Abstract: A high-frequency noise detection antenna is provided with a fine coaxial line that includes a center conductor, an insulator provided so as to surround the whole periphery of the center conductor, and a ground shield provided so as to surround the whole periphery of the insulator, and in which a tip of the center conductor is exposed so as to protrude from the end of the insulator and the end of the ground shield, and an exposed ground shield provided so as to protrude from the end of the ground shield and surround a part in a circumferential direction of an exposed portion from which the center conductor protrudes.

Abstract: A golf club head has a hollow therein and comprises a face portion, a crown portion and a sole portion. The face portion comprises a central zone including a face center, and a peripheral zone surrounding the central zone. Each of the central zone and the peripheral zone has a flexural stiffness defined by E×t3/12, wherein E is the Young's modulus (GPa) and t is the thickness (mm) of the zone concerned. The ratio sc/sp of the flexural stiffness Sc of the central zone to the flexural stiffness sp of the peripheral zone is 5.0 to 55.0.

Abstract: A golf club head has a hollow therein and comprises a face portion, a crown portion and a sole portion. The face portion comprises a central zone including a face center, and a peripheral zone surrounding the central zone. Each of the central zone and the peripheral zone has a flexural stiffness defined by E×t3/12, wherein E is the Young's modulus (GPa) and t is the thickness (mm) of the zone concerned. The ratio sc/sp of the flexural stiffness Sc of the central zone to the flexural stiffness sp of the peripheral zone is 5.0 to 55.0.

Abstract: A hollow golf club head comprises a face portion having a club face for hitting a ball, and a main body portion including a crown wall, a side wall and a sole wall which extend from the face portion toward the rear of the head. At least one of the walls of the main body portion is provided with a folded portion for facilitating a partial elastic deformation of the main body portion when the face portion hits a ball. The folded portion includes a first folded portion and a second folded portion each extending in the front-back direction of the head while swinging in the thickness direction of the wall. The first folded portion and the second folded portion are continuous with each other and extend along the peripheral edge of the club face, and have different phases in the swing.

Abstract: A hollow golf club head 1 comprises a face portion 2 which includes a club face 2a for striking a ball, and a main body 3 extending rearward of the head from the face portion 2. The face Portion 2 is made of a low-specific-gravity material having a specific gravity of 4.0 or less. The main body 3 is provided in its face portion 2 side with a low stiffness zone 10 where the stiffness is locally reduced.

Abstract: A hollow golf club head comprises a face part having a face for striking a ball, and a main body extending rearward from the face part. The main body is provided with a low-rigidity zone which comprises through holes and connecting portions arranged alternately along a peripheral edge of the face. The through holes penetrate the main body from the outside to the inside of the main body. The connecting portions extend in the front-back direction of the head, and include an oblique connecting portion comprising an oblique part inclined with respect to the front-back direction.

Abstract: A hollow golf club head comprises a face portion having a club face for hitting a ball, and a main body portion including a crown wall, a side wall and a sole wall which extend from the face portion toward the rear of the head. At least one of the walls of the main body portion is provided with a folded portion for facilitating a partial elastic deformation of the main body portion when the face portion hits a ball. The folded portion includes a first folded portion and a second folded portion each extending in the front-back direction of the head while swinging in the thickness direction of the wall. The first folded portion and the second folded portion are continuous with each other and extend along the peripheral edge of the club face, and have different phases in the swing.

Abstract: A hollow golf club head 1 comprises a face portion 2 which includes a club face 2a for striking a ball, and a main body 3 extending rearward of the head from the face portion 2. The face Portion 2 is made of a low-specific-gravity material having a specific gravity of 4.0 or less. The main body 3 is provided in its face portion 2 side with a low stiffness zone 10 where the stiffness is locally reduced.

Abstract: A golf club head 1 having a hollow (i) therein comprises a face portion 2 having a face 2a for striking a ball, a crown portion 3 forming the head top surface, and a sole portion 4 forming a bottom of the head. One of or each of the crown portion 3 and the sole portion 4 is provided with a plurality of grooves bent in the same direction.

Abstract: A hollow golf club head comprises a face part having a face for striking a ball, and a main body extending rearward from the face part. The main body is provided with a low-rigidity zone which comprises through holes and connecting portions arranged alternately along a peripheral edge of the face. The through holes penetrate the main body from the outside to the inside of the main body. The connecting portions extend in the front-back direction of the head, and include an oblique connecting portion comprising an oblique part inclined with respect to the front-back direction.

Abstract: A golf club head 1 having a hollow (i) therein comprises a face portion 2 having a face 2a for striking a ball, a crown portion 3 forming the head top surface, and a sole portion 4 forming a bottom of the head. One of or each of the crown portion 3 and the sole portion 4 is provided with a plurality of grooves bent in the same direction.

Abstract: An object of the present invention is to provide a novel fiber-reinforced epoxy resin material having improved strength. The fiber-reinforced epoxy resin material of the present invention comprises a cured product of an epoxy resin composition and a reinforcing fiber, wherein the epoxy resin composition comprises a novolac type epoxy resin as an epoxy resin component, and the cured product of the epoxy resin composition has a swelling ratio in a range from 20 mass % to 44 mass % in methyl ethyl ketone.

Abstract: An object of the present invention is to provide a novel fiber-reinforced epoxy resin material having improved strength. The fiber-reinforced epoxy resin material of the present invention comprises a cured product of an epoxy resin composition and a reinforcing fiber, wherein the epoxy resin composition comprises a novolac type epoxy resin as an epoxy resin component, and the cured product of the epoxy resin composition has a swelling ratio in a range from 20 mass % to 44 mass % in methyl ethyl ketone.

Abstract: An object of the present invention is to provide a golf ball having high resilience. The present invention provides a golf ball having a constituting member, wherein at least a part of the constituting member is formed from a rubber composition containing (a) a base rubber, (b) a co-crosslinking agent, (c) a crosslinking initiator, and (d) an organic sulfur compound, the organic sulfur compound being derivatives of thiophenols and disulfide with a strong electron withdrawing substituent.

Abstract: An object of the present invention is to provide a golf ball having high resilience. The present invention provides a golf ball having a constituting member, wherein at least a part of the constituting member is formed from a rubber composition containing (a) a base rubber, (b) a co-crosslinking agent, (c) a crosslinking initiator, and (d) an organic sulfur compound, the organic sulfur compound being derivatives of thiophenols and disulfide with a strong electron withdrawing substituent.