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Any typos are as a result of direct translation of the
original French.
The "trailing" meter
The stop watches are generally supplemented by a needle moving on a small dial
carrying 30 or 45 divisions.
This needle "of meter" advances of a division by turn of second hand;
it thus counts the minutes.
Terminology:
A: stem of the "oscillating" pinion
B: rock of meter
C: "oscillating" pinion
D: coil with column
E: caster
F: eccentric stud
G: coil meter
H: great average
K: comes out from rocker
Operation:
The needle of a "trailing" meter moves slowly and regularly ,
to pass from one division to the other, while the second hand carries out a
rotation.
The wheel of meter with fine teeth, swivels in the turntable and the bridge of
stop watch.
It is under the action of a spring of friction and changes a heart for the
handing-over to zero.
The great average gears constantly with the "oscillating" pinion which
swivels in the turntable and, by its higher pivot in the rocker of meter.
The stem of the pinion carries a caster to fine teeth.
When the stop watch does not work, the rocker is drawn aside by the column and
the caster does not gear with the wheel of meter (fig. above).
At the time of the starting of the stop watch, the nozzle of the rocker is found
between two columns and fall into the vacuum under the action of its spring; the
oscillating pinion takes a light slope and the caster with fine teeth gears with
the wheel of meter, involving this one at the speed of a turn into 30 min. or a
turn in 45 min. according to the meter.
The penetration of the gears caster - wheel of meter is regulated by the
eccentric stud.
It is necessary to take guard so that the gears pinion - large-average is not
too strong when the stopwatch is not in catch, because it "would slow
down" the large-average.
The needle of the meter is posed slightly in front of division 30 (or 45) to
compensate for the plays of gears.
This meter is not very widespread.
The half-instantaneous meter
One recognizes this meter by the fact that its needle is started only at the
time when the second hand arrives on the 58ème second approximately.
Terminology:
C: Coil stop watch
D: Finger of the wheel of stop watch
E: Eccentric of the intermediate rocker of meter
K: Rock of meter
K ': Intermediate gear meter
L: Saltire of meter minutes
M: Coil meter minutes
P: Bridge of stopwatch
U: Comes out from intermediate rocker of meter
M '': Switch meter
M: Coil meter
O: Heart
P: Bridge of stop watch
P': Platinize
P '': Bridge of barrel
P: Pierre of the bridge
The wheel of meter crosses the bridge of barrel; it swivels very freely, on the
one hand in the turntable and on the other hand inside the stone fixed at the
bridge of stop watch.
The needle, known as "of meter" is fixed on the end of the long lower
pivot of the stem of meter.
Operation:
The wheel of meter gears with the intermediate gear of meter carried by the
rocker of meter.
With each turn of wheel of center stopwatch, the finger which is adjusted under
this one comes into contact with the tooth k' of the intermediate gear of meter
to approximately of the 58ème dry, actuating in its turn the wheel of meter.
As soon as that the point of the tooth exceeds the top of the saltire, that is
to say exactly in the passing of the second hand on division 60 of the dial, the
tilted one of the saltire acts on the point of the tooth and makes turn of a
step the wheel of meter.
Development and checking of the half-instantaneous meter:
So that an half-instantaneous meter functions correctly, it is necessary that
the tooth which will be in function with the finger, is on the locus of centres
intermediate gear - wheel of stopwatch.
It is necessary that the penetration of the finger with the tooth of the wheel
is sufficiently large to involve the latter, so that it can pass the point of
the saltire, to carry out the explosion correctly and not to involve the
following tooth.
If the penetration is insufficient, the explosion will not be done and meter
switches it will carry out a return ticket on same division.
If the engagement of the finger is too significant, it will involve two teeth
instead of one.
If the engagement of the finger is slightly too strong, the finger will be
propped up against the second tooth and will cause the stop.
