Piezoresistive force-measuring element and its use for determining forces acting on a component
US4738146A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 24, 1986 |
| Grant date | Apr 19, 1988 |
| Priority date | — |
| Expiry date | Nov 24, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L1/20
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A piezoresistive force-measuring element comprises at least two force-introduction plates with an electrical conductor subjected to plastic deformation arranged between them. The force-introduction plates transmit the forces acting on them without mechanical shunting onto the conductor between them. The change of electrical resistance caused by the force sustained can be used to measure force, accompanied by plastic as well as elastic deformation of the conductor. The typically annular or rectangular force-introduction plates can be fitted inside a housing which may include a bridge circuit for determining the resistance change as well as other electronics enabling the device to be used as a transmitter. By placing the conductor in grooves or anchoring it in the pores of the adjacent plates, an essentially hydrostatic loading of the conductor is obtained, bringing an enormous extension of the measuring range while the measuring accuracy is enhanced owing to the reduced hysteresis. The sensitivity and the measuring range can be adjusted by appropriate prior deformation of the conductor. Permanent deformation of the conductor resulting from high loads makes possible subsequent determ…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.