Patent US3768267A successfully refreshed from Google Patents.
US3768267A
Expired / Lapsed
US
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Telescoping lining and support structure and method for lining tunnels and shafts
Assignee: Commercial Shearing Inc
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Filing: 1971-10-13
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Granted: 1973-10-30
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Expires: 1991-10-13
Abstract
Abstract A novel telescoping lining and support structure and method for lining tunnels and shafts is provided in which a plurality of first chordal segments are drawn into a tunnel or shaft hole in a reduced diameter state of compression, expanded diametrically one after another in place in said tunnel or shaft and keyed in the expanded state by a second smaller chordal segment which completes an annular ring segment with the first chordal segment in place.
Inventors
- 👤 N Chlumecky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:13
CPC Classifications
E; E21; E21D; E21D11/00; E21D11/40; E21D11/04; E21D11/05
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
80 words
A tunnel lining segment comprising a primary arcuate segment of finite length having an included angle of at least 230* but less than 360* and formed of a material having limited elastic properties such that the segment can be diametrically compressed a sufficient amount to permit its passage through a like segment diametrically uncompressed and at least one secondary segment adapted to engage the primary segment at its ends and forming with said primary segment an included angle of 360*.
Claim 2
Dependent Claim
80 words
A tunnel lining segment comprising a primary arcuate segment of finite length having an included angle of at least 230* but less than 360* and formed of a material having limited elastic properties such that the segment can be diametrically compressed a sufficient amount to permit its passage through a like segment diametrically uncompressed and at least one secondary segment adapted to engage the primary segment at its ends and forming with said primary segment an included angle of 360*.
Claim 3
Dependent Claim
12 words
A tunnel lining segment as claimed in claim 1 made of steel.
Claim 4
Dependent Claim
13 words
A tunnel lining segment as claimed in claim 1 made of reinforced plastic.
Claim 5
Dependent Claim
13 words
A tunnel lining segment as claimed in claim 1 made of reinforced concrete.
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) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |