US4747598A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Racket frame having interiorly located stringing lugs
Assignee: Dunlop Ltd
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Filing: 1985-06-26
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Granted: 1988-05-31
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Expires: 2005-06-26
Abstract
Abstract The invention relates to a frame for a games racket e.g. tennis, of the type made as a hollow injection moulding of reinforced thermoplastics material. The frame has attachments for stringing in the form of a series of discrete lugs moulded integrally with the walls of the hollow frame and so positioned that the racket strings in their desired positions do not pass to the outer periphery of the head. The discrete lugs may for example be around the inner periphery of the head of the frame and each contain an integrally-moulded circumferential bore for string passage. The frame may be made by injection moulding around a fusible core and the shape of the core required to give the desired lugs provides strong resistance to movement under the injecting pressures hence giving improved product uniformity.
Inventors
- 👤 Michael E. Curtis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:47
CPC Classifications
A; A63; A63B; A63B49/00; A63B49/02; A63B49/022; Y; Y10; Y10S; Y10S273/00; Y10S273/01; Y10S273/02; Y10S273/07; Y10S273/10; Y10S273/11; Y10S273/23
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
190 words
A games racket frame comprising a head and a shaft at least the head of which is a hollow injection-moulding of thermoplastics material reinforced with short filament reinforcing material, at least the head being of generally C-shaped cross section with the open end of the C-shape defining an inner periphery of the head, said head having an outer periphery opposite said inner periphery, said outer periphery being provided with a series of apertures giving access to the inside of the hollow head, said head provided with stringing means adjacent the inner periphery for holding a racket string, said stringing means being unitary with and bridging the open end of the generally C-shaped cross section, wherein the spaces between adjacent stringing means define stringing holes in the head and at least one racket string strung on the head through the stringing holes and about the stringing means such that the string does not pass through the hollow frame to the outer periphery of the head, in which the stringing means defining the stringing holes are formed of one piece with the moulding in the form of a series of discrete lugs.
Claim 2
Dependent Claim
190 words
A games racket frame comprising a head and a shaft at least the head of which is a hollow injection-moulding of thermoplastics material reinforced with short filament reinforcing material, at least the head being of generally C-shaped cross section with the open end of the C-shape defining an inner periphery of the head, said head having an outer periphery opposite said inner periphery, said outer periphery being provided with a series of apertures giving access to the inside of the hollow head, said head provided with stringing means adjacent the inner periphery for holding a racket string, said stringing means being unitary with and bridging the open end of the generally C-shaped cross section, wherein the spaces between adjacent stringing means define stringing holes in the head and at least one racket string strung on the head through the stringing holes and about the stringing means such that the string does not pass through the hollow frame to the outer periphery of the head, in which the stringing means defining the stringing holes are formed of one piece with the moulding in the form of a series of discrete lugs.
Claim 3
Dependent Claim
43 words
A games racket frame according to claim 1 in which the series of discrete, integrally-moulded lugs lies inside the hollow head of the frame, an integrally-moulded continuous opening in the inner periphery of the head providing access to the lugs for stringing purposes.
Claim 4
Dependent Claim
30 words
A games racket frame according to claim 1, in which the reinforcing material is selected from the class consisting of carbon fibres, glass fibres, aromatic polyamide fibres and mixtures thereof.
Claim 5
Dependent Claim
28 words
A games racket frame according to claim 1, in which the thermoplastics material us selected from the class consisting of polyamide, polycarbonate, acrylonitrile-butadiene-styrene, acetal resin and poly(phenylene oxide).
Claim 6
Dependent Claim
31 words
The games racket of claim 1, wherein the generally C-shaped cross section is comprised of walls and wherein the walls of the generally C-shaped cross section of the head are arcuate.
Claim 7
Dependent Claim
31 words
The games racket of claim 1, wherein the generally C-shaped cross section is comprised of walls and wherein the walls of the generally C-shaped cross section of the head are planar.
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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) | 1991-05-31 | 1991-11-30 | 1992-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-31 | 1995-11-30 | 1996-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-31 | 1999-11-30 | 2000-05-31 | $7700.00 | Window Closed / Lapsed |