Racket or club consisting of magnesium

Abstract

The present invention relates to a frame for a ball-game racket comprising a head portion and a handle portion, wherein the frame is configured as a hollow profile and comprises magnesium and wherein the wall thickness of the hollow profile varies along a cross-section through the hollow frame profile, as well as to a process for producing such a racket.

1 . A frame for a ball-game racket comprising a head portion and a handle portion, wherein at least a part of the frame is configured as a hollow profile and comprises magnesium and wherein the wall thickness of the hollow profile varies along a cross-section through the hollow frame profile. 
     
     
         2 . The frame according to  claim 1 , wherein further the wall thickness of the hollow profile varies in the longitudinal direction of the frame. 
     
     
         3 . The frame according to  claim 1 , wherein the variation in the wall thickness along at least one cross-section and/or longitudinal section relative to the minimum wall thickness is at least 25%, preferably at least 50%, more preferably at least 75%, particularly preferably at least 100%. 
     
     
         4 . The frame according to  claim 1 , wherein the wall thickness of the frame in sections is thinner than 1 mm, preferably thinner than 0.8 mm, more preferably thinner than 0.7 mm, particularly preferably thinner than 0.6 mm. 
     
     
         5 . The frame according to  claim 1 , wherein the frame profile of the frame comprises an outer portion, an inner portion and two side portions in the head portion, and wherein the wall thickness of the inner and/or outer portion at least in sections is thicker than the wall thickness of the side portions. 
     
     
         6 . The frame according to  claim 1 , wherein the frame profile of the frame comprises an outer portion, an inner portion and two side portions in the head portion, and wherein the wall thickness of the inner and/or outer portion at least in sections is thinner than the wall thickness of the side portions. 
     
     
         7 . The frame according to  claim 1 , wherein the frame profile of the frame comprises an outer portion, an inner portion and two side portions in the head portion, and wherein the wall thickness of the inner portion at least in sections is thinner than the wall thickness of the outer portion. 
     
     
         8 . The frame according to  claim 1 , wherein the frame comprises at least 50% (by weight), preferably at least 80% (by weight), more preferably at least 90% (by weight), particularly preferably at least 95% (by weight) of magnesium. 
     
     
         9 . The frame according to  claim 1 , wherein the frame comprises a magnesium alloy, preferably a fiber-reinforced or particle-reinforced alloy, particularly preferably SAE SiC/AZ91. 
     
     
         10 . The frame according to  claim 1 , wherein the frame is locally reinforced with carbon fiber material and/or glass fiber material. 
     
     
         11 . The frame according to  claim 10 , wherein the frame is reinforced with carbon fiber material and/or glass fiber material in the area of the transition between the head portion and the handle portion. 
     
     
         12 . The frame according to  claim 1 , wherein the frame comprises two frame halves which are welded to each other, pressed together and/or bonded to each other. 
     
     
         13 . The frame according to  claim 12 , wherein the two frame halves are identical and wherein each of the two frame halves is asymmetrical with respect to the longitudinal axis of the frame. 
     
     
         14 . The frame according to  claim 1 , wherein the frame comprises a frame portion comprising magnesium, and wherein the wall thickness of the hollow profile varies along a cross-section through this frame portion. 
     
     
         15 . The frame according to  claim 14 , wherein the frame in said frame portion comprises at least 50% (by weight), more preferably at least 80% (by weight), more preferably at least 90% (by weight) and particularly preferably at least 95% (by weight) of magnesium. 
     
     
         16 . The frame according to  claim 14 , wherein said frame portion comprises two frame portion halves which are welded to each other, pressed together and/or bonded to each other. 
     
     
         17 . A process for producing a frame for a ball-game racket, in particular a frame according to  claim 1 , wherein the process comprises the following steps:
 providing an injection mold and a core, wherein the core consists of a material having a melting temperature below 400° C.;   casting the frame by inserting a material comprising magnesium between the injection mold and the core, preferably by means of the thixo process; and   melting the core by heating the racket including the core to above the melting temperature of the core, wherein the heat resistance temperature of the frame is not exceeded.   
     
     
         18 . The process according to  claim 17 , wherein the frame material comprises at least 50% (by weight), preferably at least 80% (by weight), more preferably at least 90% (by weight), particularly preferably at least 95% (by weight) of magnesium. 
     
     
         19 . The process according to  claim 17  or  18 , wherein the frame material comprises a magnesium alloy, preferably a fiber-reinforced or particle-reinforced alloy, particularly preferably SAE SiC/AZ91. 
     
     
         20 . The process according to  claim 17 , wherein the core material comprises or consists of one of or a combination of the following materials: an alloy on the basis of tin, an alloy on the basis of bismuth, an alloy on the basis of lead, an alloy on the basis of zinc, an alloy on the basis of indium, glass, plastics with or without glass-fiber reinforcement, polyamide.