Patent Publication Number: US-11643807-B2

Title: Clamp for connecting panels in surface coating structure, and manufacturing method

Description:
TECHNICAL FIELD 
     The present invention relates to a clamp for connecting panels in a surface coating structure. 
     BACKGROUND ART 
     In this type of structures the connection, which takes place between the panels and a base frame, is removable and is generally made by means of clamps. WO 2008/093383 A1 discloses a clamp. 
     DE 297 07 884 U1 describes a clamp formed by two parts, a lower one that can be fixed with screws on the base frame, and an upper one rotatable on the lower part to protrude, with its ends, and pass from a disengagement position between two adjacent panels to a position of engagement of the same with the base frame. To achieve this engagement, the ends of the upper part are inserted into the longitudinal grooves, made for this purpose, in the panels. In the above German document it is shown that the upper part has a plurality of hook-like feet projecting downwards and engaged with a circular opening provided in a raised portion of the lower part. This arrangement allows the upper part of the clamp to rotate with respect to its lower part. 
     EP 3106585 A1 discloses a fastening system for decking boards including a series of supports connected to a frame. Each support has a stem with a semi-circular washer. The decking boards define slots which run along both sides of the board. The washer is rotated so that it extends into the slot in the side of the decking board. The washer is then fixed in place by a screw. 
     A drawback of the clamps of the prior art lies in the fact that the rotatable part does not have an efficient support on the base frame. 
     Another drawback of the clamps of the prior art is due to the fact that the rotatable part is not easily controllable in its position. 
     Furthermore, the insertion of the rotatable part in the longitudinal grooves of the panels is not facilitated. 
     SUMMARY OF THE INVENTION 
     Therefore, the general object of the present invention is to obviate the drawbacks of the prior art. 
     In particular, an object of the invention is to create a rotatable coupling that is stable and easy to be operated between the upper part and the lower part of a clamp for connecting panels in a surface coating structure. 
     Another object of the invention is to allow the rotation of the upper part with respect to the lower part with a tool for installing and removing panels. 
     Yet another object of the invention is to provide a comfortable fastening of the clamp on the base frame. 
     A further object of the invention is to provide an effective simultaneous gripping of two adjacent panels. 
     These and other objects and advantages are achieved in a first embodiment of the invention. 
     In a second aspect of the invention, there is provided a method of manufacturing a clamp for connecting panels in a surface coating structure. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Two embodiments are disclosed in the detailed description that follows, referring to the attached drawings in which: 
         FIGS.  1  and  2    are an exploded and, respectively, assembled perspective view of a first embodiment of the clamp for connecting panels according to the present invention, the clamp being in the open position; 
         FIGS.  3  and  4    are a top plan view and a side view, respectively, of an element of the clamp which can be fastened to the base frame; 
         FIGS.  5  and  6    are a top plan view and a side view, respectively, of the rotatable element of the clamp in  FIGS.  1  and  2   ; 
         FIGS.  7  and  8    are a plan view from above and a perspective view of the clamp in  FIG.  2   , without the support plate and in a closed position; 
         FIG.  9    is a partial perspective view of a surface coating structure in which the clamp according to the present invention is applied; 
         FIG.  10    is an exploded perspective view of a second embodiment of a clamp; 
         FIG.  11    is an exploded top plan view of the clamp in  FIG.  10   ; 
         FIG.  12    is an exploded side view of the clamp in  FIG.  10   ; 
         FIG.  13    is an exploded end view of the clamp in  FIG.  10   ; and 
         FIG.  14    is an exploded cross-section view along the line A-A of the clamp in  FIG.  11   . 
     
    
    
     DESCRIPTION OF INVENTION EMBODIMENTS 
     First of all, reference is made to  FIGS.  1  and  2   , which are an exploded and assembled perspective view, respectively, of a clamp for connecting panels according to a first embodiment of the present invention in an open position. The configuration of the surface coating structure in which the clamp is applied is widely known in the art. However, an example is given in  FIG.  9   , which is a partial perspective view of a surface coating structure in which the clamp according to the present invention is applied. In  FIG.  9   , indicated as P are panels and as T a base frame, and clamps according to a first embodiment of the present invention are generically indicated as  50 . 
     Returning to  FIGS.  1  and  2   , the clamp  50  comprises a fixable element  1 , i.e. that it is designed to be fixed to the base frame T ( FIG.  9   ), and a rotatable element  2 , that is rotatably connected to the fixable element  1 . Preferably, the fixable element  1  can be fixed on the base frame with the interposition of a support plate  3 . 
