US3830456A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mining apparatus
Assignee: FLETCHER J AND CO
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Filing: 1972-12-22
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Granted: 1974-08-20
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Expires: 1992-12-22
Abstract
Abstract A temporary roof support apparatus attachable to mining roof drilling and bolting machines advances a boom with a pivotally moveable extendible column at the boom end into unsupported roof areas in a mine room, pivots the columns into vertical disposition, extends them into load bearing compression between the mine room roof and floor and temporarily supports the roof against cave-in while roof bolting proceeds.
Inventors
- 👤 J Fletcher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 10:08
CPC Classifications
E; E21; E21D; E21D20/00; E21D20/003; E21D19/00; E21D19/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
190 words
Apparatus for effecting roof support in confined roofed spaces comprising, in combination, a. column means continuously extendible from a first length to a second length within a range of second lengths; b. boom means having a proximal end and a remote end, extending substantially horizontally from a boom anchor support affixed to said boom means at the proximal end thereof; c. pivot means connecting said column means pivotally to said boom means at the remote end thereof, adapted to permit pivotal movement of the column means in substantially coplanar orientation with the longitudinal axis of the boom means from a first position in which the column means is disposed towards the horizontal, towards and into a second position in which the column means is erect, substantially vertical, and substantially normal to the longitudinal axis of the boom means; d. first motive means to move the column means pivotally between and into its said first and said second positions; and e. second motive means to extend the column means from its first length to a second length, and to retract said column means from said second length towards its first length.
Claim 2
Dependent Claim
190 words
Apparatus for effecting roof support in confined roofed spaces comprising, in combination, a. column means continuously extendible from a first length to a second length within a range of second lengths; b. boom means having a proximal end and a remote end, extending substantially horizontally from a boom anchor support affixed to said boom means at the proximal end thereof; c. pivot means connecting said column means pivotally to said boom means at the remote end thereof, adapted to permit pivotal movement of the column means in substantially coplanar orientation with the longitudinal axis of the boom means from a first position in which the column means is disposed towards the horizontal, towards and into a second position in which the column means is erect, substantially vertical, and substantially normal to the longitudinal axis of the boom means; d. first motive means to move the column means pivotally between and into its said first and said second positions; and e. second motive means to extend the column means from its first length to a second length, and to retract said column means from said second length towards its first length.
Claim 3
Dependent Claim
34 words
Apparatus according to claim 1 in combination with roof underspanning means mounted on said column means at the portion thereof which is uppermost when said column means is in its erect, substantially vertical position
Claim 4
Dependent Claim
35 words
Apparatus according to claim 2 wherein said roof underspanning means is pivotally mounted on said column means so as to be maintainable in a substantially horizontal disposition for all positions assumed by said column means.
Claim 5
Dependent Claim
23 words
Apparatus according to claim 1 wherein the pivot means connecting the column means to the boom means is a selectably detachable pivot means.
Claim 6
Dependent Claim
22 words
Apparatus according to claim 1 wherein the boom means is selectably extendible and retractable between its proximal end and its remote end.
Claim 7
Dependent Claim
18 words
Apparatus according to claim 1 wherein said first motive means and said second motive means are hydraulically actuated.
Claim 8
Dependent Claim
16 words
Apparatus according to claim 1 wherein the boom means is cantilevered from the boom anchor support.
References Cited (Backward Citations)
GB654985A
Cited
US2826898A
Cited
US2857125A
Cited
FR1198866A
Cited
GB865922A
Cited
GB870486A
Cited
GB968668A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-19 | 1978-02-18 | 1978-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-19 | 1982-02-18 | 1982-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-19 | 1986-02-18 | 1986-08-20 | $7700.00 | Window Closed / Lapsed |