# US 2018/0178085 A1 · Tennis racket frame > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0178085 A1 - Document ID: US20180178085A1 - Status: Published application - Kind: A1 - Application number: 15/807,576 - Filed: 2017-11-09 - Published: 2018-06-28 - Earliest claimed: 2016-12-26 - Assignees: Dunlop Sports Co. Ltd. - Applicants: Dunlop Sports Co. Ltd. - Inventors: YOSUKE YAMAMOTO - Web page: https://patentgrep.com/patent/US20180178085A1 ## CPC - A63B 49/02: Frames - A63B 49/10: made of non-metallic materials, other than wood - A63B 2049/0211: {with variable thickness of the head in a direction perpendicular to the string plane} - A63B 2049/0217: {with variable thickness of the head in the string plane} - A63B 2209/02: with reinforcing fibres, e.g. carbon, polyamide fibres - A63B: APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT (apparatus for passive exercising, massage A61H) ## Abstract A racket frame has an inner thick part (28) having an outer surface (12), an inner surface (14) and a pair of middle surfaces (16) each positioned between the outer surface (12) and the inner surface (14). A thickness (Ti) of the inner surface (14) is greater than a thickness (To) of the outer surface (12). A thickness of the inner thick part (28) gradually increases toward the inside. Consequently, the middle surface (16) is inclined with respect to an X direction. A distance (Ld) between an outer end and an inner end in a thickness direction of the middle surface (16) is equal to or greater than 0.5 mm. ## Claims ### Claim 1 A tennis racket frame formed of a pipe having an outer surface, an inner surface, and a pair of middle surfaces each disposed between the outer surface and the inner surface, the tennis racket frame comprising: an inner thick part in which the middle surfaces are inclined with respect to a ball hitting surface such that a thickness of the pipe is gradually increased inward; and an outer thick part in which the middle surfaces are inclined with respect to the ball hitting surface such that the thickness of the pipe is gradually increased outward. ### Claim 2 (depends on 1) The tennis racket frame according to claim 1, further comprising: a uniform thickness part in which the middle surfaces are parallel to the ball hitting surface. ### Claim 3 (depends on 2) The tennis racket frame according to claim 2, wherein, when the tennis racket frame is divided into a top section, a grip-side section, and a central section disposed between the top section and the grip-side section, the top section has any of the inner thick part, the outer thick part and the uniform thickness part, and the central section has the remainder of the inner thick part, the outer thick part and the uniform thickness part. ### Claim 4 (depends on 2) The tennis racket frame according to claim 2, wherein, when the tennis racket frame is divided into a top section, a grip-side section, and a central section disposed between the top section and the grip-side section, the central section has any of the inner thick part, the outer thick part and the uniform thickness part, and the grip-side section has the remainder of the inner thick part, the outer thick part and the uniform thickness part. ### Claim 5 (depends on 1) The tennis racket frame according to claim 1, wherein a distance between an outer end and an inner end of the middle surface of the inner thick part in a thickness direction is 0.5 mm or more. ### Claim 6 (depends on 2) The tennis racket frame according to claim 2, wherein a distance between an outer end and an inner end of the middle surface of the inner thick part in a thickness direction is 0.5 mm or more. ### Claim 7 (depends on 3) The tennis racket frame according to claim 3, wherein a distance between an outer end and an inner end of the middle surface of the inner thick part in a thickness direction is 0.5 mm or more. ### Claim 8 (depends on 4) The tennis racket frame according to claim 4, wherein a distance between an outer end and an inner end of the middle surface of the inner thick part in a thickness direction is 0.5 mm or more. ### Claim 9 (depends on 1) The tennis racket frame according to claims 1, wherein a distance between an inner end and an outer end of the middle surface of the outer thick part in a thickness direction is 0.5 mm or more. ### Claim 10 (depends on 2) The tennis racket frame according to claim 2, wherein a distance between an inner end and an outer end of the middle surface of the outer thick part in a thickness direction is 0.5 mm or more. ### Claim 11 (depends on 3) The tennis racket frame according to claim 3, wherein a distance between an inner end and an outer end of the middle surface of the outer thick part in a thickness direction is 0.5 mm or more. ### Claim 12 (depends on 4) The tennis racket frame according to claim 4, wherein a distance between an inner end and an outer end of the middle surface of the outer thick part in a thickness direction is 0.5 mm or more. ### Claim 13 (depends on 5) The tennis racket frame according to claim 5, wherein a distance between an inner end and an outer end of the middle surface of the outer thick part in a thickness direction is 0.5 mm or more. ### Claim 14 A tennis racket frame formed of a pipe having an outer surface, an inner surface, and a pair of middle surfaces each disposed between the outer surface and the inner surface, wherein the tennis racket frame is divided into a top section, a grip-side section, and a central section disposed between the top section and the grip-side section, the central section has an inner thick part, and in the inner thick part, the middle surfaces are inclined with respect to a ball hitting surface such that a thickness of the pipe is gradually increased inward. ### Claim 15 (depends on 14) The tennis racket frame according to claim 14, wherein the top section has an outer thick part, and in the outer thick part, the middle surfaces are inclined with respect to the ball hitting surface such that a thickness of the pipe is gradually increased outward. ### Claim 16 (depends on 15) The tennis racket frame according to claim 15, wherein the grip-side section has a uniform thickness part, and in the uniform thickness part, the middle surfaces are parallel to the ball hitting surface. ### Claim 17 (depends on 14) The tennis racket frame according to claim 14, wherein the grip-side section has a uniform thickness part, and in the uniform thickness part, the middle surfaces are parallel to the ball hitting surface.