     The fixable element  1 , which is rectangular prismatic with central longitudinal axis x, has two communicating concentric cylindrical holes: an upper hole  10  of smaller diameter with respect to a lower hole  11 . Moreover, the fixable element  1  has two through holes generally indicated as  12 , having a truncated conical invitation from the top. The through holes  12  are offset with respect to the longitudinal symmetry plane of the fixable element  1 . Furthermore, the fixable element  1  has two blind holes  13  made from the bottom towards its top. The long sides  14  of the fixable element  1  have a plurality of vertical ridges  15 , preferably with a triangular cross-section. They have the function of spacers with respect to the adjacent panels. When the panels dilate due to weather changes, their deformations are compensated by their possibility of expansion against the clamps. Obtained on the top surface  16  of the fixable element  1 , in the vicinity of the corners, are angular depressions indicated as  17  to facilitate rotation of the rotatable element  2  with respect to the fixable element  1 . On the top surface  16  of the fixable element  1  there are shown a pair of arrows  18  indicating the positioning direction of the clamp  50  with respect to the panel to its left. Furthermore, two segments  37  being orthogonal to the arrows  18  indicate the correct positioning of the rotatable element  2  with respect to the fixable element  1 , when the rotatable element  2  is in the closed position of the clamp. For clamping, the segments  37  must be in the same direction as slit between adjacent panels P. 
     The rotatable element  2  has an upper part  20  which, after the assembly of the clamp  50 , protrudes upwardly with respect to the top surface  16  of the fixable element  1 . The rotatable element  2  has the shape of a rectangular plate with size substantially equal to that of the fixable element  1 . Conventionally, the rotatable element  2  engages, in its rotation, with its ends in lateral grooves of adjacent panels P, as shown in  FIG.  9   . The upper part  20  of the element rotatable  2  is tapered toward the bottom in the short sides  21 ,  22  of the rectangular plate. The tapered short sides  21 ,  22  are beveled in two diametrically opposed corners  23 ,  24  thereof. Centrally, the upper part  20  of the rotatable element  2  has a butterfly-shaped cavity  25  for engagement with a rotation key, for example a T key, and has a central hexagonal hole  26  for engagement with an Allen key or for passing a fastening screw (not shown) of clamp  50  to the base frame. Curved recesses  27  are made centrally on the long sides of the upper part  20  of the rotatable element  2  for a purpose which will be clarified below. 
     Moreover, the rotatable element  2  has, preferably in one piece with the upper part  20 , an intermediate part  28  in the form of a disc of such dimensions as to be rotatably received in the upper hole  10  of the fixable element  1 . Finally, the rotatable element  2  has a disc-shaped lower part  29 , with a diameter greater than the diameter of the intermediate part  28  but such to be rotatably received in the lower cylindrical hole  11  of the fixable element  1 . The lower part  29  of the rotatable element  2  is received, as the intermediate part  28 , with a wide coupling to allow rotation of the rotatable element  2  with respect to the fixable element  1 . The joining of the intermediate part  28  with the lower part  29  can be by gluing, but preferably by ultrasonic welding, since the clamp  50  according to the present invention is made of plastic material. The central hexagonal hole  26  continues in the intermediate part  28  as well as in the lower part  29  of the rotatable element  2 . 
     The support plate  3  has a rectangular plan with through holes  32  concentric with the through holes  12  of the fixable element  1 , and furthermore a pair of mounting pins  33  concentric with the blind holes  13  of the same fixable element  1 . The support plate  3  extends in two opposite side arms  34 , centrally formed on the long sides  35  of its rectangular plan. 
     According to the invention, a manufacturing process of the clamp  50  for connecting panels in a surface coating structure is provided. The prismatic fixable element  1  is molded in plastic material with the two concentric holes, the upper one  10  having a smaller diameter than the lower one  11 . The rotatable element  2  is also molded in plastic material with its upper part  20  in one piece with the intermediate part  28  constituted by a disc of diameter such as to be rotatably received in the upper cylindrical hole  10  of the fixable element  1 . The intermediate part  28  of the rotatable element  2  is inserted into the upper cylindrical hole  10  of the fixable element  1  while the lower part  29  of the rotatable element  2  is rigidly joined to its intermediate part  28 . Alternatively, the intermediate part  28  and the lower part  29  could be made in one piece and subsequently joined rigidly to the upper part  20 , when positioned on either side of the fixable element  1 . 
