초록 ▼

According to this method windings of reinforcing fibers are impregnated with resin and are wound, along a given length, around a flexible sheath placed onto a rigid rotary-driven mandrel. At least one additional winding of said impregnated reinforcing fiber around the flexible sheath is wound over a

According to this method windings of reinforcing fibers are impregnated with resin and are wound, along a given length, around a flexible sheath placed onto a rigid rotary-driven mandrel. At least one additional winding of said impregnated reinforcing fiber around the flexible sheath is wound over a different length and according to a different pitch.

대표청구항 ▼

A method for embodying for subsequent moulding operation a tubular flexible element impregnated with resin, for realizing a tennis racket frame, which comprises the following steps: (a) impregnating reinforcing fibers with resin; (b) winding said impregnated reinforcing fibers around a tubular flexi

A method for embodying for subsequent moulding operation a tubular flexible element impregnated with resin, for realizing a tennis racket frame, which comprises the following steps: (a) impregnating reinforcing fibers with resin; (b) winding said impregnated reinforcing fibers around a tubular flexible sheath placed onto a rigid rotary-driven mandrel having a longitudinal axis, so that at least one additional winding of said reinforcing fibers is wound over a different length and according to a pitch which varies during winding operation of the additional winding, to obtain a tubular flexible element to be molded of which anisotrophy is controlled; said tubular flexible element having a length comprised between 1200 and 1800 mm; the impregnated reinforcing fibers winding laid over the flexible sheath having a total weight comprised between 150 and 250 g.; and the impregnated fibers winding being laid over with angles contained between 18 degrees and 42 degrees with relation to the mandrel longitudinal axis; said impregnated fibers winding comprising; a first winding performed over a first length of the tubular flexible element and having a weight contained between 58% and 70% of the total weight; a second winding performed over a second length, symmetrical to a middle of the first length of the tubular flexible element, comprised between 72% and 85% of the first length, the said second winding having a weight comprised between 12% and 26% of the total weight; a third winding performed over a third length, symmetrical to the middle of the first length of the tubular flexible element, contained between 50and 62% of the first length, the said third winding having a weight comprised between 8% to 20% of the total weight; and a fourth winding performed over a fourth length, symmetrical to the middle of the first length of the tubular flexible element, comprised between 16% and 33% of the first length, the said fourth winding having a weight comprised between 2% and 8% of the total weight; and (c) separating said tubular flexible element from the mandrel and performing molding thereof.