Tension frame for sports rackets - uses mandrel-like tool pieces to produce string holes

摘要

The tension frame is for a sports racket esp. a tennis racket. It has a profiled bar (33) which is moulded from a fibre-containing material and hardened. Apertures for the strings (18,19) are provided connecting the two outsides (22,24) together. The apertures extend into blind holes (25s) in the material and the deepest point of the blind holes is at least partially removed. During the moulding process mandrel-like tool members (45,45a) are guided from each side against the material blank. The mandrels (45,45a) project from the side wall of the moulding chamber into the blank. The length of the mandrels is less than the thickness of the material blank. USE/ADVANTAGE - Low cost mfr. of tennis racket without the need for separate inserts or secondary tooling processes to provide the apertures.