A. Lange & Söhne

An understanding of the RL PLM vs 1915 PLM and RL

 

Hi,

trying to understand the differences on the 3 different watches.

1) RL PLM

This complex system can only function flawlessly if three additional precautions are taken. The first one is a system that blocks the winding process just before the mainspring is fully wound and thus prevents the chain from tearing. In this mechanism, the vertical motion of the chain is used to actuate an intricate system of levers that block the ratchet wheel at the right moment. The second precaution is a mechanism that stops the movement before the mainspring is fully relaxed. This function is assumed by a modified power-reserve wheel that controls a stop lever. After exactly 36 hours, the lever drops into a recess in the wheel. Assisted by a spring, the longer arm of the lever moves into the engagement radius of a specially shaped finger seated on the fourth wheel arbor. The arbor is stopped when the two elements make contact. The seconds hand stays at the 12 o’clock position. Finally, the fusée-and-chain transmission needs a construction to ensure that the transmission does not stop while the watch is being wound. A complex planetary gearing inside the fusée preserves the power flow from the fusée to the movement during the winding phase. The most interesting details such as the chain, the blocking mechanism, and the ratchet wheel over the fusée that incorporates the planetary gearing are visible through apertures in the lavishly decorated three-quarter plate.

 

A further detail illustrates the degree to which the calibre designers pursued their quest for precision: to find the optimised match of the characteristics of the mainspring and of the fusée, the 36-hour working range of the mainspring can be adjusted in the direction of higher or lower torque. This can be done by a service watchmaker with a proprietary Lange tool that engages with a pretensioning ratchet on the mainspring barrel. The setting is locked with a pawl. Located above the three-quarter plate, this mechanism is easily accessible.

The above excerpt is the one from Lange press release. I presume this is a stop works and remontoire system of some kind?

2) RL PLM vs RL

What is the diameter of the balance of RL PLM? The RL is 10.2mm but nothing was mentioned about the RL PLM.

3) RL PLM vs RL

Why is the balance design different with one traditional design and one with compensation weights on the rims ala Patek? I like the ones on the RL. The ones with weights on the rim presumably allows a bigger balance and have a theoretical aerodynamic advantage. My understanding is that a bigger balance is less susceptible to disturbances and hence increases stability in time keeping.

4) RL PLM

Is the balance spring on the RL PLM same as the one used on RL? The one produced inhouse by Lange?

5) 1815 PLM

Is there a stopworks of some kind in the original 1815 PLM like the ones on RL PLM?


thanks