Mystery tool #1

Discussion in 'Horological Tools' started by Skutt50, Jul 14, 2018.

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  1. Skutt50

    Skutt50 Registered User

    Mar 14, 2008
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    I visited an old watch collector today and were given some old parts and tools.

    This one I can't make out what it is:

    Tool I.jpg

    There is a German patent number D.R.G.M. 246055 CW7 I Googled the number but nothing came up.

    The disc (broken) can be turned after pulling a stop pin, to expose some differently sized holes. There is a pointed center pin. Turning the big wheel on the right moves a slanted piece that seems to push inwards between the pointed pin and the wheel.

    Does anyone have any ideas what it is?
    Could it e.g. be a tool to put a friction dent in canon pinions?

    (I can post more pictures if required.)
     
  2. sharukh

    sharukh Registered User
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    Looks like a tool for drilling an arbor for a new pivot. The arbor is chucked up in a collet. This tool would be used as a tailstock or fitted in place of the tool rest and the wheel with the holes rotated (after loosening the screw in it's center) till the arbor goes into the countersink that best holds the arbor. The pointed pin would ensure that the whole is positioned correctly and then be replaced by a drill.

    Sharukh.
     
  3. wefalck

    wefalck Registered User

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    I think this is a somewhat altered tool to cut pivots. The disc with the centring recessions come from a tailstock drilling attachment. Normally, the tool has in front a bore for different size bushings (that would be soft and drilled to the need) - the centring disc replaces the bushings. The thumbscrew to the right raises or lower a small round lathe cutting tool. The tool goes into the lever- or screw-tailstock and is fed onto the workpiece until the desired length of pivot is achieved. The cutter is then adjusted to give the desired diameter.

    The tool has a similar function as the set of rose cutters.

    The patenting company is CWZ, which stands for C.W. Zipperer, a company specialising inter alia in attachments to lathes, which was founded 1869 in Munich.

    I have such tool in original condition.
     
  4. wefalck

    wefalck Registered User

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    Just remembered that I actually took a couple of pictures of my original tool:

    zapfenfraeser-2.jpg

    zapfenfraeser-1.jpg
    [​IMG]
     
  5. Skutt50

    Skutt50 Registered User

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    Thats very interessting.....

    Can you make out the DRGM number on your tool. (I can't read the last numbers in your picture.)
    The CW7 on my tool could be CWZ as you suggested with a mising line at the bottom of the Z.

    The "lathe cutting tool" on my device is however not straight but has an angle of some 30-45 degrees making it impossible to cut a straight pivot. All parts seems original and not home made so either a pro altered the tool or is was made this way at the factory.....
     
  6. wefalck

    wefalck Registered User

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    The 'Deutsches Reich Gebrauchs-Muster' no. is 246055, the same as stamped on yours. D.R.G.M. is not actually a real patent, but rather a protection for a particular design, it would literally translate into something like 'German Empire Usage Pattern'.

    The tool doesn't need to be straight, but rather pointed with a lot of bottom and after rake. It seem then that in your case the tool has been turned the wrong way.

    I have come across several of these tools over the past 20 or so years on ebay and they always looked the same. I also have an 20th German watchmaker's tool suppliers catalogue with an engraved picture that is identical to the real thing. So I am quite sure that someone modified your specimen - otherwise it may have had a different D.R.G.M. number.

    BTW, I tried to check with the number and/or the name C W Zipperer on the German Patent-Office Web-site, but it did not turn up anything. The only entries for them are from the 1950s, when they switched to dental instruments.
     
  7. Skutt50

    Skutt50 Registered User

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    Thanks wefalck.
    Nice that the numbers match. Then we must have very similar tools.....

    I took some more pictures of the cutting tool:
    Tool III.jpg

    and how it was mounted:

    Tool IV.jpg

    Some oddly shaped sides of the "graver!

    I don't see this as something I will use on a daily basis but I will give it a try to cut something when I am back in my workshop...
     
  8. wefalck

    wefalck Registered User

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    Should have looked earlier into my 1911 catalogue: your tool is original and not owner-modified. Somehow I forgot that there were two versions of it:


    [​IMG]

    zapfenfraeser-3.jpg zapfenfraeser-4.jpg
     
  9. Skutt50

    Skutt50 Registered User

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    Great job wefalck, you nailed it!

    That is exactly my tool. I think I got most of how it was used however a few questions remain:

    1 : Is it intended for clock pivots or should it work also for watches?
    2 : I still don't understand how it would cut a pivot. Having an arbor turning and screwing the cutter towards the rotating arbor would create a cut but it would only be a pivot suitable for an alarm clock i.e. a pointed balance arbor for a pin lever type escapement.....
    Is it perhaps so that the small pin sticking out horizontaly in your picture shall be pushed towards the left and the pivot thereby being cut when the arbor moves towards the left.

    PS. Formally you were right in the tool being "modified" by the previous owner. He broke off a piece of the round plate.....LOL. DS.
     
  10. wefalck

    wefalck Registered User

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    Ad 1: I gather this is all a question of the lengths and diameters of the pivots ...
    Ad 2: No, you don't cut the pivot by advancing the cutting tool ! The pivot diameter is set by screwing the cutting-tool in or out and then fixing it with the set-screw. The whole tool is held in the tailstock - I gather a screw-feed tailstock would be the best, and then the whole tool is advanced towards the headstock - as you would do with a rose-cutter in the tailstock.
     
  11. Skutt50

    Skutt50 Registered User

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    Thanks wefalc, I got it!
     
  12. wefalck

    wefalck Registered User

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    I think you are lucky, your version seems to be much more useful for ad hoc work and also on short pivots. For the other version one has to first make a bushing with a carefully executed deep bore ...
     
  13. wefalck

    wefalck Registered User

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    On the US American recently a specimen of the advanced model went up for auction, but the price went a bit through the roof ...

    CWZ pivot cutter
     
  14. Skutt50

    Skutt50 Registered User

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    Big WOW!

    I had forgotten about this thread. Thanks for the information....
     

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