Patent US3218812A successfully refreshed from Google Patents.
US3218812A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mobile mine roof support
Assignee: Rheinstahl Wanheim GmbH
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Filing: 1962-05-14
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Granted: 1965-11-23
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Expires: 1982-05-14
Abstract
No abstract record available.
Inventors
- 👤 Wilkenloh Wilhelm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:26
CPC Classifications
E; E21; E21D; E21D23/00; E21D23/0004; E21D23/0017; E21D23/003; E21D23/006; E21D23/0069
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
185 words
A MINE ROOF SUPPORT COMPRISING, IN COMBINATION, TWO EXTENSIBLE AND CONTRACTIBLE PIT PROPS EACH HAVING TWO RELATIVELY MOVABLE PORTIONS INCLUDING AN UPPER PORTION AND A FLOOR ENGAGING LOWER PORTION; FLUID OPERATED MEANS OPERATIVELY CONNECTED TO SAID PROPS FOR MOVING THE PORTIONS OF SAID PROPS WITH RESPECT TO EACH OTHER; ROOF ENGAGING CAP MEANS COMPRISING TWO ARTICULATELY CONNECTED SECTIONS EACH SECURED TO THE UPPER PORTION OF ONE OF SAID PROPS; AND BIASING MEANS ARRANGED TO BIAS ONE OF SAID SECTIONS IN A DIRECTION TOWARD THE MINE ROOF WHEN THE OTHER SECTION ENGAGES THE MINE ROOF IN RESPONSE TO EXTENSION OF THE RESPECTIVE PROP, SAID BIASING MEANS BEING OF SUCH RIGIDITY AND STRENGTH THAT SAID ONE SECTION CAN SUPPORT, WITHOUT SUBSTANTIAL TURNING RELATIVE TO SAID OTHER SECTION, THE CORRESPONDING PROP IN SUSPENDED POSITION WHEN SAID CORRESPONDING PROP IS CONTRACTED TO LIFT ITS LOWER PORTION ABOVE THE MINE FLOOR WHEREBY ANY DEPRESSIONS FORMED BY SAID LOWER PORTIONS IN THE MINE FLOOR MAY BE FILLED IN BEFORE THE MINE ROOF SUPPORT IS MOVED ALONG AND WHILE THE LOWER PORTIONS OF THE PROPS ARE ALTERNATELY LIFTED ABOVE THE MINE FLOOR.
Claim 2
Dependent Claim
185 words
A MINE ROOF SUPPORT COMPRISING, IN COMBINATION, TWO EXTENSIBLE AND CONTRACTIBLE PIT PROPS EACH HAVING TWO RELATIVELY MOVABLE PORTIONS INCLUDING AN UPPER PORTION AND A FLOOR ENGAGING LOWER PORTION; FLUID OPERATED MEANS OPERATIVELY CONNECTED TO SAID PROPS FOR MOVING THE PORTIONS OF SAID PROPS WITH RESPECT TO EACH OTHER; ROOF ENGAGING CAP MEANS COMPRISING TWO ARTICULATELY CONNECTED SECTIONS EACH SECURED TO THE UPPER PORTION OF ONE OF SAID PROPS; AND BIASING MEANS ARRANGED TO BIAS ONE OF SAID SECTIONS IN A DIRECTION TOWARD THE MINE ROOF WHEN THE OTHER SECTION ENGAGES THE MINE ROOF IN RESPONSE TO EXTENSION OF THE RESPECTIVE PROP, SAID BIASING MEANS BEING OF SUCH RIGIDITY AND STRENGTH THAT SAID ONE SECTION CAN SUPPORT, WITHOUT SUBSTANTIAL TURNING RELATIVE TO SAID OTHER SECTION, THE CORRESPONDING PROP IN SUSPENDED POSITION WHEN SAID CORRESPONDING PROP IS CONTRACTED TO LIFT ITS LOWER PORTION ABOVE THE MINE FLOOR WHEREBY ANY DEPRESSIONS FORMED BY SAID LOWER PORTIONS IN THE MINE FLOOR MAY BE FILLED IN BEFORE THE MINE ROOF SUPPORT IS MOVED ALONG AND WHILE THE LOWER PORTIONS OF THE PROPS ARE ALTERNATELY LIFTED ABOVE THE MINE FLOOR.
References Cited (Backward Citations)
US2795935A
Cited
US3115754A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-11-22 | 1969-05-24 | 1969-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-11-22 | 1973-05-24 | 1973-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-11-22 | 1977-05-24 | 1977-11-23 | $7700.00 | Window Closed / Lapsed |