Racquet having centralized sweet spot

#The present invention relates to a racquet.

#The "sweet-spot" of a racquet is that region of the head of the racquet for which impact by a ball during play imparts little or no reaction at the hand grip of the racquet, so that the player experiences little or no jarring or kicking action of the hand grip in his hand as the stroke is played.

#The "sweet-spot" of a racquet may alternatively be defined as that region of the head of the racquet for which the coefficient of restitution, being the quotient of (a) the velocity of the ball relative to the racquet on rebound divided by (b) the relative approach velocity, is at its greatest, or nearly so, during play.

#Examples of a tennis racquet made in accordance with the present invention are illustrated in the accompanying drawings in which:

#FIG. 1 shows a plan view of a first example;

#FIG. 2 shows a side view of the racquet shown in FIG. 1;

#The tennis racquet shown in FIG. 1 comprises an aluminium extrusion 10 which has been bent around a former to define a circular frame 12 for the head of the racquet, two concave mutually converging curved portions 14 and 16 extending from the circular frame 12, and two straight parallel adjacent portions 18 and 20 continuing from the curved portions 14 and 16 to define a shaft 22 of the racquet, the two ends 24 and 26 of the extrusion 10 being adjacent to one another at a base 28 of the racquet.

#A plastics moulding bridging piece 30 is bonded between the two inwardly curved portions 14 and 16 of the extrusion 10. The edge 32 of this bridging piece 30 which faces the head of the racquet is arcuate and concave. The frame 12 and the bridging piece 30 thereby together define a substantially geometrically circular head of the racquet. Thus the radius of curvature of the edge 32 is the same as that of the inside of the extrusion 10 where it defines the head frame 12, the edge 32 being a continuation of the circle defined by the inside of that frame.

#Grommets 34 extend radially through the extrusion, centrally in relation to its thickness. These grommets are spaced apart around the frame 12. Bores 36 extend diagonally through the bridging piece 30 in registration with associated grommets 34 in the inwardly curved portions 14 and 16 of the extrusion 10. By means of the grommets in the extrusion 10, and the holes in the bridging piece 30, nylon or gut strings 38 are threaded onto the frame 12 in such a manner as to provide first and second sets of mutually parallel strings all extending at substantially 45 degrees to the shaft centre-line, with the first set of strings being perpendicular to the second set. The racquet has a sweet spot, shown diagrammatically at 40, the centre of which coincides with the geometrical centre line of the frame 12. The grommets 34 may be so spaced around the frame 12 that the strings of each set are spaced apart uniformly, or alternatively with a greater density of strings in the central area of the racquet head.