Patent US3745772A successfully refreshed from Google Patents.
US3745772A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic roof support frame
Assignee: Hemscheidt Hermann Maschinenfabrik GmbH and Co
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Filing: 1971-12-10
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Granted: 1973-07-17
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Expires: 1991-12-10
Abstract
Abstract An hydraulic roof-support frame comprising floor and roof beams each of articulated construction, two outer hydraulic props extending between outer sections of the beams, at or near the ends of the latter, and at least one intermediate hydraulic prop, of greater strength than the outer props, extending between central portions of the beams, the said central portions having roof-engaging and floor-engaging surfaces of substantially greater area than the corresponding surfaces on the outer sections of the beams.
Inventors
- 👤 J Welzel
- 👤 H Bull
- 👤 A Maykemper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:05
CPC Classifications
E; E21; E21D; E21D11/00; E21D11/14
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
196 words
An hydraulic roof-support frame comprising a floor beam and a roof beam, each of said beams being composed of a central section and two outer sections articulated thereto, two outer hydraulic props extending between the respective outer sections of the roof beam and the floor beam at locations adjacent the ends of the beams, at least one intermediate hydraulic prop, of greater loadbearing capacity than either of the said outer props, extending between the said central sections of the beams, roof-engaging and floor-engaging surfaces on the central and outer sections of the roof beam and floor beam respectively, the roof-engaging and floor-engaging surfaces on the central sections of the roof and floor beams each being of substantially greater area than the individual roof-engaging and floor-engaging surfaces on the outer sections of the beams, guide-ways on the beam sections extending longitudinally thereof, and locking shoes slidingly mounted on the said guide-ways, each of said locking shoes being movable from an inoperative position in which the shoe is located on one beam section only into a locking position where the shoe straddles two adjacent beam sections and thus locks the said adjacent beam sections against relative pivoting movement.
Claim 2
Dependent Claim
196 words
An hydraulic roof-support frame comprising a floor beam and a roof beam, each of said beams being composed of a central section and two outer sections articulated thereto, two outer hydraulic props extending between the respective outer sections of the roof beam and the floor beam at locations adjacent the ends of the beams, at least one intermediate hydraulic prop, of greater loadbearing capacity than either of the said outer props, extending between the said central sections of the beams, roof-engaging and floor-engaging surfaces on the central and outer sections of the roof beam and floor beam respectively, the roof-engaging and floor-engaging surfaces on the central sections of the roof and floor beams each being of substantially greater area than the individual roof-engaging and floor-engaging surfaces on the outer sections of the beams, guide-ways on the beam sections extending longitudinally thereof, and locking shoes slidingly mounted on the said guide-ways, each of said locking shoes being movable from an inoperative position in which the shoe is located on one beam section only into a locking position where the shoe straddles two adjacent beam sections and thus locks the said adjacent beam sections against relative pivoting movement.
Claim 3
Dependent Claim
44 words
An hydraulic roof-support frame as claimed in claim 1, in which the ends of the hydraulic props are removably seated in bearing surfaces which form recesses in the beams, the bearing surfaces for the intermediate prop being larger than those for the outer props.
Claim 4
Dependent Claim
46 words
An hydraulic roof-support frame as claimed in claim 1, in which the outer sections of each beam are pivotally connected to the central section of the respective beam in a releasable manner by means of cooperating, inter-engaging surfaces on the adjacent ends of the beam sections.
Claim 5
Dependent Claim
19 words
An hydraulic roof-support frame as claimed in claim 1, in which the two beams are identical to each other.
Claim 6
Dependent Claim
29 words
An hydraulic roof-support as claimed in claim 2, in which the ends of the props are of part-spherical shape so as to seat in the recesses in the beams.
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) | 1976-07-16 | 1977-01-15 | 1977-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-16 | 1981-01-15 | 1981-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-16 | 1985-01-15 | 1985-07-17 | $7700.00 | Window Closed / Lapsed |