US3885365A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-adjusting stair
Assignee: Individual
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Filing: 1974-06-06
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Granted: 1975-05-27
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Expires: 1994-06-06
Abstract
Abstract A self-adjustable stair construction wherein the treads of the stair are supported by spacers between upper and lower stringers in a truss assemblage. This stair readily accommodates all variations in landing construction and stairwell sizes such as vertical and horizontal variance. Both rise and run between the treads are simultaneously adjusted with the adjustments being cumulative over stair flight run while maintaining the treads level. The stair may be prefabricated and is to be assembled from parts, installed during or after building construction, is removable and can be relocated and re-adjusted to the new location. This stair may be fitted with a variety of tread shapes which can be replaced, reversed or new treads substituted. The framework of this invention may be used in a form to cast concrete stairs, it can become an integral part of the reinforcement, or it may be used and removed. The stair performs lilke an on-site variable jig to suit variable field conditions.
Inventors
- 👤 Joe Warren Cox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:38
CPC Classifications
E; E04; E04F; E04F11/00; E04F11/02; E04F11/022; E04F11/025; E04F11/0255; E04G; E04G13/00; E04G13/06; E04G13/062
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
181 words
A self-adjusting stair framework formed of a plurality of interconnected linkage members, said framework comprising: a plurality of treads positionable in a substantially horizontal relationship, each of said treads havIng a front side and a rear side and a pair of lateral sides, each of said treads supported by a pair of tread carriers, a said tread carrier located at each said lateral side of each of said treads; a pair of upper stringers, each said upper stringer pivotally connected to said tread carriers; a pair of lower stringers, each said lower stringer pivotally connected to said tread carriers; a vertical tread spacer located between and pivotally connected to each adjacent pair of said treads; and at least one longitudinal slot means formed within one of said linkage members, said slot means located at the pivotal interconnection between a pair of said members, said slot means permitting adjustment of said framework between a minimum rise adjustment position and a maximum rise adjustment position, said maximum adjustment position being displaced horizontally and vertically from said minimum adjustment position throughout the adjusting movement.
Claim 2
Dependent Claim
181 words
A self-adjusting stair framework formed of a plurality of interconnected linkage members, said framework comprising: a plurality of treads positionable in a substantially horizontal relationship, each of said treads havIng a front side and a rear side and a pair of lateral sides, each of said treads supported by a pair of tread carriers, a said tread carrier located at each said lateral side of each of said treads; a pair of upper stringers, each said upper stringer pivotally connected to said tread carriers; a pair of lower stringers, each said lower stringer pivotally connected to said tread carriers; a vertical tread spacer located between and pivotally connected to each adjacent pair of said treads; and at least one longitudinal slot means formed within one of said linkage members, said slot means located at the pivotal interconnection between a pair of said members, said slot means permitting adjustment of said framework between a minimum rise adjustment position and a maximum rise adjustment position, said maximum adjustment position being displaced horizontally and vertically from said minimum adjustment position throughout the adjusting movement.
Claim 3
Dependent Claim
29 words
The framework as defined in claim 1 wherein: during said adjusting movement the amount of said horizontal movement is equal to two-thirds of the amount of said vertical movement.
Claim 4
Dependent Claim
41 words
The framework as defined in claim 1 wherein: therebeing a said upper stringer and a said lower stringer located on each said lateral side of said treads, on each said lateral side said upper stringer being parallel with said lower stringer.
Claim 5
Dependent Claim
24 words
The framework as defined in claim 3 wherein: each of said upper stringers being parallel and in transverse alignment with respect to each other.
Claim 6
Dependent Claim
23 words
The framework as defined in claim 4 wherein: each said lower stringers being parallel and in transverse alignment with respect to each other.
Claim 7
Dependent Claim
39 words
The framework as defined in claim 5 wherein: each said upper stringer pivotally connected to said tread carriers adjacent said front side of said treads, each of said lower stringers pivotally connected to said rear side of said treads.
Claim 8
Dependent Claim
23 words
The framework as defined in claim 1 wherein: said longitudinal slot means includes a slot horizontally located within each of said thread carriers.
Claim 9
Dependent Claim
29 words
The framework as defined in claim 7 wherein: said slot means further includes a second longitudinal slot, said second longitudinal slot being vertically disposed within each said tread spacers.
Claim 10
Dependent Claim
67 words
The framework as defined in claim 8 further including: an inclined tread spacer assembly, said inclined tread spacer assembly comprising at least a pair of links pivotally connected between said upper and lower stringers on each lateral side of said framework, the length and selection of interconnection points being such that said vertical tread spacers are fixed in a right angle relationship with respect to said treads.
Claim 11
Dependent Claim
23 words
The framework as defined in claim 1 wherein: said slot means includes a single longitudinal slot formed within each of said tread spacers.
Claim 12
Dependent Claim
27 words
The framework as defined in claim 10 wherein: said slot means includes a second longitudinal slot, said second longitudinal slot located within each of said tread carriers.
Claim 13
Dependent Claim
61 words
The framework as defined in claim 11 wherein: an inclined tread spacer assembly comprising at least a pair of links pivotally connected between said upper and lower stringer on each lateral side of said framework, the length and selection of interconnection points being such that said vertical tread spacers are fixed in a right angle relationship with respect to said treads.
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) | 1978-05-26 | 1978-11-25 | 1979-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-26 | 1982-11-25 | 1983-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-26 | 1986-11-25 | 1987-05-27 | $7700.00 | Window Closed / Lapsed |