A Brief History of the Marque
Willi Haussherr GmbH, Berlin, Alexanderstrasse 22 W.
Produced motorcycles from 1902 to 1912 under three brands, Sigurd, Komet and Royal. Most, possibly all, used versions of the French Ixion engine built in Germany under licence.
The firm sold bicycles and many motorcycle-related products: accumulators, ammeters, motorcycle stands (Orpneumatic), cables, leather bags, glow tubes, etc.
An advertisement from 1936-37 gives the address as Bülowstrasse 3, Berlin W 35, and states "Allerhand fürs Auto!"
N.B. There appears to be no relationship between the Sigurd by Haussherr and Sigurd Gesellschaft mbH of Cassel (Kassel), founded in 1919.
Sources: GTU Oldtimerservice, et al