Patent US3962838A successfully refreshed from Google Patents.
US3962838A
Expired / Lapsed
US
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Shelf-adjusting stair
Assignee: Individual
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Filing: 1975-03-14
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Granted: 1976-06-15
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Expires: 1995-03-14
Abstract
Abstract A self-adjustable stair construction wherein the treads of the stair are supported by spacers between parallel upper and lower stringers in a truss assemblage. The rise and run and nosing are simultaneously adjusted for each tread with the adjustments being cumulative for each stair flight total run while maintaining the treads level. Each tread is located in a right angle relationship with each spacer. The treads, spacers and stringers are pivotally connected together with an elongated slot formed in each spacer to permit the adjusting movement. The slots are inclined and may be either curved or straight with the slope of either being in substantial alignment with the direction of the adjusting movement. The minimum number of repeated parts to produce the whole stair may be two.
Inventors
- 👤 Joe Warren Cox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:59
CPC Classifications
E; E04; E04F; E04F11/00; E04F11/02; E04F11/022; E04F11/025; E04F11/0255
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
252 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 being inclined with respect to the longitudinal axis of the said member which contains said slot, said slot means permitting an adjusting movement 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, the direction of said inclined slot means substantially coinciding with the direction of said adjusting movement, means interconnecting a said stringer and a said tread spacer and a said tread carrier, said means passing through said slot means, said means being movable within said slot means during said adjusting movement.
Claim 2
Dependent Claim
252 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 being inclined with respect to the longitudinal axis of the said member which contains said slot, said slot means permitting an adjusting movement 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, the direction of said inclined slot means substantially coinciding with the direction of said adjusting movement, means interconnecting a said stringer and a said tread spacer and a said tread carrier, said means passing through said slot means, said means being movable within said slot means during said adjusting movement.
Claim 3
Dependent Claim
65 words
The framework as defined in claim 1 wherein: said vertical tread spacer connected by said means to said upper stringer establishing a first connection point, said vertical tread spacer connected by said means to said lower stringer establishing a second connection point, during said adjusting movement said first connection point being gradually displaced horizontally and vertically from said second connection point during said adjusting movement.
Claim 4
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 5
Dependent Claim
28 words
The framework as defined in claim 1 wherein: said vertical tread spacer being gradually displaced horizontally and vertically during said adjusting movement while maintaining its substantially vertical position.
Claim 6
Dependent Claim
43 words
The framework as defined in claim 1 wherein: said adjusting movement being arcuate, said slot means includes a single curved slot formed within each of said vertical tread spacers, the curvature of said slot substantially coinciding with the curvature of the adjusting movement.
Claim 7
Dependent Claim
63 words
The framework as defined in claim 1 wherein: there being a said upper stringer and a said lower stringer located on each said lateral side of said treads, on each side lateral side said upper stringer being substantially parallel with said lower stringer, however, during the adjusting movement the distance between a said upper stringer and the respective said lower stringer will vary.
Claim 8
Dependent Claim
24 words
The framework as defined in claim 6 wherein: each of said upper stringers being parallel and in transverse alignment with respect to each other.
Claim 9
Dependent Claim
23 words
The framework as defined in claim 7 wherein: each said lower stringers being parallel and in transverse alignment with respect to each other.
Claim 10
Dependent Claim
39 words
The framework as defined in claim 8 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 11
Dependent Claim
25 words
The framework as defined in claim 1 wherein: said slot means includes a single longitudinal straight slot formed within each of said vertical tread spacers.
Claim 12
Dependent Claim
48 words
The framework as defined in claim 10 wherein: said adjusting movement being slightly arcuate, said straight slot being oversized in width in respect to said means, said straight slot being constant in width, whereby said means is permitted to move in a slight arc within said straight slot.
Claim 13
Dependent Claim
40 words
The framework as defined in claim 1 wherein: said slot being lineal and having a longitudinal center axis, said adjusting movement being arcuate defining a movement axis, said longitudinal center axis of said slot substantially coinciding with said movement axis.
Claim 14
Dependent Claim
18 words
The framework as defined in claim 12 wherein: said movement axis being tangent to said longitudinal center axis.
Claim 15
Dependent Claim
16 words
The framework as defined in claim 12 wherein: said longitudinal center axis intersecting said movement axis.
Claim 16
Dependent Claim
18 words
The framework as defined in claim 12 wherein: said movement axis being spaced from said longitudinal center axis.
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) | 1979-06-15 | 1979-12-15 | 1980-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-15 | 1983-12-15 | 1984-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-15 | 1987-12-15 | 1988-06-15 | $7700.00 | Window Closed / Lapsed |