Patents
US 8000078 B2: Method and apparatus for controlling a lifting magnet supplied with an AC source
- Granted
- 2011-08-16
- Filed
- 2008-02-29 application 12040741
- Type
- Utility · 11 claims
- Elsewhere
- Google Patents ↗ · USPTO patent document ↗ · USPTO Patent Center record ↗
Abstract
A magnet controller supplied by an AC source controls a lifting magnet. Two bridges allow DC current to flow in both directions in the lifting magnet. During “Lift”, relatively high voltage is applied to the lifting magnet until it reaches its cold current. Then voltage is lowered. After a desired interval, once the magnet has had time to build its electromagnetic field, voltage is further reduced to prevent the magnet from overheating. The magnet lifting forced is maintained due to the magnetic circuit hysteresis. During “Drop”, reverse voltage is applied briefly to demagnetize the lifting magnet. At the end of the “Lift” and the “Drop”, most of the lifting magnet energy is returned to the line source. A logic controller controls current and voltage of the magnet and calculates the magnet's temperature. In one embodiment, a “Sweep” switch is provided to allow reduction of the magnet power to prevent attraction to the bottom or walls of magnetic rail cars or containers.
Source: PVGPATDIS, file of 2026-04-10 (ipg110816.xml).
Assignees
| Assignee | Type | Place | Also on furp.org | Source |
|---|---|---|---|---|
| The Electric Controller & Manufacturing Company, LLC 4 patents | US company or organization | St. Matthews, SC | PVGPATDIS, file of 2026-04-10 |
Inventors
| Inventor | Place | Patents | Person page | Source |
|---|---|---|---|---|
| Jean Maraval | Columbia, SC | 4 | PVGPATDIS, file of 2026-04-10 |
CPC categories
| Subclass | Category | First group | Source |
|---|---|---|---|
| B66C | Cranes; load-engaging elements or devices for cranes, capstans, winches, or tackles | B66C1/08 | PVGPATDIS, file of 2026-04-10 |
| H01F | Magnets; inductances; transformers; selection of materials for their magnetic properties | H01F7/1811 | PVGPATDIS, file of 2026-04-10 |
Cooperative Patent Classification, as currently assigned (one row per subclass).
Assignments and security interests
| Recorded | What | From | To | Reel/frame | Source |
|---|---|---|---|---|---|
| 2015-08-28 | Merger Merger | ELECTRIC CONTROLLER & MANUFACTURING COMPANY, LLC, THE signed 2015-01-28 | HUBBELL INDUSTRIAL CONTROLS, INC. SHELTON, CT | 36449/158 | ECORSEXC, file of 2026-09-25 |
| 2010-08-13 | Assignment Assignment of assignor's interest | MARAVAL, JEAN signed 2007-12-18 | ELECTRIC CONTROLLER & MANUFACTURING COMPANY, LLC, THE ST. MATTHEWS, SC | 24839/110 | ECORSEXC, file of 2026-09-25 |
Documents recorded with the USPTO Assignment Recordation Branch that list this patent. A security interest is a lender’s claim on the patent as collateral; a release ends it.
USPTO bulk data: PatentsView granted patents, disambiguated (PVGPATDIS) for patents, assignees, inventors, places and CPC categories; the USPTO Patent Assignment Dataset (ECORSEXC) for assignments and security interests. Patents filed in the last 20 years. No claims or full text. Links to other records are by name (and state): EXACT means the identical full name and state; FUZZY means a looser name match, with the confidence shown.