Shields for antennas of borehole logging devices
US4536714A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 16, 1982 |
| Grant date | Aug 20, 1985 |
| Priority date | — |
| Expiry date | Apr 16, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01Q1/52
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The disclosed invention is suited for use in conjunction with a borehole logging device wherein transmitting and receiving antenna coils are wound on insulating media around the axis of a support means that includes an elongated electrically conductive pipe. In accordance with the invention there is provided a shield for shielding each coil of the device, the shield being adapted to reduce spurious electromagnetic field components (especially transverse magnetic components) while not substantially interfering with the desirable transverse electric components. The shield for each coil comprises a hollow closed-end cylinder mounted on the pipe and surrounding the coil, the cylinder being formed of an electrically conductive material and having a series of equally spaced slots therein. Each slot extends radially outward from the support means along a plane which passes substantially through the axis of the pipe so as to pass through the ends and sides of the cylinder. The defined slots in the cylinder thereby form a series of elongated cylindrical side sections, each of which is joined to the pipe by a pair of opposing end sectors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.