Patent US4170352A successfully refreshed from Google Patents.
US4170352A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Visual aid practice tennis ball
Assignee: Individual
•
Filing: 1977-07-18
•
Granted: 1979-10-09
•
Expires: 1997-07-18
Abstract
Abstract A tennis training aid comprising a tennis ball having a pair of figure eight panels combining to cover the entire outer surface of the ball. The panels are colored of contrasting colors for indicating the spin or rotation of the ball while in flight wherein the spin imparted to the ball is easily discernible so as to enable a viewer of the ball to determine what type of spin has been imparted to the ball to facilitate learning delivery or receiving maneuvers enabling tennis participants to more effectively participate in the sport of tennis.
Inventors
- 👤 Vlastimil Vcala
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:42
CPC Classifications
A; A63; A63B; A63B43/00; A63B43/008
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
120 words
A conventional tennis ball having a cover comprised of two identically shaped panels of the same size, each panel having rounded ends and concave sides, with a length sufficient to permit each panel to extend partially around the ball such that the geometric center of each rounded end will be diametrically opposite the geometric center of the other rounded end, said centers of a panel being aligned on a common axis passing through the center of said ball, and the axis of one panel being normal to the axis of the other panel, and one panel having a color contrasting with the color of the other panel as an aid to detecting spin imported on the ball while in play.
Claim 2
Dependent Claim
120 words
A conventional tennis ball having a cover comprised of two identically shaped panels of the same size, each panel having rounded ends and concave sides, with a length sufficient to permit each panel to extend partially around the ball such that the geometric center of each rounded end will be diametrically opposite the geometric center of the other rounded end, said centers of a panel being aligned on a common axis passing through the center of said ball, and the axis of one panel being normal to the axis of the other panel, and one panel having a color contrasting with the color of the other panel as an aid to detecting spin imported on the ball while in play.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-10-08 | 1983-04-09 | 1983-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-08 | 1987-04-09 | 1987-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-08 | 1991-04-09 | 1991-10-09 | $7700.00 | Window Closed / Lapsed |