Important Modern and Vintage Timepieces

Hong Kong, Jun 25, 2011

LOT 300

Haas - Patent Keyless Cover Winding B. Haas Jeune, de S. M. l?Empereur, Genève, Besançon- Paris, "Remontoir Perpetuel, Chronometre", No. 1008. Made circa 1875. Very fine and rare, 18K gold, hunting-cased lever chronometer pocket watch with ?remontoire perpétuel à décrochement? keyless cover winding to the English patent (No. 3945) of Benjamin Haas 1873.

HKD 45,000 - 62,000

USD 5,800 - 8,000 / EUR 4,000 - 5,700

Sold: HKD 57,500

C. Five-body, ?bassine et filets?, entirely engine-turned and engraved with foliage and geometric patterns, the front cover with central engraved fleur-de-lis beneath a crown, handsetting button in the pendant. Hinged gold cuvette. D. White enamel, radial Roman numerals, outer minute track with five-minute Arabic numerals, subsidiary seconds. Blued steel Breguet hands. M. 40 mm (18'''), matte gilt, bar caliber, stamped with three coats of arms, calibrated and counterpoised straight line lever escapement, cut bimetallic compensation balance with blued steel Breguet balance spring, index regulator, patented winding mechanism by closing the cover which transmits the power via two levers to a ratchet wheel on the barrel arbor, a safety device disengaging the mechanism when fully wound, going train with an additional wheel driving a steel wheel fixed to the center wheel having half the diameter of the driving one, second motion train driven from the canon pinion and advanced directly by pushing the teeth of the minute wheel. Dial, cuvette and movement signed, movement also punched R.T. & F. Diam. 50 mm.


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Grading System
Grade: AA

Very good
Case: 3

Good
Movement: 3*

Good

Overhaul recommended, at buyer's expense
Dial: 3-01

Good

HANDS Original

Notes

In 1873 Benjamin Haas patented a winding mechanism (English patent No. 3945 of Dec. 2, 1873). The idea was to use the energy generated by closing the front cover to wind the watch. The initial idea was improved upon; his watch features a well developed system with a 36-hour power reserve generated by 12 closings. To achieve this, Haas changed the going train, adding a wheel, which allowed him three hours' winding by a single closing. He designed a safety device disengaging the mechanism when fully wound, which prevents damage to the cover.