Waiting is a torment, especially when there is an exact waiting target. However, don’t worry, because the waiting has come to an end! Patek Philippe launches a new self-developed manual winding movement and horizontal clutch, a two-second chronograph with perpetual calendar ref. 5204P, adding a new member to the chronograph series.
First, let’s take a brief look at the source of power for the 5204P. After the introduction of the CHR 29-535Q movement, the CHR 27-70 was retired. Compared with the original 27-70, the 29-535 movement is 2 mm in diameter and 32 mm in length, but thinner. The Gyromax® balance has an oscillation frequency of 4 Hz, compared to 2.5 Hz. In addition, the minute display of the chronograph is now equipped with a jump function.
The two-second chronograph has two seconds hands, each of which has a different purpose. Under normal operating conditions, the two pointers remain synchronized. When the tracing function is enabled, the chronograph hand will stop immediately to record the interval time. After release, the chronograph hand will resynchronize with the chronograph hand. There is a mechanical game between these two pointers, which we call ‘chasing game’. Playing this game requires a heart cam, a follower fork, and a ruby roller that rotates along the edge of the heart cam. With two innovative technologies, Patek Philippe has incorporated these important functions in the new CHR 29-535Q movement.
Here comes the interesting thing. The old octopus gear is gone. What is an octopus gear? Why was it replaced? The octopus-shaped gear is a part of the separating device, which is used to completely separate the two chronograph hands, thereby reducing drag and friction during the follow-up cam’s rotation along the heart-shaped cam. This problem is often encountered with the two-second chronograph without a separate device when the tracing function is activated. Changing the ‘octopus-shaped gear’ is very simple, but the octopus-shaped gear itself is very complicated and the adjustment work of the watchmaker is also very difficult.
The gooseneck separation system is described next. The previous separation system had eight wheel arms, and each had to be individually adjusted, while the gooseneck-shaped separation system had only one wheel arm and spring. This separation system is actually a horizontal clutch device. The release gear ‘A’ rotates in synchronization with the chronograph hand. After the chronograph hand is activated, everything starts to work in an orderly manner. First, the chronograph hand will stop immediately under the action of the two clamp arms ‘B’, at the same time, the split fork lever ‘C’ meshes with the split gear ‘A’ and pushes it forward about 30 degrees Loosen the wheel arm ‘D’ of the follower cam with a protruding thin needle. In this way, the separation of the chronograph hands and the chronograph hands that are still rotating is completed. It is essential that these two functions are activated at the same time, otherwise the chase timing function will be inaccurate.
After the chase chronograph function, the chase chronograph hands must be completely consistent with the chronograph hands again. First, the separation system must stop functioning. The release gear ‘A’ releases the wheel arm ‘B’ of the follower cam, and the two clamp arms ‘D’ release the chronograph hand. Secondly, the follower cam wheel arm must return the chronograph hand to the middle position, as shown at ‘E’.
Returning the chronograph hand to perfect unification (re-adjustment) with the chronograph hand has always been a tricky issue. The relative proportions of the heart cam, follower cam, and ruby roller should be as small as possible, especially when included inside the watch. Therefore, the chronograph hand is always narrower than the chronograph hand to cover up the deviation in the adjustment.
In order to eliminate any possible adjustment deviation, Patek Philippe has completely redesigned the double-second heart-shaped cam and follower cam. The wheel arm of the heart cam is wider than before, and the shape of the base of the follower cam is completely different from the previous one, so that the wheel arm can be placed. Of course, the new design still uses a ruby roller to track the heart-shaped cam to the center point, but unlike the previous, which is completely responsible for adjusting the chronograph hands, the sides of the roller rely on the wheel arm of the heart-shaped cam. This ensures perfect adjustments every time.
Zeroing the hands is also a major problem in adjusting. This is to ensure that all functions of the chronograph can be performed accurately. The hands must start from the zero scale. It is important for watchmakers and users to return the hands to the zero scale after they have functioned. Today we have found a solution. We call them ‘hammers’, but they look more like two feet, and together with the connected heart-shaped cam, they reset the chronograph to zero.
Both hammers have traditionally been made from a single piece of steel. There is always a problem with this construction method. If one of the hammers is heavy, the other hammer will be too light, which will make it impossible to adjust to the zero mark. Patek Philippe’s solution was to create connected hammers that kept them synchronized from start to finish. This is like the legs of a human being. They are combined at the hips and work in synchronization until they hit uneven surfaces, such as steps. In that case, they will move independently and adjust their movements accordingly.
It is not easy to produce a new and innovative watch with loyalty to the brand heritage. After years of research and development, Patek Philippe launched the 5204P as a model work. Its appearance is restrained and low-key, and the innovative mechanical movement is hidden in the platinum case.