Author Topic: Early stationary engines; Douglas and Bosch "relations"  (Read 668 times)

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Offline mschenker

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Hi all!

Around WW I Douglas and Bosch made very similar looking stationay engines for generating electricity and other purposes. The  Bosch "Benzin-Dynamo" looks like a direct copy of the 1912 Douglas engine. There has been discussions and rumors about licenses and fees paid after the Great War by Bosch to Douglas but nothing written could be found so far (by me)...

My plea for help... has anybody anything period about those Bosch/Douglas engines? Esp. if those Bosch engines were "official" copies?!

Btw., I used to own an early Douglas one which is now living "up the road" in the shed of a fellow Douglas enthusiast, it's now running with a Bosch mag. and a manual German stationary carb, the original AMAC was missing when it was found in Poland

This picture here https://www.douglasmotorcycles.net/index.php?topic=4059.msg14565#msg14565 shows a typical Bosch "Benzin-Dynamo" engine, no Douglas! Here are some pics out of the Bosch manual which show the pedigree...

Best, Martin











Images converted to linked files - Dave, 02Jan2022
« Last Edit: 13 Jan 2022 at 16:50 by Dave »

Offline EW-Ron

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Re: Early stationary engines; Douglas and Bosch "relations"
« Reply #1 on: 02 Jan 2022 at 21:26 »
Fascinating !
Thanks for posting.

Its perhaps worth mentioning that previous discussions here about these 'generating' engines
has established that they were mostly for producing  high voltage sparks for radio transmissions. 
Think morse code ..

But note the reference to removing this function, and making a proper generator set to provide lighting .

https://www.greatwarforum.org/topic/249805-marconi-500watt-pack-wireless-set/


Offline mschenker

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Re: Early stationary engines; Douglas and Bosch "relations"
« Reply #2 on: 02 Jan 2022 at 22:22 »
The Bosch "Benzin-Dynamo" was not built as a spark generator, it really drives a DC dynamo with 800-1000W and was used for charging lead-acid batteries and powering carbon arc lamps (output 65V so no resistor needed).

There was a high frequency "spark" generator attachment for radio equiment available as an "extra" with a boom and drive setup. FT is the spark generator.

I have got a manual for the Bosch engine so I can cite from it...

I'm looking for any references that this engine was "nicked" or licensed from Douglas... did Bosch had to pay royalties after the war to Douglas?!

Best, Martin

Offline EW-Ron

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Re: Early stationary engines; Douglas and Bosch "relations"
« Reply #3 on: 03 Jan 2022 at 05:44 »
Once the war was over, would they still have been in use ?
There are quite lengthy docs on the reparations extracted after the war. ?
Not that I have perused them.

Have you seen one in the metal ?

There is nothing cast-in or stamped on them to identify the source/maker ?
Have you gone to Bosch and asked them ?
You may be better placed to try this.
Somewhere/sometime there would have been drawings and blueprints and patterns.
Quite a while back now though ...

There is quite a lot of info about about the Australian built engines by the Aust Navy in Randwick.
Including that Marconi tried, for some time, to sue over them, for blatant patent infringement.
Which was blocked by the Government, it seems.


Offline mschenker

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Re: Early stationary engines; Douglas and Bosch "relations"
« Reply #4 on: 03 Jan 2022 at 06:27 »
Yes, all engines are marked "Bosch"... last picture above shows a near-complete survivor (painted in grey) which just turned up and sparked this query (again)!

An enquiry with Bosch is under way... but I doubt that something like "patent infringment" will be publicised. That's why I'm looking on the Douglas side of things. There might be more information kept by the "winners"...

I don't seek information on the Bosch engine. I'd like to know if there was anything known that the Douglas Company disputed that this was an illegal copy...

Usage: of course any generator was of "use"... you could adjust the output for lighting systems... any farm or remote location could use them. Like the Honda generator "cubes" today...

Best, Martin
« Last Edit: 03 Jan 2022 at 06:45 by mschenker »

Offline EW-Ron

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Re: Early stationary engines; Douglas and Bosch "relations"
« Reply #5 on: 03 Jan 2022 at 08:22 »
That's why I'm looking on the Douglas side of things. There might be more information kept by the "winners"...

How true that is !

I've seen it said that BMW paid some sort of royalty to Douglas for their early 1920s bikes.
But not seen any documentation to support this even.
Often when a company goes to the wall, this sort of info is all discarded.
And fades from the memories of those who would have known.

We will see if anyone knows of these matters....