Abstract: A composite golf club shaft having a reinforcing ribbon of composite material spiraling along an intermediate portion of the shaft and bonded thereto to reinforce the hoop strength of the shaft. The ribbon is shaped into a rib of different cross-sectional shapes, the preferred embodiment being a thin rectangular shape approximately 0.125 wide of an inch and spiraling at a rate of four turns per inch, producing a groove of equal width. The methods of the invention produces the shaft by providing a mandrel having the outside shape desired for the shaft's inside surface; wrapping a ribbon of reinforcing material around the shaft in a spiral groove therein; forming the shaft body around the mandrel; and separating the mandrel from the shaft after curing, by unscrewing the mandrel.

Abstract: A golf club shaft is formed having a flexural rigidity layer at last one third the length of which is encased in an outer layer. The shaft is formed by applying sheets of composite material to a mandrel. Sheets forming the flexural rigidity layer include unidirectional fibers oriented substantially in parallel with the longitudinal axis of the shaft. The outer layer may include composite material sheets each having unidirectional fibers oriented at an angle with respect to the shaft's longitudinal axis. An innermost layer of the shaft may be formed of composite material sheets having fibers oriented at an angle with respect to the shaft's longitudinal axis.

Abstract: A composite golf club shaft having a reinforcing ribbon of composite material spiraling along an intermediate portion of the shaft and bonded thereto to reinforce the hoop strength of the shaft. The ribbon is shaped into a rib of different cross-sectional shapes, the preferred embodiment being a thin rectangular shape approximately 0.125 wide of an inch and spiraling at a rate of four turns per inch, producing a groove of equal width. The methods of the invention produces the shaft by providing a mandrel having the outside shape desired for the shaft's inside surface; wrapping a ribbon of reinforcing material around the shaft in a spiral groove therein; forming the shaft body around the mandrel; and separating the mandrel from the shaft after curing, by unscrewing the mandrel.

Abstract: The method of producing tubular golf club shafts (10) of the same longitudinal stiffness and varying weights by wrapping composite materials on a tapered mandrel (15), or mandrels, having a given taper profile, producing a core (30) of angle-fiber-and-resin material and a shell (31) of longitudinal-fiber-and-resin material, and varying the weight of the cores to vary the shaft weight while maintaining the core size and the shell size the same. This is accomplished by moving the core along a taper profile to compensate for the change in the amount of material, thus maintaining the longitudinal stiffness/bending profile the same in the shafts of greatly varying weight. A representative family of shafts (10) has nominal weights of 55, 65, 75, 85, 95 and 105 grams, with the same stiffness/bending profile.

Abstract: A composite golf club shaft having a reinforcing ribbon of composite material spiraling along an intermediate portion of the shaft and bonded thereto to reinforce the hoop strength of the shaft. The ribbon is shaped into a rib of different cross-sectional shapes, the preferred embodiment being a thin rectangular shape approximately 0.125 wide of an inch and spiraling at a rate of four turns per inch, producing a groove of equal width. The methods of the invention produces the shaft by providing a mandrel having the outside shape desired for the shaft's inside surface; wrapping a ribbon of reinforcing material around the shaft in a spiral groove therein; forming the shaft body around the mandrel; and separating the mandrel from the shaft after curing, by unscrewing the mandrel.

Abstract: The method of producing tubular golf club shafts (10) of the same longitudinal stiffness and varying weights by wrapping composite materials on a tapered mandrel (15), or mandrels, having a given taper profile, producing a core (30) of angle-fiber-and-resin material and a shell (31) of longitudinal-fiber-and-resin material, and varying the weight of the cores to vary the shaft weight while maintaining the core size and the shell size the same. This is accomplished by moving the core along a taper profile to compensate for the change in the amount of material, thus maintaining the longitudinal stiffness/bending profile the same in the shafts of greatly varying weight. A representative family of shafts (10) has nominal weights of 55, 65, 75, 85, 95 and 105 grams, with the same stiffness/bending profile.

Abstract: Apparatus and method for locating the neutral bending plane of an elongated flexible shaft, typically a golf club shaft, by mounting one end portion of the shaft in a clamping mechanism having a rotatable clamp member that permits the shaft to turn about its longitudinal axis while being driven through a motion simulating a golf swing, with sufficient speed to cause the inertial loading of the shaft by its own mass, enhanced by a head weight, to turn the clamp member and the shaft into alignment with the path of movement of the shaft during the simulated swing. A brake fixes the shaft in this position during the swinging motion. A first embodiment uses a rotary motor to rotate the shaft in a radially projecting position about a stationary axis, with a clamping mechanism and brake mechanism on a base plate mounted on the motor shaft.

Abstract: A flex-segmented golf club shaft having tip and butt sections of preselected stiffness and flex characteristics, respectively, that are formed as separate pieces, with the larger butt section overlapping and fused to the smaller tip section and forming an external step in the shaft profile. An alternative embodiment has three such sections and two steps. The method of forming the shaft by wrapping a preselected tip section from a selection of available sections on a mandrel having a pronounced step, and then wrapping a preselected butt section from a selection of available sections on the mandrel in overlapping relation with the tip section, to provide optimized characteristics for a particular golf swing.

Abstract: Presented is a golf shaft designed to have a "kick" point or "flex" zone at a predetermined location along the length of the shaft. How and where the shaft bends or flexes during the down swing has a strong influence on how the club "feels" to the golfer. How and where the shaft bends during the down swing is determined by the construction of the golf shaft and presented herewith is a golf shaft structure and method of making it which controls the position of the flex point along the length of the shaft so that a variety of shafts having different flex characteristics may be manufactured to suit the dictates of individual players.