US3801099A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tennis racquet
Assignee: Individual
•
Filing: 1971-06-23
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Granted: 1974-04-02
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Expires: 1991-06-23
Abstract
Abstract An improved tennis racquet constructed of magnesium, beryllium or other metal with a low ratio of weight to stiffness and strength wherein the elliptical head of the racquet is disposed so that the long axis of the ellipse is transverse to the axis of the racquet handle, thereby to increase the rotational moment of inertia about the longitudinal axis of the racquet.
Inventors
- 👤 J Lair
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:12
CPC Classifications
A; A63; A63B; A63B49/00; A63B49/02; A63B49/12; A63B60/00; A63B60/02; A63B2208/00; A63B2208/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
152 words
A tennis racquet comprising a rigid frame structure forming a handle and a head frame in the shape of an elliptically closed loop having a continuous concave curvature presented towards the interior thereof, said head frame having a long axis and a short axis, the interior of said loop providing an elliptical string area which is substantially symmetrical with respect to both said axes, said head frame being provided with means for stringing the encompassed elliptical area with resilient stringing, and the long axis of said head frame being perpendicular to the longitudinal axis of the handle and the short axis of said head frame being coaxial with the longitudinal axis of the handle, whereby greater inertial stability against roll about the handle axis is provided than is the case with a conventional racquet wherein the long axis of the elliptical head frame is coaxial with the longitudinal axis of the handle.
Claim 2
Dependent Claim
152 words
A tennis racquet comprising a rigid frame structure forming a handle and a head frame in the shape of an elliptically closed loop having a continuous concave curvature presented towards the interior thereof, said head frame having a long axis and a short axis, the interior of said loop providing an elliptical string area which is substantially symmetrical with respect to both said axes, said head frame being provided with means for stringing the encompassed elliptical area with resilient stringing, and the long axis of said head frame being perpendicular to the longitudinal axis of the handle and the short axis of said head frame being coaxial with the longitudinal axis of the handle, whereby greater inertial stability against roll about the handle axis is provided than is the case with a conventional racquet wherein the long axis of the elliptical head frame is coaxial with the longitudinal axis of the handle.
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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) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |