Piezoelectric touch probe
US6708420B1 · kind B1 · utility
Inventor
Key dates
| Filing date | Jan 6, 1999 |
| Grant date | Mar 23, 2004 |
| Priority date | — |
| Expiry date | Jan 6, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B7/012
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The instant invention is a dynamic piezoelectric touch probe for use with coordinate measurement machines. The touch probe is characterized by five subsystems; (1) piezoelectric vibrator controlled by a self-tuning drive circuit that adjusts operating frequency and amplitude, (2) a high sensitivity, resonant accelerometer unit coupled to the piezoelectric vibrator, (3) a flexible suspension/stylus with transverse resonant frequencies tuned to the operating frequency band of the piezoelectric vibrator, (4) a digital control circuit that automatically sweeps the operating band of the piezoelectric vibrator to (a) detect the resonant frequency of the stylus/suspension, (b) set the drive signal frequency at the resonance of the stylus/suspension and (c) control the drive signal amplitude, and (5) a triaxial load cell system that is useful for detecting excessive low frequency suspension/stylus vibration, and excessive impact force during a touch event.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.