US3709323A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-leveling strips
Assignee: Individual
•
Filing: 1971-04-12
•
Granted: 1973-01-09
•
Expires: 1991-04-12
Abstract
Abstract An adjustable height self-leveling set of steps and landing, including a pair of trapezoidal shaped side frames having legs at each corner thereof. The four members making up the side frames are pivotally connected with the exception of one rigid joint between two of the members to prevent the side frame from collapsing. Each corner will self-level by shifting the shape of the side frame while the steps and landing remain substantially horizontal.
Inventors
- 👤 G Trible
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 18:52
CPC Classifications
E; E06; E06C; E06C1/00; E06C1/02; E06C1/14
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
121 words
A self-leveling adjustable height step structure comprising: a plurality of step treads and a landing; a pair of parallel spaced trapezoidal shaped side frames supporting the ends of the treads and landing, each frame having upper and lower parallel spaced horizontal members joined at their ends by two non-parallel members, the first non-parallel member being vertically spaced normal to the horizontal members and the second non-parallel member being a tread supporting member canted with respect to the horizontal members, all of the members being pivotally connected together with the exception of one rigid joint allowing the trapezoid to change its shape as the lower ends of the non-parallel members adjust to the uneven bearing surface the step structure is placed on.
Claim 2
Dependent Claim
121 words
A self-leveling adjustable height step structure comprising: a plurality of step treads and a landing; a pair of parallel spaced trapezoidal shaped side frames supporting the ends of the treads and landing, each frame having upper and lower parallel spaced horizontal members joined at their ends by two non-parallel members, the first non-parallel member being vertically spaced normal to the horizontal members and the second non-parallel member being a tread supporting member canted with respect to the horizontal members, all of the members being pivotally connected together with the exception of one rigid joint allowing the trapezoid to change its shape as the lower ends of the non-parallel members adjust to the uneven bearing surface the step structure is placed on.
Claim 3
Dependent Claim
66 words
A step structure as set forth in claim 1, wherein the canted tread supporting member of each frame includes two closely spaced parallel structural members, each pivotally connected at separate points to each tread member and to the upper horizontal member, whereby the step treads always remain parallel to the landing regardless of the angle of the canted member to the horizontal members of the frame.
Claim 4
Dependent Claim
82 words
A step structure as set forth in claim 1, wherein the canted non-parallel member includes two closely spaced parallel structural members, each pivotally connected at separate points on each tread member and the upper horIzontal member, whereby the step treads always remain parallel to the landing regardless of the angle of the canted member to the horizontal members of the frame, and cross brace means connecting the rear vertical members of each frame to prevent any lateral tilting of the side frames.
Claim 5
Dependent Claim
45 words
A step structure as set forth in claim 1, wherein the rear vertical members and the lower horizontal member include telescoping means whereby the lengths of said members can be varied to change the height of the step structure and angle of the canted member.
Claim 6
Dependent Claim
74 words
A step structure as set forth in claim 1, wherein the rear vertical members and the lower horizontal member includes telescoping means whereby the lengths of said members can be varied to change the height of the step structure, and an adjustable height stub leg attached to the lower end of the canted member whereby the height to the first tread member can be varied to correspond with the height to the remaining treads.
Claim 7
Dependent Claim
95 words
A step structure as set forth in claim 1, wherein the rear vertical members and the lower horizontal member include telescoping means whereby the lengths of said members can be varied to change the height of the step structure, and the canted tread supporting member of each frame includes two closely spaced parallel structural members, each pivotally connected at separate points on each tread member and the upper horizontal member, whereby the step treads always remain parallel to the landing regardless of the angle of the canted member to the horizontal members of the frame.
Claim 8
Dependent Claim
46 words
A step structure as set forth in claim 1, wherein the canted member of each frame includes means for adjustably supporting the treads and maintaining the treads substantially parallel to the upper horizontal member regardless of the angle between the canted member and the horizontal members.
Claim 9
Dependent Claim
66 words
A step structure as set forth in claim 1, wherein the canted member of each frame includes means for adjustably supporting the treads and maintaining the treads substantially parallel to the horizontal members regardless of the angle between the canted member and the horizontal members, and cross brace means connecting the rear vertical members of each frame to prevent any lateral tilting of the side frames.
Claim 10
Dependent Claim
75 words
A step structure as set forth in claim 1, wherein the rear vertical members and the lower parallel member include telescoping means whereby the lengths of said members can be varied to change the height of the step structure, and the canted member of each frame includes means for adjustably supporting the treads and maintaining the treads substantially parallel to the horizontal members regardless of the angle between the canted member and the horizontal members.
Claim 11
Dependent Claim
24 words
A step structure as set forth in claim 1, wherein the rigid joint is between the first non-parallel member and the upper horizontal member.
References Cited (Backward Citations)
US3283853A
Cited
US3593821A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |