Microtor Technology by Universal Genève - Universal Geneve

S
4
elf-winding watches
The first watch automatically wound by means of
a central oscillating weight appeared in the latter
half of the 18 th century, in Le Locle. It stemmed
from the ingenious work of watchmaker Abraham-Louis
Perrelet (1729-1826), who had
observed that the rotation of the oscillating
weight generated sufficient energy to wind the
mainspring.
The first self-winding wristwatch was developed
by Englishman John Harwood, who filed a patent
for it in Switzerland in 1932. The oscillating
weight, which was wound in one direction only,
described a 130° arc of a circle. The disadvantage of
this watch was that it could not be wound by hand.
Ever since, this major technical innovation has
been constantly perfected, driven by an ongoing
quest for miniaturisation and precision.
Universal Genève watchmakers were pioneers in
the development of self-winding movements,
particularly due to the integrated micro-oscillating
weight that made them extremely thin and
uniquely elegant.
Universal Genève assembly workshop 1940
In the late 1940s, at a time when Universal
Genève was still known as Universal Watch
Factory, Perret & Berthoud Ltd (a name linked to
the names of its founders), the watchmakers
Universal Genève trademarks 1936, 1940, 1957
of the Manufacture presented a men’s self-winding
wristwatch equipped with Calibre UG 138. The
oscillating weight, located at the centre of the
movement, made a partial revolution of 315° and
was limited along its trajectory by two cylindrical
buffer-springs placed on the edge of the mainplate.
Calibre UG 138, displaying the hours, minutes and
small seconds at 6 o’clock, measured 28.20mm in
diameter and was 4.85mm thick. The balance
oscillated at a frequency of 18,000 vibrations per
hour. The first caliber was to be followed in the
early 50s by two movements featuring the same
technical characteristics : the 5.55mm thick
Calibre UG 138.SS-SC with centre seconds; and
the 6mm thick Calibre UG 138.C.C complete with
date disc and small seconds at 6 o’clock, which
drove the “Monodatic” model.
Calibre UG 138.SS-SC