Since their release, the Rolex watch Cosmograph Daytona models were run by three different systems: the Valjoux 72 calibre (which coded in the next versions: 72B or 722, 722-1 and 727), the Rolex watch 4030 movement (in line with the Zenith El Primero) and also the current in-house Rolex watch 4130. These 3 systems could be taken to illustrate the mechanical chronograph’s development in the ‘60s to the present days.
Let’s start with trustworthy Valjoux manual winding chronograph, that was outfitted having a column wheel as well as an horizontal clutch (the coupling yoke): probably the most logical option for a wrist watch producer in early ‘60s. In 1969, the Swiss watch industry released itself into the development of a computerized chronograph. The match was won by Zenith, which launched the very first integrated automatic chronograph running in a high frequency of 36.000 shake each hour: the El Primero watch.
In 1988, (when Zenith had finally restarted at full pace producing the calibre, which stopped for quite some time throughout the mechanical watch crisis), Rolex watch fitted its new Cosmography Daytona pieces using the El Primero mechanism. However, this movement was heavily modified and re-named Quality 4030 (initially Rolex watch declined even going to communicate the Zenith derivation). Even though the 4030 calibre was outfitted having a column wheel as well as a horizontal clutch, the real novelty was the development of the automated winding system: the perpetual mechanism. The El Primero self-winding movement powered the Daytona models for 12 years, before the 2000 breakthrough year: the launch from the modern manufacture 4130 calibre. A brand new generation of chronographs was created. This mechanism, completely in-built by Rolex watch, featured a vertical clutch i465 black and it is design was analyzed to maximise the development industrialization systems and simplify the manual procedures of watch set up. Unquestionably, it marked the start of a brand new mechanical chronograph era.
The calibre Valjoux 72B replaces the 72A
Since 1966, the Valjoux 72B mechanism completely changed the ‘based’ Valjoux 72A movement. This movement is different from the prior version by presenting the Rolex watch Microstella adjustable-inertia balance wheel: a set of screws situated around the rim from the balance wheel allows the inertia adjustment by focusing on the regularity with no need of a regulator, which featured within the former 72A calibre movement. The flat hairspring was changed with a better carrying out Breguet over coil hairspring, which will keep its concentric poise throughout its expansion and contraction (the so-known as ‘breath’ from the coiled spring). The 2 screws displayed within the picture are members of the adjustable-inertia system: notice among the Microstella screws around the left (each pair is positioned in the far finishes from the balance wheel), along with a thicker controlling screw around the right contrarily, another ones are fixed.
The 72b calibre can also be called the 722. A 13 ligne design (30 millimetres diameter) managing a frequency of 18.000 shake each hour. The chronograph system relies on a column wheel outfitted having a yoke coupling system. The axis from the Rolex watch Microstella controlling screw balance wheel remains safe and secure from eventual shocks with a Kif shock absorber unit, which frequently shows the clover-formed Flector version (as proven within the inset). The actions show different types of adornments: the calibre highlighted here sports mirror-shine screws and perlage finished bridges. Another distinguishing feature of the typology of actions may be the screwed setting lever: to be able to disengage the winding crown, a screw placed near to it should be loose. This component will later be changed with a pusher setting lever.
The calibre Valjoux 722
You will find no substantial variations between your 72B and also the 722 Valjoux quality actions. However, today small versions between your systems may consequently be observed throughout the maintenance procedures gone through the actions through the years. According to the chronograph part, the standard mechanism is outfitted having a coupling system sporting a driving wheel (as proven around the left) along with a setting wheel (in the center).
The driving wheel, being integral using the second hands, is definitely moving and also engaged using the setting wheel, pivoted around the coupling yoke. By initiating the chronograph start button, the yoke drives the setting wheel (as proven within the inset) which engages the chronograph center wheel (around the right), offering energy in the driving wheel (around the left) towards the center wheel: the chronograph hands then begins to maneuver the dial. The sudden engagement between your setting wheel and also the chronograph center wheel may cause the 2nd hands to jump slightly forwards or backwards when triggered. Spot the ‘Swiss Made Fabr.Suisse’ inscription.
Among the elements we’d define as ‘stylistic’, and which differentiates the 722 mechanism from the 722-1 successor, may be the positioning from the ‘Rolex Genève’ inscription around the plate seen in the dial side: a detail which may be better appreciated by evaluating the enlarged photographs we’ll meet within the following pages. As pointed out above, you will find no variations between your 722 and also the 72B actions. Rolex watch itself used the 2 variations indifferently, even around the technical documentations from the calibres. Small enhancements were constantly created by the Swiss watch manufacturer, despite the fact that today you will find no known documentations. For instance, the alternative from the anti-shock spring which protected the total amount, with another of identical size, same functions but more contemporary. Sometimes, these technical choices may have been made following a new releases created by Rolex’s providers.
The calibre Valjoux 722-1
In 1967, the Daytona watch was run by the Valjoux-based 722-1 mechanism. Many actions of the generation featured a guard spring which protected the total amount hairspring. This spring includes a metal sheet (as proven within the picture) which prevents the hairspring from sliding within the stud supporter throughout an eventual shock. The alteration had recently been introduced within the 722, but it wasn’t always applied. Therefore, today, many actions aren’t outfitted with this particular safeguarding spring, because despite its advantages this element also triggered functional problems. The 722-1 quality is shown by Rolex watch like a Valjoux 72A-based mechanism: both dimensions (30 millimeter diameter and 6,95 thickness) along with the frequency (18.000 beats each hour) are identical.
Another modification created by the 722-1 calibre may be the hour recorder conveyor. This element (within the picture above) connects the chronograph hour recorder wheel (that is situated around the dial in the 6 o’clock position) towards the barrel, that it’s directly triggered at the beginning of the chronograph. The brand new conveyor pivots on the flat eccentric screw and it is pressed for the chronograph hour wheel by way of a wing-formed spring (around the left), which replaces the greater simply-formed one featured through the 722 calibre. The eccentric screw which the conveyor rotates (as proven within the picture within the right corner below) supplies a perfect regulating its position along with a better engagement from the hour wheel. Spot the different position from the ‘Rolex Genève’ inscription engraved around the plate.