Patent US3228300A successfully refreshed from Google Patents.
US3228300A
Expired / Lapsed
US
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Mining apparatus
Assignee: Dowty Mining Equipment Ltd
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Filing: 1963-05-22
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Granted: 1966-01-11
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Expires: 1983-05-22
Abstract
No abstract record available.
Inventors
- 👤 Potts Michael Charles
- 👤 Bolton Douglas Herbert Hewlett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:58
CPC Classifications
E; E21; E21D; E21D23/00; E21D23/006; E21D23/0073; E21D23/12; E21D23/14; Y; Y10; Y10T; Y10T137/00; Y10T137/8158; Y10T137/8326
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
176 words
A ROOF SUPPORT ASSEMBLY INCLUDING A SERIES OF FLUIDPRESSURE-OPERATED ADVANCEABLE ROOF SUPPORTS, A SOURCE OF FLUID PRESSURE, A CONDUIT CONNECTING SAID SOURCE WITH EACH ROOF SUPPORT EACH ROOF SUPPORT INCLUDING AT LEAST ONE FLUID-PRESSURE-OPERATED PROP TO WHICH SAID CONDUIT IS CONNECTED, AND A FLUID-PRESSURE-OPERATED MEANS TO ADVANCE IT ALSO CONNECTED TO SAID CONDUIT, AND A CONTROL VALVE ASSEMBLY INDIVIDUAL TO EACH ROOF SUPPORT AND OPERABLE TO SUPPLY PRESSURE FLUID FROM SUCH SOURCE TO CAUSE ITS ROOF SUPPORT TO UNDERGO AN ADVANCING OPERATION, EACH CONTROL VALVE ASSEMBLY BEING ARRANGED TO SEND A SIGNAL TO THE CONTROL VALVE ASSEMBLY OF THE NEXT ROOF SUPPORT, TO INITIATE ADVANCE THEREOF, UPON COMPLETION OF THE ADVANCE OF ITS OWN ROOF SUPPORT, A WARNING DEVICE INCLUDING A PRESSURE SENSITIVE MEANS OPERATIVELY CONNECTED TO SAID CONDUIT AND OPERABLE BY DEPARTURE OF PRESSURE THEREIN ITS NORMAL RANGE FLUCTUATION OCCURING DURING AN ADVANCING OPERATION, TO INDICATE INTERRUPTION OF SUCH OPERATION, AND TIME DELAY MEANS OPERATIVELY DURING SUCH NORMAL PRESSURE MEANS TO DELAY ITS INDICATION DURING SUCH NORMAL PRESSURE FLUCTUATIONS, BUT ABNORMAL PRESSURE IN SAID CONDUIT.
Claim 2
Dependent Claim
176 words
A ROOF SUPPORT ASSEMBLY INCLUDING A SERIES OF FLUIDPRESSURE-OPERATED ADVANCEABLE ROOF SUPPORTS, A SOURCE OF FLUID PRESSURE, A CONDUIT CONNECTING SAID SOURCE WITH EACH ROOF SUPPORT EACH ROOF SUPPORT INCLUDING AT LEAST ONE FLUID-PRESSURE-OPERATED PROP TO WHICH SAID CONDUIT IS CONNECTED, AND A FLUID-PRESSURE-OPERATED MEANS TO ADVANCE IT ALSO CONNECTED TO SAID CONDUIT, AND A CONTROL VALVE ASSEMBLY INDIVIDUAL TO EACH ROOF SUPPORT AND OPERABLE TO SUPPLY PRESSURE FLUID FROM SUCH SOURCE TO CAUSE ITS ROOF SUPPORT TO UNDERGO AN ADVANCING OPERATION, EACH CONTROL VALVE ASSEMBLY BEING ARRANGED TO SEND A SIGNAL TO THE CONTROL VALVE ASSEMBLY OF THE NEXT ROOF SUPPORT, TO INITIATE ADVANCE THEREOF, UPON COMPLETION OF THE ADVANCE OF ITS OWN ROOF SUPPORT, A WARNING DEVICE INCLUDING A PRESSURE SENSITIVE MEANS OPERATIVELY CONNECTED TO SAID CONDUIT AND OPERABLE BY DEPARTURE OF PRESSURE THEREIN ITS NORMAL RANGE FLUCTUATION OCCURING DURING AN ADVANCING OPERATION, TO INDICATE INTERRUPTION OF SUCH OPERATION, AND TIME DELAY MEANS OPERATIVELY DURING SUCH NORMAL PRESSURE MEANS TO DELAY ITS INDICATION DURING SUCH NORMAL PRESSURE FLUCTUATIONS, BUT ABNORMAL PRESSURE IN SAID CONDUIT.
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) | 1969-01-10 | 1969-07-12 | 1970-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-01-10 | 1973-07-12 | 1974-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-01-10 | 1977-07-12 | 1978-01-11 | $7700.00 | Window Closed / Lapsed |