Chronograph Watches Explaining the Movement Mechanism of Chronographs

Chronograph operation surface

As is common throughout the watchmaking industry, the various parts of a chronograph mechanism have specific, unchanging names.

Unfortunately, the prevalence of non-uniform technologies across countries and regions means
The same parts are called by different names.

To avoid confusion, we will use these names to refer to the products used by the manufacturers, in particular Ebauches SA,
Use the individual part names listed in the spare parts catalogues and lists.

There are two main types of chronographs:

a. Crown wheel chronograph
b. Chronograph without a crown wheel

The b chronograph is
A further distinction can be made:

b1. No crown wheel, with swing pinion, chronograph
b2. Chronograph without crown wheel, with friction wheel.

We'll discuss these types separately later.

The Z37 in the figure is
It shows the chronograph mechanism (Valjoux 23 caliber) with its crown wheel and its individual parts designated by numbers.

The given name is both German and Swiss,
It has now been translated into its common English name.

Here is a list of the most important names and numbers.

This is not the shape of the part,
Rather, it has the role of determining the name.

Figure Z38 shows:
Not just parts that are already numbered,
Also shown are some special levers that are only found on chronographs without a crown wheel (Landeron 48 caliber).

They are marked with a star in the following list.

== ...
No. 8000 Central chronograph wheel with heart
No. 8020 Minute counter wheel with heart
No. 8060 Drive wheel
No. 8070 Crown Wheel
No. 8080 Carrying Arm
No. 8100 Spur gear pivot with engaging ring
No. 8139 *Start arm
No. 8140 Start Arm
No. 8180 Zero Setter
No. 8200 Blocking Lever
No. 8219 *Heart Peace Lever
No. 8220 Heart Peace Lever
No. 8270 Mini Counter Wheel Spring
No. 8290 Friction Spring
No. 8320 Carrying Arm Spring
No. 8325 *Spur gear pivot spring
No. 8335 Start Arm Spring
No. 8340 *Zero setting spring
No. 8345 Blocking Lever Spring
No. 8350 *Heart Piece Lever Spring
No. 8355 Starting wheel spring == ...

To be thorough,
The "unique" parts for the split-second chronograph began with 88 pieces,
I'll also put it in a table here.

The Z39 is
Based on the Venus 185 caliber.

The other numbers are
This is the part number listed on the previous page.

Only these names are used,
The same name can be given to levers of very different shapes on wheels.

== ...

No. 8801 Split Second Wheel
No. 8803 Split Second Lever
No. 8805 Roller for split second lever
No. 8820 Split Second Crown Wheel
No. 8821 Split Second Switching Lock
No. 8831 Split Second System Starting Arm
No. 8851 Spring catch for split second system
No. 8860 Split Second System Catch Holder
No. 8870 Split Second Wheel Potential
No. 8880 Transmission Wheel

== ...

Chronograph Dials

It is important to note two systems of dials.

The Z 40 shows the mechanism of the watch.

This is typically located under the dial.
It takes many different forms.

The most important individual parts are named:

I've listed them here in a table along with their numbers.

== ...
250 Time Wheel
401 Scroll
435 piece drawer
445 Spring Adjustment
8600 Clock Number Wheel
8610 Transmission Locker
8620 Accountant Bridge
8651 Outlet Control
8680 hours of heart piece lever
8760 Friction spring for hour chronograph

== ...

The Z41 has a dial,
There is also a calendar mechanism.

There are also many calendar mechanisms, including those with hands and disks.

The calendar display is not related to the chronograph mechanism.
These can be seen clearly from the wrist chronograph.
Only the most important parts are listed here.

== ...

856 Date Hand
2556 Date Star Driving Wheel
2557 Date Star Wheel
2560 Daystar Drive Wheel
2561 Date calendar disc with star wheel
2562 Moon calendar disc with star wheel
2567 Date setting device
2568 Moon Setting Device

== ...

Chronograph Technology: Part 2

How it works: Crown wheel chronograph movement

To explain the function of the chronograph,
We will step through the order in which the functions occur when manually activated by one or two push buttons.

The mechanism of the chronograph is
Since it is almost always attached to the background of the action,
When the case is open,
You will be able to see clearly.

In order to make the explanation easier to understand,
Only the necessary instructions for the normal functioning of the watch are provided.

The parts needed for the minute counter are also omitted here.

For information on the various mechanisms for counting minutes, see
This will be explained in more detail elsewhere.

The chronograph function control element with the crown wheel is
Crown Wheel F,
The lower part is
A locking wheel with triangular teeth,
The top has a vertical point shaped like a pie (or column).

