Patent ID: 8128772
Filing Date: 2012-03-06
Classification: A63B,B29C,B29L

Abstract:
1. A method of making a golf club shaft having a grip end opposite a head end defining a length of the shaft extending between those two ends, comprising: wrapping a composite matrix completely around a mandrel tapering from the larger grip end of the mandrel toward a smaller head end of the mandrel, the mandrel having a first portion with a polygon outer periphery formed of a plurality of between 16-24 flats joined at rounded corners, the mandrel having a second portion extending over the head end of the mandrel in which the mandrel has a generally circular outer periphery; subjecting the mandrel and wrapped composite matrix to pressure and increased temperature sufficient to cause the matrix to bind strands in the matrix to form a unitary composite structure in the shape of a tubular shaft, the corners of the mandrel being sufficiently round and the matrix being sufficiently thick to form the tubular shaft with a cross-sectional shape that is generally circular along the length of the shaft while having a plurality of flats on a first portion of the inside of the tubular shaft and having a generally circular cross-sectional shape on a second of the shaft at the head end of the shaft; and separating the shaft from the mandrel.