摘要 |
<p>The tennis racket has crossing strings which tend to loose their proper spacing during play. to prevent the strings (3, 4) from sliding relative to each other a grooved insert (5) is located at each point where two strings cross. The inserts, which are made from a material of a high friction coefficient, have also VEE-shaped string grooves to provide wedge location on the strings. The inserts (5) protrude above the strings (4, 3) on each side of the racket. They thus produce a racket surface which gives a high friction when in contact with a tennis ball. It is therefore easily possible to produce tennis strokes which provide plenty of ball spin.</p> |