Abstract: A method for selecting a golf ball suitable for a golfer, comprising the steps of (i) obtaining head speed and backspin when a golfer hits a golf ball with a golf club; (ii) obtaining from the golfer ball-type selection data for determining which among a plurality of ball types is suitable for the golfer; and (iii) selecting a golf ball of a type (e.g., a distance-type ball or a control-type ball) suitable for the golfer on the basis of the head speed and backspin obtained in step (i) and the ball-type selection data obtained in step (ii), in such a manner that the selected golf ball produces backspin close to optimal backspin corresponding to the above-described head speed.

Abstract: A golf club swing weight balance and scale according to the invention includes a weighing beam having and extending between first and second ends, a grip backstop disposed at the second end of the weighing beam and including a grip cap compensator movable within the grip backstop between an extended position and a retracted position, a slide weight slideably mounted on the weighing beam, and a pivot assembly pivotally supporting the weighing beam at a location intermediate the first and second ends and including a single support member disposed on only one side of the weighing beam so that the slide weight can be moved from the first end to the second end in a single stroke. The pivot assembly preferably includes a knife edge fulcrum, one end of which includes a knife edge pivotally connected to the weighing beam. The slide weight indicator includes a balance indicator indicating when the weighing beam is balanced, most preferably a bubble level mounted on the slide weight.

Abstract: A device for measuring alignment of a golf club is provided, and allows measurement of the lie angle and loft angle simultaneously. The strike face of the club is placed against an abutment member that is fixed to a base member, and held in place with a clamping member. An alignment member is coupled to the base member and spaced from the clamping member in generally opposing relation thereto. The alignment member is movable with respect to the clamping member to receive the golf club shaft in a cradle.

Abstract: A device for measuring alignment of a golf club is provided, and allows measurement of the lie angle and loft angle simultaneously. The strike face of the club is placed against an abutment member that is fixed to a base member, and held in place with a clamping member. An alignment member is coupled to the base member and spaced from the clamping member in generally opposing relation thereto. The alignment member is movable with respect to the clamping member to receive the golf club shaft in a cradle.

Abstract: Methods and apparatus for testing a striking-type sports implement such as a bat is disclosed. In terms of apparatus, a system according to the invention includes a bat-swinging module, a ball-delivery module, and one or more programmed computers. The bat-swinging module includes means to grip a bat at its handle end, and an independent, computer servo-controlled motor to swing the bat. The ball-delivery module includes a ball support and a second, independent, computer servo-controlled motor to place the ball into the swing of the bat along a delivery path such that the bat is able to strike the ball and cause the ball to travel along a precise trajectory path. Various sensors are disposed to measure swing speed, “pitch” speed and exit velocity, with the computer(s) being operative to construct a database of bat performance characteristics based upon swing speed, pitch speed and exit velocity, and display selected portions of the database in accordance with a user input.

Abstract: A golf club is evaluated by measuring a moment of inertia about an axis perpendicular to a face plane of the golf club head through a center of a mass of the golf club head. The golf club has the evaluation imparted by a moment of inertia information relating to a value of the moment of inertia or a value obtained by dividing the moment of inertia by a mass value of the golf club head. A golf club set is composed of at least three golf clubs having different loft angles and each of the golf clubs has the size of the moment of inertia adjusted corresponding to an order of golf club number or an order of a value of the loft angle. The moment of inertia changes linearly corresponding to the order of the golf club number or the loft angle.

Abstract: An apparatus and a method for measuring the flexural characteristic of a golf club shaft. The apparatus includes a table having a clamping structure for clamping the golf club shaft thereto. A data collection system having a computer coupled to an image recording device measures the amount of deflection of the golf club shaft before and after a bending moment is applied to the golf club shaft. The stiffness of the golf club shaft is determined from the amount of deflection.

Abstract: Golf practice apparatus, comprising two sphere segments of a simulated golf ball mounted on opposing sides of a pivotal structure, strain gauges mounted on the structure to measure strains caused by a strike force to the simulated ball, an electronics unit for digitally encoding voltages resulting from the strains, and software for determining a three-dimension strike force, torque content thereof, and strike force duration. Strain gauges mounted on the structure between the ball segments determine one component of the strike force and torque about both horizontal and vertical axes. Strain gauges mounted on a support column of the pivotal structure determine the remaining strike force components. Additional software is disclosed for deriving an initial three-dimension velocity vector and spin rates about both horizontal and vertical axes of a free ball similarly struck whereby a three-dimension trajectory of a free golf ball may be computed.

Abstract: Disclosed is an evaluation method of a golf club, where a rear end portion of a club shaft is vibrated in a state where a tip portion of the club shaft is fastened to measure a frequency per unit time, and a golf club using the club shaft is evaluated based on the frequency.

Abstract: A dynamic inertial balancing system (10) uses a shaft (20) mounted to a base (16). A motor (46) or pulley system (42) imparts rotational torque on the shaft. A swing arm (18) is coupled to the shaft and moves through an arc in a horizontal plane in response to the rotational torque. A golf club is mounted to the swing arm. A timer (38) records the time for the swing arm to traverse the arc. The system balances the golf clubs within a set by measuring their moments of inertia. Each golf club is placed on swing arm 18 and the time is measured for the each golf club to complete the swing arc. If torque is constant for all clubs, then by comparing the moments of inertia, i.e. by comparing the time for each club to complete the swing arc, the club set can be balanced.

Abstract: The present invention relates to a golf club head provided with a face and a body. The face has a central zone and a intermediate zone adjacent and surrounding the central zone. The central zone has a first flexural stiffness and the intermediate zone has a second flexural stiffness. The club head face is configured and dimensioned such that the first flexural stiffness is significantly greater than the second flexural stiffness such that upon ball impact with the face, the intermediate zone exhibits substantial deformation so that the central zone moves into the club head. At the same time, the central zone exhibits minimal deformation so that it moves into and out of the club head as a unit. Furthermore, the face exhibits a high coefficient of restitution.

Abstract: An apparatus and a method for determining a vibrational characteristic of a golf club shaft. The apparatus includes a table having a clamping structure for clamping the golf club shaft thereto. A multi-dimensional accelerometer is coupled to a tip end of the golf club shaft. The multi-dimensional accelerometer is also coupled to a computer. When the golf club shaft is vibrated, the multi-dimensional accelerometer converts the vibrational signal into an electrical signal which is transmitted to the computer. The computer conditions the electrical signal and outputs a signal indicative of the frequency of vibration of the golf club shaft. The stiffness of the golf club shaft is determined from the vibrational frequency of the golf club shaft.

Abstract: A method and a system for measuring the spin decay rate of a golf ball. The system includes an indoor testing area, a launching device, and a measuring device positioned at a final position along the ball's flight path. When the ball is launched by the launching device, the measuring device measures the spin rate and speed at the final position. Then, the launching device can launch the ball at the speed and spin rate of the final position and a new final speed and spin rate are measured again. The spin rate difference from launching to the final position is used to determine the spin decay rate. By using discrete spin decay rate measurements, the spin decay rate profile of a golf ball during its entire flight can be measured in the indoor area.

Abstract: A method of making a truly balanced golf putter that is normally swung in a parabolic path during the execution of a putting stroke. The putter shaft is attached to a golf putter head. The exact center of gravity of the putter head is determined and the golf putter is dynamically swung in a parabolic path. The amount of rotation of the putter head is determined relative to a straight line along the parabolic path and the putter head and putter shaft are adjusted relative to each other by rotating the shaft with respect to the putter head until a perfect balance is achieved.