Abstract: A tennis racket is formed with a plurality of transverse grooves extending from one face around the frame to the opposite face. The grooves are distributed along the periphery, but are intermittent at four corners of the frame. A single longitudinal groove extends circumferentially at substantially the center lone on the outside face of the frame, and crosses over all transverse grooves. At the corners of the frame, a series of stringing holes are formed. The frame is provided with corresponding bumps comprising a substrate having a central longitudinal recessed channel and a plurality of discrete stringing tubes in paris suspended along opposing longitudinal edges of the substrate. With connecting guide channels extending between the two tubes of each pair. Outside of this region series of central stringing tubes are suspended from the recessed channel.

Abstract: A racket comprising a head consisting of a frame and a plurality of interwoven strings, the frame is formed with a number of stringing holes which are obliquely passed from the outside of the frame substantially at the center of the thickness thereof through the frame itself to the inside of the frame in alternative different inclined directions with respect to the thickness of the frame, thereby only one row of the openings of the stringing holes is appeared on the outside of the frame along periphery at substantial center line while two rows of the openings of the stringing holes are formed on the inside of the frame along two opposite rims thereof.

Abstract: An arrangement of stringing holes in the yoke of a racket, comprising at least two rows of the stringing holes in the yoke in substantially parallel to each other and in alternative sequence so as to make the strings passing over different rows of stringing holes in sequential order.

Abstract: A bumper for the racket frame consists of two identical half members, in which each half member comprises a flat strip having inner and outer surfaces in parallel, with one lateral side in substantial straight-cross-section while another lateral side in corrugated cross-section having alternative peak and valley portions, and a plurality of tubes integrally formed an distributed on the inner surface of the flat strip at respective peak portion and extended at an angle with respect to the inner surface of the flat strip along a direction either toward or opposite to the rising of the peak portion to a certain extent. When two half members are respectively installed onto the racket frame to complete an unitary bumper structure, the tubes are so arranged that obliquely extended in opposite directions alterately.

Abstract: A racket with frame attachments disposed on two diametrically opposite positions, each attachment comprises two rows of a plurality of stringing passages along both edges in respective inclined alignment to each other and a recess at the central space in the area between two rows of the stringing passages for fittingly enclosing the corresponding frame portion.