Pink Pages
for Timepieces
All Items
Ranfft Items
Brand Shops
Commit an Item
How to do right
Condition of Watches
About Watches
  Help   Log In  Register, Clients   Deutsch  English  EUR  US$  CHF  UKŁ 
 Index  Timepiece Archive, Categories  Archive: Watch Movements    Timepiece Market 
View picture in original size
Fig. 1

View picture in original size
Fig. 2

View picture in original size
Fig. 3

Invar 19'''

stem wind and set
sub second

18.75''', Dm= 42.1mm, Do= 42.75mm
H= 6.0mm
(winding gear +0.2mm)
F= 0.75mm
T= 2.3mm
15 jewels
f = 18000 A/h
power-reserve 39h

Balance staff Ronda 1548

1.75 x 1.05 / 0.20mm

Comments about the data

hunter or open face calibre
bimetallic screw balance with 4 adjustment screws
Breguet hairspring with terminal curve after Philipps, optimized for a wide adjustment range (Fig.3)
crown mechanism without setting lever spring
The setting lever is held in place by a spring (Fig.2). To unlock the stem, the locking screw must be screwed down to lift the setting lever from the stem. As watchmakers are used to turn this screw left to unlock the stem, it is left handed.
Advantage of this strange assembly: It can't happen that the setting works falls apart by turning the screw too far. If the screw is turned down to the stop, the stem is released. If turned loose (no matter how far), the stem is locked.

Example, year: signature; shock device
ca. 1915: 350699, Invar - 350699
(open face)

Not for Sale!
The movements presented in this caliber finder are not for sale. This is only a data sheet for identification and evaluation of the movement calibre, as well as for approximate dating.

bidfun-db 21.3 © 02-08-15, mtr-Ranfft

bidfun home
...the alternative - free of charge!
Dr. Roland Ranfft
Erkelenzer Str. 98
41844 Wegberg
phone +49 (0)2434 6034670

email: info@ranfft.de