Noninvasive valve monitor using alternating electromagnetic field
US5193568A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 1991 |
| Grant date | Mar 16, 1993 |
| Priority date | — |
| Expiry date | Jun 20, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/8242
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
One or more electrical coils are carefully located on the outside of a valve body. An alternating current passing through the coil(s) results in an alternating electromagnetic field being transmitted into the valve body and valve internals. The electromagnetic field varies in intensity and polarity in the valve. As the position of a valve internal part is changed, the electromagnetic field throughout the valve body and its internals is altered. A passive receiver coil carefully located on the outside of the valve body detects the intensity of the electromagnetic field at that location as an induced electrical voltage in the coil. With the change in position of the valve internal part, there is a corresponding change in the induced voltage as a result of the alteration in the alternating electromagnetic field at that location. Changes in the voltage provide an indication of the position and motion of valve internals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.