Sectional doors, capable of being installed at an entry space to a room and used for closing industrial warehouses, civil or industrial buildings, as well as for closing loading bays for industrial of civil vehicles, are currently known.

Sectional doors essentially comprise a pair of profiles, arranged near to the frames of the entry space to the room, and a series of panels, placed on top of each other and hinged together, which laterally carry sliding rollers in vertical side guides, formed on the respective profiles, so as to guide the panels in their opening and closing movement, upwards and downwards respectively.

In particular, figure 1 shows a side section view of a preferred but not limiting example embodiment of a sectional security door, according to the prior art.

The door, generically indicated with 10, foresees a pair of profiles 11,12, positioned near to each frame 14 of an entry space to a room, a series of panels, placed on top of each other and hinged together at said entry to the room, and a lifting group for the panels, schematically indicated with 13 and preferably

positioned above the vertical structure of the door, next to the wall.

The panels of the sectional door 10 are equipped, on each side, with sliding rollers, not visible in figure 1, which engage inside vertical side rails 12, so as to allow the opening and closing movement of the door 10, thanks to the vertical movement, upwards and downwards, of the panels themselves, which can rotate horizontally under the ceiling, when there is not sufficient space for completely vertical opening.

In the case of installations like the one represented in figure 1, two springs 17 can also be foreseen, positioned close to the ends of the rails 12, which act as end stop abutments when the door 10 is opening.

The profiles 11, foreseen in a position in front of the rails 12, are used for attaching them to walls. These profiles 11, 12 can also have at least one reinforcement and protection element, which partially covers them, starting from the bottom.

The aforementioned sectional doors are intended for closing civil and industrial openings and their degree of permeability to air, i. e. the seal which the door itself realises against the perimeter of the room and between one panel and the next is usually considered to be of little importance.

Nevertheless, in some specific cases, such permeability

to air is an essential factor.

The permeability to air relationship is usually measured in m3 per m2 of surface of the door at the time, at a predetermined pressure, and there are specific European regulations which establish common criteria for the classification of permeability and indications for carrying out tests.

A low permeability to air is, for example, essential in the case of banana ripening rooms or else in dry storage.

Indeed, in the case of banana ripening, these let off a particular gas, which can artificially be released in ripening rooms, speeding up and thus controlling ripening. A low permeability to air of the sectional door is thus essential so as not to disperse the gas into the atmosphere.

Equally important is dry storage, where the warehouse foresees a dehumidifier inside of it and the sealing of the sectional door becomes essential for keeping the air inside dehumidified.

The purpose of the present invention is, therefore, that of indicating an airtight sectional door, which avoids the aforementioned drawbacks and which, in particular, constitutes an improvement to standard sectional doors due to its reduced permeability to air from the outside.

Another purpose of the present invention is that of realising an airtight sectional door which is substantially simpler and more cost-effective with respect to conventional doors.

Such purposes are accomplished by an airtight sectional door, according to claim 1, to which we refer for the sake of brevity.

Further purposes and advantages of the present invention shall become clear from the following description and from the attached drawings, provided as a non-limiting example, wherein: -figure 1 shows a side section of a sectional door of the known type ; - figure 2 is a side view of an enlarged portion of the base panel of an airtight sectional door, according to the present invention ; - figure 3 is a partial overhead view of the airtight sectional door, according to the present invention; - figure 3a is an enlargement of a side portion according to figure 3; - figure 4 is a section view made along the line IV-IV of figure 3; - figure 5 is a section view made along the line V-V of figure 3; - figure 6 is a section view made along the line VI-VI of figure 3 ;

- figure 7 is an overhead view of a panel-gasket- roller-rail-profile group, which constitutes an enlarged detail of the coupling of the panel guided by the roller in the rail 12, with the vertical gasket GUG present along all of the frame, in the room ; - figure 8 is a partial vertical section of the airtight sectional door, according to the present invention.

With particular reference to figure 8, the airtight sectional door 10 according to the invention foresees a series of panels PNL, preferably insulated, consisting of two metal sheets containing an insulating material, with its outer surface SU smooth.

The joint between the panels PNL is equipped with a gasket GU, which seals the air passage between the panels PNL, and the panels PNL are also hinged together with the hinge CE, so as to allow them to be articulated when they fold horizontally, going back inside the room and sliding up under the ceiling 16.

