an axial sealing between the collar 14 and the tube 12 by bearing against the surfaces 18 of the tube adjacent to the tube portions and extending transversally to the axis of the tube. Although it is indicated in the figures for the sake of illustration that it would be a distance between the lip 15 and the surfaces 18, but this is in practise not the case. The same is valid for the distances indicated between the tube portions 16 and the collar 14. The tight fixation of the tube portions 16 with re¬ spect to the collar 14 has neither been shown in the figures. Fur¬ thermore, it appears from Fig. 3 that the tube portions 16 have a larger outside diameter than the following tube part 22 extending through the opening but substantially the same diameter as the opening 9.

Furthermore, the free extremity of the tube 12 is in a conventional way provided with a surrounding slot 20 receiving a conventional rubber seal ring 19 for enabling an air tight connection of an air conducting tube to the tube 12 through pushing thereof on the out¬ side of the tube and over a climbing chamfering 21 terminating the tube.

Accordingly, the device according to the invention achieves a lead- through form the interior of the fan house through the insulation and out to the exterior while providing connection means for external air conducting members and sealing against the outer impermeable house wall layer 8 by means of one single tube 12. This fact in combination with the simplicity through which the tube may be ap- plied in the opening 9 lead to a remarkable saving of costs with re¬ spect to the prior art devices of this type in a production in large series.

A device according to a second embodiment of the invention is il- lustrated in Fig. 4, said device differing from the first by the fact that the opening 9 has a rectangular cross-section and by that also the tube 23 led through the opening and out of the house 1 has a rectangular cross-section for connection of the interior of the insu¬ lated house to an air channel having a rectangular cross-section. The construction of this device will now be explained with refer¬ ences to both Fig. 4 and 5. This tube 23 is arranged to be pushed from the outside through the opening 9 and has at the innermost end means 24 for receiving an edge of a sheet secured to the fan arranged in the house.

The tube 23 has a first part 25, which is arranged to extend through the wall and has a first outside cross-section, which substantially corresponds to the cross-section of the wall opening 9. Further¬ more, the tube has a second part 26, which projects outside the wall. The two opposite walls 27 of the second part 26 are folded outwardly with respect to the corresponding walls of the first part

25, so that the cross-section of the second part 26 increases in the direction towards the extremity thereof. The size of the opening 9 is determined by the size of the house and the fan arranged therein, so that in this way a connection of an air channel having a larger cross-section than the opening 9 to the interior of the house may be obtained.

The outer impermeable house wall layer 8 is in the region of the opening 9 folded outwardly by suitable shaping for forming a collar 14 surrounding said opening, said collar being folded so as to fol¬ low the extension of the second part 26 of the tube and bear exter¬ nally thereagainst. Cut-outs 28, here making an angle of 45° with the fold line, have been made in said collar so as to enable this adaption. The collar 14 is in a similar way as the collar in the first embodiment sealingly secured to the tube 23.

The tube 23 is terminated in a conventional way by portions 29 and 30 folded outwardly and rearwardly, respectively, said portions 29 folded outwardly providing surfaces bearing against corresponding surfaces of an air conducting member on connection thereof to the tube. The portions 30 folded rearwardly are arranged to enable se¬ curing of an air conducting channel to the tube 23 by in conven¬ tional way laterally displacing C-profiles over these portions 30 and corresponding portions of the air conducting channel pointing in the opposite direction. Furthermore pieces 31 are arranged at each corner of the extremity of the tube 23 for enabling securing of an air conducting channel in a conventional way through a screw joint or the like. The device according to the invention may by this be se¬ cured to either an air conducting channel having portions folded rearwardly corresponding to the portions 30 or an air conducting member having securing means fitting to the holes in the pieces 31 without any modifications.

It is shown in Fig. 6 and 7 how the second part 26 and by that the collar 14 may be differently directed so as to enable connection of the interior of a house having an opening of a determined dimen-

sion to external air conducting members, such as air conducting channels, having different cross-sections. There are different stan¬ dards for air conducting channels, and thanks to the possibility to fold the collar 14 in different directions one and the same house may be adapted to different tubes and by that air conducting chan¬ nels according to different standards.

The invention is of course not restricted to the advantageous em¬ bodiments described above, but several possibilities to modifica- tions thereof would be apparent to a man with skills in the art with¬ out departing from the basic idea of the invention.

The proportions of the different parts of the tube, the thickness of the insulating wall, the length of the collar and so on with respect to each other may be totally different than what has been illustrated above.

When it is mentioned that the lip of the collar bears against sur¬ faces of the tube extending transversally to the axis of the tube or that an axial sealing is formed thereby, it should also be comprised that said surfaces have a perpendicular having a component in the radial direction and the sealing takes place in a direction being oblique with respect to the axis of the tube.

The wall may have more than two layers.

The definition air conducting members is intended to comprise every object conducting air by letting air flow therethrough - also without conducting the air in the meaning that the air is directed thereby. Thin filter elements are for instance comprised.