These points are:
Transmission arm W, heart piece wheel N,
and actuate blocking lever B,
Crown Wheel F is
The crown wheel lever hook E of the crown wheel lever D rotates clockwise to lock the lower locking wheel.
Press one tooth and press button G.

The position remains the same until the next switching procedure is performed.
Crown wheel lever locking spring R
Maintained by

In the Z 42,
The opening moment is shown.

The driving wheel S is
It is held firmly in place by a second wheel pivot at the top of the bridge.
It rotates constantly with a clockwork wheel.

The transmission wheel is
movably mounted within the transport arm W;
In the moment shown,
The large seconds hand of the dial is attached to the central chronograph wheel C,
The transport arm W is
It is attached to an eccentric screw T which forms a straight line with the mounts of the driving wheel S and the transmission wheel K.

The contact depth with the transmission wheel is
Eccentric screw In the position of the crown wheel shown in the figure,
Heart Piece Wheel N is Heart Piece Wheel Spring N'
and against the pressure of the blocking lever B,
The blocking lever is actuated by a point (drawn in black) against the spring.

The end W' of the transmission arm is
Between two points,
Contact between the transmission wheel K and the central chronograph wheel C can be caused.

The point that the end W' can reach is determined by the eccentric screw.
It is determined by the depth of contact between the transmission wheel K and the central chronograph wheel C.

In very general terms,
These three wheels must always have a very fine gearing with triangular teeth.

This shape is designed to prevent sudden contact between the transmission wheel K and the central chronograph wheel C during starting.
This is to ensure that the seconds hand on the dial moves as smoothly as possible.
They fit together smoothly without pushing against each other.

In many cases,
The central chronograph wheel is
The other two wheels
It has twice the fineness.

The finer the gearing, the
The wheels will be less likely to put pressure on each other.

If there is more pressure,
Disturbances appear in the movement of the large seconds hand on the dial.

When push button G is pressed again (Z43),
By moving the crown lever D and the crown lever hook,
Crown wheel F moves it one more tooth away.

During this process,
A point is pressed under the end W' of the transmission arm,
Lift the transmission wheel K so that it does not come into contact with the central chronograph gear C.

It is easy to see that the transmission arm W moves away from the eccentric screw U.
The transmission wheel K remains in contact with the drive wheel S.

at the same time,
Blocking lever B moves away from that point.
To hold the central chronograph momentary position firmly by the shielding lever spring B',
Wheel C is included.

In this process:
The chronograph hands also stop on the dial.

This moment is shown in Z 43.

Repeatedly pressing the push button G shown in Z44
A zero setting of the chronograph hand C or the central chronograph wheel C occurs.

Crown wheel F again moves one tooth further away,
When the end point N of the heart piece lever is released,
The heart piece lever spring N' presses the heart piece lever against the second heart piece H of the central chronograph wheel.

The second form of heart piece is,
The central chronograph wheel instantly and precisely takes position.

On the dial, set the chronograph hand (or the minute counter, if there is one) to the number 0 or 12 in this process.

For this to be done,
The blocking lever B is first lifted to disengage the central chronograph wheel and pass over the crown wheel.

Now, as shown in Z 43,
To be held in place,
The start, stop and zero cycle is complete.

Press the button again to
The start function will start again.

The first wristwatches were the result of a redesign of the pocket watch.
The push button and the wraparound crown are usually located in the same place.
i.e. strap direction (compare #1 and #3)
Or located on the 6 o'clock to 12 o'clock extension line.

It was soon discovered that operating the chronograph with the push button on the crown was insufficient due to wear on the watch.

In the 1920s,
When watches became mass-produced,
Remove the rolled crown from the strap.
Move it to the 90 degree position.
I was able to wind and set the watch without having to take it off my wrist.

There have been very similar changes to wrist chronographs.

The push button is
Was it left in the Crown?
Although it was rare, both of them were almost always moved upwards,
Two controls were next to each case.

To operate such a wrist chronograph,
You have to be used to it.
I was trying to remedy this situation.

The operation of a typical pocket watch was "easy on the hand."

I always used my thumb to operate the push button on the Lépine model.

With the new wrist chronograph,
I had to hold this down with my index finger and provide counter pressure with my thumb.

The dial surface was often covered by hand,
This kind of activity was not very elegant.

The assistance of Marcel Depraz of Le Rue, Switzerland, was enlisted.
And in 1932,
He came up with a design (patent no. 157096) in which the winding crown 14 and the push button 9 were at right angles to each other.
We obtained the patent rights for this product.

