In the wood-processing field there is a known need for the actual wood to undergo various types of treatment such as steaming and drying.

In particular the drying treatment is carried out to evaporate away the water and liquid resins contained in the wood. In order to improve certain features this treatment is performed by specific plants called dryers, where the material undergoing the treatment is placed.

Inside the dryer, suitable devices control the temperature and humidity of the internal air and allow to control the airflow by means of aeration ducts fitted with special fans.

The hot air, as it comes into contact with the surface of the wood being treated, removes the humidity contained in the wood.

It is fundamentally important that this kind of plant has an environment that is completely isolated from the outside atmosphere and controlled.

For this reason the dryers have been produced with panels of insulating material having one or both of its outside surfaces made of aluminium.

In some types of dryers the edges of these panels are shaped so that male to female type couplings are created.

The dryer is produced by slotting together a series of panels that in turn are mounted, usually by screws, onto a loadbearing frame prepared earlier.

Each panel is filled with insulating material, suited to guarantee the necessary heat insulation.

What's more, suitable silicon mastic is then applied to the panel's joints to guarantee the necessary hermetic seal within the construction.

According to another form of execution, first sheets are set along the inside walls of the dryer, usually made of an aluminium alloy, and screwed to the loadbearing frame.

Sheets of heat insulating material are then applied, firmly attached to the construction by suitable anchoring systems.

Finally, second sheets are applied to the outside walls of the dryer, which are also usually made of an aluminium alloy. Common screws fasten these sheets to the dryer's loadbearing frame to protect the insulation panels from being

damaged by the humidity inside the actual dryer.

An initial inconvenience in the productions described above is that the load of the whole construction rests entirely on the dryer's loadbearing frame. This makes the loadbearing frame a very expensive part of the whole plant.

There is an additional disadvantage of known productions, because of the difficulty and the cost of installing the insulation panels. In effect, each panel has to be fastened to the loadbearing frame by many screws, creating the need for several workers.

Similar considerations affect the application of the sheets to the inside walls of the dryer.

It should also be noted that the installation, of both panels and sheets, requires specialist technicians to carry out the alignments that are necessary at this stage. This makes the installation work on the dryer particularly costly, which has a strong influence on the overall cost of the plant.

Another inconvenience is caused by the poor reliability of a hermetic seal provided by the silicon products.

The scope of this invention is to overcome the inconveniences found in known systems.

More specifically, the scope of this invention is to produce a modular structural member, suitable for producing dryers.

Another scope is to produce a structural member that simplifies the assembly and installation work, so that it can also become accessible to unqualified workers.

Another scope of this invention is to produce a dryer that has a simpler, lightweight loadbearing frame than constructions made up until now by endeavouring to transfer part of the load onto the panel.

An additional scope is to produce a structural member that guarantees the hermetic seal in the joints between one component and another.

Last but not least a scope is to produce a structural member that enables the design of a standard, easy to assemble dryer.

A further scope is to produce a structural member that allows to significantly reduce or even practically eliminate the quantity of screws used to fasten the actual components to the loadbearing frame, so that assembly operations are quicker and thereby less costly.

Said scopes are achieved by a self-supporting structural member suited to

produce modular constructions that in accordance with the main claim includes a skeleton made up of one or more frames where each side of said frames is made up of section elements, said skeleton being suited to receive one or more panels, characterised in that each of said section element in correspondence of the outside surface and of the surface of said skeleton, has one or more cavities suited to receive one or more snap-lock fixing strips between said structural member and the one closed to it.

An advantage of the structural member invention is that it allows to produce self-supporting constructions in a quick and simple manner, without the need for screws or anything else by simply coupling one component to another.

Another advantage of the invention is that it provides the opportunity to produce standard constructions, easy to build and in such a way that they can be built by unqualified workers.

Another advantage is that, since the structural member is self-supporting, this enables the whole loadbearing frame of the dryer to be made much lighter in weight, without loosing in its overall stability and rigidity.

Said scopes and advantages shall be better illustrated during the description of a preferred form of execution of the invention, given as a guideline but not a limitation, illustrated in the attached diagrams where: -fig. 1 illustrates an isometric view of the structural member invention; -fig. 2 illustrates a cross-section of the assembly stage of the structural member in fig. 1; -fig. 3 illustrates an isometric view of the assembly and coupling together of two structural members in fig. 1; -fig. 4 illustrates a cross-section of two structural members in fig. 1 facing each other and coupled together; -fig. 5 illustrates a cross-section of a detail of two coupled structural members in fig. 1; -fig. 6 illustrates an isometric view of the two coupled structural members in fig. 4; -fig.'s 7 to 8 illustrate the cross-section of parts of the structural member in fig.

1; -fig.'s 9 to 10 illustrate variants to the structural member in fig. 1.

The self-supporting structural member invention is illustrated generally in fig. 1 where it is indicated by 1.

It includes a skeleton made up of two identical frames 2, which has a section element 3 on each side having a basically L-shaped outside face. The two frames 2 are facing each other and spaced so that they can receive an insulation panel 28.

As seen in fig. 7, the outer face of each section element 3 and flush with the surface of the skeleton, there is a cavity 6 with a no linear inside section, which runs along the whole length of the section element 3 and is suited to receive one or more snap-lock fixing strips 7 that will be described later.

