Patent US3190393A successfully refreshed from Google Patents.
US3190393A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ladder having removable rungs
Assignee: Individual
•
Filing: 1963-10-10
•
Granted: 1965-06-22
•
Expires: 1983-10-10
Abstract
No abstract record available.
Inventors
- 👤 Michael P Alfano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:49
CPC Classifications
E; E06; E06C; E06C7/00; E06C7/08; E06C1/00; E06C1/02; E06C1/38; E06C7/16
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
117 words
A LADDER HAVING REMOVABLE RUNGS, COMPRISING A PAIR OF EQUALLY SPACED AND PARALLEL SIDE MEMBERS IN CHANNEL FORM HAVING A PLURALITY OF EQUALLY SPACED BLOCKS THAT ARE TRIANGULAR WHEN VIEWED FROM THE END SECURED TO THE INNER SIDE THEREOF IN WHICH IS REMOVABLY PLACED AND SECURED A PLURALITY OF EQUALLY SPACEDD SPRING-LOADED RUNGS AND EACH ONE OF THE RUNGS EMBODYING A HOLLOW RECTANGULAR HOLDER HAVING A STATIONARY BRACE MEMBER IN THE CENTER THEREEOF AGAINST EACH OUTWARD SIDE OF WHICH IS LOCATED A COIL SPRING THAT PRESSES AGAINST A SLIDING BLOCK THAT HAS ITS OUTER END RESTING ON TOP OF ONE THE BLOCKS THAT IS SECURED TO THE SAID SIDE MEMBER OF THE SAID LADDER AND A SUBSTANTIALLY
Claim 2
Dependent Claim
117 words
A LADDER HAVING REMOVABLE RUNGS, COMPRISING A PAIR OF EQUALLY SPACED AND PARALLEL SIDE MEMBERS IN CHANNEL FORM HAVING A PLURALITY OF EQUALLY SPACED BLOCKS THAT ARE TRIANGULAR WHEN VIEWED FROM THE END SECURED TO THE INNER SIDE THEREOF IN WHICH IS REMOVABLY PLACED AND SECURED A PLURALITY OF EQUALLY SPACEDD SPRING-LOADED RUNGS AND EACH ONE OF THE RUNGS EMBODYING A HOLLOW RECTANGULAR HOLDER HAVING A STATIONARY BRACE MEMBER IN THE CENTER THEREEOF AGAINST EACH OUTWARD SIDE OF WHICH IS LOCATED A COIL SPRING THAT PRESSES AGAINST A SLIDING BLOCK THAT HAS ITS OUTER END RESTING ON TOP OF ONE THE BLOCKS THAT IS SECURED TO THE SAID SIDE MEMBER OF THE SAID LADDER AND A SUBSTANTIALLY
References Cited (Backward Citations)
US388066A
Cited
US1450312A
Cited
US1495197A
Cited
US1691976A
Cited
US2419065A
Cited
US2599976A
Cited
US2982373A
Cited
US3092207A
Cited
US3059723A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-06-21 | 1968-12-21 | 1969-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-06-21 | 1972-12-21 | 1973-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-06-21 | 1976-12-21 | 1977-06-22 | $7700.00 | Window Closed / Lapsed |