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| Date/Report Number ..052711.T70.50 Item: 1940-WWII-HELOISA-BUMPER-AUTOMATIC-MILITARY-WATCH | |||||||
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| Description of item: VINTAGE
1940 EXCELLENT ALL ORIGINAL CONDITION WWII HELOISA BUMPER AUTOMATIC MILITARY WATCH WITH
WITH G-20 NATO STYLE GREEN NYLON MILITARY STRAP WITH BRUSHED KEEPERS.SIZE IS 32 X 40 MM.
THIS HELOISA IS A RARE EDITION WWII 1940 ORIGINAL MILITARY HELOISA BUMPER AUTOMATIC IN
STAINLESS STEEL WITH ORIGINAL TWO-TONE DIAL, SIGNED HELOISA AUTOMATIC, WITH ORIGINAL
STILL GLOWING RAISED RADIUM NUMBERS, INNER MARKED SECOND & HOUR CHAPTER RING,
RELUMED BLACK ORIGINAL HOUR & MINUTE HAND WITH RED SUB-SECOND HAND AND WATERPROOF,
ANTIMAGNETIC AND SHOCK PROTECTED DESIGNATION. CROWN IS ORIGINAL NOTICE THAT IT IS A
LARGE MILITARY TYPE AND CASE IS SUBSTANTIAL AND ALL STAINLESS STEEL. LUGS & END
ZONES ARE EXCELLENT. SCREW DOWN CASE BACK IS SIGNED INCABLOC ANTIMAGNETIC WATERPROOF
STAINLESS STEEL AUTOMATIC. MOVEMENT 1935-1945 AS 1171 1940 Swiss Made 17 Jewels Brevet+ AS
Sub Second Incabloc Automatic (bumper) & Manual Wind. THE AS 1171 IS A REDESIGN OF THE
ORIGINAL AS HARWOOD AUTOMATIC MANUAL WINDING & SHOCK PROTECTION WERE TWO
OF THE 1171 UPGRADES 1171 DATA = 11''' Dm= 24.8mm H= 5.2mm 15/17 jewels f = 18000
A/h power reserve 36h 1171 ALSO UTILIZED IN Favre-Leuba 437 (AS 1171) Fortis 250 (AS
1171). CONDITION IS FINE. Estimated Retail Replacement Value $399.00 |
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| Reports are supplied at the request of the customer and it is for the customer's exclusive use. Reports express an opinion of the time of the examination of the jewelry. This report is for customers use only for the following two purposes, indicating estimated retail replacement value to obtain insurance coverage, or for the purpose of providing geological information. GoldSmith Works does not guarantee that the appraisal valuation will result in a sale at the price. Estimated retail replacement value is arrived after analyses of what the approximate high retail cash asking price is for labor, materials, and design. These prices may be substantially higher than actual transaction or warranty with regards to any item described in the report, since jewelry grading is not an exact science, this report represent the best opinion of the company. GoldSmith Works is in no case responsible for differences that occur by repeated grading by other experts in the field and/or use of other standards, norms, methods or criteria other than those used by GoldSmith Works. GoldSmith Works is expressly held harmless by customers including, but with out limitation for any claims or actions that may arise out of negligence in connection with the preparation of this laboratory report, or actions based upon the customer's use of the report. The information on the carat weight, clarity grade, color grade on the report is approximate due to the limitations in jewelry grading. The item was tested, graded, and examined under 10x magnification using the techniques and equipment available to GoldSmith Works, including fully corrected triplet loupe, binocular microscope, master color comparison guides, diamond color comparison tools, electronic carat balance, non-contact optical measuring device, and ancillary instruments necessary at the time of Examination. |
Harwood
(AS)
automatic
(bumper)
no manual wind
Data
11.5''', Dm= 24.7mm
(with bumper Do= 25.6mm)
H= 5.35mm
15 jewels
f = 18000 A/h
1925-1931
A. Schild
Fortis
1926-1931
A. Schild
Blancpain
ca. 14000
first serial-production automatic
bimetallic screw balance
set by revolving bezel
bumper bearings on dial and back
winding torque limited
by friction coupled bumper
Britsh Patent 1576120
selfwinding mechanism
deposited 1920
Swiss Patent 106583:
selfwinding mechanism
deposited 10-16-1923
by John Harwood,
Baldrine-Lonon
(Ile of Man, GB)
Harry Cutts
Brighton (GB)
Example, year: signature; shock device
1-3) ca. 1925: SF,
Harwood Selfwinding Watch Co Inc
Patent No. 1576120
2 Adjts, 15 Jewels - 697
4-5) 1926:
Harwood Selfwinding Watch Co Ltd
Swiss, Patent No. 106583
2 Adj., 15 Jewels
'Bumper' wristwatches: 1923
Self winding mechanisms were more successful in wristwatches because the rotor could
operate every time the owner moved his or her arm. The first version did not appear until
after World War I, when wristwatches became popular. It was invented by a watch repairer
from the Isle of Man named John Harwood in 1923,[11] who took out a UK patent with his
financial backer, Harry Cutts, on 7 July 1923, and a corresponding Swiss patent on 16
October 1923.[12] The Harwood system used a pivoting weight which swung as the wearer
moved, and which in turn wound the mainspring. The ratchet mechanism only wound the
mainspring when moving in one direction. The weight didn't rotate a full 360°; spring
bumpers limited its swing to about 180°, to encourage a back and forth motion.[13] This
early type of self-winding mechanism is now referred to as a 'hammer' or 'bumper'.
When fully wound, Harwood's watch would run for 12 hours autonomously. It did not have a
conventional stem winder, so the hands were moved manually by rotating a bezel around the
face of the watch. The watches were first produced with the help of Swiss watch
manufacturer Fortis and went on sale in 1928. 30,000 were made before the Harwood
Self-Winding Watch Company collapsed in 1931 as a result of the Great Depression. 'Bumper'
watches were the first commercially successful automatic watches; they were made by
several high grade watch manufacturers during the 1930s and 1940s.