Fiber composite and process of manufacture
View Patent ↗The inventive fiber manufacturing process is particularly adapted for demanding applications such as sports racquets, including tennis racquets, badminton racquets and other sports applications. Because of the improved strength to weight ratio of components formed using the inventive method, a wide range of flexibility is achieved, allowing use of the inventive process to manufacture, for example, a fiber reinforced (for example, graphite) modular sports racquet, optionally provided with user-selectable weights and/or handle replacements. From the standpoint of the player, this allows a racquet frame featuring self customization. From the standpoint of a retailer, the benefit provided is reduction of inventory. The inventive fiber, for example graphite fiber) racquet frame is filled with a plastic foam and is formed using, for example, microencapsulation technology to time, generate and apply the pressure used to form the graphite composite material of which the racquet is comprised. Advantageously, inner and outer tubular members may be used to form the racquet frame, with the inner tubular member extending around the head of the racquet frame. This compares to the standard industry technique of air injection. The racquet is thus not hollow like conventional graphite racquets, and the walls therefore can be made thinner than those of existing graphite racquets still being of the same strength or being stronger, which gives the racquet exceptional performance. In addition, the overall dimensions of, for example the cross-section, of the racquet can also be reduced while still maintaining performance characteristics.
1. A resin and fiber composite racket comprising a first tubular member which extends around the head of the racquet and a second tubular member which extends from the base of the handle of the racquet, around the head of the racquet and back to the base of the handle of the racquet, each of said tubular members comprising:
(a) an outer shell defining a cavity, said outer shell comprising:
(i) a plurality of layers of fibers;
(ii) a first resinous material disposed between said fibers and securing said fibers to each other;
(b) a second resinous material disposed inside said cavity, said second resinous material being configured and dimensioned to define voids within said cavity between portions of said second resinous material; and
(c) a gaseous material contained within said voids, said gaseous material being under a pressure in excess of 30 pounds per square inch.
2. A resin and fiber racket as in claim 1 , wherein said first tubular member is an inner tubular member and said second tubular member is an outer tubular member and those portions of said outer member which form part of the head may be made with less material than other portions of outer member, and those portions of said inner member which form part of the head may be made with less material than other portions of inner member.
3. A resin and fiber composite racket comprising a first tubular member which extends around the head of the racquet and a second tubular member which extends from the base of the handle of the racquet, around the head of the racquet and back to the base of the handle of the racquet.
4. A racquet as in claim 3 , wherein said first and second tubular members made from strips of graphite fiber material including a resinous component surrounding an expandable material which expands under heat and are formed by expanding said expandable material and driving said graphite fiber material to the edges of said mold.