- Museum number
CHROME-PLATED CASED PIN-PALLET LEVER WATCH.
Ingersoll Revally alarm watch.
Three-quarter plate movement with jewelled club-tooth lever escapement and alarm mechanism; alarm bell mounted on back of movement; single push-piece for hand-setting.
Painted metal dial with luminous Arabic numerals and subsidiary seconds dial.
Minute hand missing.
Chromium-plated case with snap-on bezel and hinged back which is designed to be used as a stand.
- Production date
Diameter: 49.30 millimetres
- Curator's comments
- Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript)
Made by Ingersoll
Germany, c. 1930
Keyless wound pocket watch with an alarm and a pin pallet lever escapement.
Signature: On the dial 'INGERSOLL REVALLY' and 'FOREIGN MADE'. Also on the bell is 'INGERSOLL FOREIGN'
Case: Three piece chrome plated case with a hinged back and a snap on bezel. The hinge for the back is at the pendant with a thumb piece at 6 o'clock.
The chrome plated bell should be fixed to the movement at the centre by two screws, these are missing and as a result the bell is disassociated from the movement. It has two apertures one for access to the regulator this marked with a divided scale, and 'S F' and the other for the silencing lever for the alarm, this is marked SILENT ALARM. The bell is also marked 'INGERSOLL FOREIGN'.
Dial and Hands: A silvered metal dial with bold luminised Arabic numerals. A sunk subsidiary seconds dial. The hands are skeletonised and luminised but the minute hand is missing. There is an alarm hand of baton type. The hands including the seconds hand are of blued-steel.
Movement: the movement not numbered and with a gilt finish.
The back plate is supported by two turned pillars and the keyless block and contains the barrel and both the trains. Most unusually the balance cock also supports the pallet back pivot which this means that a long lever is required.
Ebauche Marks: None.
Jewelling: Jewelled bearings for the balance only, the jewels rubbed in. Ruby endstones to the balance jewels.
Train: Brass wheels the centre third and fourth wheels with five crossings, the escape wheel with four.
Escapement: A straight line layout pin pallet lever escapement with a long lever with steel pins. Effectively a double roller with the cylindrical inpulse pin set into the balance arm.
An equal impulse escapement.
No. of teeth embraced 3 ½.
Balance and Spring: A nickel silver balance with nibs to simulate screws. Balance diameter thickness mm. The balance staff is broken. A beryllium copper flat spiral balance spring with 9 3/4 turns.
Means of Regulation: A blued steel regulator is mounted on the balance cock and registers against stamped divisions with also stamped 'S F' and 'A R'.
Train And Beat Rate
Great wheel 90 (barrel)
Centre wheel 80 pinion 10
Third wheel 60 pinion 10
Fourth wheel 70 pinion 8
Escape wheel 15 pinion 7
Beat rate: 18,000
Motion work: cannon pinion 10
minute wheel 30, minute pinion 10
hour wheel 40
Alarm Work: A stop wheel mounted on the back plate prevents the alarm train from running for more than about half a turn. The barrel ratchet wheel drives the first pinion in the alarm train, which has a steel wheel mounted on it, this assembly is secured by a shoulder screw. The steel wheel in turn drives the pinion of the brass escape wheel which acts with steel pallets whose arbor carries the alarm hammer. The alarm silencer when pushed over intersects the teeth of the steel wheel and prevents the alarm from working.
Dimensions: Case diameter 48.8 mm., height 17.5 mm., over the glass.
Movement diameter 45 mm., height 14.5 mm.
Provenance: Donated by the Heron Corporation Ltd in 1983.
- Not on display
- Acquisition date
- Britain, Europe and Prehistory
- Registration number