US3340433A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Safety cut-off for electrical power operated hand tools
Assignee: Individual
•
Filing: 1965-02-15
•
Granted: 1967-09-05
•
Expires: 1985-02-15
Abstract
No abstract record available.
Inventors
- 👤 Harry G Almquist
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:36
CPC Classifications
H; H02; H02H; H02H5/00; H02H5/12; B; B28; B28D; B28D1/00; B28D1/14; B28D7/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
156 words
A SAFETY CUT-OFF MEANS COMPRISING, IN COMBINATION AN ELECTRICAL POWER DRIVEN HAND TOOL, A CURRENT SOURCE, A SPLIT COIL RELAY HAVING A PAIR OF RELAY CONTACTS, A POWER CIRCUIT FOR SAID TOOL INCLUDING ONLY SAID RELAY CONTACTS IN SERIES WITH SAID TOOL, A STEP-DOWN TRANSFORMER THE PRIMARY OF WHICH IS CONNECTED ACROSS SAID CURRENT SOURCE, ONE SIDE OF THE SECONDARY OF SAID TRANSFORMER BEING CONNECTED INTERMEDIATE SAID SPLIT RELAY COIL, THE OTHER OF SAID SECONDARY BEING CONNECTED TO ONE SIDE OF SAID RELAY COIL AND TO A GROUND LEAD, THE OTHER SIDE OF SAID RELAY COIL BEING CONNECTED TO THE HOUSING OF SAID TOOL, ONE-HALF OF SAID RELAY COIL WHEN ENERGIZED EFFECTING CLOSING OF SAID CONTACTS TO CLOSE THE POWER CIRCUIT TO SAID TOOL, THE OTHER ONE-HALF OF SAID RELAY COIL BEING ENERGIZED UPON THE HOUSING OF SAID TOOL BEING GROUNDED WHEREBY SAID CONTACTS ARE OPENED THEREBY CUTTING OFF POWER AND STOPPING OPERATION OF SAID TOOL.
Claim 2
Dependent Claim
156 words
A SAFETY CUT-OFF MEANS COMPRISING, IN COMBINATION AN ELECTRICAL POWER DRIVEN HAND TOOL, A CURRENT SOURCE, A SPLIT COIL RELAY HAVING A PAIR OF RELAY CONTACTS, A POWER CIRCUIT FOR SAID TOOL INCLUDING ONLY SAID RELAY CONTACTS IN SERIES WITH SAID TOOL, A STEP-DOWN TRANSFORMER THE PRIMARY OF WHICH IS CONNECTED ACROSS SAID CURRENT SOURCE, ONE SIDE OF THE SECONDARY OF SAID TRANSFORMER BEING CONNECTED INTERMEDIATE SAID SPLIT RELAY COIL, THE OTHER OF SAID SECONDARY BEING CONNECTED TO ONE SIDE OF SAID RELAY COIL AND TO A GROUND LEAD, THE OTHER SIDE OF SAID RELAY COIL BEING CONNECTED TO THE HOUSING OF SAID TOOL, ONE-HALF OF SAID RELAY COIL WHEN ENERGIZED EFFECTING CLOSING OF SAID CONTACTS TO CLOSE THE POWER CIRCUIT TO SAID TOOL, THE OTHER ONE-HALF OF SAID RELAY COIL BEING ENERGIZED UPON THE HOUSING OF SAID TOOL BEING GROUNDED WHEREBY SAID CONTACTS ARE OPENED THEREBY CUTTING OFF POWER AND STOPPING OPERATION OF SAID TOOL.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-09-04 | 1971-03-06 | 1971-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-09-04 | 1975-03-06 | 1975-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-09-04 | 1979-03-06 | 1979-09-05 | $7700.00 | Window Closed / Lapsed |