Re: '71 squareback clock repair

[jadney@vwtype3.org (Melissa & Jim)]

This was so interesting that I wanted everyone to see it.  Hope you don't mind.

>From: <stans4@ix.netcom.com>

>On 05/18/97 00:15:34 you wrote:
>>
>>>From: stans4@ix.netcom.com
>>
>>This clock had seven jewels! First time I'd ever seen an auto clock with a 
>>jeweled !
>>>movement and an Incabloc type pivot jewel on the balance, too!
>>
>>None of the ones I have ever seen were jeweled.  In fact I have a couple 
>>that apparently ran for a long time and wore out their bearings.  (elongated 
>>the bearing hole)
>>
>>What is an Incabloc type pivot jewel?
>>
>>I'm gonna have to look at one of these again.
>>
>>BTW, I think I may have a good pancake coil from one of the late 
>>transistorized clocks.  Do you still want to fix yours?

>Don't have the old clock anymore, got rid of it long ago.  Thanks for the 
offer, though.  I always thought that the oscillator driving the balance 
wheel was kind of an elegant idea, but apparently not robust enough for the 
environment.
>
>An Incabloc setup has a spring-loaded cap jewel(the end of the balance 
wheel pivot turns on it) on each end with the pivot jewels(part with the 
pivot hole in it) set up so that when the clock or watch movement takes a 
shock, it doesn't punch through the cap jewels or break the pivots.  One of 
my Dad's high school friends was a watchmaker and jeweler, had an enlarged 
demonstrator, a really quite clever system.  If you look at an old 
mechanical watch and it's marked "Shock-Proof" on the dial or back, chances 
are it has an Incabloc or derivative system.
>
>  Don't know what vintage clock I have, might be early, might be late, fits 
the hole and runs, though.  Like I said, I picked it out of a large(3' cube) 
box of clocks. The back is marked "7 jewels", there was an import tariff at 
one time depending upon how many jewels a watch or clock had.  Most of the 
car clocks I've seen had bronze or brass bearings at best, punched holes in 
the steel movement plates at worst. The original I think had some brass 
bushes for the works, don't remember that clearly though.  My current clock 
has a metal cover over the works, my original had a plastic cover saying "no 
jewels" on a small paper tag.  I'll have to look when I get it out again, 
there might be a VW part number on it somewhere, if you're interested.

Thanks for the explanation.  This has forced me to open up one of the old 
clocks to see what you are talking about.  The one I grabbed is a '70 and 
the balance wheel indeed has jewels and one of them is spring loaded 
axially--that would be the Incablock feature, I presume.  the other pivots 
just seem to be machined into the bronze plates.  I don't have any older 
clocks at hand here.  I think a few more jewels would be nice here, but 
wouldn't they always come in pairs?  How do we get 7?

I see that I was also wrong on the "fuse."  There is no wire; it is just a 
spring loaded part soldered to a fixed part.  When the solder melts, one 
pulls away.  The rear plate contains all the electrical parts and can be 
removed with three nuts.  This is useful for cleaning and if you want to 
replace the resistor with a diode.

Jim
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       Melissa Kepner                                    Jim Adney
       jadney@vwtype3.org               jradney@njackn.com
                             Laura Kepner-Adney
                             Madison, Wisconsin
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