Release of the intermediate gear
In a stop watch with half-instantaneous meter, it is significant that, during
the restoring and possibly at the time of the stop, the intermediate gear of
meter moves away from the finger from stop watch to avoid a contact between this
last and the intermediate gear.
In the illustration opposite the part is with the stop and the wheel meter is
not released.
If at the time of the stop, a tooth of the wheel meter is spirit to go up on the
tilted one of the saltire of meter minute and if this one is stronger than the
spring of friction located under the wheel of stopwatch, there will be a retreat
of the second hand at the time or the saltire will reposition the wheel meter.
During the restoring, if the part remains as opposite (rocks intermediate of
meter not released), at the time or the hammer will fall and to involve the
wheel meter in the direction of the arrow, the intermediate gear of meter will
involve the finger and will block the restoring.
Tuning of the hammer of an half-instantaneous meter
During the restoring, the tilted one of the branch of center of the hammer
naturally must, as in the stop watch with continuous meter, to press on the
shoulders of the heart of the wheel of stop watch, while the tilted one of the
branch of meter of the hammer will not press on the shoulders of the
heart of meter, with which it will have a certain play.
This play will be a little stronger than in the continuous meter, because the
tilted ones of the saltire of minutes bring back and maintain the needle of
meter on division zero of the dial.
The value of the play is controlled by looking at the displacement of the wheel
meter on the saltire by making it move by means of a "stick".
 The
teeth should not exceed half of tilted saltire.
The
play must be well distributed on each side of the saltire.
The instantaneous meter
Definition: The needle "of meter" of a stop watch with
instantaneous meter "jumps" quickly of one graduation to the other,
with the passage of the second hand on division 60 of the dial.
Terminology:
B: Instantaneous rocker
C: Hammer
D: Instantaneous pawl
E: Comes out from pawl
F: Rock of release
G: Coil meter
H: Eccentric
K: Comes out from instantaneous rocker
L: Saltire of wheel of meter
M: Coil stopwatch
P: Comes out from rocker of release
b: Nozzle of the instantaneous rocker
Operation:
When, in consequence of the rotation of the wheel of center stop watch, the
nozzle of the instantaneous rocker leaves the high part of the eccentric
"to fall" on the low part, the pawl follows the movement of the rocker
and involves the wheel of meter which advances angular value "of a
step" in the direction of the arrow (Figure above).
This jump is very fast, from where the name of instantaneous meter.
During the restoring, it is necessary that the instantaneous pawl is not any
more in contact with the wheel of meter.
 fig.2
To this end, a rocker of release is raised by the branch of meter of the hammer,
when one puts the stop watch walks from there (fig.1); this makes it possible
the pawl to come into contact with the teeth of the wheel of meter, while the
hammer releases the rocker of release, to the restoring.
Actuated by its spring, the rocker whose end ends in "fork" in which a
pin fixed at the pawl penetrates, raises this one (fig.2) and moves away it from
the wheel of meter, in order to allow the latter to turn during the restoring.
The modern meter of hour
Unless noting the hour at which one starts the second hand of a stop watch
meter, one cannot, with safety, to carry out observations of a few hours, the
meter of minutes adding up only 30, respectively 45 or 60 minutes.
This is why the stop watches are sometimes supplemented by a meter of hours.
At the time of the starting of the stop watch, the needle of the meter of hours
is also put moving, to advance very slowly, since it makes a turn in 12 hours.
This needle is immobilized when one stops the stop watch and returns to his
starting point, at the time of the function of restoring.
The meter of hours thus makes it possible to make observations of long duration.
The mechanism of the meter of hours is completely independent of that of the
meter of minutes.
It is an additional mechanism laid out under the dial.
Terminology:
A: Coil meter of the hours
B: Coil
C: Pinion (identical to the pinion of center)
D: Conveyor.
E: Rock
F: Bridge
G: Rock of restoring
H: Hammer
K: Rock flexible
N: Comes out from hammer
P: Comes out from rocker
Operation:
The transmission with the needle of meter of the hours of its rotational
movement, takes place by means of a spur gearing driven by the barrel.
This one, which carries 72 teeth, gears with the pinion C, identical to the
pinion of the wheel of center of the wheel of the watch.
Its diameter is the same one, as well as the number of wings, is 12.
This pinion, placed in an opening of the turntable, turns by its lower pivot in
the bridge of barrel and, by its higher pivot, in the rocker D, whose point of
swivelling is into 3 on a pin.
The following mobile is the wheel B, pulled by the pinion, it is screwed very
freely, without play, under the same rocker D.
It carries 36 epicycloidal teeth and makes a turn on itself while the pinion
makes three of them.
On its axis and its upper surface the small wheel B is rivetted carrying 45
triangular, similar teeth with the teeth of a wheel of center of the stop watch.
This small wheel involves the wheel of meter of hours A, swivelled between the
turntable and the special bridge F and whose higher pivot is sufficiently long
to receive the adjustment of the needle of meter.
The wheel is provided with 180 triangular teeth and thus makes a turn, while the
wheel B makes of them four and the pinion C twelve, which corresponds well to
the twelve hours traced on the dial of meter.
The function departure:
The departure is produced by pressing poussette of starting.
End of rocker intermediate of stop watch fall in vacuum between two columns,
involving with it pin 6 (in red) which crosses right through bridge barrel and
platinizes it and penetrates in hole practised in rocker E which swivels as in
point 4, which causes to return freedom to the rocker D and to make it possible
this one to move in the direction of arrow 10, under the pressure of the spring
P.
La petite roue b entre alors en contact avec la roue du compteur des heures et
l'entraînera jusqu'à la fin de l'observation.
L'engrenage de ces deux roues est réglé par le plot excentrique 7.
La fonction arrêt :
Pour obtenir l'arrêt de l'aiguille, la petite roue b doit s'éloigner de la
roue A suffisamment pour que l'engrènement des deux roues soit rompu.
C'est la bascule intermédiaire du chronographe qui est chargée d'opérer cette
fonction par le moyen de la goupille 6.
Nous avons vu que lorsqu'on exerce une pression sur la poussette de mise en
marche et d'arrêt (dans les chronographes à double poussoir), la bascule
intermédiaire de chronographe accomplit un petit mouvement de recul, provoqué
par la roue à colonnes, afin de rompre l'engrènement des roues intermédiaire
et de centre du chronographe.
Ce recul est transmis par la goupille 6 à la bascule E et, par la suite, à la
bascule D par le plot 5 et le contact est rompu entre les roues A et b.
Il est nécessaire que le plot 5 soit excentrique pour régler l'espace minimum
entre ces deux roues.
Fonction de remise à zéro :
Le retour à zéro s'opère de la même manière que pour le chronographe ou le
compteur des minutes.
Sur l'axe de la roue de compteur des heures A est vissé un cœur destiné à la
ramener à son point de départ, lorsque le marteau H exerce une pression sur
son pourtour.
Ce marteau, dont l'axe est en 2 sur une goupille, est entraîné contre le cœur
par la bascule de poussoir G qui pivote au point 1.
Celle-ci est actionnée par la même poussette qui fait mouvoir le marteau des cœurs
de chronographe et de compteur des minutes.
Un bras flexible K est vissé sur la bascule G et a pour but de donner plus de
souplesse au poussoir, afin que le marteau des cœurs du chronographe et celui
du compteur des heures appuient sur leurs cœurs respectifs en même temps.
Le ressort N, en fil d'acier recourbé, sollicite le marteau H à s'éloigner du
cœur, suffisamment, pour que celui-ci puisse accomplir sa rotation sans
rencontrer d'obstacle.
Cette position est réglée parle plot excentrique 9.
Deux ressorts de friction sont disposés sur les roues A et B pour limiter la
liberté de ces roues pendant la marche du compteur, pour que l'aiguille ne
subisse pas l'influence du jeu qui existe dans les engrenages.
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