Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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BACKGROUND OF THE INVENTION
This invention has as its object to provide a wrist-
watch of reduced thickness comprising a watch case, a crystal
and at least two time indicating discs such discs coupled
together by a gear train itself driven by an electric motor
controlled by an electronic circuit.
A mechanical wrist-watch~with the same type of display
has been previously known from the prior art. Swiss patent
No. 307 045 describes a mechanical wrist-watch in which the
barrel drives an hours disc and a minutes disc through the
intermediate of the usual motion work. In this form the bar-
rel is coaxially mounted with the indicator discs and the
motion work as well as the final train are found at the ex-
terior o~ the indicating discs and within two diametrically
opposed wings arranged between the bxacelet attaching lugs.
In addition to the fact that the purpose sought in the above-
cited patent was not that of obtaining a reduced thickness
watch but rather to produce an aspecl of mystery in giving
to the watch hands the impression of being suspended, it
will be appreciated that the space employed by the barrel
renders it unsuitable for showing the reduced thickness over-
all and that only methods employing elements of the most
modern techniques may be used to displace the motor element
beyond the periphery of the indicating discs. Moreover neither
of the Swiss patents Nos. 312 519 and 312 520 which were
patents of addition to the above previously mentioned
patent suggest solutions to the problem which the present
inventon proposes to solve.
Other propositions have been made for replacing the
hands by indicating discs. The German laid open applications
DEOS 22 04 907 and DEOS 25 48 559 each describes a clock pro-
vided with transparent discs. Figure 1 of the first mentioned
shows that no means has been employed to reduce the thick-
ness of the clock, the disc driving system requiring an im-
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portant amount of space between the discs. In the second ofthe above-mentioned publications the purpose is to give
the impression that the hands are not driven by any mechanism.
If this display appears to require little thickness its
driving mechanism to the contrary is lodged in a socket
having a thickness clearly greater than the clock and
forming a support therefor.
Extra flat watch movements have already been proposed.
French patent application No. 2 341 886 describes such a
movement having manual or automatic winding and for which
the thickness does not exceed 1,5 or 2 mm, and where the
moving parts suspended from the bottom plate are pivoted in
cantilever. This relatively complex system requires expen-
sive elements, notably ball bearings.
In the classic type of wrist-watch driven however bY
a quartz controlled oscillator with an electric motor ~nd
an analog type display, at least 9 el.ements are superposed
in arriving at the overall thickness of the watch. These are
the case back, the bottom plate, the minute wheel, the
motion work (dial train), the hour wheel, the dial, the min-
utes and hours hands and finally the crystal. It is the pur-
pose of the present invention to reduce as far as possible
the number of these elements juxtaposed one over the other
in order to obtain a watch of overall reduced thickness. It
is another purpose of the present invention to use electro-
nic elements to obtain the rnost flexible arrangement of said
elements with respect to one another in order to be able to
reduce greatly the overall thickness of the watch.
SUMMARY OF THE INVENTION
The wrist-watch in accordance with the invention is
characterized in that the overall thickness is constituted
by superposition of the back of the case, the time indicating
discs and the crystal, there have being sufficient play
arranged on all sides of said discs to permit free movement
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thereof. The remaining principal watch elements such~as the
motor, gear train and electronic circuit are located in por-
tions of the case extending beyond the diameter of the indi-
cating discs, said portions having a thickness no greater
than the overall thickness.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a plan view of the watch bottom plate
to a greatly enlarged scale,
Figure 2 is a cross section of the watch to a still
greater scale, the various elements having
been disposed so as to render the
mechanism more readily understandable,
Figures 3a and 3b represent in a cross section the gear
train as employed to drive the hours
indicator as well as the minutes indica-
tor.
Figure 1 and 2 clearly show how the watch is arranged
in accordance with the invention. The case is comprised of
a case back 1 and a cover 2. The case back comprises at the
same time the bottom plate of the watch which supports all
the various components either in beds or on studs. A metallic
hours indicator disc 4 and a transparent minutes indicator
disc 5 are arranged to pivot around a first central stud
3. On each of these discs there is impressed a guide mark
representing respectively an hours hand 7 and a minutes
hand 6. The cover 2 of the watch comprises a crystal 8
through which may appear the discs with their guide marks and
below which a dial is engraved or impressed. Two diametri-
cally opposed extensions project on either hand of the indi-
cator discs. The left extension carries an electric motor
9 and the gear train 10 which is arranged to pivot on studs
22 and is arranged and adapted to drive the discs 5 and 4 by
means of their peripheral teeth 11 and 12. A roller guide 18
located proximate the drive wheels maintains the teeth of
the wheels at the level of the disc teeth. The right hand
extension carries an energy source 13 (dry cell), a quartz
oscillator 14, trimmer 15 and the electronic circuit 16.
As clearly shown in figure 2 the overall thickness
of the watch is made up by the superposition of the four
elements, namely the case back 1, indicator discs 4 and 5
and crystal 8 whereas in Swiss patent No. 307 045 as pre-
viously cited this thickness comes from at least 6 elements.
The same figure 2 shows as well that the extensions containing
the various other elements included in the watch and
situated beyond the indicator discs comprise a case which
does not exceed the overall thickness. It must be here re-
called that sufficient play must be arranged on all sides of
the indicating discs in order that they may move freely.
Although the invention employs a known arrangement for dis-
playing of the hours and the minutes it employs this to
greater profit in order to achieve in connection with the
use of modern electronic elements a result until now quite
unknown, that is to say, a reduction of great magnitude in
the thickness of the watch. The con~;truction disclosed permits
effectively to obtain a thickness of the order of 1,5 mm
including watchcase such being hitherto unknown.
Figure 3a shows a development of how the hours disc 4
may be driven from pinion 19 as fixed to the axis of motor
g to the hour wheel 20. Incorporated into the gear train is
also to be found a minutes wheel 21 which drives the minutes
disc 5 as shown in figure 3b.
In a variant of the foregoing the case back may be ins-
cribed with the dial. In this case the two indicator discs
are both transparent and may be impressed with the hours
marker and minutes marker as already described in the pre-
ceding.
In a further variant of the invention the watch may
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comprise in addition to the hours and minutes discs as pre-
viously described a further disc indicating the seconds.
