Proximity monitor
US4422075A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 21, 1981 |
| Grant date | Dec 20, 1983 |
| Priority date | — |
| Expiry date | May 21, 2001 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF42C13/04
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A proximity monitor for movement at a selected distance from a surface, including a first microwave sensor having an antenna pattern directed toward the surface, the principal component of the pattern parallel to the surface being in the direction of the movement, a second microwave sensor having a second antenna pattern directed toward the surface, the principal component of the second pattern parallel to the surface being at a direction opposite to that of the movement, and the patterns being mutually spaced at the surface in the direction of movement, a magnetic anomaly sensor giving an output representative of the presence at the surface of a magnetic anomaly located between the patterns, and apparatus connected to the sensors for performing a control function when the signals from the sensors are above predetermined levels in a predetermined time relationship.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.