Patent US3342831A successfully refreshed from Google Patents.
Patent US3874136A successfully refreshed from Google Patents.
US3874136A
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US
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Telescopic mast structure
Assignee: SCADELLA ANSTALT
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Filing: 1973-06-07
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Granted: 1975-04-01
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Expires: 1993-06-07
Abstract
Abstract Telescopic mast structure having tubular sections extendible within the other guide units between complementary surfaces of associated telescoped sections, pressurized fluid for extending sections relative to each other, and expansible seal between such complementary surfaces.
Inventors
- 👤 Lucien P Michel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:54
CPC Classifications
E; E04; E04H; E04H12/00; E04H12/18; E04H12/182; F; F16; F16J; F16J15/00; F16J15/46
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
121 words
A telescopic mast structure comprising a plurality of tubular sections extendible one within the other, a guide unit adjacent one end of each section co-operable with a complementary surface of an associated tubular section, an expansible sealing joint adjacent the opposite end of each section and likewise cooperable with a complementary surface of an associated tubular section and means for introducing fluid under pressure into tubular sections whereby to extend and erect the structure, each expansible joint comprising an annular inflatable chamber extending around the tubular section, an annular resilient sealing member extending about the periphery of the inflatable chamber, and a lubricant cavity in the sealing member communicating through radial bores with the outer peripheral surface of the sealing member.
Claim 2
Dependent Claim
121 words
A telescopic mast structure comprising a plurality of tubular sections extendible one within the other, a guide unit adjacent one end of each section co-operable with a complementary surface of an associated tubular section, an expansible sealing joint adjacent the opposite end of each section and likewise cooperable with a complementary surface of an associated tubular section and means for introducing fluid under pressure into tubular sections whereby to extend and erect the structure, each expansible joint comprising an annular inflatable chamber extending around the tubular section, an annular resilient sealing member extending about the periphery of the inflatable chamber, and a lubricant cavity in the sealing member communicating through radial bores with the outer peripheral surface of the sealing member.
Claim 3
Dependent Claim
35 words
A telescopic mast structure according to claim 1, including two axially spaced flanges on the tubular section for containing the inflatable chamber and the resilient sealing member, at least one of the flanges being detachable.
Claim 4
Dependent Claim
59 words
A telescopic mast structure according to claim 1, and secondary guide rollers arranged adjacent the lower end of each tubular section and which normally do not bear against the interior of the associated outer tubular section but are arranged to absorb stresses in the wall of said outer section whenever said expansible joint is compressed beyond a predetermined amount.
References Cited (Backward Citations)
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US2888111A
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US3263382A
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US3423890A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |