US3207259A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spiral stairway
Assignee: Individual
•
Filing: 1963-10-03
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Granted: 1965-09-21
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Expires: 1983-10-03
Abstract
No abstract record available.
Inventors
- 👤 Dave F Gebhart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 01:49
CPC Classifications
E; E04; E04F; E04F11/00; E04F11/02; E04F11/022; E04F11/032
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
129 words
A SPIRAL STAIRCASE COMPRISING A VERTICAL, CENTRAL, COLUMNAR ELEMENT FORMED IN THE SHAPE OF A HELIX WHOSE DIAMETER IS AT LEAST ABOUT 16" AND PITCH ITS AT LEAST ABOUT 78", A PLURALITY OF STAIRS FASTENED TO AND EXTENDING RADIALLY OUTWARDLY FROM SAID COLUMNAR ELEMENT, SAID COLUMNAR ELEMENT CONNECTED TO THE INNER ENDS OF SAID STAIRS AND CONSTITUTING THE PRIMARY COLUMNAR SUPPORT FOR THE STAIRS THROUGHOUT THE ENTIRE HEIGHT OF SAID STAIRCASE, A HELICAL OUTER MEMBER CONNECTED TO THE OUTSIDE LEADING EDGE OF EACH OF SAID STAIRS, A PLURALITY OF VERTICAL MEMBERS CONNECTED TO SAID HELICAL MEMBER AND TO THE OUTSIDE TRAILING PORTION OF EACH OF SAID STAIRS, AND MEANS CONNECTING SAID COLUMNAR ELEMENT AT EACH OF ITS EXTREMITIES TO AT LEAST TWO SURFACES BETWEEN WHICH SAID SPIRAL STAIRCASE CONNECTS.
Claim 2
Dependent Claim
129 words
A SPIRAL STAIRCASE COMPRISING A VERTICAL, CENTRAL, COLUMNAR ELEMENT FORMED IN THE SHAPE OF A HELIX WHOSE DIAMETER IS AT LEAST ABOUT 16" AND PITCH ITS AT LEAST ABOUT 78", A PLURALITY OF STAIRS FASTENED TO AND EXTENDING RADIALLY OUTWARDLY FROM SAID COLUMNAR ELEMENT, SAID COLUMNAR ELEMENT CONNECTED TO THE INNER ENDS OF SAID STAIRS AND CONSTITUTING THE PRIMARY COLUMNAR SUPPORT FOR THE STAIRS THROUGHOUT THE ENTIRE HEIGHT OF SAID STAIRCASE, A HELICAL OUTER MEMBER CONNECTED TO THE OUTSIDE LEADING EDGE OF EACH OF SAID STAIRS, A PLURALITY OF VERTICAL MEMBERS CONNECTED TO SAID HELICAL MEMBER AND TO THE OUTSIDE TRAILING PORTION OF EACH OF SAID STAIRS, AND MEANS CONNECTING SAID COLUMNAR ELEMENT AT EACH OF ITS EXTREMITIES TO AT LEAST TWO SURFACES BETWEEN WHICH SAID SPIRAL STAIRCASE CONNECTS.
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) | 1968-09-20 | 1969-03-22 | 1969-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-09-20 | 1973-03-22 | 1973-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-09-20 | 1977-03-22 | 1977-09-21 | $7700.00 | Window Closed / Lapsed |