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US 4,340,226 AGranted
Games racket
AssigneeDunlop Limited
InventorRobert C. Haines
Life of this patent
Estimating the term…
Abstract
A hollow injection moulded thermoplastics games racket frame comprising a head (21) and a shaft (20), the head (21) having integrally-formed internal supports (25) containing the stringing holes (23) and the moulding being polyurethane foam-filled. The foam filling is provided in two parts, a lighter filling (32) for the head and a denser filling (33) for the shaft. The shaft filling (33) is integrally-formed with a foam handle portion (34). The handle end of the shaft is preferably provided with moulded-in holes (31) through which filling (33) can flow during its foaming.
Claims13
A games racket comprising:
- A head and a shaft, the head being of hollow tubular cross section over a majority of its perimeter, the shaft having a hollow tubular cross section in communication with the hollow tubular cross section of the head so that both said hollow tubular cross sections may be filled with foam material injected from the distal end of said shaft,
- a first foam material of polyurethane foam of density from 0.10 to 0.25 g/c.c., filling at least the hollow cross section of said head,
- a second foam material of rigid polyurethane foam of density from 0.30 to 0.50 g/c.c., filling the entire remaining hollow portion of said shaft from an interface with said first foam, said second foam material also covering the outer surface of the shaft adjacent the distal end thereof so as to form a handle thereon of a larger diameter than said shaft which is integral with the second foam material inside said hollow cross section of said shaft.
Dependencies are inferred from the claim text.