Electronic weighing device
US5321209A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 1992 |
| Grant date | Jun 14, 1994 |
| Priority date | — |
| Expiry date | Dec 17, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01G3/16
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A spring structure for a weight scale is described which is assembled from four extruded aluminum parts. The structure readily lends itself to the addition of a platform for placing weights and its deflection resulting from a weight is essentially invariant to the location of the weight on the platform. The sensor which converts deflection of the structure into an electrical signal includes two conducting plates, attached to the structure, which constitute a variable capacitor. The variable capacitor is part of a self-excited oscillator circuit which yields a frequency which is accurately related linearly to the value of the weight. Means are provided for distorting one of the capacitor plates to provide further improvement of invariance to weight location on the platform.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.