What's more the section element 3 has a first elastic coupling element 8, creating a relevant first cavity 9 suited to receive an infill sheet made of aluminium 10 and a locking element 15 for said sheet 10.

Each elastic coupling element 8 has two opposing faces 11 and 12, where the first face 11 has serrated teeth 13, and the second is provided with an intrinsic elasticity to press sheet 10 onto the serrated grip 13 by means of the locking element 15.

In more detail, in the preferred form of execution, the locking elements 15 consist of a strip having a circular section.

According to the example being described, the structural member is made with a double frame 2 of section elements 3 facing each other and spaced by means of at least one spacer strip 17 held in a second cavity 18, created by a second elastic coupling element 19 set at approximately 90° to the other coupling element 8.

The second elastic coupling element 19 consists of two opposing faces 20 and 21 having serrated teeth 23, where at least one, in this case 21 is provided with an intrinsic elasticity, so that the spacer 17 is pressed against the serrated teeth 23.

In the preferred form of execution being described the spacer strip 17 consists of a sheet of heat insulating material such as, for instance polypropylene thereby creating a thermal cut between the two complementary sections 3.

It should also be noted that each section element 3 that makes up one side of the skeleton of the structural member 1 has a seat 25 around its outside perimeter suited to receive a sealing element that, in the preferred form of execution described, consists of a silicon gasket 27.

Fig. 2 illustrates the assembly stage of the structural member invention 1.

The structural member invention 1 is assembled by beginning to put together

one side of each frame 2 starting from joining a section element 3, whose ends are cut at a 45° angle, with one side of the aluminium sheet 10. Said sheet 10, sliding in the direction 14, slips into the cavity 9 of the section element 3 and is anchored in said cavity by means of the locking element 15.

The three remaining sides of the frame are assembled in a similar way to then be respectively connected to sections 3 so they form two rectangles set on opposite sides of the insulation panel 28 made, for instance, of polyurethane and/or mineral wool, prepared earlier by spreading it with adhesive so that it becomes solidly attached to the skeleton.

After this the two rectangles are brought together, keeping the insulation panel 28 positioned between them, so that is finally enclosed, until the four spacer strips 17 have been firmly inserted into their corresponding seats 18 of each section element 3.

The assembly is completed by pressing each silicon gasket into its relevant slot 25 provided, as explained earlier, in each section element 3.

It has to be noted that, in another form of execution of the invention the section element that makes up the sole frame of the skeleton, instead of being L- shaped is given a U-shaped section where the opposing sides are shaped like the members 3 with the exception of the second coupling element 19 that becomes superfluous since the spacer strip 17 in this case is an integral part of the section as seen in fig. 11. For the rest nothing changes regarding fixing the internal insulation panel 28 or outside sheets 10, nor does anything change for the coupling system between adjacent structural members.

Fig. 8 shows a cross-section of the fixing device 7 that connects two adjacent structural members together. Said element is constructed with a flat component having its ends 24 bent inwards each forming an open circle thereby maintaining a certain elasticity, necessary to achieve the snap-lock fixing strip. The free end of each circle 24 has a lip 241 bent outwards from the circle so that it meets with the edge 61 of the irregularly formed cavity 6.

The snap-lock fixing strips 7 are inserted in their respective cavities 6 provided in each section element 3, allowing the structural member 1 to be coupled to another adjacent structural member in a quick and simple manner.

Guaranteeing the mechanical continuity of the construction that has been created.

Fig. 3 illustrates an isometric view of the coupling together of two structural

members 100 and 200, while figures 4 to 6 illustrate a cross-section, a detail and an isometric view respectively, of the two structural members 100 and 200 already joined together.

Said figures also show another section element 90, having a purely decorative function, that is pressed onto the fixing device 7.

Fig. 5 also gives an excellent view of how the silicon gasket 27 is positioned when the coupling is completed, which, as mentioned earlier, guarantees the hermetic seal of the joint.

A variant in execution of the structural member 1 described until now, is illustrated in fig. 9. In this case, as can be seen, the member, generally indicated by 30, developed mainly in a longitudinal direction and consists of two sections 300 facing each other and spaced by the spacer strip 317, having the insulation panel 328 and the seats 306 to receive the fixing device 307.

In this second execution the structural member has slots 308 running parallel to the seats 306, suited to receive fixing devices such as self-tapping screws or similar.

This is so that said structural member 30 can be used as a skeleton to make an opening in the dryer, such as a door or window.

Fig. 10 also shows how the section illustrated in fig. 9 can be coupled to the structural member in fig. 1 thereby connecting it to the construction already created by a series of structural members of the type in fig. 1 when coupled together.

An advantage of the structural member 1, even in combination with the member 30, allows to produce modular constructions by simply putting together and coupling similar structural members.

The mechanical rigidity of the skeleton 2 is guaranteed by the actual rigidity of the section elements that make up the skeleton. This allows to lighten the weight of loadbearing frames to which these panels are anchored by means of suitable sections.

As an advantage the finding therefore enables the scopes set to be achieved.

It is, in fact, easy to understand how extremely easy it is to join two structural members, joined with considerable speed by merely fitting snap-lock fixing strips of the type indicated by 7.