This is an instance in which the original patent document by which we found the classification does not display the nature of the classification. This classification may involve peculiarities of design and technical principle which are not at all exclusive to aeronautics.
This wiki has 1 patents in category "AT 33d".
Patents in category AT 33d
- Patent AT-1912-61755 (English title: Tents, in particular for the recovery of airplanes, Inventors: Gustav Behrens, Supplementary to patent: Patent DE-1911-04-03 Gustav Behrens, Filing date: 1912-01-04)
|Enclosing categories||AT 33, Austrian patent classifications, Patent classification systems|