In particular, the base panel, indicated with PNB in figure 2, is equipped at the bottom with an elastic gasket GE, preferably made from rubber, which, thanks to the weight of the door 10, seals the space existing between the lower end of the base panel PNB and ground level GL.

As can clearly be seen from figure 7, the two vertical

sides of the door 10, which consists of the panels PNL on top of each other, press with their smooth outer face SU against an elastic gasket GUG, preferably made from rubber shaped with four lips. In preferred embodiments, the rubber of the gasket GUG is also inserted inside an aluminium profile PAL, to be applied to the wall 15 with silicon for making an airtight seal.

The profile PAL is preferably equipped with a side flap AT, which allows its attachment through screw anchors TS set back from the corner of the opening and, therefore, less subject to breaking.

In the same way, the upper panel PNL of the sectional door 10 is advantageously able to be sealed against the lintel 16. In this last case, however, the sealing gasket, indicated with GSU in the figures, is preferably equipped with three lips, with the elimination of the upper lip, with respect to that which is foreseen for the gasket GUG, given that the direction of sliding of the upper panel PNL, when closing, knocks the lip downwards and substantially increases the counterpressure and thus the flexing of the panel PNL.

The perimetric gaskets GUG, GSU, GE are preferably conceived with many sealing lips, so as to minimise the air leaks.

Moreover, there is the danger that the air slips under the first sealing lip, discharging to the outside through the gap existing between the first and second lip, making this and the subsequent ones useless.

To avoid such a risk, the gaps between the sealing lips of the gaskets GUG, GSU, GE are closed with suitable elastic means, preferably with rubber screw anchors stuck at least to the two ends of the profile, but preferably also in-between the two ends.

The pressure of the sectional door 10 against the side gasket GUG and against the upper gasket GSU takes place in about the last 30-50 cm of the closing stroke of the door 10, with an advance of all of the door 10 in parallel towards the perimetric gasket, so that the guides of the rails 12, which contain the sliding rollers RU and side support for the panels PNL, are tilted with respect to the wall 15 of the room which must be closed, whereas the small wheels RU for supporting the panels PNL are adjusted with different lengths along the support brackets STA, which compensate the different distance between the wall 15 and the various positions of the small wheels RU.

The most critical zone for the airtight seal consists of the contact of the upper panel PNL against the entire horizontal gasket GSU arranged on the lintel 16 (regarding which see figures 3-6).

The difficulty derives from the counterpressure generated laterally by the thrust of the panels PNL against the side and horizontal gaskets GUG, GSU, which derives from the tilting of the rails 12, with respect to the vertical direction of the wall 15. In fact, the aforementioned counterpressure ensures that the panel PNL flexes towards the side opposite the wall 15.

In order to solve such a problem, it is not sufficient to foresee a simple reinforcement for the panel PNL, because in any case the structure made up of panel plus reinforcement has a displacement, which varies according to the length of the panel PNL.

It is thus necessary to foresee a proper adjustment system, which allows an opposite and measured flexing of the panel PNL towards the horizontal gasket GSU to be obtained, so as to achieve a correct situation of compromise at the time of the thrust of the upper panel PNL against the horizontal gasket GSU and to thus have the contact and seal on the whole length of the panel PNL.

To take care of such a need, a sectional door 10 is used constructed according to that which is illustrated in figures 3 to 6.

The panel PNL, as stated previously, preferably consists of a sandwich panel, with two outer thin metal sheets having insulating material inside, which is

well-known to be compressible.

To avoid, when fixing a profile PU (fig. 5) inside the panel PNL, preferably U-shaped, the heads of the screws VIT from being able to penetrate into the insulating panel PNL when they are tight, a profile PCH is preferably applied, which is better if it is rigidified in length by one or more folds, which can also constitute closing and upper finishing elements of the panel PNL.

The profile PU is fixed, for a portion of the panel PNL, with at least two through screws VIT, which simultaneously also attach the profiles PCH.

In the U-shaped seat of the profile PU a further profile BA is inserted, which can have a dimension perpendicular to the panel PNL having a length measurement proportional to the length of the panel PNL (usually greater).

The profile BA is preferably fixed to the profile PU by means of the two bolts BU passing through the two flaps of the profile PU and through the profile BA already placed inside the profile PU. The bolts BU are coplanar to the face of the panel PNL and are placed at the two ends of the profile PU, so as to allow a thrust between the profile BA and the profile PU without lateral displacement.

