Level with two guide frames and ball in each
US4514908A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 6, 1984 |
| Grant date | May 7, 1985 |
| Priority date | — |
| Expiry date | Aug 6, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01C9/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A level characterized wherein two guide frames are arranged within a base member one above the other so that they cross each other at right angles. The guide frames are provided with internal rolling-contact surfaces each shaped as an upward-curving circular arc, respectively, the lowest parts of the rolling-contact surfaces being positioned at the point at which the guide frames cross, and the interiors thereof being visible through top surfaces thereof. Balls are contained rotatably in the two guide frames, respectively. The ball in the upper guide frame is formed so as to have a diameter slightly smaller than that of the ball in the lower guide frame.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.