Next-Generation Wooden Racket

Abstract

The invention relates to a tennis racket including a frame, delimiting a surface strung with cords and forming a screen, and a sleeve extending the frame outside the screen, characterized in that the frame consists of, at least within a peripheral region, a curved laminate comprising at least two layers of different materials adhered together, the laminate being shaped such that, in a closed cross-section of said peripheral region considered to be perpendicular to the neutral fiber of the frame, the center of mass of said cross-section is offset, relative to the surface center of gravity of said cross-section, toward the screen with a value at least equal to 5% of the width of said cross-section, said width being defined by the intersection of the cross-section and the plane of the screen.

1 . Racket for ball games, particularly tennis, comprising a frame delimiting a strung surface forming a mesh, a handle extending the frame outside the mesh, characterised in that the frame is formed, at least in a peripheral region, from a bent lamination of at least two layers of different materials placed adjacent to each other, the lamination being shaped so that, in a closed cross-section of said peripheral region, considered perpendicular to the neutral axis of the frame, the centre of mass of said cross-section is offset towards the mesh relative to the centre of area of said cross-section, by a value of at least 5% of the width of said cross-section, said width being defined by the intersection of the cross-section with the plane of the mesh. 
     
     
         2 . Racket according to  claim 1 , characterised in that the frame is formed from a lamination comprising at least two layers of different materials, a first layer of which, located on the inner side of the frame, has a greater density than the second layer, located on the outer side of the frame. 
     
     
         3 . Racket according to  claim 1 , characterised in that the lamination is formed from at least three layers of at least two different materials. 
     
     
         4 . Racket according to  claim 1 , characterised in that the lamination is formed from at least four layers of at least three different materials. 
     
     
         5 . Racket according to  claim 1 , characterised in that the lamination comprises several layers of different types of wood, said types of wood being selected from acacia, balsa, walnut. 
     
     
         6 . Racket according to  claim 5 , characterised in that the lamination comprises at least one acacia layer located on the inner side of the frame and delimiting the mesh. 
     
     
         7 . Racket according to  claim 5 , characterised in that said at least one acacia layer is formed from two acacia layers arranged so that the respective fibres thereof are in opposite directions to each other. 
     
     
         8 . Racket according to  claim 5 , characterised in that the lamination comprises at least one walnut layer located on the outside of the frame. 
     
     
         9 . Racket according to  claim 5 , characterised in that the lamination comprises at least one balsa layer. 
     
     
         10 . Racket according to  claim 9 , characterised in that said at least one balsa layer is inserted between said at least one acacia layer and said at least one walnut layer. 
     
     
         11 . Racket according to  claim 9 , characterised in that said at least one balsa layer is encased in a fibreglass sheath. 
     
     
         12 . Racket according to  claim 11 , characterised in that the fibreglass sheath comprises a reinforcement selected from carbon threads or basalt threads. 
     
     
         13 . Racket according to  claim 1 , characterised in that the layers are bonded together by polymerisation of a synthetic resin. 
     
     
         14 . Racket according to  claim 5 , characterised in that the wooden layers of the lamination represent substantially the following proportions in the width of the cross-section:
 between 20 and 40% acacia,   between 30 and 50% balsa,   between 20 and 40% walnut.   
     
     
         15 . Racket according to  claim 1 , characterised in that it is a tennis racket.