Weight or force measuring apparatus
US4418774A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 8, 1981 |
| Grant date | Dec 6, 1983 |
| Priority date | — |
| Expiry date | Dec 8, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S177/06
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This apparatus is for use in measuring a weight, or force, and it is particularly useful as a scale. The apparatus includes a single vibrating wire and wire supports that rigidly clamp the two ends of the wire. A weight to be measured is applied to the wire in substantially the direction of its length, and the applied weight changes the tension in the wire. The apparatus includes a wire drive circuit that causes the wire to vibrate at essentially its natural resonant frequency. The frequency varies as a known cubic equation with respect to the applied weight, and a computer, operating in accordance with the equation, converts the measured frequency to a weight signal. The apparatus further includes vibration dampers and isolators for reducing the effects of sympathetic vibrations and of externally induced vibrations, and means to correct for external influences such as disturbing frequencies and ambient temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.