US4031181A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for molding high strength facing
Assignee: General Dynamics Corp
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Filing: 1976-05-10
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Granted: 1977-06-21
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Expires: 1996-05-10
Abstract
Abstract A composite game racket having improved stiffness and uniformity and method of making same. Rackets are light bats consisting of a netting stretched in an open frame attached to a handle and which are used for striking the ball in tennis and similar games. The racket comprises a shell with a high strength fiber reinforced plastic facing laminated to each face of the shell. A preferred fiber orientation in the novel facing is disclosed. The facing is made by a method including steps of arranging a resin impregnated fiber tow in a mold, placing resin impregnated fiber cloth sheets over the tow in a specific selected arrangement and curing the resin under pressure in the mold. The shell may be internally recessed in a truss-like pattern to provide lightness with strength. The handle of the racket includes a pair of plastic pallets secured to the handle portion of the shell and covered with a covering material, such as a thin leather strip winding. The finished racket is finally strung in a conventional manner and is then ready for use.
Inventors
- 👤 William H. Schaefer
- 👤 Richard E. Bender
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:16
CPC Classifications
A; A63; A63B; A63B49/00; A63B49/02; A63B49/10; A63B49/08; A63B60/00; A63B2049/103; A63B2209/00; A63B2209/02; A63B2209/023; A63B60/54; Y; Y10; Y10S; Y10S428/00; Y10S428/902
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
256 words
The method of making a reinforcing facing for a game racket having an open frame connected to an elongated handle by a throat area which comprises: impregnating a tow of substantially continuous, substantially parallel high Young's modulus fibers with a synthetic resin; arranging said tow in a mold having an open frame area connected to a handle area by a throat area; molding said tow into a substantially U-shaped cross-section in the frame area, modified through the throat area to a substantially rectangular cross-section in the handle area; impregnating at least two sheets of high Young's modulus fiber cloth with a synthetic resin, said cloth having from about 0 to 50% woof fibers and from about 50 to 100% warp fibers; placing said at least two sheets of fiber cloth over said tow in said mold so as to contact the base of said U-shape and cover the frame area, handle area and throat area; placing said sheets of cloth with the warp fibers in each succeeding layer in the frame area at an angle of at least about 45° to the fibers in the preceding layer and placing said layers of cloth in the handle area at an angle of at least 30° to the fibers in the preceding layer, the warp fibers in all layers in the handle area being placed at angles of no more than about 60° to the handle centerline; and applying pressure to said mold and hardening said resin to form a unitary facing comprising fibers in a resin matrix.
Claim 2
Independent Claim
256 words
The method of making a reinforcing facing for a game racket having an open frame connected to an elongated handle by a throat area which comprises: impregnating a tow of substantially continuous, substantially parallel high Young's modulus fibers with a synthetic resin; arranging said tow in a mold having an open frame area connected to a handle area by a throat area; molding said tow into a substantially U-shaped cross-section in the frame area, modified through the throat area to a substantially rectangular cross-section in the handle area; impregnating at least two sheets of high Young's modulus fiber cloth with a synthetic resin, said cloth having from about 0 to 50% woof fibers and from about 50 to 100% warp fibers; placing said at least two sheets of fiber cloth over said tow in said mold so as to contact the base of said U-shape and cover the frame area, handle area and throat area; placing said sheets of cloth with the warp fibers in each succeeding layer in the frame area at an angle of at least about 45° to the fibers in the preceding layer and placing said layers of cloth in the handle area at an angle of at least 30° to the fibers in the preceding layer, the warp fibers in all layers in the handle area being placed at angles of no more than about 60° to the handle centerline; and applying pressure to said mold and hardening said resin to form a unitary facing comprising fibers in a resin matrix.
Claim 3
Dependent Claim
24 words
The method according to claim 1 wherein at least some sheets of said cloth comprise a substantially single layer of substantially parallel contiguous fibers.
Claim 4
Dependent Claim
56 words
The method according to claim 2 wherein four cloth sheets are laid up over said tow in said mold with fibers at angles to the handle centerline of about 0°, 90°, 0°, and 90° in the frame and upper throat areas and of about 0°, -30°, 0° and +30° in the handle and lower throat areas.
Claim 5
Dependent Claim
46 words
The method according to claim 1 wherein said mold forms said tow into a substantially U-shaped cross-section in the frame area, modified through the throat area to a rectangular configuration in the handle area, and said cloth layers are bonded to the base of said U-shape.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-20 | 1980-12-20 | 1981-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-20 | 1984-12-20 | 1985-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-20 | 1988-12-20 | 1989-06-21 | $7700.00 | Window Closed / Lapsed |