Ultra-precision lapping apparatus
US4996798A · kind A · utility
Inventor
Key dates
| Filing date | May 31, 1989 |
| Grant date | Mar 5, 1991 |
| Priority date | — |
| Expiry date | May 31, 2009 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB24B37/26
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A lapping apparatus of the "planetary" type that laps a workpiece to a true flat surface instead of to the domed surface characterizing the prior art: it includes a mechanism for spinning and orbiting the workpiece against a lapping disk that has a 360-degree mid-radial portion formed to abrade less rapidly than the radially inboard and outboard portions thereof. In one embodiment, the inboard and outboard portions of the disk are partly or entirely cut away (i.e., recessed) so as to present equal or smaller lapping surface areas than that of the mid-radial portion of the disk. In another embodiment, the abrading surfaces of the disk are formed as raised lands each of which has a shape derived as the mean length, at each orbiting radius, of the orbiting arcs that are swept by the disk across the workpiece while the workpiece is spinning through at least one full revolution. In another form, the lands are made narrower and more numerous, but have the same proportions along the various orbiting arcs. In another embodiment, the lands are made smaller in orbiting arcuate dimension everywhere but at the mid-radius. In another form, various arcuate slices of the lands are staggered with …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.