US3301136A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Advanceable roof support assemblies
Assignee: Dowty Mining Equipment Ltd
•
Filing: 1965-01-08
•
Granted: 1967-01-31
•
Expires: 1985-01-08
Abstract
No abstract record available.
Inventors
- 👤 Bolton Douglas Herbert Hewlett
- 👤 Potts Michael Charles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:30
CPC Classifications
F; F15; F15B; F15B13/00; F15B13/02; F15B13/04; F15B13/042; F15B13/0422; E; E21; E21D; E21D23/00; E21D23/16
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
88 words
AN ADVANCEABLE ROOF SUPPORT ASSEMBLY INCLUDING A SERIES OF ADVANCEABLE FLUID-PRESSURE-OPERATED ROOF SUPPORTS, A CONDUIT INCLUDING TO EACH ROOF SUPPORT IN TURN, EACH ROOF SUPPORT INCLUDING A VALVE ASSEMBLY RESPONSIVE TO THE RECEIPT OF A FLUID-PRESSURE SIGNAL ALONG SAID CONDUIT TO CAUSE THE ROOF SUPPORT TO UNDERGO AN ADVANCING OPERATION AND RESPONSIVE TO THE COMPLETION OF THE ADVANCING OPERATION TO PASS THE SIGNAL ON ALONG SAID CONDUIT, A SOURCE OF FLUID PRESSURE AND A CONTROL VALVE OPERABLE TO CONNECT THE CONDUIT TO THE SOURCE OF FLUID PRESSURE TO
Claim 2
Dependent Claim
88 words
AN ADVANCEABLE ROOF SUPPORT ASSEMBLY INCLUDING A SERIES OF ADVANCEABLE FLUID-PRESSURE-OPERATED ROOF SUPPORTS, A CONDUIT INCLUDING TO EACH ROOF SUPPORT IN TURN, EACH ROOF SUPPORT INCLUDING A VALVE ASSEMBLY RESPONSIVE TO THE RECEIPT OF A FLUID-PRESSURE SIGNAL ALONG SAID CONDUIT TO CAUSE THE ROOF SUPPORT TO UNDERGO AN ADVANCING OPERATION AND RESPONSIVE TO THE COMPLETION OF THE ADVANCING OPERATION TO PASS THE SIGNAL ON ALONG SAID CONDUIT, A SOURCE OF FLUID PRESSURE AND A CONTROL VALVE OPERABLE TO CONNECT THE CONDUIT TO THE SOURCE OF FLUID PRESSURE TO
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) | 1970-01-30 | 1970-08-01 | 1971-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-01-30 | 1974-08-01 | 1975-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-01-30 | 1978-08-01 | 1979-01-31 | $7700.00 | Window Closed / Lapsed |