Patent Abstract:
The invention concerns a roofing element (E) of the type of the one consisting of a material board ( 100 ) maintained inside a frame ( 200 ), characterized in that it consists of a single-walled solid material board and of at least one tensioning means ( 300 ) linked to the frame ( 200 ) tending to space apart certain parts constituting the frame ( 200 ) so as to stress said board ( 100 ), the frame consisting of two transverse profiled sections ( 210  and  220 ) fixed to two opposite sides of the board ( 100 ), the tensioning means ( 300 ) tending to space apart said profiled sections ( 210  and  220 ), the edges of the board ( 100 ) subjected to a tensile stress and slid into the profiled sections being provided with at least one projection ( 110 ) facilitating the transmission of said stress, the profiled section being itself preformed to retain said projection in the direction of the tensile stress. The invention is applicable to swimming pool low shelter, veranda and the like.

Full Description:
FIELD OF APPLICATION OF THE INVENTION 
     This invention relates to the field of roofing elements such as those used in low swimming pool shelters and in particular to the adaptations making it possible to improve the transparency and reduce the weight thereof. 
     DESCRIPTION OF THE PRIOR ART 
     The roofing elements can be those proposed in document FR 2776000, which describes a swimming pool roofing element structure of the type composed of a cover formed by panels made of a translucent material such as double-wall polycarbonate and a rigid, lightweight and resistant reinforcement for supporting the transparent cover, which reinforcement is formed by arcs arranged in transverse planes and spaced apart by cross-members with two outermost lateral cross-members delimiting two edges of the roofing element. These two lateral edges rest on the longitudinal edges of the basin defining a contact surface with said roofing elements. 
     These roofing elements have the disadvantage of using double-wall alveolar polycarbonate for the translucent panel. 
     This alveolar polycarbonate is expensive and does not provide the best possible transparency since it is formed by at least two sheets connected to one another by partitions. 
     Moreover, the thickness of such an alveolar material defines a bulk that must be dealt with when transporting said panels. 
     The prior art discloses more transparent, non-alveolar materials, but their use presents other problems, for example:
         a sheet of solid material of lower thickness is too flexible,   a sheet of solid material with the same rigidity as the alveolar material is too heavy.       

