Noninvasive ultrasonic proximity detector for a fluid actuated cylinder
US5459698A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 8, 1993 |
| Grant date | Oct 17, 1995 |
| Priority date | — |
| Expiry date | Mar 8, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S15/88
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention provides a generally noninvasive device and method for detecting a reciprocative piston located within a cylinder bore. An ultrasonic transducer mounted on the outside of the cylinder wall selectively generates an ultrasonic transmission signal directed through the cylinder. The transducer then receives any desired ultrasonic signal produced by propagation of the ultrasonic transmission signal. Control circuitry processes electrical signals produced on the ultrasonic transducer by the propagated ultrasonic signal to indicate presence or absence of the piston. In presently preferred embodiments, the control circuitry determines whether the piston is present by comparing a signal level in the received ultrasonic signal during a sample time window in which the desired signal may be expected with a predetermined threshold level. To perform this function, electrical signals produced on the transducer by the propagated ultrasonic signal are first passed to an amplifier having a selected gain. An output of the amplifier is then fed to an detector circuit which produces an detection level signal which may be representative of energy present in the received ultrasonic signal d…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.