Ultrasonic drive/sense circuitry for automated fastener tightening
US5216622A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 1990 |
| Grant date | Jun 1, 1993 |
| Priority date | — |
| Expiry date | Aug 30, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/2691
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An ultrasonic signal drive/sense circuitry is provided, which circuitry is adaptable to a variety of automated or manual fastener tightening operations. This circuitry operates for measuring tension in a fastener as a function of change in time of flight of an ultrasonic wave. A microcontroller directs the operation of circuit components to generate high amplitude, high repetition rate, drive pulses with these amplitude and repetition rate factors being electronically adjustable to compensate for fastening tool and fastener acoustical properties and tightening rates. Software driven timing circuitry calculates, calibrates and adjusts pulse echo detection window width and center location and also optimum echo detection threshold. This timing circuitry is implemented by digital techniques to measure pulse time of flight and incorporates analog interpolation of data between digital counts. Sampling rates of the echo pulses are adjusted to tool speed. An auto-calibration technique is implemented prior to each fastener tightening operation to overcome circuit errors and set detection window position and to optimize pulse voltage and echo threshold detection levels. Time of flight data i…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.