     The rigid joining between the lower part  29  of the rotatable element  2  and the intermediate part  28  can be achieved by means of an ultrasonic welding sonotrode. As previously stated, the fixable element  1  has two through holes  12  near its short sides being offset with respect to the central longitudinal axis x of the fixable element  1 , and the rotatable element  2  has a double pair of opposite recesses  27  in the its long sides. The recesses  27  have a circular sector shape. When the rotatable element  2  is rotated about the axis y ( FIGS.  4  and  6   ) that is perpendicular to the central longitudinal axis x of the fixable element  1 , a pair of opposite recesses  27  are located with their axis of curvature concentric with the two through holes  12 . Thus, if the fixable element  1  is fastened with screws to the base frame through the holes  12 , the clamp  50  can be easily mounted and disassembled from the base frame by acting with a screwdriver on the screws (not shown) in the through holes  12 . 
     The fixable element  1  has superiorly the triangular depressions  17  on the top surface  16  at each corner. The depressions serve to facilitate the rotation of the rotatable element  2  with respect to the fixable element  1 , which has inferiorly projections  36  ( FIG.  6   ). 
     Carved superiorly in the fixable element  1  are two parallel arrows  18  orthogonal to the lateral grooves of the panels. The arrows  18  serve to indicate the positioning direction of the clamp  50  and are directed towards the panel to its left with respect to its longitudinal direction. 
     The fixable element  1  has at its bottom two blind holes  13  which receive the pins  33  of the support plate  3  for a precise and stable positioning of the fixable element  1  on the base frame. The opposite lateral arms  34  of the support plate  3  serve to widen the gripping surface of the clamp  50  since they are placed under the panel opposite to the wings  21 ,  22  of the upper part  20  when the clamp  50  is in the closed position. In this way, the panels are sandwiched by the clamps. 
     This is shown in the aforementioned  FIG.  9   , wherein clamps  50  are fixed on a base frame T to retain the panels P. The panels P rest on the opposite side arms  34  of the support plates  3 . In this way, the panels P do not rest in contact with the base frame T, with result that an interspace I is formed which avoids stagnant water. In the closed position the wings  21 ,  22  of the upper part  20  of a same rotatable element  2  are inserted into the lateral grooves S of panels P that are adjacent. 
     Reference is made now to  FIG.  10    which is an exploded perspective view of a second embodiment of a clamp, and to  FIGS.  11 ,  12 ,  13  and  14    which are exploded top, side, end plan and cross-section views thereof along line A-A. Identical or similar reference numerals are used to mark parts that are the same or similar to those of the first embodiment. 
     The clamp of the second embodiment of the invention, indicated as  51 , differs from the clamp  50  of the first embodiment in the connection of the rotatable element, indicated as  200 , with the fixable element, indicated as  100 . 
     The difference of this connection lies in the fact that the disc of the intermediate part  280  of the rotatable element  200  is cylindrical, while the disc of the lower part  290  is tapered downwards, having a diameter larger than the intermediate part  280 ; moreover, the fixable element  100  has the upper hole  101  that is tapered downwards and the lower hole  111  that is cylindrical. 
     The lower part  290  of the rotatable element  200  and the upper hole  101  of the fixable element  100  are correspondingly tapered for the forced insertion of one in the other, with the possibility that the two parts may have a relative movement. For this purpose, the dimensions in which the above cooperating parts are made are important. Preferably, the cylindrical disc of the intermediate part  280  has a thickness of 3.1 mm and a diameter of 20 mm, while the disc tapered downwards of the lower part  290  has a thickness of 2.7 mm and a maximum diameter of 21 mm 
     The taper of the downwardly tapered disc of the lower part  290  is 69.16 degrees. The fixable element  100  has the upper hole  101  that is tapered downwardly with a maximum diameter slightly smaller than the maximum diameter of the tapered disc of the lower part  290  and a lower hole  111  that is cylindrical with a diameter of 21.3 mm and a thickness of 2.8 mm. However, these measures are to be considered indicative and not characterizing. 
     It should be understood that the insertion of the rotatable member  200  in the fixable element  100  is allowed by the elastic deformation of the material with which they are made. The insertion is stable because the two parts can be scarcely stressed to a traction that can determine an accidental separation thereof. 
     The second embodiment is certainly more convenient thanks to a substantial reduction of the time necessary for its manufacture, and therefore of its cost. 
     It is understood that the intended objects have been achieved by the invention: to create a stable and comfortable rotatable coupling to be operated between the rotatable element and the fixable element of a clamp for connecting panels in a surface coating structure; to allow the rotation of the upper part with respect to the lower part with a tool for installing and removing panels; to make the fixing of the clamp on the base frame more comfortable; and finally to make the simultaneous gripping of two adjacent panels more effective. Furthermore, the dimensions of the slits between one panel and the next one are considerably reduced.