Patent US3196756A successfully refreshed from Google Patents.
US3196756A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Roof support assemblies
Assignee: Dowty Mining Equipment Ltd
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Filing: 1963-10-07
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Granted: 1965-07-27
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Expires: 1983-10-07
Abstract
No abstract record available.
Inventors
- 👤 Douglas H H Bolton
- 👤 Michael C Potts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:51
CPC Classifications
E; E21; E21D; E21D23/00; E21D23/16
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
116 words
A ROOF SUPPORT ASSEMBLY INCLUDING A SERIES OF FLUIDPRESSURE-OPERATED ROOF SUPPORTS ARRANGED TO ADVANCE SEQUENTLY, A SOURCE OF FLUID PRESSURE CONNECTED TO THE ROOF SUPPORTS FOR OPERATING THE ROOF SUPPORTS, A FLUID-CARRYING LINE ALONG WHICH FLUID PASSES WHEN EACH ROOF SUPPORT UNDERGOES AN ADVANCING OPERATION, AND SOUND-PRODUCING MEANS RESPONSIVE TO THE FLUID PRESSURE IN THE FLUID-CARRYINGING LINE AND ARRANGED TO EMIT ONE SOUND WHEN THE PRESSURE IS ABOVE A CHOSEN VALUE AND A DIFFERENT SOUND WHEN THE PRESSURE IS BELOW A CHOSEN VALUE, THE VALUES BEING SO CHOSEN THAT THE VARIATION IN PRESSURE WHICH OCCURS IN THE FLUID-CARRYING LINE WHEN EACH ROOF SUPPORT UNDERGOES AN ADVANCING OPERATION CAUSES A CHANGE FROM ONE SOUND TO THE OTHER.
Claim 2
Dependent Claim
116 words
A ROOF SUPPORT ASSEMBLY INCLUDING A SERIES OF FLUIDPRESSURE-OPERATED ROOF SUPPORTS ARRANGED TO ADVANCE SEQUENTLY, A SOURCE OF FLUID PRESSURE CONNECTED TO THE ROOF SUPPORTS FOR OPERATING THE ROOF SUPPORTS, A FLUID-CARRYING LINE ALONG WHICH FLUID PASSES WHEN EACH ROOF SUPPORT UNDERGOES AN ADVANCING OPERATION, AND SOUND-PRODUCING MEANS RESPONSIVE TO THE FLUID PRESSURE IN THE FLUID-CARRYINGING LINE AND ARRANGED TO EMIT ONE SOUND WHEN THE PRESSURE IS ABOVE A CHOSEN VALUE AND A DIFFERENT SOUND WHEN THE PRESSURE IS BELOW A CHOSEN VALUE, THE VALUES BEING SO CHOSEN THAT THE VARIATION IN PRESSURE WHICH OCCURS IN THE FLUID-CARRYING LINE WHEN EACH ROOF SUPPORT UNDERGOES AN ADVANCING OPERATION CAUSES A CHANGE FROM ONE SOUND TO THE OTHER.
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) | 1968-07-26 | 1969-01-25 | 1969-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-07-26 | 1973-01-25 | 1973-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-07-26 | 1977-01-25 | 1977-07-27 | $7700.00 | Window Closed / Lapsed |