Patent US3240125A successfully refreshed from Google Patents.
US3240125A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Roof support assembly
Assignee: Dowty Mining Equipment Ltd
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Filing: 1964-03-30
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Granted: 1966-03-15
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Expires: 1984-03-30
Abstract
No abstract record available.
Inventors
- 👤 Pawling Frank
- 👤 Potts Michael Charles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:18
CPC Classifications
E; E21; E21D; E21D23/00; E21D23/16
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
140 words
A ROOF SUPPORT ASSEMBLY INCLUDING A SERIS OF FLUIDPRESSURE-OPERATED ROOF SUPPORTS ARRANGED IN GROUPS, A VALVE ASSEMBLY INCLUDED IN EACH ROOF SUPPORT, AND CONNECTIBLE TO A FLUID PRESSURE SOURCE, A PILOT LINE CONNECTED IN SUCCESSION TO THE VALVE ASSEMBLY OF EACH ROOF SUPPORT IN A GIVEN GROUP, A CONTROL VALVE OPERATIVELY CONNECTED TO EACH GROUP, AND CONNECTED TO A SOURCE OF FLUID PRESSURE AND TO SAID PILOT LINE, TO PRESSURIZE THE LATTER, EACH VALVE ASSEMBLY WHEN SO PRESSURIZED BEING ARRANGED TO CAUSE ITS ROOF SUPPORT TO UNDERGO AN ADVANCING OPERATION, AND UPON COMPLETION THEREOF TO PASS A PRESSURE SIGNAL ALONG THE PILOT LINE TO INITIATE AN ADVANCING OPERATION OF THE FOLLOWING ROOF SUPPORT, AND SAID CONTROL VALVE BEING SHIFTABLE TO CONNECT THE ASSOCIATED PILOT LINE TO LOW PRESSURE, WHEREBY THE PRESSURE SIGNAL IS LOST AND THE ADVANCING SEQUENCE IS HALTED.
Claim 2
Dependent Claim
140 words
A ROOF SUPPORT ASSEMBLY INCLUDING A SERIS OF FLUIDPRESSURE-OPERATED ROOF SUPPORTS ARRANGED IN GROUPS, A VALVE ASSEMBLY INCLUDED IN EACH ROOF SUPPORT, AND CONNECTIBLE TO A FLUID PRESSURE SOURCE, A PILOT LINE CONNECTED IN SUCCESSION TO THE VALVE ASSEMBLY OF EACH ROOF SUPPORT IN A GIVEN GROUP, A CONTROL VALVE OPERATIVELY CONNECTED TO EACH GROUP, AND CONNECTED TO A SOURCE OF FLUID PRESSURE AND TO SAID PILOT LINE, TO PRESSURIZE THE LATTER, EACH VALVE ASSEMBLY WHEN SO PRESSURIZED BEING ARRANGED TO CAUSE ITS ROOF SUPPORT TO UNDERGO AN ADVANCING OPERATION, AND UPON COMPLETION THEREOF TO PASS A PRESSURE SIGNAL ALONG THE PILOT LINE TO INITIATE AN ADVANCING OPERATION OF THE FOLLOWING ROOF SUPPORT, AND SAID CONTROL VALVE BEING SHIFTABLE TO CONNECT THE ASSOCIATED PILOT LINE TO LOW PRESSURE, WHEREBY THE PRESSURE SIGNAL IS LOST AND THE ADVANCING SEQUENCE IS HALTED.
References Cited (Backward Citations)
US1905065A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-03-14 | 1969-09-13 | 1970-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-03-14 | 1973-09-13 | 1974-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-03-14 | 1977-09-13 | 1978-03-15 | $7700.00 | Window Closed / Lapsed |