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Harwood First Automatic Wristwatch Assembly Walkthrough


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This Harwood base movement has been stripped down, cleaned and oiled. The mainspring looks good. It is the A.Schild 8.75 lignes, 15 jewels 2 adjustments, used by Harwood from 1925 as a base for his first automatic watch. This automatic movement was an early one since the it does not have either the UK or Swiss patent numbers on the winding bridge. Later examples with these numbers can be viewed on the Ranfft site at:

 

http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&&2uswk&Harwood

 

You will see later on this assembled movement that in place of the patent number Harwood stamped: 'HARWOOD SELFWINDING WATCH Co. LTD', copying the inscription on the bumper (but with LTD instead of JLC)).

 

I start the photo re-assembly from here to illustrate only the features particular to the Harwood.

From its condition I suspect that it was either a prototype or a movement that has been used many times for demonstrations. Screw heads damaged and plating missing on some of the Harwood parts.

 

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The base movement A. Schild 8.75 lignes. No conventional stem for setting.

 

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Left: the winding wheels in place Middle: the uni-directional winding bridge (clic arrowed) Right: the bridge in place. (assembled by placing the movement down onto the upturned bridge with wheels and clic engaged). A little clockwise turn of the exposed gear wheel (arrowed) and the balance turns.

 

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Left the basic movement with intermediate wheel in place. Right: The setting gear. The large toothed wheel on the stem engages with teeth under the watch bezel and it is rotated by turning the bezel. Then the small pin set into the stem engages the cam face on the outer end of the castle wheel (Harwood calls it the crown wheel). This also has a rotating inset pin (as shown) that engages the lever to move a red flag (see later) that indicates the position of the castle wheel. The castle wheel moves inwards until the stem pin meets the protruding stop (see photo). The hand setting can the be completed. A short back-wind of the bezel releases the castle wheel.

 

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Left: The three parts of the setting mechanism in place together with the flag lever return spring. Right: The cover plate in position

 

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Left: The red flag in place. Right: The dial-side bearing plate and stud for the bumper arm.

 

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Left: The bumper in place with the end stops through which the stem is now inserted. The red flag is in the running position. Right: the frame that holds the bumper stops and setting stem to the movement. The red flag is in the setting position.

 

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Left: Back to the movement side showing the screw holding the stem in place. Right: the bumper and frame added.

 

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Left: The winding wheel (arrowed) in place. Centre: the underside of the winding bridge showing the pawl that turns the uni-direction wheel. Right: the winding bridge in place. The winding lever has a slipping clutch at the centre (arrowed) that prevents over-winding

 

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With a dial on the movement.  Left: The red flag in the dial window indicates the running position. Right: The setting position.

The watch is set by rotating the bezel in either direction. Then a back-turn corresponding to just 5 minutes of setting releases the crown wheel and the red flag appears in the window.

 

The beat error was 0.1 ms and the timing error some second per day.

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I apologise for this screwed up post.  - I had made a correction to this post putting the attachments in the correct places. But when I asked to submit the corrected version I received the message : "Sorry you do not have permission for that"

 

The last pair of photos should go before the caption starting: "Left: the winding wheel (arrowed) in place ...... 

 

The penultimate pair of photos should go before the caption starting :Left: the bumper in place with the end stops .......

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Colin, I found that write up really interesting and well put together, thank you so much for taking the time to do it. What an unusual movement, both in design and function, the only trouble is I'll be keeping a look out for one now. I just so enjoy working on unusual pieces of history (not just watches) and restoring them to their former glory.

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Colin, I found that write up really interesting and well put together, thank you so much for taking the time to do it. What an unusual movement, both in design and function, the only trouble is I'll be keeping a look out for one now. I just so enjoy working on unusual pieces of history (not just watches) and restoring them to their former glory.

Glad you liked it Geo. You might start your search for a Harwood here:

 

http://qp.granularit.com/media/38316/Harwood.pdf

 

Exmoor - a short ride down from BF.

Edited by cdjswiss
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Hi Colin, I have been studying your pictures and fully understand the workings. One thing I'm not sure about is how you remove the movement from the case. I suspect it is by a half turn lock on one side of the movement and a pin on the other, and that it comes out the front once the rotating bezel is removed. Could you please clarify?

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Hi Colin, I have been studying your pictures and fully understand the workings. One thing I'm not sure about is how you remove the movement from the case. I suspect it is by a half turn lock on one side of the movement and a pin on the other, and that it comes out the front once the rotating bezel is removed. Could you please clarify?

 

Yes Geo, exactly as you supposed. The bevel above the pin helps clear the case and you should have the bumper on the side of the pin to make it easy.

 

 

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