Described is a knob for application to the gripping end of a hollow stick. The knob comprises a rounded, oblique, cylindrical support structure, transitional shaft and tang aligned on a common longitudinal central axis. The support structure comprises a greater diameter rounded, cantle-like support and gripping structures.

A motion measurement apparatus includes an inertial sensor and a host terminal. The inertial sensor measures a motion. The host terminal includes an input section and a control section. The input section is used to input an item identifier allocated to each motion of a user. The control section generates a control signal for controlling a sampling rate of the inertial sensor according to the item identifier which is input via the input section, and outputs the control signal to the inertial sensor.

A ball bat includes at least one disc member in the bat barrel. The at least one disc member may include at least one solid disc member or at least one non-solid disc member with an opening, or both. The outer perimeters of the disc members may optionally be separated from the inner wall of the ball bat by a buffer layer, such as a layer of open-cell foam or adhesive. In some embodiments, the ball bat may further include at least one positioning member, such as an insulation foam member. The at least one positioning member may be located between two disc members, and multiple positioning members may optionally be arranged in alternating fashion with disc members within the bat. The at least one positioning member may be an insulation foam member having a hollow center portion.

A ball bat includes at least one disc member in the bat barrel. The at least one disc member may include at least one solid disc member or at least one non-solid disc member with an opening, or both. The outer perimeters of the disc members may optionally be separated from the inner wall of the ball bat by a buffer layer, such as a layer of open-cell foam or adhesive. In some embodiments, the ball bat may further include at least one positioning member, such as an insulation foam member. The at least one positioning member may be located between two disc members, and multiple positioning members may optionally be arranged in alternating fashion with disc members within the bat. The at least one positioning member may be an insulation foam member having a hollow center portion.

To provide a bat gripping structure that enables a batter to achieve a proper grip, a grip structure is provided in which the bat is in the “top” position during the take-back of batting, in order to accomplish the swing “to put the bat outwardly from inside” along a line of the bottom hand, a locking structure that enables a lower region (bottom grip) of the grip portion to be gripped at the grip portion of the bat under the palmar grip is employed to provide the grip structure effective to lock the palmar grip of the bottom hand, so that a proper swing to “put the bat out from inside” may be achieved and the angular velocity during the bat swinging is increased. Also, the bat structure is also provided in which by adding a weight ΔM (10˜100 gr) to the bat head H of the bat having the grip structure of the kind referred to above, the batting energy at the sweet spot is improved to enhance the impact having the maximum batting effect.

A method of forming a barrel portion including obtaining a mandrel shaped to define at least an inner surface of a barrel portion of the bat, wrapping a first plurality of layers of fiber composite material about the mandrel, placing a removable material over a first portion of the first plurality of layers, and wrapping a second plurality of layers of fiber composite material over the removable material and the portion of the first plurality of layers not covered by the removable material for form an assembly. The method further includes separating the mandrel from the assembly, inserting an expandable member within the assembly, inserting the assembly into a barrel-forming mold, and molding the assembly in a single molding cycle, curing the first and second layers with the removable material to form the barrel portion of the bat, and removing the removable material and the member from the barrel portion.

A composite ball bat includes multiple failure planes within a barrel wall. By including multiple failure planes in a barrel wall, the bat exhibits a drop in performance when subjected to rolling or other extreme deflection, with no temporary increase in barrel performance. Because the barrel performance does not increase, the ball bat is able to comply with performance limitations imposed by regulatory associations.

A composite ball bat includes multiple failure planes within a barrel wall. By including multiple failure planes in a barrel wall, the bat exhibits a drop in performance when subjected to rolling or other extreme deflection, with no temporary increase in barrel performance. Because the barrel performance does not increase, the ball bat is able to comply with performance limitations imposed by regulatory associations.

A motion sensor package with an elastomer layer that encases the sensor electronics, including the sensors, a processor, an antenna, and a battery. The elastomer layer may provide shock isolation and water resistance to protect the enclosed electronics. Embodiments may also include an outer housing into which the elastomer encased package is installed. The outer housing may for example comprise two cylindrical sections that screw together to close the outer housing. In one or more embodiments part of the outer housing may be integrated into an item of sports equipment. Embodiments for golf may also include a golf club grip adapter that is inserted into the top of a grip, and which attaches to the outer housing containing the elastomer enclosed sensor package.

A resilient rod that provides adjustable directional resistance is disclosed. In one aspect of the invention, a resistance level may be determined based on a thickness of the rod and a position of an applied force with respect to a fulcrum point. In another aspect of the invention, at least one spine may be attached to the beam to increase a diameter of the beam along one axis. The resistance level may be determined based on the thickness of the rod, the position of the applied force and an orientation of the at least one spine with regard to the direction of the applied force. In other aspects of the invention, the resilient rods may be incorporated into a golf club that provides for adjustable resistance levels.