Originally Posted By: kuduae
In 1910 Jaeger again patented a similar arrangement with sidplates to the same effect, DRP 229531.


Axel, you have a typo here and the DRP is 229521 for 23rd December, 1910, a 1910 Christmas present?

So from the patents:

Austrian Patent 9862 - 1900/1902

DRP 176578 - 1904 - Original Patent
DRP 201505 - 1907 - Bittiner's Improvement w/out frame sides
DRP 229521 - 1910 - Jäger's Improvement with screw on left/right side

We may be able to narrow the date range of manufacture & patent enforcement.

Kind Regards,

Raimey
rse