Shaped body for production of sports equipment and method for production of said shaped body

Abstract

The invention relates to a shaped body ( 2 ), for production of sports equipment, in particular tennis, squash, and badminton rackets, golf clubs, hockey and ice hockey sticks and baseball bats, comprising two tubular resonant bodies ( 4, 6 ), running parallel to and at a separation from each other, surrounded by a common shell ( 12 ) and a spacer body ( 8 ), which is arranged between the resonance bodies ( 4, 6 ), in such a way that the resonance bodies ( 4, 6 ) are coupled, whereby the mass relationship between each resonance body ( 4, 6 ) and the spacer body ( 8 ) is greater than 1. The vibrations of the two vibrating systems, in the form of the resonance bodies ( 4, 6 ), are overlaid in a advantageous manner, by means of the coupling of the resonance bodies ( 4, 6 ). The invention further relates to a method for the production of the shaped body ( 2 ).

1 . A structural member to manufacture a sports equipment, in particular tennis, squash, badminton racquets, golf clubs, field hockey and ice hockey sticks and baseball bats, having two parallel tubular resonating elements ( 4 ,  6 ,  18 ,  20 ) that are placed at a distance from one another and are enclosed by a common covering ( 12 ,  26 ), and with a distancing element ( 8 ,  22 ) that is placed between the resonating elements ( 4 ,  6 ,  18 ,  20 ), 
 characterized in that the mass of each resonating element ( 4 ,  6 ,  18 ,  20 ) is greater than the mass of the distancing element ( 8 ,  22 ) and that the compressive strength of the distancing element ( 8 ,  22 ) is the highest in the direction of an axis ( 10 ,  24 ) that connects the center points of the resonating elements ( 4 ,  6 ,  18 ,  20 ):    
     
     
         2 . A structural member to manufacture a sports equipment according to  claim 1 , characterized in that the distancing element ( 8 ,  22 ) is made of wood or a material similar to wood.  
     
     
         3 . A structural member to manufacture a sports equipment according to  claim 2 , characterized in that the distancing element ( 8 ,  22 ) is made of balsa wood.  
     
     
         4 . A structural member to manufacture a sports equipment according to one of claims  1  through  3 , characterized in that the width (B 1 , B 2 ) of the resonating elements ( 4 ,  6 ,  1   8 ,  20 ) is greater than the width (A) of the distancing element ( 8 ,  22 ).  
     
     
         5 . A structural member to manufacture a sports equipment according to one of claims  1  through  4 , characterized in that the covering ( 26 ) on the side ( 18 ″,  20 ″) of the resonating element ( 18 ,  20 ) that faces away from the resonating element ( 20 ,  18 ) opposite to it has a greater wall thickness.  
     
     
         6 . A structural member to manufacture a sports equipment according to one of claims  1  through  5 , characterized in that the covering ( 26 ) is comprised of one or more layers of at least two plastic-impregnated laminar materials ( 28 ,  30 ).  
     
     
         7 . A structural member to manufacture a sports equipment according to  claim 6 , characterized in that the covering ( 26 ) has first sections ( 26 ′) on the side ( 18 ″,  20 ″) of the resonating element ( 18 ,  20 ) that faces away from the opposite resonating element ( 20 ,  18 ), said sections being connected together via two second sections ( 26 ″), wherein the laminar materials ( 30 ) of the first sections ( 26 ′) overlap the laminar materials ( 28 ) of the second sections ( 28 ) in the transition zone ( 32 ).  
     
     
         8 . A structural member to manufacture a sports equipment according to  claim 7 , characterized in that the laminar materials ( 30 ) in the first sections ( 26 ′) of the covering ( 26 ) are thicker than the laminar materials ( 28 ) in the second sections ( 26 ″) of the covering ( 26 ) and/or that more laminar material ( 30 ) exists in the first sections ( 26 ′) than in the second sections ( 26 ″).  
     
     
         9 . A structural member to manufacture a sports equipment according to one of claims  7  or  8 , characterized in that the plastic-impregnated laminar material ( 28 ,  30 ) is made of GFK, AFK, CFK, KFK, MFK fiber-reinforced plastic in a resin matrix or of other metal or plastic layers, fabrics or foils that can absorb external forces.  
     
     
         10 . A structural member to manufacture a sports equipment according to one of claims  1  through  9 , characterized in that there are lateral through holes ( 14 ) located in the distancing element ( 8 ,  22 ) and the covering ( 12 ,  26 ), in particular for the strings of the webbing.  
     
     
         11 . Sports equipment, in particular tennis, squash, badminton racquets, golf clubs, field hockey and ice hockey sticks, and baseball bats that contain a structural member ( 2 ,  16 ) according to one of claims  1  through  10 .  
     
     
         12 . A tennis racquet with a handle and frame according to  claim 11 , in which a structural member ( 2 ,  16 ) forming the frame and/or grip contains within at least one resonating element ( 18 ,  20 ) mass particles that move about freely, or fluid droplets, that dampen the recoil forces and vibrations acting on the structural member, or alternatively contains on the wall of at least one resonating element ( 18 ,  20 ) a mass support strip or a number of mass support strips ( 36 ) for kinetically damping mass systems.  
     
     
         13 . A process to manufacture a structural member for a sports equipment, in particular tennis, squash, badminton racquets, golf clubs, field hockey and ice hockey sticks and baseball bats, comprising the process steps of; 
 the arrangement in parallel of two tubular resonating elements and a distancing element in between them, wherein the distancing element is oriented such that the direction of maximum compression strength of the distancing element is directed parallel to an axis that connects the center points of the resonating elements,    the attachment of plastic-impregnated laminar materials that only partially surround the resonating elements and the distancing element, wherein each individual laminar material layer overlaps another laminar material only at the side of the resonating element that faces away from the respective opposite resonating element,    placement into a heated die ( 42 ),    production of mechanical pressure in the resonating elements and lateral deformation of the distancing element by means of a punch ( 48 ) inside the die ( 42 ) and    hardening inside the die ( 42 ).    
     
     
         14 . A process according to  claim 13  which further comprises the process step of making lateral penetrations in the cover and the distancing element at points, said penetrations displacing the fibers, after the distancing element is laterally deformed and prior to or during the hardening step.  
     
     
         15 . A process according to  claim 14  in which the covering and the distancing element is penetrated in the die by means of a pin ( 50 ) from one side.  
     
     
         16 . A process according to  claim 14 , in which two pins ( 50 ,  52 ) are pushed through the covering into the distancing element from opposite sides until their ends meet inside the distancing element.