US2747154A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Concrete tool immobilizing circuit
Assignee: EIDP Inc
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Filing: 1953-09-30
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Granted: 1956-05-22
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Expires: 1973-09-30
Abstract
No abstract record available.
Inventors
- 👤 Walter F Abrams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:48
CPC Classifications
B; B25; B25D; B25D9/00; B23; B23Q; B23Q5/00; B23Q5/54; B23Q5/58; B28; B28D; B28D1/00; B28D1/14; B28D7/00; H; H02; H02H; H02H5/00; H02H5/12; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49826; Y10T29/49861; Y10T408/00; Y10T408/13; Y10T408/15; Y10T408/21
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
142 words
A CONCRETE TOOL IMMOBILIZING CIRCUIT FOR AN ELECTRICALLY DRIVEN TOOL COMPRISING AN ELECTRICAL RELAY HAVING FOUR PAIRS OF CONTACTS, THE FIRST AND THIRD PAIRS OF WHICH ARE NORMALLY CLOSED AND THE SECOND AND FOURTH PAIRS OF WHICH ARE NORMALLY OPEN, A THREE-WIRE POWERING CIRCUIT FOR SAID TOOL CONSISTING OF A POWER, GROUND AND NEUTRAL LEADS, A CURRENT SOURCE CONNECTED AT ONE TERMINAL TO ONE SIDE OF THE COIL OF SAID RELAY AND AT THE OTHER TERMINAL TO GROUND, SAID FIRST PAIR OF RELAY CONTACTS BEING CONNECTED IN SERIES RELATIONSHIP WITH AN ELECTRICAL SAFE OPERATING INDICATION DEVICE BETWEEN THE POWER SUPPLY SIDE OF SAID RELAY COIL AND SAID GROUND LEAD, SAID SECOND PAIR OF RELAY CONTACTS BEING CONNECTED BETWEEN THE OTHER SIDE OF SAID RELAY COIL AND SAID GROUND LEAD, SAID THIRD PAIR OF RELAY CONTACTS BEING CONNECTED IN CIRCUIT BETWEEN SAID POWER
References Cited (Backward Citations)
US527988A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-05-22 | 1959-11-21 | 1960-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-05-22 | 1963-11-21 | 1964-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-05-22 | 1967-11-21 | 1968-05-22 | $7700.00 | Window Closed / Lapsed |