1. Field of the Invention
This invention relates to rackets for tennis, badminton or other similar games, particularly to rackets having weights provided on a portion of the frame thereof.
2. Description of the Related Art
Rackets provided with weights are publicly disclosed in Japanese unexamined Utility Model Publication No. 54-41364. This type of racket has a frame made from foam synthetic resin, and has weights made from aluminum, titanium or other similar material. These weights are fixed onto the lateral sides of a head-frame so as to oppose each other across the sweet spot of the racket. The frame and the weights are both covered with fiber-reinforced material. With this structure, the mass of the frame can be concentrated at the sweet spot, which results in mitigation of shock transmitted to the handle upon striking a ball, and offers a pleasant feeling upon striking of a ball.
Generally, the weight of such a part is limited to be less than a few grams. Thus, if metal having a large weight per unit area is to be used as the weight, as is the case with conventional rackets, the position to which the weight is fixed had to be limited to a small area. Therefore, even though the shock being transmitted to the handle can be mitigated, these weights could not contribute much to stabilizing the face of the head-frame and reducing the amount of bending deformation.
Further, in conventional cases, the weights had to be covered with cylindrically-knitted fiber reinforced material upon fixing, in order to realize firm attachment. This covering procedure was extremely laborious. It is also possible to flatten the conventional metal weights into thin strips and fix them to the frame. In this case, however, the repetitive bending of the frame caused by the shock imparted upon each ball-strike impairs the bond between the metal weight and the frame, owing to the large difference in ratio of extension of the metal and the fiber reinforced resin-made frame. Thus, it is not possible to integrally maintain the weight and the frame as one body.