Figures 1 and 2 of the Z 45
Represents the arrangement of visible fixed wheel combinations.

As shown in Figure 1,
Starting arm slide 4 is
Attached to the end of the actuation arm 10,
An additional lever 9 attached to point 7 secures it in place at pin 7 in the direction of the arrow.

The position of the five points of the crown wheel 2 is determined or maintained by the crown wheel spring 3.

Also shown are the winding wheel 15 and the lock wheel 16 for a normal mainspring.

At point 14 is the winding stem.

FIG. 2 shows the crown wheel 10 omitted.
At the point where the lever 9' is attached directly to the plate 1 by the screw 8',
An improvement on the design in Figure 1 is shown.

This design is
It was used in wrist chronographs,
It comes from the crown, which is usually made up of three strands.
It had six push buttons.

This is operated with the thumb,
The index finger compensated for more than 12 counter pressure.

In this operation method,
The dial was left uncovered.

Such wrist chronographs are
(Compare #31)
It was on the market for a while,
Other designs include
Especially L.Breitling
It did not become popular because the advantages of the "two-button chronograph" were being promoted more.

Influenced by fashion,
In the 1920s, they started making men's watches.
In the early 1930s, there were many attempts to create the chronograph as a shaped movement.

Some of these experiments resulted in patents.

Henry Jacquot Guillot of Neuchâtel
In 1933, he received a patent (number 161093) for a "shaped movement chronograph" with a minute counter.

His design features include:
dial (Z 46, Fig. 2) and a separate second hand
With a separate seconds hand marked from 1 to 10 seconds
"Digital" was the second display.

The mechanics of his design are shown in Figure 1.

The entire mechanism is located under the dial.

The winding stem 20 is located in the middle of the movement.

The lever 4 actuates the crown wheel 2 when pulled towards the winding stem 20.

The drive wheel 7 is not mounted on the second axle as is customary;
Separately mounted,
It is driven by the third wheel.

It drives the chronograph wheel 9 via a transmission wheel 8.

The chronograph wheel 9 is fitted with a disc 10 with the numbers 0 ... 5 ... 10 ... 15 ... 20.

The second hand engages the disk 11 on the pivot to which it is attached,
It rotates once every 10 seconds.

The dial usually has
In the counterclockwise direction as a result of transmission
The watch is numbered 0 to 9, but the patent drawings do not show the lever for setting the zero and the wheel for the minute counter.
Naturally, these were not present in the watches made later either (see #2 and #3).

Even if it wasn't the turn of the century,
Developments were taking place in the watch industry.

Georg Friedrich Rothkopf
In the 70s,
He found a way to produce reliable, inexpensive clocks, which he called Roscoff clocks.

It's a train of wheels
One wheel less, no jewel,
The steel parts are not shrink fitted.
The plates and wheels were not gold plated.

after that,
After the patent expires,
These watches based on these principles have been copied by many manufacturers.
has been launched into the market.

When wristwatches became a popular topic,
The Rothkopf system was applied in a similar way.

In 1933,
Venus SA, an industrial ébauche from Moutier, Switzerland, patented a chronograph with counters for a Rothkopf movement.

Z47 shows patent drawing (No. 159450).

The power of the balance (not shown) is
It comes from barrel 1 through the pinion of the first wheel 6 which contacts the pinion of wheel 7'.

This drives the pinion of escape wheel 8,
Another wheel 7 is wheel 7'
It is securely connected to the arbor.

The wheels 7,7 'are
Mounted below the plate and above the transfer arm 16,
That point has a turning point of point 17.

The one-button mechanism has three functions:
Z47 shows where to start.

The teeth of wheel 7 mesh with the central chronograph wheel 11,
The heart piece 12 and finger 19 are attached on top of it.

Every turn,
The finger 19 contacts the star rocker wheel 18 which drives the minute counter wheel 13 .

The next push of button 10
The crown wheel 9 moves one tooth further away,
As a result, the nose of the transmission arm is dotted on the chronograph wheel (shown in black)
When lifted by
Wheel 7 no longer makes contact with the central chronograph wheel 11.

The chronograph hands remain stationary,
Press button 10 again to
The transmission arm 16 is held in that position,
The heart piece wheel 15 slides from a point on the crown wheel 9.

This means that both the central chronograph wheel and the minute counter wheel are reset to zero.

The actual needle is
Driven by wheel 2,
Wheel 2 rides on barrel 1 with light friction.

The minute hand is
It is attached to a loose quadrant tube 3,
The fourth wheel 4 is a conversion wheel,
The hour wheel 5 of the fourth barrel 3 loosens again.