Richard Jensen (fl. 1902-1917) Berlin.
Reisszeugfabrik Richard Jensen first appears in the Berlin directory in 1902. His factory, how large the factory is and how many workers employed is unknown, sells wholesale and exports. The directory has the factory's address at Dennewitzstraße 32. Several patents by Jensen are known. DRGM 217485 from 1904 seems to be Jensen's first drawing instrument patent. This patent is described in length in Pädagogischer Jahresbericht in 1905.
The drawing set at right has compasses based on Jensen's patent DRGM 286358 from 1906. The compasses in this drawing set are stamped Jensen, and the joint can be manually fastened or loosened by twisting the top. The pen and pencil inserts as well as the lengthening bar are of a simple press fit construction, and they are held in their sockets without the use of a thumbscrew.
Reisszeugfabrik Richard Jensen probably went out of business before the close of WW1 - they are last listed in the Berlin directory of 1917.
Jensen's first directory listing. Jensen's last directory listing.
[Berlin Adressbuch 1902] [Berlin Adressbuch 1917]
Patent DRGM 217485.
[Pädagogischer Jahresbericht p.536, 1905, Internet Archive]
DRGM 217485 [Der Mechaniker p.60, 1904, Internet Archive]
DRGM 233102 [Der Mechanilker p. 228, 1904.]