Any Gruen and Eterna Bumper experts out there?

[wisconsinwalter]

I found this eterna 1158H and the 460ss Gruen the other day. They go great with my Omega 342.

Does anyone recognize these? The eterna is not in the pink pages.

http://i53.photobucket.com/albums/g51/wisconsinwalter/P1010109-1.jpg

http://i53.photobucket.com/albums/g51/wisconsinwalter/P1010112-1.jpg

[pacifichrono]

No pictures, Walter. :-(

[JohnF]

Hi -

All I know is the Gruen. The 460SS was one of their better latter-day movements, not quite up to the quality of the Curvex of the 1930s, but one that my watchmaker loves to work on, as it was built just right. It's a bumper automatic, i.e. the rotor of the automatic has a limited movement range. I have an absolute jewel of a Gruen in stainless steel with the 460 movement, which is the same movement with the subsecond dial rather than the central seconds.

Properly taken care of, this is a great movement, very accurate. The only real downside is that the reserve generally tends to be fairly weak, mine runs down after around 30 hours or so, and of course that funky noise made when the rotor hits the spring stops (thunk, whirrr, thunk, whirrr, thunk, whirr...), which can be annoying if you aren't into it. I wear mine every 3-4 months whenever I get the urge for a bumper...

JohnF

[wisconsinwalter]

No pictures, Walter. :-( Thats weird. I see them on my computer. Please let me know if they are still not there

http://i53.photobucket.com/albums/g51/wisconsinwalter/P1010109.jpg


http://i53.photobucket.com/albums/g51/wisconsinwalter/P1010112.jpg

I have to quit doing posts at night! LOLo|

[JohnF]

Hi -

I see them fine, didn't before either. :-)

The Gruen looks to be in much better shape than the Eterna...

JohnF

[767Geoff]

Have both and they are great early examples of bumper automatics. My gruen requires a new case and I haven't got a photo of it. The Eterna bumper was of course designed before their famous patent on the Eternamatic ball bearing full rotor design that revolutionized the automatic industry.

I had the dial redone to it's original specs and of course new seals, dis-assembly and cleaning along with restoring the case. As you can see there are many similarities to yours, hands and case as well as inscription. What you won't see is the ubiquitous 5 dot signature so many of their dials and crowns have as the ball bearing rotor had not been patented or even invented when these bumpers were produced.

http://i45.photobucket.com/albums/f96/geoff_q/Collection073.jpg

[lysanderxiii]

I have three of those Gruens, nice little movements.

You should probably replace your bumper springs, their free length should be about twice as long as they are in the picture. Those need to be in good shape as there is a bunch of energy that has to be absorbed when stopping the rotor. Otherwise all that energy is going to go into the rotor support jewel, and auto-wind bridge.

[wisconsinwalter]

I appreciate it!