     Another problem encountered in the exterior use of large panels of a solid material sheet involves the variation of the dimensions to which it can be subjected due to the variation in temperatures. 
     DESCRIPTION OF THE INVENTION 
     On the basis of the above, the applicant has conducted research to find an alternative to the use of alveolar panels in roofing elements. 
     This research has resulted in a technical solution making it possible to use panels of more flexible material with a lower thickness, overcoming the disadvantages mentioned above. 
     According to the main feature of the invention, the roofing element of the type consisting of a panel of material held inside of a frame is remarkable in that it is composed of a panel made of a single-wall solid material and at least one tensioning means linked to the frame tending to separate certain parts constituting the frame so as to apply tension to said panel, 
     the frame is composed of two transverse profiles attached to two opposite sides of the panel, with the tensioning means tending to separate said profiles, 
     the edges of the panel subjected to a pulling force and slid into the profiles are equipped with at least one projection facilitating the transmission of this force, with the profile being itself preformed in order to retain this projection in the direction of the pulling force. 
     This feature is particularly advantageous in that it makes it possible to use a single-wall panel in spite of its lack of rigidity. It is thus possible to use any material capable of being placed in a frame and capable of supporting the pulling force to which it will be subjected. The tensioning of the panel makes it possible to prevent it from collapsing in the event of dilation due to climatic conditions. 
     This feature therefore ensures a panel that perfectly matches the general shape of the frame in spite of its flexibility. 
     This feature is possible whether the panel is transparent or not. Indeed, the feature allows the use of perfectly transparent single-wall non-alveolar panels. The transparency of the material used for the panel makes it possible to see through and offers the possibility of seeing inside the basin protected by the roofing, which is particularly secure. This security functionality could not be implemented in the panels of the prior art, which were alveolar and which could not be considered to be translucent. 
     The use of a single-wall panel reduces the weight of the structure and requires less bulk for storage or transport. 
     Thus a special feature of the invention is the association, with the frame or with the reinforcement supporting the flexible and transparent panel, tensioning means tending to separate certain parts forming the frame in order to maintain the tension of said panel. 
     According to another particularly advantageous feature of the invention, this roofing element consists of two transverse profiles attached to two opposite sides of the panel and connected to one another by cross-members of which at least one comprises tensioning means tending to separate said profiles. The tensioning can be performed for each element ensuring the connection between the two profiles, i.e. for each cross-member. 
     In the case of a low swimming pool shelter, the profiles into which the panels slide are conventionally arched and form arcs of which each end rests on the edge of the basin. In addition, the two outermost lateral cross-members, which delimit two edges of the roofing element and which rest on the longitudinal edges of the basin, define a contact surface with said roofing elements. 
     To transmit and control the pulling force, the edges of the panel subjected to a pulling force, slid into the profiles, are equipped with at least one projection facilitating the transmission of this force. The profile is itself preformed to retain said projection in the direction of the pulling force. 
     These tensioning means can be implemented in a plurality of embodiments. 
     A first embodiment proposes that at least one end of a cross-member slide transversely with respect to the profile and comprise at least one tensioning means composed of a casing housing a spring that comes into contact with said profile, thus tending to separate the cross-member from the profile. 
     A second embodiment proposes that the cross-member equipped with tensioning means consist of two parts capable of being moved one with respect to the other and connected to one another by a sliding connection controlled by a spring. 
     According to a preferred technological choice, the material of the single-wall panel is polycarbonate. 
     The fundamental concepts of the invention having been described above in their most basic form, other details and features will become clearer on reading the following description and in view of the appended drawings, provided for non-limiting purposes, of an embodiment of a roofing element according to the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagrammatic drawing of a perspective view of an embodiment of a low swimming pool shelter composed of roofing elements according to the invention, 
         FIG. 2  is a diagrammatic drawing of a partial cross-section view of a roofing element using a first embodiment of the tensioning means, 
         FIG. 2   a  is a diagrammatic drawing of a cross-section of a detail of said tensioning means, 
         FIG. 3  is a diagrammatic drawing of a partial cross-section view of a roofing element using a second embodiment of the tensioning means. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The drawing of  FIG. 1  shows an embodiment of a low swimming pool shelter referenced A in its entirety ensuring the coverage of a basin referenced B. This low shelter includes a plurality of roofing elements E. 
     Each roofing element E is composed of a panel of material  100  held inside a frame  200 . This frame  200  is composed of two transverse arched profiles  210  and  220  connected to one another by the panel  100  and by cross-members  230  arranged under the panel  100 . Two outermost lateral cross-members  231  and  232  delimit two edges of the roofing element E. These two lateral edges rest on the longitudinal edges of the basin B defining a contact surface with said roofing elements E. 
     The edges of the panel  100  slide into the arched profiles  210  and  220  of the frame  200  and cause the panel  100  to adopt the curvature of said profiles. The cross-members ensure the spacing of said profiles in order to ensure the rigidity thereof. 
     According to the invention, the roofing element E includes a panel  100  made of a single-wall solid material and tensioning means connected to the frame tending to apply tension to said panel  100 , which is flexible due to its thickness and size. 
     According to a preferred embodiment and according to the invention, the material used is transparent. According to a preferred technological choice, this material is transparent polycarbonate. This polycarbonate is associated with an aluminium frame. The polycarbonate is in the form of a sheet with a thickness of between 1.4 and 2 millimetres, which enables the deformation of its edges, and which provides flexibility enabling it to follow the curvature of the transverse arcs, but which causes a longitudinal bending that must be solved by tensioning means. 
     According to the invention, at least one cross-member  230  comprises tensioning means tending to separate said profiles  210  and  220 , which hold the edges of the panel  100 , and therefore tension said panel  100 . 
     According to the embodiment shown in the drawings of  FIGS. 2 and 3 , the edges of the panel  100  according to the arrows F 1  subjected to a pulling force are equipped with at least one projection facilitating the transmission of this force. More specifically, each panel edge is preformed in order to have a C-shaped edge, which is positioned in the profile  210  and  220  so that its branches come from each side of a lug  211  and  221  provided for this purpose in the profiles  210  and  220 . Thus, once the panel  100  has slid into the profiles, said panel  100  cannot be released from said profiles  210  and  220  in a longitudinal translation movement, i.e. in the direction of the pulling force. The cooperation between this return  110  and the lugs  210  and  220  provided inside the profiles  100  ensures successful transmission of the pulling force exerted by the tensioning means  300 . 
     According to the embodiment shown in the drawing of  FIG. 2 , at least one end of a cross-member  230  slides transversely according to the double arrow F 2  with respect to one of the profiles  210  and comprises at least one tensioning means  300  composed of a casing  310  housing a spring  320 , which comes into contact with said profile  210 , thus tending to separate the cross-member  230  from the profile  210 . 
     More specifically, and according to the invention, said casing  310  adopts the shape of a cylindrical tube, which is attached to the cross-member  230  and at a first end of which a stop  311  is provided, with which the spring  320  comes into contact, and the other end of which is open to enable the spring  320  to come into contact with said profile. According to a particularly advantageous feature, the position of the stop  311  can be adjusted inside the casing  310  so as to ensure the adjustment of the force exerted by the spring. According to a preferred embodiment, said stop  311  is threaded and is connected in a screw-type manner to the casing  310  so as to move axially inside it. The end of the spring  320  that comes into contact with the profile  210  or  220  is associated with a stop  321 . 
     According to a preferred embodiment, each cross-member includes means for tensioning the frame. According to a preferred technological choice, the two outermost lateral cross-members  231  and  232  forming edges are equipped with tensioning means  300  and the cross-members  230  between the two outermost cross-members are equipped with two tensioning means  300 . 
     An embodiment of the attachment of the two tensioning means at the end of a cross-member  230  is shown in the drawing of  FIG. 2   a . In this embodiment, two tubular casings  210   a  and  310   b  are arranged on each side of the cross-member  230  by being associated with a profile  312  internally including the external profile of the cross-member  230  for its positioning and attachment to the latter. According to a preferred embodiment, the cross-members  230  have a rectangular profile and are slidingly connected at a first end and stationarily connected at the other end to the transverse profiles  210  and  220 , by means of T-shaped parts  400  provided for this purpose. 
     According to another embodiment shown in the drawing of  FIG. 3 , the cross-member  230  equipped with tensioning means  300  consists of two parts  231  and  232  capable of moving according to the double arrow F 2 , one with respect to the other, and connected to one another by a sliding connection controlled by a spring forming the tensioning means  300 . 
     The two ends of the cross-member are then stationarily connected to the transverse profiles  210  and  220 . 
     More specifically, said tensioning means  300  consist of a female element  330  associated with a first part  232  of a cross-member  230  cooperating with a male element  340  associated with a second part  231  of the cross-member  230 . 
     It is understood that the roofing element has been described and shown above for the purpose of disclosure rather than as a limitation. Of course, various arrangements, modifications and improvements can be made to the example above without going beyond the scope of the invention.

Technology Classification (CPC): 4