Sports racquet with insert members for anchoring strings

Abstract

The sides of a sports racquet, and optionally the tip and throat bridge, include axially extending cutout portions. An insert member, having a plurality of string port holes and optionally conventional string holes, is seated in each cutout portion. The frame and insert member are preferably formed of different materials.

Description

BACKGROUND OF THE INVENTION [0001] The present invention relates to sports racquets, for example tennis, squash, badminton, and racquetball racquets. Such racquets have a head portion containing an interwoven string bed, a handle, and a shaft portion connecting the head portion to the handle. [0002] Most high performance sports racquets have a frame molded from composite materials, e.g., a carbon fiber-reinforced resin. Holes for anchoring the ends of the strings are drilled through the frame after the racquet is molded. Plastic grommet pegs, which are formed on a grommet strip or bumper strip that rests against the outside surface of the frame, extend through the string holes to protect the strings from the sharp edges of the drilled holes. [0003] Proposals have been made to form string holes during the molding process. For example, commonly owned U.S. Pat. No. 6,800,239 discloses a racquet made of two frame tubes, in which the string holes are formed during the molding process usi...

AI Technical Summary

Benefits of technology

[0008] The present invention is an improved sports racquet, e.g., a tennis, squash, badminton, or racquetball racquet. In one embodiment according to the present invention, along the sides of the racquet frame, and optionally in the tip region and throat bridge, the racquet frame includes elongated cutout portions that extend through the frame to provided openings in the string bed plane. Each cutout portion includes a seat surface. A separate insert member containing string holes is positioned in each cutout portion and includes a bearing surface which bears against the seat surface when the strings are tensioned, to secure the ends of the strings in place.

[0009] Preferably, the insert members are removably positioned in the cutout portions, and can be replaced with different insert members, e.g., of different weights or with different string hole spacing, in order to modify the playing characteristics of the racquet or change the string bed pattern. If desired, racquet frames may be offered by retailers along with a selection of insert members, from which the customer or a club professional can choose prior to stringing. If desired, the racquet may be sold with two or more sets of insert members, allowing the customer to switch when the racquet is re-strung.

[0012] The use of insert members provides flexibility in customizing the playing characteristics of the racquet, insofar as it allows the player easily to vary a number of playing characteristics of the racquet, including: mass, balance, polar and mass moments of inertia, stiffness, and vibration and shock absorption. The player can also change the relative spacing of the strings in the string bed, to vary its playing characteristics. Thus, the player can readily customize the racquet to suit his or her playing abilities and preferences.

[0013] The invention further allows the player to vary the appearance of the racquet, e.g., by using insert members having different colors or different outer surface designs.

[0014] The invention also simplifies the frame construction process, in that it does not require molding in string holes, or drilling individual string holes after the racquet has been molded. It also simplifies the painting process, reducing production cost.

[0017] The string port holes can have any suitable shape, such as elliptical, circular, polygonal, rounded, convex, concave, or irregular. The use of string port holes allows the overall weight of the racquet to be reduced and makes stringing easier. Examples of suitable string port holes are disclosed in WO 2004 / 075996, the disclosure of which is incorporated by reference.

Problems solved by technology

Once a racquet has been designed and built, it is difficult to alter its playing characteristics to any significant degree.

However, such measures make the racquet heavier than its original design, which is normally undesirable.

Moreover, the frame stiffness and the stringing pattern of the racquet cannot be changed after the racquet has been molded and the string holes formed.

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