The Reason
An example of an industrially executed cam driven chronograph.
The name Valjoux comes from "Vallée de Joux", a mountain region of Switzerland associated with chronograph design and construction. Valjoux was founded in the "Valley de Joux" in the mid-to-late part of the 19th century. When the watch business collapsed in the latter half of the 20th century, Venus chronograph manufacturer failed and Valjoux bought them, thereby Valjoux attained the rights to the new cam/lever and switch of Cal 188 that Venus had made. This was rebranded as Val 7730 and sold for a year or two until the Valjoux redesign of this movement was made - the 7733.
View fullsize
The index regulating system sits above the balance
View fullsize
Vertical pusher lever
View fullsize
Cam assembly, replacing the pillar wheel.
View fullsize
Jumper spring. Indexing the minute recorder wheel
View fullsize
Chronograph wheels. Triangular profile for ease of meshing when the chronograph is activated.
View fullsize
Screws & Eccentrics. The first screw holds a wire spring in place.
View fullsize
Under dial. Showing the calendar mechanism.
View fullsize
Calibre. Found under the balance wheel. The -R- symbol in its shield always signifies Valjoux, today owned by ETA.
View fullsize
Chronograph seconds wheel removed from the image.
View fullsize
Cam lever top view
View fullsize
Cam lever. View from underneath, the polished piece to the left is riveted in place
View fullsize
Minute recorder wheel
View fullsize
Chronograph wheel, upon which the sweep seconds chronograph hand sits
View fullsize
Friction spring. To add tension to the chronograph wheel to take up any slack..
View fullsize
Brake. For the chronograph wheel which touches this wheel when the watch is -stopped- to prevent it moving instantly.
View fullsize
Chronograph wheel bridge. Which holds the pivoting axes for the chronograph wheel and the minute recorder. Only one is jewelled, the other is bushed.
View fullsize
Underside of balance
View fullsize
Stud and index. More recently the balance springs are differently held in place, but for several hundred years they were pinned as shown.
View fullsize
Intermediate wheel. Pushed by the finger piece on the chronograph wheel intern turning the minute recorder wheel carrying the minute recorder hand.
View fullsize
Intermediate wheel. Underside, the small bridge holding the wheel in place is formed by a stamping process, crude in finish but exact in precision.
View fullsize
Partially dismantled
View fullsize
Principle operating lever
View fullsize
Chrono-plate. Covering the ratchet wheel granting the additional chronograph components surface area.
View fullsize
Chrono-plate removed
View fullsize
Under dial, calendar removed. View showing the mainplate dial side with the calendar removed.
View fullsize
Calendar driving wheel
View fullsize
Calendar ring
View fullsize
Calendar bridge. Which holds all the calendar parts in place.
View fullsize
Hour wheel
View fullsize
Coupling clutch