US Patent: 2,981,141
|
| Optical Compensator and Tilt Detector
|
|
Patentees:
|
| John Argent Armstrong (exact or similar names) - Wembley Park, Greater London County, England |
| Douglas William Berry (exact or similar names) - Grove Park, Greater London, England |
|
|
Patent Dates:
|
| Applied: |
Jan. 16, 1958 |
| Granted: |
Apr. 25, 1961 |
|
Patent Pictures:
[
1 | 2
]
|
|
|
USPTO (New site tip)
Google Patents
Report data errors or omissions to steward
Joel Havens
"Vintage Machinery" entry for Hilger & Watts
|
|
Description: |
| Claims priority, application Great Britain 16 Jan., 1957.
Claim:
Optical instruments used in surveying and engineering, often employ a telescope of which the line of sight is required to be level when observations are taken. Heretofore it has been customary for the telescope body to be set up truly horizontal in order to ensure that the optical axis of the instrument is also horizontal, and the operations necessary to do this are both tedious and time wasting. Furthermore, when, as is usually the case, a bubble is used to obtain the level inaccuracies occur due to the sensitivity of the bubble to changes of temperature, such as may occur from the effects of direct sunlight or cold draughts. |
|
){kind=link}
){kind=link}