Patent US4311208A successfully refreshed from Google Patents.
US4311208A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ladder safety lamp
Assignee: Individual
•
Filing: 1980-07-18
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Granted: 1982-01-19
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Expires: 2000-07-18
Abstract
Abstract A warning light assembly for use on ladders having a plurality of rungs to indicate the presence of someone on the ladder. The warning light assembly has a switch activated by a person's foot placed on one of the lower rungs of the ladder. When first activated, the switch turns on a flashing light positioned about eye level. As the person disembarks from the ladder, his foot on the lower rung again activates the switch turning off the flashing light.
Inventors
- 👤 Patrick L. Macrorie
- 👤 Ronald C. Rohrenbacher
- 👤 Stephen B. Austin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:57
CPC Classifications
E; E06; E06C; E06C7/00; E06C7/003
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
63 words
A warning signal assembly for use on ladders having a plurality of rungs to indicate the presence of someone on the ladder, said warning signal assembly comprising: switch means activated by a person's foot placed on one of the lower rungs, said switch means activating signal means, said signal means being deactivated by a person's foot placed on one of said lower rungs.
Claim 2
Dependent Claim
63 words
A warning signal assembly for use on ladders having a plurality of rungs to indicate the presence of someone on the ladder, said warning signal assembly comprising: switch means activated by a person's foot placed on one of the lower rungs, said switch means activating signal means, said signal means being deactivated by a person's foot placed on one of said lower rungs.
Claim 3
Dependent Claim
15 words
The assembly of claim 1 wherein said switch means is positioned above the lowermost rung.
Claim 4
Dependent Claim
12 words
The assembly of claim 1 wherein said signal means comprises light means.
Claim 5
Dependent Claim
13 words
The assembly of claim 3 wherein said signal means is a flashing light.
Claim 6
Dependent Claim
18 words
The assembly of claim 1 wherein said switch means is activated by the interruption of a light beam.
Claim 7
Dependent Claim
20 words
The assembly of claim 1 wherein said signal means is a light source and photocell positioned above the lowermost rung.
Claim 8
Dependent Claim
13 words
The assembly of claim 6 wherein said signal means is a flashing light.
Claim 9
Dependent Claim
20 words
The assembly of claim 7 wherein said flashing light is positioned at about eye level below one of said rungs.
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) | 1985-01-18 | 1985-07-20 | 1986-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-01-18 | 1989-07-20 | 1990-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-01-18 | 1993-07-20 | 1994-01-19 | $7700.00 | Window Closed / Lapsed |