Patent US2964538A successfully refreshed from Google Patents.
US5199825A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Grid composite for longwall shield recovery in underground coal and trona mines
Assignee: ELECTRA Inc
•
Filing: 1991-12-06
•
Granted: 1993-04-06
•
Expires: 2011-12-06
Abstract
Abstract A grid composite for protecting men and longwall mining equipment during longwall shield recovery includes a regular polymer geogrid structure formed by biaxially drawing a continuous sheet of select polypropylene material which is heat bonded to a polyester fabric. The grid composite is secured over caving shields of longwall mining equipment during a longwall mining operation.
Inventors
- 👤 Brian E. Travis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 07:22
CPC Classifications
E; E21; E21D; E21D11/00; E21D11/14; E21D11/15; E21D11/152
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
123 words
A system for longwall shield recovery, said system comprising: longwall mining equipment for cutting sections of a longwall face of a mine and said longwall mining equipment being advanced for subsequent cuts, a longwall screening package for supporting a roof above the longwall mining equipment during advancement of the longwall mining equipment, said longwall screening package including a grid composite formed of a polymer geogrid secured to a geotextile at interstitial nodes of the polymer geogrid, said polymer geogrid being positioned above and facing caving shields of the longwall mining equipment during longwall shield recovery and the geotextile being positioned facing an overhead gob whereby the geotextile aids in preventing cutting through by the overhead gob of the geogrid located below the geotextile.
Claim 2
Independent Claim
123 words
A system for longwall shield recovery, said system comprising: longwall mining equipment for cutting sections of a longwall face of a mine and said longwall mining equipment being advanced for subsequent cuts, a longwall screening package for supporting a roof above the longwall mining equipment during advancement of the longwall mining equipment, said longwall screening package including a grid composite formed of a polymer geogrid secured to a geotextile at interstitial nodes of the polymer geogrid, said polymer geogrid being positioned above and facing caving shields of the longwall mining equipment during longwall shield recovery and the geotextile being positioned facing an overhead gob whereby the geotextile aids in preventing cutting through by the overhead gob of the geogrid located below the geotextile.
Claim 3
Dependent Claim
25 words
A system as claimed in claim 1, wherein the geotextile is bonded to the polymer geogrid at ribs and the nodes of the polymer geogrid.
Claim 4
Dependent Claim
26 words
A system as claimed in claim 1, wherein the longwall screening package includes a length of geogrid on at least one side of the grid composite.
Claim 5
Dependent Claim
24 words
A system as claimed in claim 3, wherein the longwall screening package includes a length of geogrid on opposite sides of the grid composite.
Claim 6
Independent Claim
141 words
A method of longwall shield recovery, said method comprising: advancing longwall mining equipment to remove a longwall face until the longwall mining equipment reaches a terminal position, said longwall mining equipment including caving shields located adjacent to an overhead gob, supporting a longwall screening package above the longwall mining equipment during advancement of the longwall mining equipment, and locating a grid composite of the longwall screening package formed of a polymer geogrid secured to a geotextile at interstitial nodes of the polymer geogrid with the polymer geogrid located above and facing the caving shields of the longwall mining equipment with the geogrid being positioned below the geotextile and the geotextile being positioned to face the overhead gob with the geogrid being positioned below the geotextile for aiding in preventing penetration of the gob through the grid composite during longwall shield recovery.
Claim 7
Independent Claim
141 words
A method of longwall shield recovery, said method comprising: advancing longwall mining equipment to remove a longwall face until the longwall mining equipment reaches a terminal position, said longwall mining equipment including caving shields located adjacent to an overhead gob, supporting a longwall screening package above the longwall mining equipment during advancement of the longwall mining equipment, and locating a grid composite of the longwall screening package formed of a polymer geogrid secured to a geotextile at interstitial nodes of the polymer geogrid with the polymer geogrid located above and facing the caving shields of the longwall mining equipment with the geogrid being positioned below the geotextile and the geotextile being positioned to face the overhead gob with the geogrid being positioned below the geotextile for aiding in preventing penetration of the gob through the grid composite during longwall shield recovery.
Claim 8
Dependent Claim
25 words
A method as claimed in claim 1, wherein the geotextile is bonded to the polymer geogrid at ribs and the nodes of the polymer geogrid.
Claim 9
Dependent Claim
27 words
A method as claimed in claim 1, wherein in the longwall screening package includes a length of geogrid on at least one side of the grid composite.
Claim 10
Dependent Claim
24 words
A method as claimed in claim 7, wherein the longwall screening package includes a length of geogrid on opposite sides of the grid composite.
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) | 1996-04-05 | 1996-10-05 | 1997-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-04-05 | 2000-10-05 | 2001-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-04-05 | 2004-10-05 | 2005-04-06 | $7700.00 | Window Closed / Lapsed |