The profile BA is also equipped with one or more screws

VSP for thrusting the profile PU, preferably arranged in a position perpendicular to the face of the panel PNL and pressing on the inside of the profile PU (see fig. 4).

The screws VSP are preferably of the type with an Allen key head so as to be able to also make it stay inside a through hole made on the side in view of the profile BA, a hole which can be tapped on the other side of the profile BA, or rather it can be a through-hole and can have a self-blocking nut DA placed outside of said last hole. When the profile BA is mounted inside the profile PU with the bolts BU, by screwing in the screws VSP the desired effect is achieved of being able to adjust the pressure of the profile BA against the profile PU until the panel PNL is cambered to counter its flexing and thus to obtain the adherence of all of the upper panel PNL against the horizontal gasket GSU.

Generally, the small sliding wheels RU in the opening of known sectional doors are applied laterally to the panel PNL and are connected to these with adjustable brackets STA, which are normally fixed with simple self-threading screws to the side portion of the panel PNL of the sectional door 10, so as to be able to fix the small wheels RU more or less far with respect to the panel PNL.

The upper small wheels RU must press the upper panel

PNL to a substantial degree so as to be able to squash it against the horizontal gasket GSU on the whole length of the lintel 16.

It derives from this that the attachment of the small wheel-carrying bracket with simple self-threading screws is not sufficient, both because the torsion generated by the lateral thrust of the small wheels RU tends to pull out the screws arranged furthest inside the panel PNL, and because, in any case, the same screws, even if reinforced, generate a flexing of the upper panel PNL due to the contrast between the pressing of the small wheels RU and the counterpressing of the side or vertical gaskets GUG arranged furthest inside the small wheels RU.

To avoid this serious drawback, instead of applying the usual small wheels RU to the sides of the upper panel PNL, two small wheel-carrying brackets ST, are fixed to the profile BA, arranged at the two ends, as illustrated in figures 3 and 3a.

The application of the small wheels RU to these two brackets ST, with the known adjustable small wheel- carrier, in practice allows a profile BA to be obtained which slides with the side small wheels RU inside the guide rails 12, whereas the upper panel PNL is connected to the profile BA through the profile PU and the two bolts BU. From this there is a neutralisation

of almost all of the torsional thrusts applied to the panel PNL and, moreover, the possibility of obtaining an adjustable cambering of the upper panel PNL, thanks to the perfect adherence of the horizontal gasket GSU at the lintel 16.

In an advantageous and exemplifying, but not limiting embodiment of the invention, the lifting group 13 of the sectional door 10 essentially consists of a hydraulic cylinder actuating a plurality of fixed and/or mobile lifting and return pulleys.

The fixed lifting pulleys are rotatably mounted on a suitable pin, whereas a stem of the hydraulic cylinder has a further pin, on which the mobile lifting pulleys and devices for attaching ad adjusting the lifting cables are mounted. The hydraulic lifting group can be arranged immediately above the sectional door 10, at the lintel of the room, that is at the end of the profiles 11 and the rails 12, whether they are curved horizontally, as shown in figure 1, or they have a lesser inclination on the vertical, or if they are completely vertical.

From this derives the obvious advantage of being able to install sectional doors according to the invention with whatever height of the ceiling 16, without taking away useful space.

The extension of the stem of the hydraulic cylinder

caused by the introduction of pressurised oil, actuating the tackle system consisting of lifting cables and pulleys in a completely symmetrical manner, takes care of lifting the door 10 perfectly parallel.

Finally, in the case of a lack of electrical energy, the electric motor of the electrohydraulic power unit can be actuated through a simple and effective emergency device, arranging a connection seat for a drill of the type powered by compressed air, batteries or electricity, at the end of the axis of the electric motor opposite the side connected to the hydraulic pump.

In such a way, the drill is able to make the motor rotate, thus actuating the mechanism of the power unit.

The connection seat can, as an example, be a cut or protruding hexagon, realised directly on the axis.

Alternatively, it is possible to realise a tapping on the axis, on which to screw a screw, the head of which creates the connection with the drill.

From the description which has been made the characteristics of the airtight sectional door, object of the present invention, are clear, just as the advantages are also clear.

It is clear, however, that numerous other variants can be brought to the sectional door in question, without for this reason departing from the novelty principles

inherent to the inventive idea, just as it is clear that, in the practical embodiment of the invention, the materials, the shapes and the sizes of the illustrated details can be whatever according to the requirements and they can be replaced by others which are technically equivalent.