Multipurpose disk protractor
US4057902A · kind A · utility
8Cited by
4References
4Claims
0Family size
Inventor
Key dates
| Filing date | Sep 30, 1976 |
| Grant date | Nov 15, 1977 |
| Priority date | — |
| Expiry date | Sep 30, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B3/56
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A circular disk protractor made of a transparent plate material and having a peripheral circumference of 400 mm has a length scale graduated in millimeters around the circumferential edge thereof from an origin, an angle scale graduated in degrees of angle around a circle concentric with the disk from an origin angularly coincident with the origin of the length scale, and a polar distance scale comprising a plurality of concentric radially spaced apart circles which are concentric with the disk and constitute graduations to indicate distances in millimeters from the center of the disk.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.