Liquid level gauge for tanks
US4983855A · kind A · utility
Inventor
Key dates
| Filing date | Feb 14, 1989 |
| Grant date | Jan 8, 1991 |
| Priority date | — |
| Expiry date | Feb 14, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01F23/446
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A liquid level gauge for tanks includes a float located in the tank to follow the level of liquid in the tank. A cable extends from the float to the top of the tank and over a pulley to the outside of the tank, where it is attached to a weight for maintaining tension in the cable. The pulley is attached to a signal generator that generates two electrical signals. These are lead from the signal generator to a counter which decodes the two signals and produces a running count representing the height of liquid in the tank. The preferred embodiment of the invention uses a segmented optical disk and two phototransistors for producing two out of phase pulsed signals. The number of pulses represents the magnitude of float movements, while the sequence of the phase-shifted pulses represents the direction of float movement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.