Abstract: To improve repulsion performance when a ball is hit by a racket. Grommets each include a strip-shaped portion and a cylinder portion protruding from one surface of the strip-shaped portion. The cylinder portion includes a plurality of ribs extending along an extending direction of a central axis of a cylinder main body. The plurality of ribs is constituted of first ribs protruding from an outer peripheral surface of the cylinder main body toward both sides in the extending direction of the strip-shaped portion, and second ribs protruding from the outer peripheral surface of the cylinder main body toward both sides in a direction orthogonal to the extending direction of the strip-shaped portion. Two or more of the first ribs are formed on each of the both sides in the extending direction of the strip-shaped portion, and one or more of the second ribs are formed on each of the both sides in the direction orthogonal to the extending direction of the strip-shaped portion.

Abstract: Repulsive-performance upon ball hitting with a racket is enhanced, and good feeling of ball hitting is ensured. A grommet includes a cylindrical part which is mounted pierced through a through hole formed in a frame of a racket and through which a string passes. The string is extended in a tensioned state on the frame and deflected with one end side of the cylindrical part as a deflection position. The cylindrical part includes a first formation section located on a deflection-position side with reference to a central axis position of an outer peripheral face of the cylindrical part and a second formation section located on an opposite side of the central axis position from the first formation section. The first formation section has a greater thickness than the second formation section in a radial direction of the cylindrical part.

Abstract: Structures with racket performance varied according to the configurations of cylindrical parts can be easily used. A grommet (25-28) includes a cylindrical part (32) which is mounted pierced through a through hole (23) formed in a frame (20) of a racket (10) and through which a string (21) passes. The string is extended in a tensioned state on the frame so as to form front and back faces as hitting faces (22). The cylindrical part includes a first formation section (35) forming both sides of a central axis position (C) of the cylindrical part and a second formation section (36) rotationally shifted with reference to the central axis position by 90 degrees relative to the first formation section and forming both sides of the central axis position. One of the first and second formation sections is disposed on both sides in a front/back direction. The first and second formation sections each have a different rigidity.

Abstract: An object is to provide a badminton racket capable of easily achieving different performance properties on both sides of the hitting surface easily. A racket includes a frame which extends annularly, a grip, and a string which is stretched across the frame to form a hitting surface on both sides of the frame. The frame is formed to make the front surface portion and the back surface portion thereof asymmetrical in shape in a cross sectional view taken along a plane orthogonal to the extension direction of the frame. The formation of the frame into such an asymmetrical shape makes it possible to change performance properties on shuttlecock hitting between the front and back sides of the hitting surface at the time of hitting the shuttlecock, thus making it possible for the player to obtain two difference capabilities with the single racket simply by changing his or her grip.

Abstract: To enhance a resilience performance of a ball at hitting the ball, a grommet is configured to include a strip-shaped portion extending in a predetermined direction and a cylindrical portion projecting from one surface of the strip-shaped portion, the cylindrical portion being a portion through which a string passes. A bulge portion is formed on a part on another surface of the strip-shaped portion, the part being along an inner periphery of the cylindrical portion. The bulge portion has a shape bulged more than the other surface of the strip-shaped portion, and the string is folded back at the bulge portion. A plurality of the protrusions are formed between the cylindrical portions adjacent to one another, the plurality of the protrusions being portions to which the string contacts.

Abstract: An object is to provide a badminton racket capable of easily achieving different performance properties on both sides of the hitting surface easily. A racket includes a frame which extends annularly, a grip, and a string which is stretched across the frame to form a hitting surface on both sides of the frame. The frame is formed to make the front surface portion and the back surface portion thereof asymmetrical in shape in a cross sectional view taken along a plane orthogonal to the extension direction of the frame. The formation of the frame into such an asymmetrical shape makes it possible to change performance properties on shuttlecock hitting between the front and back sides of the hitting surface at the time of hitting the shuttlecock, thus making it possible for the player to obtain two difference capabilities with the single racket simply by changing his or her grip.

Abstract: A string set is a string set strung on a racket as a main string and a cross string, and is configured to include a first string strung as any one of the main string and the cross string and has a small friction force and a small diameter and a second string strung as another one of the main string and the cross string and has a larger friction force and a larger diameter than the diameter and the surface friction force of the first string. This distributes functions to the first string and the second string to obtain both the hairpin performance, which is improved by the large surface friction force and outer diameter of the string, and the cut smash performance, which is improved by the small surface friction force and outer diameter of the string, at the same time.

Abstract: To enhance a resilience performance of a ball at hitting the ball, a grommet is configured to include a strip-shaped portion extending in a predetermined direction and a cylindrical portion projecting from one surface of the strip-shaped portion, the cylindrical portion being a portion through which a string passes. A bulge portion is formed on a part on another surface of the strip-shaped portion, the part being along an inner periphery of the cylindrical portion. The bulge portion has a shape bulged more than the other surface of the strip-shaped portion, and the string is folded back at the bulge portion. A plurality of the protrusions are formed between the cylindrical portions adjacent to one another, the plurality of the protrusions being portions to which the string contacts.

Abstract: An object is to provide a badminton racket capable of easily achieving different performance properties on both sides of the hitting surface easily. A racket includes a frame which extends annularly, a grip, and a string which is stretched across the frame to form a hitting surface on both sides of the frame. The frame is formed to make the front surface portion and the back surface portion thereof asymmetrical in shape in a cross sectional view taken along a plane orthogonal to the extension direction of the frame. The formation of the frame into such an asymmetrical shape makes it possible to change performance properties on shuttlecock hitting between the front and back sides of the hitting surface at the time of hitting the shuttlecock, thus making it possible for the player to obtain two difference capabilities with the single racket simply by changing his or her grip.

Abstract: An object is to make it possible for a single racket to present different design appearances easily. A racket includes a frame which extends annularly, a grip, and a string which is stretched across the frame to form a hitting surface on both sides of the frame. The frame and the shaft is provided with a first colored portion and a second colored portion. As the racket is viewed from a certain angle in a direction nonparallel and non-orthogonal to the hitting surface, the first colored portion appears visible while the second colored portion is hidden from view, and flipping the hitting surface from this state causes the second colored portion to appear visible and causes the first colored portion to be hidden from view.