US3781913A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical safety block
Assignee: Individual
•
Filing: 1972-06-08
•
Granted: 1973-12-25
•
Expires: 1992-06-08
Abstract
Abstract A device adapted for attachment to one of the male prongs of an electrical plug to prevent insertion of the plug into an electrical receptacle.
Inventors
- 👤 F Liburdi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:16
CPC Classifications
H; H01; H01R; H01R13/00; H01R13/60
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
72 words
In combination with a male electrical plug for an electrical tool or the like said male plug having a pair of prongs, each of said prongs having an aperture, a lock for preventing insertion of said prongs into a female plug, said lock comprising a block and means securing said block to one of said prongs, said means comprising a screw extending through the aperture of said prong and into said block.
Claim 2
Dependent Claim
72 words
In combination with a male electrical plug for an electrical tool or the like said male plug having a pair of prongs, each of said prongs having an aperture, a lock for preventing insertion of said prongs into a female plug, said lock comprising a block and means securing said block to one of said prongs, said means comprising a screw extending through the aperture of said prong and into said block.
Claim 3
Dependent Claim
25 words
The combination as defined in claim 1 and in which said block member is rectangular and includes a recess for receiving one of said prongs.
Claim 4
Dependent Claim
18 words
The combination as defined in claim 1 and in which said screw means comprises a buttonhead Allen screw.
References Cited (Backward Citations)
US595196A
Cited
US3123424A
Cited
US812287A
Cited
US1517017A
Cited
US2537370A
Cited
US3414866A
Cited
US3662296A
Cited
US3710287A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |