Posted 6 years ago
Caroliner
(1 item)
Looking for information on this apparently very rare speedo/odometer. Can only find one one other similar, which is kph (were they a pair?)
Stamped BT , patented by Bernhardt Thormann.
Still working, probably 1910-1930s.
Any info would be great, has so far been a mystery with nobody’s having seen anything like it! Thanks.
You might try researching Thormann Firma. He was German. The original patent expired in 1929 and this appears to be 1931 or later from what I have found.
Thormann Firma wasn’t a person, just the company name attributed to the patent. The original patent was filed but expired late 1920s, then was accepted again in 1931. From then on there are no records of BT speedos but Smiths took off, one website suggested he had sold the patent to them. It appears there are only 2 in existence with the BT stamp on, one currently for sale by a German on EBay (kph) and this one. The German doesn’t know anything about the product and his is not working.
This remains a mystery, has nobody heard of this man?
BT tachometers appeared in some Dutch bike/motorbike manufacturers' catalogues in the '30s, sometimes with description only and sometimes with depictions. One of the catalogues from 1933 has a depiction of one which has "m.p.S" on it (or Km.p.S - it is impossible to tell if there was a "K". This would stand for the German: Kilometer pro Stunde). The accompanying text says they had them for 26" wheels as well as 28" wheels. I also have a (non-illustrated catalogue from 1934/1935 that mentions them.
A couple of years ago I saw one for sale on a Dutch Website. It mentioned "B.Thormann-Berlin" and the BT logo (no mention of M.p.H.). By the time I saw it, it has already been reserved so I could not buy it unfortunately (but I kept some pictures).
I would be interested to see the one you refer to with Kph and I would be very interested to buy one to complete my oldtimer.
Further to my comment two years ago, I can confirm the text on the tacho says Km.p.s. I just managed to purchase one. It is very similar to the one on the first picture above, only that the numbers go from 1 - 60 (kilometre) and the top mentions "DRP u Ausl PAT". Would like to share pictures but don't see how I can.
Eysink,
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Thank you Falcon61.
https://www.collectorsweekly.com/stories/317165-bt-speedometer