Abstract: A golf club head having a face part, a sole part, a side part, a crown part and a hosel part, all of which surround a hollow part comprises a penetration hole that is provided on the crown part, penetrating the crown part so that the hollow part is connected with an outer atmosphere of the golf club head and a non-metal cover that is provided over the penetration hole. A recess part, which forms a recess, is provided on a surface of the non-metal cover.

Abstract: An iron type golf club head includes: a main body portion having a face surface and a sole surface; a backward bulging section provided at a lower back section of the main body portion, the bulging section including: an upper surface side recess formed to extend downward from the upper surface of the backward bulging section; and a lower surface side recess formed to extend upward from the lower surface of the backward bulging section; and a hosel portion connected to the main body portion, wherein the upper surface side recess and the lower surface side recess are overlapped at least in part with each other in the perspective side view of the head when viewed from the toe side of the iron type golf club head.

Abstract: This invention provides a hollow golf club head including a metal plate portion provided with thin and thick portions. A medium thick portion having an intermediate thickness between the thicknesses of the thin and thick portions is formed at the boundary portion between the thin and thick portions. The thin and medium thick portions are formed by the steps of pressing the metal plate portion to form a recess in one surface of the metal plate portion and a projection on its other surface, performing chemical milling of the recess and a portion surrounding it, and removing the projection by grinding.

Abstract: A golf club head includes: a face portion; a crown portion, furrows being formed on an interior surface of at least a part of the crown part in a mesh-like pattern; a side portion; a sole portion, at least a front part of the sole portion being made of metal, and furrows being formed on an interior surface of at least a part of the front part in a mesh-like pattern; and a hosel portion.

Abstract: An iron golf club head includes a hosel part embedded member installed in a hosel part thereof, a sole part embedded member installed in a sole part thereof, and a top part embedded member installed in an upper portion of a face part of thereof. In a shank part (neck part) connecting the hosel part to the body part, a connecting embedded member for connecting the hosel part embedded member to the sole part embedded member is installed. These embedded members are covered with a synthetic resin layer. The hosel part embedded member and the connecting embedded member each are preferably made of a metal.

Abstract: An iron golf club head according to this invention includes a head body and a face member. The face member includes a front portion forming portion which forms the front portion of a sole portion. The head body includes a sole forming portion thicker than the front portion forming portion. The end surface of the sole forming portion on the side of a face portion includes a lower region attached to the end surface of the front portion forming portion on the back side, and an upper region above the lower region. An elastic body is disposed in the gap between the upper region and the back surface of the face member.

Abstract: An iron type golf club head includes: a main body portion having a face surface and a sole surface; a backward bulging section provided at a lower back section of the main body portion, the bulging section including: an upper surface side recess formed to extend downward from the upper surface of the backward bulging section; and a lower surface side recess formed to extend upward from the lower surface of the backward bulging section; and a hosel portion connected to the main body portion, wherein the upper surface side recess and the lower surface side recess are overlapped at least in part with each other in the perspective side view of the head when viewed from the toe side of the iron type golf club head.

Abstract: A golf club head of an iron type includes a face plate part for hitting a ball, which has a cavity part on the back side thereof; a sole part; a hosel part for connecting the head to a shaft; a viscoelastic body made to adhere to the back face of the face plate part, the viscoelastic body including a board-shaped part located on the back face of a central portion of the face plate part and extending parts extending from the board-shaped part to the toe side and the heel side of the head; and a cover plate lapping over the viscoelastic body, the cover plate including a concavity for accommodating the board-shaped part of the viscoelastic body and concave lines for accommodating the extending parts of the viscoelastic body. The cover plate has an opening, and a part of the viscoelastic body is exposed through the opening.

Abstract: A golf club includes: a shaft; a head mounted on a leading end of the shaft; and a substantially cylindrical shaft case fixed to the leading end of the shaft, wherein: the shaft case is inserted into the tubular portion of the hosel of the head; the tubular portion includes a partition plate section in the lower portion thereof; a spacer is interposed between the leading end of the shaft case and partition plate section; the shaft case is unrotatably engaged with the spacer; the spacer and partition plate section respectively include stopper portions for preventing the rotation of the spacer; and a bolt inserted through bolt insertion holes respectively formed in the partition plate section and spacer from the sole side of the head is screwed into the shaft case, whereby the shaft case is fixed to the head.

