Jaeger-LeCoultre

PeaceFrog
191

• Show profile
• Show other posts

JLC's Extreme series: Shock Absorption

If you aren't already aware, JLC incorporates a nonpareil shock-absorption system in some of its Extreme series watches. The Extreme World Chronograph, the Extreme World Alarm and the Extreme Tourbillon include this feature. These watches are actually constructed using two cases, an inner case made of tiatnium, which houses the movement, pushers and crystal and an outer case comprising the lugs, the bezel and the caseback. The outer case is made of stainless steel, titanium, platinum or rose gold, depending on the model.

JLC states that the direction of a shock which is most dangerous to a mechanical movement is shown in the photo below as "Z", and that the Extreme Series' shock absorption system can soak up 50% of this force before is gets to the movement, due to the springs and air. Further, JLC states that titanium was used not just for aesthetic reasons, but due to its lower density and overall weight compared to a heavier metal, since the force imparted to the movement is equal to mass multiplied by acceleration [ F=M*A ].



The inner case rides on a cushion, basically a sealed chamber filled with 4 springs and air. The pictures below, from a prior post on this website, with credit to the original poster, shows how this arrangement works.





So, how does this work in the real world?

This photo shows the watch as it sits with no force being exerted on the inner case, hence, no deflection of the inner case inside the outer case.




This photo shows the watch with force being exerted on the crystal with my thumbs. The amount of force I used is probably equal to the maximum amount of force an average person could exert using both their pinky fingers pressing directly down on the crystal. I certainly could have pushed harder using my thumbs, but was reluctant to press any harder on the crystal for fear of damaging it. When the force of my thumbs is released, the inner case moves back to it's original position, not with an instant snap, but more like how a car's front end rebounds after jumping off of it's front bumper. The total possible range of motion is probably 3-4 mm, with maybe 2.5mm shown here.



I haven't seen this topic addressed before, so I hope this post does a good job of explaining it to anyone who is interested. Knowing this, I always do a good job of rinsing the watch, especially after submersion in salt water, because obviously the salt water will flow in between the two cases to some extent.