Apparatus for electromagnetically measuring the distance between two opposing grinding surfaces
US4804912A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 14, 1987 |
| Grant date | Feb 14, 1989 |
| Priority date | — |
| Expiry date | May 14, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B7/14
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A transucer is encapsulated within a stainless steel housing in a recess opening within one of the grinding surfaces of a pair of opposed grinding surfaces between which material to be ground (e.g., wood chips to produce mechanical paper pulp) is disposed. Pole pieces formed of a material having wear properties corresponding to the wear properties of the grinding surfaces project through the cover of the housing to terminate flush with one of the grinding surfaces. Consequently, energization of the primary winding establishes a magnetic field through the core, pole pieces, across the gap and into the opposed grinding member, the strength of which is proportional to the distance betwen the pole pieces and the opposed grinding surface. The induced voltage from the secondary coil serves as a measure of the gap distance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.