Electronic marker device and method of making same
US4334227A · kind A · utility
31Cited by
3References
12Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Sep 26, 1980 |
| Grant date | Jun 8, 1982 |
| Priority date | — |
| Expiry date | Sep 26, 2000 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49016
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
Passive type electronic marker device is hoop shaped, with the hoop thickness in the radial direction being substantially less than the hoop width in the axial direction and with a tuned circuit disposed within the hoop. Improved structure and the method involves a mandrel portion on which the tuned circuit coil is wound, a mating cover band, and special peripheral hermetic seals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.