Patent US3244078A successfully refreshed from Google Patents.
US3244078A
Expired / Lapsed
US
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Advancing mine roof support control systems
Assignee: Coal Industry Patents Ltd
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Filing: 1963-10-03
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Granted: 1966-04-05
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Expires: 1983-10-03
Abstract
No abstract record available.
Inventors
- 👤 Kibble John Dunbar
- 👤 Penn Ronald George
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:02
CPC Classifications
E; E21; E21D; E21D23/00; E21D23/16
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
85 words
A CONTROL SYSTEM FOR A FLUID OPERATED ADVANCING MINE ROOF SUPPORT UNIT INCLUDING A UNIT-ADVANCING RAM AND A ROOF SUPPORT PROP, WHEREIN THE RAM AND PROP ARE CONNECTED TO RECEIVE OPERATING FLUID FROM A FIRST FLUID PRESSURE LINE, VALVE MEANS BEING PROVIDED TO CONTROL THE OPERATIONAL SEQUENCE OF THE RAM AND PROP, AND WHEREIN THE RAM AND PROP ARE EACH CONNECTED VIA A FLUID CUT-OFF MEANS TO A SECOND FLUID PRESSURE LINE WHEREBY THE RAM AND PROP CAN BE SELECTIVELY OPERATED IRRESPECTIVE OF THE SEQUENCE.
Claim 2
Dependent Claim
85 words
A CONTROL SYSTEM FOR A FLUID OPERATED ADVANCING MINE ROOF SUPPORT UNIT INCLUDING A UNIT-ADVANCING RAM AND A ROOF SUPPORT PROP, WHEREIN THE RAM AND PROP ARE CONNECTED TO RECEIVE OPERATING FLUID FROM A FIRST FLUID PRESSURE LINE, VALVE MEANS BEING PROVIDED TO CONTROL THE OPERATIONAL SEQUENCE OF THE RAM AND PROP, AND WHEREIN THE RAM AND PROP ARE EACH CONNECTED VIA A FLUID CUT-OFF MEANS TO A SECOND FLUID PRESSURE LINE WHEREBY THE RAM AND PROP CAN BE SELECTIVELY OPERATED IRRESPECTIVE OF THE SEQUENCE.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-04-04 | 1969-10-04 | 1970-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-04-04 | 1973-10-04 | 1974-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-04-04 | 1977-10-04 | 1978-04-05 | $7700.00 | Window Closed / Lapsed |