Patent US3990701A successfully refreshed from Google Patents.
US3990701A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tennis racket
Assignee: Individual
•
Filing: 1974-11-26
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Granted: 1976-11-09
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Expires: 1994-11-26
Abstract
Abstract A unitary tennis racket frame is formed of a relatively strong, e.g. metal, skeleton and a molded high impact thermoplastic. The skeleton serves as a mold core for the plastic and includes a generally U shaped outwardly facing channel having a plurality of oversized string holes in the bow. The mold for the composite racket includes a plurality of movable core pins which extend into the cavity in registry with the skeleton string holes. The plastic is injection molded into the cavity and around the pins which, when retracted, form the string holes.
Inventors
- 👤 Sung Baik Kim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:02
CPC Classifications
A; A63; A63B; A63B49/00; A63B49/02; A63B49/03; A63B49/10; A63B49/12; A63B60/00; A63B60/06; A63B60/22; A63B60/24
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
203 words
A projectile striking racket comprising a one piece frame skeleton having a generally oval bow with one end being rounded and the opposite end comprising an open converging throat, and a stem interconnecting the bow at the throat, the transverse cross sectional area of the skeleton being of generally U-shaped configuration including a pair of spaced parallel flanges, each of the flanges extending from a central transverse web, means forming a plurality of spaced circular apertures through the web in the bow and throat, the racket further including a one piece plastic section, the plastic section being molded between the flanges, a portion of the plastic section extending into each of the circular apertures, a further portion of the plastic section extending through selected circular apertures across the throat and being spaced from the stem to form a bridge, and means forming a plurality of string holes transversely through the plastic section, each string hole being located at a portion of the plastic section which corresponds to each of said spaced circular apertures, whereby a unitary racket frame is provided with a desired degree of longitudinal flexure, yet with sufficient torsional rigidity and with each string hole peripherally supported by the frame web.
Claim 2
Dependent Claim
203 words
A projectile striking racket comprising a one piece frame skeleton having a generally oval bow with one end being rounded and the opposite end comprising an open converging throat, and a stem interconnecting the bow at the throat, the transverse cross sectional area of the skeleton being of generally U-shaped configuration including a pair of spaced parallel flanges, each of the flanges extending from a central transverse web, means forming a plurality of spaced circular apertures through the web in the bow and throat, the racket further including a one piece plastic section, the plastic section being molded between the flanges, a portion of the plastic section extending into each of the circular apertures, a further portion of the plastic section extending through selected circular apertures across the throat and being spaced from the stem to form a bridge, and means forming a plurality of string holes transversely through the plastic section, each string hole being located at a portion of the plastic section which corresponds to each of said spaced circular apertures, whereby a unitary racket frame is provided with a desired degree of longitudinal flexure, yet with sufficient torsional rigidity and with each string hole peripherally supported by the frame web.
Claim 3
Dependent Claim
21 words
A game racket constructed in accordance with claim 1 wherein each string hole is substantially concentric with its respective circular aperture.
Claim 4
Dependent Claim
38 words
A game racket constructed in accordance with claim 1 further including a string matrix, the matrix including a plurality of string reaches extending across the bow, each string reach extending through a string hole in the plastic section.
Claim 5
Dependent Claim
18 words
A game racket constructed in accordance with claim 1 wherein the skeleton is constructed of a lightweight metal.
Claim 6
Dependent Claim
14 words
A game racket constructed in accordance with claim 4 wherein the metal is aluminum.
Claim 7
Dependent Claim
16 words
A game racket constructed in accordance with claim 4 wherein the metal is a magnesium alloy.
Claim 8
Dependent Claim
19 words
A game racket constructed in accordance with claim 1 wherein the skeleton is constructed of a graphite reinforced plastic.
Claim 9
Dependent Claim
22 words
A game racket constructed in accordance with claim 1 wherein the plastic section is formed of a low density injection moldable plastic.
Claim 10
Dependent Claim
15 words
A game racket constructed in accordance with claim 8 wherein the plastic is a thermoplastic.
Claim 11
Dependent Claim
14 words
A game racket constructed in accordance with claim 9 wherein the thermoplastic is polypropylene.
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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) | 1979-11-09 | 1980-05-10 | 1980-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-09 | 1984-05-10 | 1984-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-09 | 1988-05-10 | 1988-11-09 | $7700.00 | Window Closed / Lapsed |