Patent US3309054A successfully refreshed from Google Patents.
US3309054A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pivotal supporting devices particularly for mine roof supports
Assignee: Gullick Ltd
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Filing: 1965-08-02
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Granted: 1967-03-14
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Expires: 1985-08-02
Abstract
No abstract record available.
Inventors
- 👤 Davis-Ratcliffe Peter Derek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:21
CPC Classifications
E; E21; E21D; E21D23/00; E21D23/04; E21D23/0418; E21D15/00; E21D15/50; E21D15/54
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
54 words
A MINE ROOF SUPPORT COMPRISING AT LEAST ONE PRESSURE-FLUID EXTENSIBLE PROP MEMBER AND TWO PIVOTAL SUPPORTS FOR SAID PROP MEMBER SPACED APART ALONG THE LENGTH THEREOF, AT LEAST ONE OF SAID PIVOTAL SUPPORTS BEING MOVABLE WITH RESPECT TO THE OTHER SO THAT THEY HAVE A POSITION IN WHICH THEIR PIVOTAL CENTRES COINCIDE, WHEREBY SAID
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-03-13 | 1970-09-12 | 1971-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-03-13 | 1974-09-12 | 1975-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-03-13 | 1978-09-12 | 1979-03-14 | $7700.00 | Window Closed / Lapsed |