- Museum number
NICKEL PLATE CASED LEVER WATCH WITH DIGITAL TIME INDICATION.
Full-plate Roskopf-type with a separate cock for the pallets.
Pin-pallet lever escapement; keyless winding and hand-set.
Hours and minutes in apertures in case front..
- Production date
Diameter: 50 millimetres (case)
Thickness: 13 millimetres
- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Switzerland, c. 1930
Watch with digital display and a pin pallet lever escapement
Signature: The back plate stamped in a circular manner around a Helvetia cross within a circle 'BREVETS DEPOSES SWISS MADE'
Case: A two piece chrome plated case with apertures for the hours and minutes. On the back of the case is stamped 'SWISS MADE'.
Dial & Hands: The glass covering the two digital discs is mounted on the head of a screw and holds down the hour and minute discs. The minute disc which is painted white has black numerals 5 10 15 20 25 30 35 40 45 50 55 60. It also has a black minute ring. The hour disc has black Arabic numerals and is marked in 12 minute intervals.
Movement: A brass movement.(1)
Frame: A ¾ plate layout, the back plate supported by four pillars one of which is a steel shoulder screw, otherwise the back plate is secured by three screws.
The back plate covers the keyless work, the barrel and the train, and there is a cock for the pallets and one for the balance. A steel bridge covers the winding wheels and the barrel ratchet spring.
Barrel and Mainspring: A steel great wheel with the minute wheel mounted friction tight upon it. Four lugs are bent up from the great wheel and locate the mainspring, there is no conventional barrel.
Diameter between the lugs 22 mm.
Mainspring: height 1.5 mm., thickness 0.25 mm.
Barrel Arbor: diameter 5.3 mm, not snailed.
Hooking: The outer end of the spring is hooked over one of the bent up lugs.
Train: Brass wheels, not gilded, the second and third wheels with five crossings. The escape wheel with four.
Jewelling: No jewels. The balance staff with cone pivots running in steel cups.
Escapement: A straight line layout pin pallet lever escapement with long lever, effectively a double roller and a brass impulse finger. The pallet pins steel set in a brass lever. A brass escape wheel with four crossings.
An equal impulse escapement.
No. of teeth embraced 3½.
Balance & Spring: a brass balance with three arms and a plain rim. Balance diameter 16.0 mm., thickness 0.7 mm. A self compensating flat spiral spring with 9 turns.
Means of Regulation: An index on the balance cock registers against a divided scale with 'F S' and 'A R' stamped on the cock. The index is in one with the endpiece which is held by a single screw so that as the watch is regulated the endpiece moves across the cock. A very peculiar arrangement.
Train Counts and Beat Rate:
Great wheel 140 (rotates once in four hours)
Second wheel 84 pinion 8
Third wheel 48 pinion 7
Escape wheel 18 pinion 6
Beat rate: 15,120
Motion work: cannon pinion 12
minute wheel 48, minute pinion 12
hour wheel 36
Winding System: Keyless work, the button is pressed in to effect hand setting.
Case : Diameter 49.8 mm., height 13 mm.
Movement: diameter 45 mm, height 10 mm.
Provenance: Formerly in the Ilbert Collection.
(1) There are striking similarities between this watch and registration nos 1984,0702.9 and 1958,1201.956.
- Not on display
- Latest: 3 (2017)
- Acquisition date
- Britain, Europe and Prehistory
- Registration number
- Additional IDs
Previous owner/ex-collection number: CAI.0964 (Ilbert Collection)
Previous owner/ex-collection number: N17 (Ilbert Ledger)