US4098504A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tennis ball
Assignee: Aerojet Rocketdyne Holdings Inc
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Filing: 1975-10-31
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Granted: 1978-07-04
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Expires: 1995-10-31
Abstract
Abstract A pressurized game ball including an air-permeable elastomeric wall defining a cavity containing a compressible inflation gas with the improvement being that the inflation gas includes predetermined mixed amounts of air and sulfur hexafluoride (SF6) gas which effectively enables the ball to retain its pressurized state within a desired range of pressures for a period of time significantly longer than the ball would remain pressurized if the inflation gas were air alone.
Inventors
- 👤 Dale Lee Koziol
- 👤 Thomas Freeman Reed
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:17
CPC Classifications
A; A63; A63B; A63B39/00; A63B39/02; A63B39/025; Y; Y10; Y10S; Y10S273/00; Y10S273/20
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
70 words
A tennis ball having improved pressure retention properties comprising an elastomeric gas-permeable wall defining a hollow cavity containing a compressible inflation gas under pressure, said inflation gas including: (a) air having a partial pressure equal to ambient pressure; and (b) sulfur hexafluoride in an amount sufficient to significantly improve the pressure retention properties of said ball as compared to the pressure retention properties of said ball when filled with air.
Claim 2
Dependent Claim
70 words
A tennis ball having improved pressure retention properties comprising an elastomeric gas-permeable wall defining a hollow cavity containing a compressible inflation gas under pressure, said inflation gas including: (a) air having a partial pressure equal to ambient pressure; and (b) sulfur hexafluoride in an amount sufficient to significantly improve the pressure retention properties of said ball as compared to the pressure retention properties of said ball when filled with air.
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) | 1981-07-03 | 1982-01-02 | 1982-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-03 | 1986-01-02 | 1986-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-03 | 1990-01-02 | 1990-07-04 | $7700.00 | Window Closed / Lapsed |