O-ring inspection method
US4634273A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 8, 1984 |
| Grant date | Jan 6, 1987 |
| Priority date | — |
| Expiry date | Jun 8, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/9515
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method is provided to inspect a resiliently deflectable O-ring which tends to distort under the influence of its own weight. The O-ring is placed on a transparent support member with the central axis of the O-ring in a vertical orientation. Light is directed toward the O-ring and through the support member to cause the O-ring to cast a shadow. The distance between portions of the shadow cast by diametrically spaced apart portions of the O-ring indicate diametral measurements of the O-ring. The distance between radial edge portions of the shadow cast by the O-ring indicates the thickness of the O-ring. To detect surface flaws in the O-ring, light is directed against a small area on the surface of the O-ring while it is rotated. A variation in the characteristics of the reflected light indicates the presence of a flaw in the surface of the O-ring. To provide for scanning of inner and outer surface areas of the O-ring to detect surface flaws, the O-ring may be rotated about an axis which extends perpendicular to the central axis of the O-ring and is tangential to a circle through the center of the cross section of the O-ring.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.