Abstract: A golf club head (1) having a hollow portion is partly or entirely provided with a PCCP structure (2) excluding its face portion (16). By this structure, a golf club head having an outer body structure which permits the thickness of the head to be reduced without loss in the strength to be provided.

Abstract: The golf club shaft according to the present invention is provided with a pseudo-cylindrical concave polyhedral shell structure composed of triangles or trapezoids on the entire outer circumferential surface or on a part of the outer circumferential surface. With this structure of the golf club shaft, the degradation in the mechanical strength and the increase in the material cost are prevented. At the same time, a lighter weight golf club shaft can be produced while a greater degree of freedom is allowed in designing the characteristics such as bending stiffness distribution, a kick point position, bend point, etc. upon designing the golf club shaft.

Abstract: A core (3) for a caddie bag includes three arc portions (31 to 33) each with a PCCP structure. These arc portions are connected by a hinge portion (34) without the PCCP structure, and the hinge portion is bent to form a cylindrical core. The cylindrical core has one end with a collar (5) attached thereto, and the other end with a bottom member (6) attached thereto. The collar and the bottom member are connected by a frame member (12), whereby a caddie bag (1) is constructed.

Abstract: A core (3) for a caddie bag includes three arc portions (31 to 33) each with a PCCP structure. These arc portions are connected by a hinge portion (34) without the PCCP structure, and the hinge portion is bent to form a cylindrical core. The cylindrical core has one end with a collar (5) attached thereto, and the other end with a bottom member (6) attached thereto. The collar and the bottom member are connected by a frame member (12), whereby a caddie bag (1) is constructed.

Abstract: A positioner supports an antenna at an optional rotating angle and the mirror surface of the antenna at different rotating angles is measured. A computer expands the measured value into series using polar coordinates system associated with the measuring system, whereby the intrinsic deformation of the mirror surface under the zero-gravity condition and the deformation due to gravity are separately measured.

Abstract: An extendible structure includes at least three extendible longerons and a plurality of integrated radial spacers. Each spacer includes a plurality of legs integrally formed therewith to radially extend from the central part thereof. The distal end of each of the spacers is connected to a corresponding one of the extendible longerons. In the extended state of the extendible structure, at least three longerons are deployed in parallel with one another with space intervals among them in the lateral direction which intersect with the direction of extension of the longerons, and the spacers support the longerons with the horizontally spaced interval within a plane substantially perpendicular to the direction of extension of the longerons. In the collapsed condition of the extendible structure, each of the longerons is collapsed in a loop form, and the spacers are laid one upon another inside the loop formed by the longerons while the legs of the spacers are twisted.

Abstract: An extendible structure of the invention is constructed by connecting the radially projecting legs of the spacer with differing longerons through the joints, and then fastening one joint with adjacent another joint at a diagonally opposed position with a bridle. In the extended state of the structure, the spacers are within a plane which is substantially perpendicular to the direction of extension of the structure and the bridles are extended in the diagonal lines between the adjacent joints to thereby form the longerons in a mast-shaped three-dimensional structure, while, in the collapsed state of the structure, the longerons are collapsed in a loop form and the spacers are laid one upon another inside the loop formed by the longerons to thereby produce a cylindrical form in its outer appearance.

Abstract: In a testing machine a test piece and a reference piece having a known spring constant are superposed with fulcrums interposed between the opposite ends thus establishing a mirror image relationship. A load is applied to the center of the assembly by means of an elastic ring thereby creating a definite relative displacement between the test piece and the reference piece and the relative displacement is measured to determine the bending stiffness of the test piece. According to modified embodiments the torsional stiffness and tension can be measured.