Abstract:
The invention relates to a guard for the upper part of a door ( 2 ) of an aircraft, consisting of: a composite comprising a composite and/or stainless steel strip ( 14 ) which forms the core of the guard ( 1 ) and which renders same flexible and resistant, a silicon which is optionally reinforced with fibres and a polyester.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to an improvement to the doors of aircraft cabins. 
     2. Description of the Related Art 
     These cabin doors in general have a complex closing/opening movement that combines a vertical shift and a drawing-together movement, which has had the result that a flexible, inserted part, which is called a guard, is frequently located on the outside of the door. This part is shaped so as to come into contact with the cabin of the airplane slightly before the closing of the door and so as to bend elastically during the closing. 
     While being flexible, this guard should be rigid enough not to separate from the wall of the cabin at high speed, under the effect of aspiration of the boundary layer. 
     For these various reasons, the guards that are currently used consist of an aluminum strip. 
     The results that are obtained by these guards that are made of an aluminum strip, however, are not entirely satisfactory. 
     Actually, these guards exhibit the drawbacks below: 
     First, it has been proven that at the end of about 5,000 maneuvers of the door, or about 3 years, the guard loses its qualities of elastic resistance and detaches from the cabin during flight. 
     In addition, these guards are not thick enough to make it possible to house means there that make it possible to detach them easily. 
     In the French Patent 2,789,144 of Feb. 3, 1999, an elastomer seal, inside which a rigid or elastic reinforcing structure is placed, was described. 
     Such an arrangement is powerless to provide a solution to the problem that is posed by the sealing of the doors of aircraft cabins. 
     The seal according to said Patent FR 2,789,144 is designed for a stationary panel that rests on the structure of the aircraft via said seal: such a support is static, whereas the guard according to the invention is designed to be maneuvered thousands of times during which the guard will slide against the structure. 
     In contrast, the support of the seal of the Patent FR 2,789,144 is linear, whereas it is necessary that the support of the guard of a door be along a surface. 
     SUMMARY OF THE INVENTION 
     The object of this invention is a guard that does not have any of these drawbacks. 
     The guard according to this invention is of the type that comprises a rigid attachment stub, attached to the door of the aircraft and a flexible flap, integral with the stub, characterized by the fact that it consists of a composite that comprises a composite strip and/or a stainless steel strip—a silicone that optionally is reinforced by fibers and polyester. 
     The invention also comprises the following characteristics:
         a) For the guard, the composite strip and/or stainless steel strip comprises a core that is both flexible and resistant and that is immersed in the silicone mass;   b) The attachment stub and the flap are connected to one another by a double-curved connection zone that facilitates the elastic movement of the flap;   c) The outside face of the guard is treated mechanically, so as to allow the placing of a primary coating on which it will be possible to apply paint;   d) The lower face of the guard is covered by a synthetic material that has a good coefficient of friction and anti-icing characteristics;   e) The stub comprises, in cross-section, at least two inserts, immersed in the silicone mass, allowing the fitting of the stub on the door.       

    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       By way of example and to facilitate the comprehension of the invention, in the accompanying drawings: 
         FIG. 1  shows a perspective view of the upper portion of an aircraft door that is equipped with the guard according to the invention. 
         FIG. 2  shows a view of said guard in cross-section along A-A of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows the upper portion of an aircraft door  2 , equipped in its upper portion with a flexible guard, indicated by the general reference  1 . 
     It is seen that this guard  1  is attached not only to the upper flange of the door  2  but projects slightly beyond each side. 
     In  FIG. 2 , it is seen that the guard  1  consists of an attachment stub  10 , a flexible flap  11 , and a portion  12  that ensures the connection between the stub  10  and the flap  11 . 
     The guard  1  consists of a composite strip and/or a stainless steel sheet strip  14  with a thickness of between 0.15 and 0.75 mm, which is immersed in a mass  13  of flexible material, for example silicone. 
     So that the guard  1  suitably fulfills its role, it is necessary that:
         it be attached in a rigid, but detachable, manner to the door  2  of the aircraft, which is the role of the attachment stub  10 ;   the portion that comes to rest against the cabin be relatively flexible so as not to rub too strongly against the wall of the cabin, while not deforming too much so as to remain well applied against the cabin during the flight, which is the role of the flap  11 ;   the two portions  10  and  11  be articulated elastically with one another, which is the role of the connection portion  12 .       

     At least two inserts  15 , which rest on the strip  14 , are located along the line of section A-A of  FIG. 1  in the stub  10 . There is thus a plurality of inserts  15  over the entire length of the stub  10 . 
     Thanks to this arrangement, the guard  1  can be attached to the door  2  by means of a screw  16  and is therefore easily detachable, which is not the case with the current guards that are riveted. 
     The flap  11  is covered at its end  11   a  and its lower face  11   b  by a layer  17  that should have both a good coefficient of friction for not scratching the wall of the cabin and anti-icing qualities for not bonding to the wall of the cabin in case of icing-up temperatures. 
     According to a non-limiting embodiment, the layer  17  can be made of glass fiber material. 
     The connection portion  12  should allow the flap  11  to move according to arrow F, while exerting a compression spring function keeping said flap  11  at rest against the wall of the cabin. 
     For this purpose, the strip  14 , which constitutes the core of the guard, comprises a double curvature, a first curvature of an angle A upward, followed by a second curvature, so that the strip  14  forms an angle B downward in portion  11 . This second curvature forms an angle A+B. 
     The angle A is preferably on the order of 15° to 20°, and the angle B is on the order of 25° to 30°, such that the second curvature of the strip  14  in the connection portion  12  is on the order of 40° to 50°. 
     To facilitate the bending of the flap  11  relative to the stub  10 , the elastic material mass  13  has, in the connection zone  12 , a rounded recess  18 . 
     In its three portions  10 ,  11  and  12 , the upper wall of the silicone mass  13  receives a mechanical surface treatment so as to allow the placing of a primary coating on which it will be possible to apply paint. 
     This thus treated surface preferably will be covered by a peel-off protective layer during the delivery of the guard.