Hydraulic vibration tester
US4403511A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 5, 1981 |
| Grant date | Sep 13, 1983 |
| Priority date | — |
| Expiry date | Oct 5, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2203/0048
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A hydraulic vibration tester comprises an actuator comprising a piston reciprocable in a cylinder connected with a vibration testing table and a direct drive type servo valve for supplying pressure fluid alternately to opposite ends of the cylinder. The servo valve comprises a spool valve member reciprocable in the bore of a valve body by a magnetic coil supplied with alternating current and located in a direct current magnetic field. At opposite ends of the spool valve member there are coned disc springs acting to bias the spool valve member to a median position and acting to allow only an axial reciprocating movement of the spool valve member at a frequency in the range of 650 Hz to 2000 Hz. The passages connecting the servo valve with the activator have a resonant frequency in the same range so as to achieve an effective vibration test in the high frequency range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.