Chrome-plated cased club-tooth lever wrist-watch with black leather strap

Description — British Museum

Wrist-watch. 3/4 plate movement with club-tooth lever escapement. Silvered dial with Arabic hour numerals and subsidiary seconds. Gold hands. Chromium-plated case with snap-on back. Black leather wrist-strap.

Curator's comments — British Museum

Comment from Richard Good, Catalogue of Watches in the British Museum. Vol. V (Unpublished manuscript) Maker anonymous Switzerland, c. 1960 Wrist watch with a club tooth lever escapement. Signature: Around the barrel arbor retaining screw 'PAT.' the Helvetia cross and 'D.R.P.' Case: A round chromium plated case with a snap on back and bezel. Complete with a black leather strap with a chromium plated buckle. Dial & Hands: A silvered metal dial with black Arabic numerals and minute circle. A subsidiary seconds dial. Gold hands of lozenge style. The dial secured with two dog screws. Movement: Ebauche Marks. The ebauche mark MA 345 for Adolphe Michel S.A.(1) Frame: A round movement with a nickel plated brass frame with a grained finish. A detachable barrel. The back plate, which is supported by the keyless block and two pillars, covers all but the pallets and balance which are supported by cocks. Barrel and Mainspring: The going barrel has no cover, the winding wheel acts as the spring restraint. Barrel: I diameter 8.5 mm., height 1.63 mm. Mainspring: height 1.5 mm., thickness 0.10 mm. Barrel Arbor: is staked to the winding wheel and is 3.9 mm. in diameter, it is snailed. Hooking: milled from the barrel wall. Train: All the brass wheels are gilded, the centre wheel, third and fourth wheels with five crossings. The steel escape wheel with four. Jewelling: Jewelled bearings from the third wheel onwards. All the jewels pressed in. Ruby endstones to the balance jewels. Escapement: An straight line layout club tooth lever escapement with short lever, double roller and D-shaped impulse pin. A steel escape wheel with four crossings. The acting faces of the pallet stones flat. An equidistant locking escapement. No. of teeth embraced 3½. Balance & Spring: A monometalic nickel silver balance with brass screws. Balance diameter 8.45 mm, thickness 0.66 mm. A 'self compensating' flat spiral spring with 12 turns. Means of Regulation: An index on the balance cock registers against a divided scale with 'F S' and 'A R' engraved on the balance cock table. Train Counts and Beat Rate: Great wheel (barrel) 70 Centre wheel 64 pinion 10 Third wheel 60 pinion 8 Fourth wheel 60 pinion 8 Escape wheel 15 pinion 6 Beat rate 18,000 Motion work: cannon pinion 9 minute wheel 27, minute pinion 8 hour wheel 32 Winding System: Stem set rocking bar keyless work. Dimensions: Diameter 29.6 mm., height 10.1 mm., over the glass. Movement: diameter 22 mm., height 5.8 mm. Provenance: Donated in 1983 by The Heron Corporation Ltd. Note: (1) First founded in 1898. In 1926 participated in the creation of the Ebauche Group.