# US 8,540,590 B2 · Hollow golf club head > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,540,590 B2 - Document ID: US8540590B2 - Status: Granted - Kind: B2 - Application number: 13/158,700 - Filed: 2011-06-13 - Published: 2011-12-15 - Granted: 2013-09-24 - Earliest claimed: 2010-06-14 - Assignees: K.K. Endo Seisakusho - Applicants: Daisuke Tsukada; Tomonari Funayama; Toshimitsu Oyamatsu - Inventors: Daisuke Tsukada; Tomonari Funayama; Toshimitsu Oyamatsu - Web page: https://patentgrep.com/patent/US8540590B2 ## CPC - A63B 53/0466: {wood-type} - A63B 60/52: with slits - A63B 53/0408: {characterised by specific dimensions, e.g. thickness} - A63B 53/0437: {with special crown configurations} - A63B 53/045: {Strengthening ribs} - A63B 2209/00: Characteristics of used materials - A63B: APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT (apparatus for passive exercising, massage A61H) ## Abstract There is provided a Ti alloy hollow club head which is more lightweight yet capable of realizing a better repulsion force by adjusting weight and thickness of a club head plate, with its strength ensured. Ribs are formed by chemically polishing the inner surface of a material of a crown plate to a 0.3 to 0.9 mm thickness, and a 0.3 to 4 mm width, and then first concave portions are formed to a 0.2 to 0.5 mm thickness. Thus, strength of the crown plate can be ensured by the ribs, while making the thickness thereof as thin as possible. ## Claims ### Claim 1 A hollow golf club head comprising a club head plate including thinned parts and ribs protruded therefrom, said thinned parts and ribs being formed by chemically polishing a certain area on a surface of a material of said club head plate to adjust weight and thickness of said club head plate; wherein the chemically-polished area on the surface of the material of said club head plate comprises: a first area on which a plurality of said ribs are formed, and a second area surrounded with the plurality of said ribs to define said thinned parts, wherein the thickness of the material of said club head plate is greater than that of said first area, and that of said first area is greater than that of said second area; and wherein the surface of the material of said club head plate is located on an inside of a crown plate, and said ribs are formed to have a thickness not less than 0.4 mm but less than the thickness of the material for the club head plate as well as a width in a range of from 0.4 to 4 mm, while said thinned parts are formed to have a thickness in a range of from 0.2 to 0.5 mm. ### Claim 2 (depends on 1) The hollow golf club head according to claim 1, wherein said thinned parts formed by the chemical polishing are allowed to define concave portions so that said ribs are protruded from predetermined places on the concave portions. ### Claim 3 (depends on 1) The hollow golf club head according to claim 1, wherein said ribs are arranged in a shape of a regular hexagon, and each of said ribs is continuously arranged back and forth, and right and left to be arranged in a honeycomb pattern. ### Claim 4 (depends on 1) The hollow golf club head according to claim 1, wherein said ribs are arranged in a rectangular lattice pattern in a planar view by allowing them to intersect with each other at right angles. ### Claim 5 (depends on 1) The hollow golf club head according to claim 1, wherein said ribs are arranged in a rhombic lattice pattern in a planar view by allowing them to intersect with each other at angles other than a right angle. ### Claim 6 (depends on 1) The hollow golf club head according to claim 1, wherein said ribs are arranged in parallel with each other so as not to intersect with each other. ### Claim 7 (depends on 1) The hollow golf club head according to claim 1, wherein the material of said club head plate is that for a crown plate. ### Claim 8 (depends on 1) The hollow golf club head according to claim 1, wherein the material of said club head plate is that for a sole-periphery plate. ### Claim 9 A hollow golf club head comprising a club head plate including thinned parts and ribs protruded therefrom, said thinned parts and ribs being formed by chemically polishing a certain area on a surface of a material of said club head plate to adjust weight and thickness of said club head plate; wherein the chemically-polished area on the surface of the material of said club head plate comprises: a first area on which a plurality of said ribs are formed, and a second area surrounded with the plurality of said ribs to define said thinned parts, wherein the thickness of the material of said club head plate is greater than that of said first area, and that of said first area is greater than that of said second area; and wherein the chemically-polished area on the surface of the material of said club head plate encompasses an uppermost inner area located corresponding to a top of the crown plate in a planar view such that the chemically-polished area makes up more than or equal to 60% of a whole inner surface of the crown when the club head is disposed on a horizontal plane at predetermined loft and lie angles. ### Claim 10 (depends on 9) The hollow golf club head according to claim 9, wherein the material of said club head plate is that for a crown plate. ### Claim 11 (depends on 9) The hollow golf club head according to claim 9, wherein the material of said club head plate is that for a sole-periphery plate. ### Claim 12 (depends on 9) The hollow golf club head according to claim 9, wherein said thinned parts formed by the chemical polishing are allowed to define concave portions so that said ribs are protruded from predetermined places on the concave portions. ### Claim 13 (depends on 9) The hollow golf club head according to claim 9, wherein said ribs are arranged in a shape of a regular hexagon, and each of said ribs is continuously arranged back and forth, and right and left to be arranged in a honeycomb pattern. ### Claim 14 (depends on 9) The hollow golf club head according to claim 9, wherein said ribs are arranged in a rectangular lattice pattern in a planar view by allowing them to intersect with each other at right angles. ### Claim 15 (depends on 9) The hollow golf club head according to claim 9, wherein said ribs are arranged in a rhombic lattice pattern in a planar view by allowing them to intersect with each other at angles other than a right angle. ### Claim 16 (depends on 9) The hollow golf club head according to claim 9, wherein said ribs are arranged in parallel with each other so as not to intersect with each other. ### Claim 17 A hollow golf club head comprising a club head plate including thinned parts and ribs protruded therefrom, said thinned parts and ribs being formed by chemically polishing a certain area on a surface of a material of said club head plate to adjust weight and thickness of said club head plate; wherein the chemically-polished area on the surface of the material of said club head plate comprises: a first area on which a plurality of said ribs are formed, and a second area surrounded with the plurality of said ribs to define said thinned parts, wherein the thickness of the material of said club head plate is greater than that of said first area, and that of said first area is greater than that of said second area wherein said ribs are arranged in a shape of a regular hexagon, and each of said ribs is continuously arranged back and forth, and right and left to be arranged in a honeycomb pattern; and wherein the material of said club head plate is that for a crown plate. ### Claim 18 A hollow golf club head comprising a club head plate including thinned parts and ribs protruded therefrom, said thinned parts and ribs being formed by chemically polishing a certain area on a surface of a material of said club head plate to adjust weight and thickness of said club head plate; wherein the chemically-polished area on the surface of the material of said club head plate comprises: a first area on which a plurality of said ribs are formed and a second area surrounded with the plurality of said ribs to define said thinned parts, wherein the thickness of the material of said club head plate is greater than that of said first area, and that of said first area is greater than that of said second area; wherein said ribs are arranged in a shape of a regular hexagon, and each of said ribs is continuously arranged back and forth, and right and left to be arranged in a honeycomb pattern; and wherein the material of said club head plate is that for a sole-periphery plate.