Jump to content

Impulse coupling?


JV Puleo
 Share

Recommended Posts

Well, it isn't mentioned by PM Heldt in 1912 although I'm going back and rechecking that. The ZU4 (introduced in 1911) I'm using was made in 1912 and it dosen't have one although half of the Oldham coupling is attached to the magneto drive so I am reasonably certain it didn't have one.

Link to comment
Share on other sites

22 hours ago, JV Puleo said:

The earliest patents I'm able to find date from WWI - 1917 which would imply that it was unknown before that date.

Many pre-1917 cars used dry cells to power the ignition for starting, then switched to a low tension magnetos with a coil to boost the voltage for running.  There were many different low tension magnetos made that did not hold up very well and dry cell batteries were also problematic.   So, many of those ignition systems were eventually replaced with high tension magnetos with impulse couplers.  American Bosch was one of the more successful  companies that exploited this aftermarket. 

Link to comment
Share on other sites

I'm aware of that...

American Bosch doesn't come on the scene until WWI when the assets of the German Bosch company were seized and sold by the Alien Property Custodian. After the war, the Germans couldn't get them back so the American company is completely different from the German one. The German company reestablished an office in New York after the war and all their advertising material says "absolutely no connection to the American Bosch Company." The same thing happened with Bayer Asprin - the American company is completely separate from the German one.

 

The mag I have was made in 1912 so it predates American Bosch. I did notice that the post-war German advertising material states that it gives a hot spark at low rpms which is something the gentleman I bought it from also said. There is no provision on the mag for attaching the wires we normally associate with a Bosch Dual system which is why I was wondering about the impulse coupling. If it wasn't invented in 1911 (when the ZU4 was introduced) then perhaps it was intended to be used without one. I also have a Bosch D4 - the big, earlier 4 cylinder mag but unfortunately it is too big to fit under the intake manifold.

  • Like 1
Link to comment
Share on other sites

I was able to find an answer. It appears to have been invented by G.A. Unterberg. The first US patent was applied for in 1906 and granted in 1909. It is quite possible that the Bosch DU series magnetos were developed to circumvent Unterberg's patent. Unterberg was one of the principals in U&H Magnetos. Though not well known, they did have offices in the New York and the device appears to be first mentioned in an American publication in 1909.

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...