Abstract: A thermistor layer of the present invention is configured to be disposed in an electrical current path. The thermistor layer comprises a thermosensitive particle, a plurality of electro-conductive particles covering a surface of the thermosensitive particle, and a binder adhering the electro-conductive particles, the electro-conductive particles form an electro-conductive network, at least the surface of the thermosensitive particle is made of a thermoplastic resin, the thermoplastic resin softens at a temperature lower than a temperature at which the binder softens, and the thermistor layer is provided to become highly resistive due to softening and deformation of the thermoplastic resin.

Abstract: A golf club head which can be reduced in its thickness with no fear of impairing the durability and strength of the club head. A face portion of the golf club head is configured such that the vertical dimension of the face portion is smaller than the horizontal dimension thereof, and the face portion is arranged so as to satisfy any of the following conditions: 1) the longitudinal direction of crystal grains of a material of the face portion is oriented in the vertical direction of the face portion; 2) the direction in which the material exhibits a large ductile amount at the time of breaking is oriented in said vertical direction; and 3) the direction in which the material exhibits a large ratio of ductility per unit length is oriented in said vertical direction.

Abstract: A golf club head which can be reduced in its thickness with no fear of impairing the durability and strength of the club head. A face portion of the golf club head is configured such that the vertical dimension of the face portion is smaller than the horizontal dimension thereof, and the face portion is arranged so as to satisfy any of the following conditions: 1) the longitudinal direction of crystal grains of a material of the face portion is oriented in the vertical direction of the face portion; 2) the direction in which the material exhibits a large ductile amount at the time of breaking is oriented in said vertical direction; and 3) the direction in which the material exhibits a large ratio of ductility per unit length is oriented in said vertical direction.

Abstract: A golf club head includes a pair of protrusions integral with a sole. Each protrusion elongates in a swing direction and protrudes downward from the sole. A weight having a larger specific gravity than the sole is accommodated in the protrusions.

Abstract: In a manufacturing method of a golf club head, when a portion close to the outer edge of the inserting end of the face body is press-fitted and inserted into the recess being plastically deformed along the bottom section of the recess, the probability of occurrence of blow holes in the dented section formed in the recess is low compared with the conventional head body; the engaging strength of the face body with the recess of the head body is enhanced compared with the conventional head body; and further it is easy to manufactured the club head.

Abstract: The invention relates a golf club head with a structure which can stabilize the direction of the hit ball and can enhance a ball hitting feeling. In the golf club head, a recessed portion is formed in a face portion of a head main body formed of metal with the peripheral edge portion of the face portion remaining unrecessed. A face plate formed of material smaller in specific gravity than the head main body is mounted to the recessed portion. A frame member formed of material larger in specific gravity than the head main body and softer than the face plate and head main body is held by and between the peripheral wall of the face plate and the peripheral wall of the recessed portion.

Abstract: A golf club head capable of enhancing a moment of inertia and improving a directional stability of a ball. In the golf club head, a flange is formed on a peripheral portion of a back side of a head body, and projects rearwardly from the head body to thereby form a cavity in the back side, and a weight member, made of a material larger in specific gravity than the head body is secured within a recessed formed in outer peripheral surface of the flange. The weight is positioned at a top and a sole side of the head body so as to evenly distribute the weight over the outer peripheral surface of the flange.

Abstract: The invention concerns an arrangement for a golf club head, which can enhance the surface rigidity of the ball hitting surface of a face plate to extend the carry of the ball and to stabilize the direction of the hit ball. In the golf club head, a recessed portion is formed in the back portion of a head main body formed of metal with the peripheral edge portion thereof remaining unrecessed, and a support portion having a thickness smaller than the peripheral edge portion is provided integrally with the head main body in such a manner that it is interposed between the mutually facing inner walls of the recessed portion.