Abstract: A golf club includes: a shaft; a head; and a shaft case, and a hosel column wherein: a threaded ring including a plurality of threads provided on an inner periphery of an inner hole of the threaded ring is provided on an upper side of a dividing member, the threads extending in an axis center direction of the inner hole; the shaft case includes a convex axis member provided at a top end of the shaft case; the convex axis member is inserted in the inner hole of the threaded ring, and any one of corner edges of the convex axis member and the convex threads connect with the threads of the threaded ring; and a bolt that is inserted into a bolt insertion hole provided to the dividing member from a sole side of the head is screwed into the shaft case.

Abstract: A golf club head includes: a face portion; a crown portion, furrows being formed on an interior surface of at least a part of the crown part in a mesh-like pattern; a side portion; a sole portion, at least a front part of the sole portion being made of metal, and furrows being formed on an interior surface of at least a part of the front part in a mesh-like pattern; and a hosel portion.

Abstract: This invention provides a hollow golf club head including a metal plate portion provided with thin and thick portions. A medium thick portion having an intermediate thickness between the thicknesses of the thin and thick portions is formed at the boundary portion between the thin and thick portions. The thin and medium thick portions are formed by the steps of pressing the metal plate portion to form a recess in one surface of the metal plate portion and a projection on its other surface, performing chemical milling of the recess and a portion surrounding it, and removing the projection by grinding.

Abstract: A wood type golf club head according to this invention includes a face portion and a crown portion. A center-of-gravity position mark which indicates a point where the center of gravity of the wood type golf club head is projected to the crown portion is formed on the surface of the crown portion.

Abstract: A golf club head of an iron type includes a face plate part for hitting a ball, which has a cavity part on the back side thereof; a sole part; a hosel part for connecting the head to a shaft; a viscoelastic body made to adhere to the back face of the face plate part, the viscoelastic body including a board-shaped part located on the back face of a central portion of the face plate part and extending parts extending from the board-shaped part to the toe side and the heel side of the head; and a cover plate lapping over the viscoelastic body, the cover plate including a concavity for accommodating the board-shaped part of the viscoelastic body and concave lines for accommodating the extending parts of the viscoelastic body. The cover plate has an opening, and a part of the viscoelastic body is exposed through the opening.

Abstract: An iron golf club head has a faceplate for hitting a golf ball, the faceplate having a back face; a viscoelastic body fixed onto the back face of the faceplate; and a backplate for sandwiching the viscoelastic body with the faceplate, the backplate having a flange that extends out of the periphery of the viscoelastic body and is fixed onto the back face of the faceplate.

Abstract: A golf club includes: a shaft; a head mounted on a leading end of the shaft; and a substantially cylindrical shaft case fixed to the leading end of the shaft, wherein: the shaft case is inserted into the tubular portion of the hosel of the head; the tubular portion includes a partition plate section in the lower portion thereof; a spacer is interposed between the leading end of the shaft case and partition plate section; the shaft case is unrotatably engaged with the spacer; the spacer and partition plate section respectively include stopper portions for preventing the rotation of the spacer; and a bolt inserted through bolt insertion holes respectively formed in the partition plate section and spacer from the sole side of the head is screwed into the shaft case, whereby the shaft case is fixed to the head.

Abstract: A golf club head (1) comprises a head main body (10) having a concave portion (11) formed in the face side and a face plate (20) fixed to the head main body (10). The face plate (20) is mounted on the head main body (10) such that a concave step portion (21) engages with a convex step portion (16a) of the head main body (10), and the upper edge portion, lower edge portion, and toe-side edge portion of the face plate (20) abut against edge portions (13), (14), and (15) of the head main body, respectively. The face plate (20) is laser-welded along its perimeter and fixed to the head main body (10).