Patent US3302658A successfully refreshed from Google Patents.
US3302658A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mechanical vent for tanks
Assignee: DEFREES BARBARA BALDWIN WIDOW OF JOSEPH H DEFREES DEC'D
•
Filing: 1964-04-15
•
Granted: 1967-02-07
•
Expires: 1984-04-15
Abstract
No abstract record available.
Inventors
- 👤 Frees Joseph H De
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 02:49
CPC Classifications
B; B60; B60K; B60K15/00; B60K15/03; B60K15/04; B60K15/0406; Y; Y10; Y10T; Y10T137/00; Y10T137/0753; Y10T137/0874; Y10T137/7722; Y10T137/7771; Y10T137/7779; Y10T137/7837; Y10T137/7838; Y10T137/7839
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
154 words
VENT MEANS FOR MOUNTING IN A MANHOLE COVER OF A TANK; SAID VENT MEANS COMPRISING MEANS DEFINING CAVITY MEANS HAVING PORTS AT THE TOP AND BOTTOM THEREOF; CHECK BALL MEANS CAPTIVELY DISPOSED IN SAID CAVITY MEANS AND ADAPTED TO CLOSE OFF EITHER OF SAID PORTS BY FORCE OF GRAVITY; FIRST SPRING BIASED VALVE MEANS OVERLYING AND NORMALLY CLOSING OFF THE UPPERMOST OF SAID PORTS; MEANS DEFINING A SEPARATE PASSAGE THROUGH SAID VENT MEANS; AND SECOND SPRING BIASED VALVE MEANS NORMALLY CLOSING OFF SAID SEPARATE PASSAGE FROM THE BOTTOM THEREOF, WHEREBY A PRESSURE DIFFERENTIAL ON EITHER SIDE OF SAID VENT MEANS IS SUBSTANTIALLY EQUALIZED EITHER THROUGH SAID CAVITY MEANS BY UNSEATING SAID CHECK BALL MEANS AND SAID FIRST VALVE MEANS OR THROUGH SAID SEPARATE PASSAGE BY UNSEATING SAID SECOND VALVE MEANS, AND WHEREBY WHEN SAID VENT IS INVERTED, SAID CHECK BALL MEANS CLOSES OFF THE UPPERMOST OF SAID PORTS TO PREVENT SPILLAGE FROM THE TANK.
Claim 2
Dependent Claim
154 words
VENT MEANS FOR MOUNTING IN A MANHOLE COVER OF A TANK; SAID VENT MEANS COMPRISING MEANS DEFINING CAVITY MEANS HAVING PORTS AT THE TOP AND BOTTOM THEREOF; CHECK BALL MEANS CAPTIVELY DISPOSED IN SAID CAVITY MEANS AND ADAPTED TO CLOSE OFF EITHER OF SAID PORTS BY FORCE OF GRAVITY; FIRST SPRING BIASED VALVE MEANS OVERLYING AND NORMALLY CLOSING OFF THE UPPERMOST OF SAID PORTS; MEANS DEFINING A SEPARATE PASSAGE THROUGH SAID VENT MEANS; AND SECOND SPRING BIASED VALVE MEANS NORMALLY CLOSING OFF SAID SEPARATE PASSAGE FROM THE BOTTOM THEREOF, WHEREBY A PRESSURE DIFFERENTIAL ON EITHER SIDE OF SAID VENT MEANS IS SUBSTANTIALLY EQUALIZED EITHER THROUGH SAID CAVITY MEANS BY UNSEATING SAID CHECK BALL MEANS AND SAID FIRST VALVE MEANS OR THROUGH SAID SEPARATE PASSAGE BY UNSEATING SAID SECOND VALVE MEANS, AND WHEREBY WHEN SAID VENT IS INVERTED, SAID CHECK BALL MEANS CLOSES OFF THE UPPERMOST OF SAID PORTS TO PREVENT SPILLAGE FROM THE TANK.
References Cited (Backward Citations)
US899462A
Cited
US1637076A
Cited
US1893942A
Cited
US2016278A
Cited
US2510098A
Cited
US2684683A
Cited
US2783913A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-02-06 | 1970-08-08 | 1971-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-02-06 | 1974-08-08 | 1975-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-02-06 | 1978-08-08 | 1979-02-07 | $7700.00 | Window Closed / Lapsed |