Apparatus for automatic lapping control
US4407094A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 3, 1981 |
| Grant date | Oct 4, 1983 |
| Priority date | — |
| Expiry date | Nov 3, 2001 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB24B49/00
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Apparatus for automatic lapping control, based on imbedding an electrode in a lap plate of a lap machine and including at least one piezoelectric wafer in the lap load. Connected with the electrode is an automatic control circuit used for sensing the resonance frequency of the piezoelectric wafer and for terminating lapping when the resonance frequency reaches a presetable target frequency. Also connected with the electrode is an impedance comparator circuit used for sensing the presence and absence of a piezoelectric wafer at the electrode face and for activating the automatic control circuit in the presence of a wafer and deactivating the control circuit in the absence of a wafer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.