Incabloc is a common shock protection system used in mechanical watches, recognizable due to its lyre-shaped spring.
Incabloc was developed and trademarked in 1933 by Portescap. It prevents a watch balance staff from breaking by allowing it to move slightly, both laterally and vertically, using a spring-mounted jewel setting. Incabloc is easy to recognize due to the golden shield- or lyre-shaped spring clip around a ruby at the top of the balance. This is hinged, allowing the shock absorber to be lifted in place so the cap stone and the rest of the anti-shock pivot can be removed.
Incabloc was developed in 1933 and introduced in its current form in 1938. It remains one of the most popular shock protection methods.
Incabloc is also the name of the company that produces these shock absorption systems, a successor to Portescap which divested itself of Incabloc assets between 1988 and 2003.
Incabloc makes both removable and hinged anti-shock mechanisms:
- Incabloc Double Cone
- Incabloc Single Cone (for thinner watches)