Patent US4493707A successfully refreshed from Google Patents.
Patent US4124957A successfully refreshed from Google Patents.
US4124957A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Structural improvements for stairs or stairs with variable geometry
Assignee: Individual
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Filing: 1977-08-08
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Granted: 1978-11-14
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Expires: 1997-08-08
Abstract
Abstract The present invention relates to staircase structures and in particular provides a staircase structure in which the components may be substantially prefabricated and erected on site. Standardized components are generally used whereby labor is minimized while the staircase is adjustable for various slopes. The structure basically comprises a pair of stringers, each formed of upper and lower shafts which are movable longitudinally with respect to each other and can be spaced apart. Tread supporting members extend between the upper shafts and lower shafts for receiving the tread members.
Inventors
- 👤 Robert A. Poulain
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:58
CPC Classifications
E; E04; E04F; E04F11/00; E04F11/02; E04F11/022; E04F11/025; E04F11/0255
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
137 words
A staircase comprising a pair of parallel stringers having a plurality of steps extending therebetween, each of said stringers comprising an upper and a lower shaft, said shafts being parallel to each other, and being longitudinally movable with respect to each other, said shafts having a mating tongue and groove arrangement for movement relative to each other, each of said shafts having a plurality of apertures therein, a plurality of step supporting members extending between respective top shafts and respective bottom shafts through said apertures therein, each of the steps being supported by at least a first step supporting member extending between said top shafts and a second step supporting member extending between said bottom shafts, means for locking said step supporting members within said apertures, and means associated with said top shaft for receiving railing members.
Claim 2
Dependent Claim
137 words
A staircase comprising a pair of parallel stringers having a plurality of steps extending therebetween, each of said stringers comprising an upper and a lower shaft, said shafts being parallel to each other, and being longitudinally movable with respect to each other, said shafts having a mating tongue and groove arrangement for movement relative to each other, each of said shafts having a plurality of apertures therein, a plurality of step supporting members extending between respective top shafts and respective bottom shafts through said apertures therein, each of the steps being supported by at least a first step supporting member extending between said top shafts and a second step supporting member extending between said bottom shafts, means for locking said step supporting members within said apertures, and means associated with said top shaft for receiving railing members.
Claim 3
Dependent Claim
14 words
The staircase of claim 1 wherein said stringers are formed of a wood material.
Claim 4
Dependent Claim
24 words
The staircase of claim 1 wherein said top shafts have a plurality of slots therein for receiving members adapted to form a hand rail.
Claim 5
Dependent Claim
28 words
The staircase of claim 3 wherein said means for supporting said steps comprises threaded metallic rods having nuts associated therewith for retaining said rods in the desired position.
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) | 1981-11-13 | 1982-05-15 | 1982-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-11-13 | 1986-05-15 | 1986-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-11-13 | 1990-05-15 | 1990-11-14 | $7700.00 | Window Closed / Lapsed |