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....Ingersoll watch
"The watch wich made the Dollar famous"

New, July 06

Manufacturer: Ingersoll Watch Co, New York, USA

Dimensions:

Watch diameter.................49.0 mm
Movement Ø.............. ...... 43.2 mm
Thickness..........................15.0 mm
Total weight ......................54 g

Indications:... Minutes, hours and center seconds.

Fig 1:
Ingersoll watch, made in USA, .Nov. 14. 1922,
lying on a 10 mm grid


klick here for a larger image
Fig 2:
Front plate of the watch, from brass.
Fig 3:
Back plate with removed barrel bridge, revealing an open main spring barrel.


Movement:.No. F0120738
All made from punched brass. Upper (visible) plate chromed brass. The gear for winding and setting hands is from punched steel.

Dial: Card dial with printed numerals.

Case: Stamped "made in USA", no serial number. Made from chromed brass tin.

What made this watch so cheep?
"Cheep" is relative, since 1 Dollar was a craftsmans weekly pay in the 1920s. But anyway, there was no cheeper watch then. This price was accomplished by
- useing all punched parts,
- an open mainspring barrel,
- no jewels at all,
- a slower ballance, making 4 beats per second instead of the usual 5 beats. That saves teeth,
- a pivot balance staff with a single roller, the impulse pin is fixed at a ballance arm and not at the roller as usual.
- very little screws. The two plates of the movement are hold together by rivets, no screws as usual. But that makes servicing impossible.
- the case is stamped from a thin brass sheet; not milled and turned as usual.


Fig 4: A fiew from the side. The balance shaft (1), the bearings (2), the roller (4) at the lower end of the shaft and the impulse pin (3), directly fixed to a balance arm are clearly visible. Fig. 5: A section demonstrating the design of a pivot bearing staff. The pivot screw allows exact seating of the staff.

Pivot bearings for balance staffs are not only seen in primitiv pocket watches but also in alarm clocks. It's an elegant solution for a simple and unbrakable balance. The problem is excessive wear. Important is ample lubrification.

History: