Patents
US 7994789 B1: Dual field search coil for pulse induction metal detectors
- Granted
- 2011-08-09
- Filed
- 2009-02-11 application 12378123
- Type
- Utility · 12 claims
- Elsewhere
- Google Patents ↗ · USPTO patent document ↗ · USPTO Patent Center record ↗
Abstract
A new dual field search coil for pulse induction metal detectors has multiple coplanar wire coils of different diameters connected in series with the output of a pulse source, overcoming the loss of target size resolution associated with a single coil search loop. Small objects are sensed by an internal small coil and larger objects are sensed by the larger outside coil, and the overall depth of target sensing remains similar to that of a single coil construction. The smaller coil is isolated from the pulse source by the inductance of the larger coil and will ring at a frequency determined by its own parameters. To prevent the smaller coil from ringing, a second damping resistor is connected across the terminals of the smaller coil at the junction of the large and small coils making up the modified search loop.
Source: PVGPATDIS, file of 2026-04-10 (ipg110809.xml).
Assignees
| Assignee | Type | Place | Also on furp.org | Source |
|---|---|---|---|---|
| White's Electronics, Inc. 9 patents | US company or organization | Sweet Home, OR | PVGPATDIS, file of 2026-04-10 |
Inventors
| Inventor | Place | Patents | Person page | Source |
|---|---|---|---|---|
| Daniel J. Geyer | Sweet Home, OR | 1 | PVGPATDIS, file of 2026-04-10 |
CPC categories
| Subclass | Category | First group | Source |
|---|---|---|---|
| G01V | Geophysics; gravitational measurements; detecting masses or objects; tags | G01V3/104 | 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 |
|---|---|---|---|---|---|
| 2022-03-01 | Assignment Assignment of assignor's interest | WHITE'S ELECTRONICS, INC. signed 2020-10-16 | GARRETT ELECTRONICS, INC. GARLAND, TX | 59129/659 | ECORSEXC, file of 2026-09-25 |
| 2009-02-11 | Assignment Assignment of assignor's interest | GEYER, DANIEL J. signed 2009-02-09 | WHITE'S ELECTRONICS, INC. SWEET HOME, OR | 22296/62 | 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.