US3447789A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Portable perlite handling apparatus and method
Assignee: Chemrock Corp
•
Filing: 1967-05-31
•
Granted: 1969-06-03
•
Expires: 1987-05-31
Abstract
No abstract record available.
Inventors
- 👤 Walter Martin Sharp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:55
CPC Classifications
F; F17; F17C; F17C13/00; C; C04; C04B; C04B20/00; C04B20/02; C04B20/04; C04B20/06; F17C2201/00; F17C2201/01; F17C2201/0128; F17C2201/05; F17C2201/054; F17C2203/00; F17C2203/03; F17C2203/0304; F17C2203/0337; F17C2203/0341; F17C2205/00; F17C2205/03; F17C2205/0302; F17C2205/0323; F17C2270/00; F17C2270/01; F17C2270/0165; F17C2270/0168
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1038781A
Cited
US1718507A
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US1935843A
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US2807453A
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US2621034A
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US2602782A
Cited
US2594072A
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GB673484A
Cited
US3152842A
Cited
US3206905A
Cited
US3311358A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-06-02 | 1972-12-02 | 1973-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-06-02 | 1976-12-02 | 1977-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-06-02 | 1980-12-02 | 1981-06-03 | $7700.00 | Window Closed / Lapsed |