Dual Ulysse Escapement

The newest escapement is the dual Ulysse escapement invented by Dr. Ludwig Oechslin in 2004 (Ludwig Oechslin 2004; Timebooth 2011). Dr. Oechslin received his Ph.D. in 1983 and his master watchmaker title in the subsequent year. Presently, he is the curator of the Musée International d’Horlogerie, in La Chauxde- Fonds, Switzerland. The dual Ulysse escapement is perhaps inspired by the independent double wheel escapement invented in 1800s. Like many old designs, the independent double wheel escapement was abandoned because of its complexity and lack of reliability. The dual Ulysse escapement consists of a balance wheel with a plate and a hairspring, a triangle-shape lever with two horns and two recesses and two escape wheels. There are also two pins used to limit the swing of the lever. Its most notable feature is the two escape wheels with specially designed tooth profile. Escape wheel 1 is driven by the gear train and meshes with Escape wheel 2. The two escape wheels also interlock with each other under the control of the lever. The lever receives pulses generated alternately by the first and the second escape wheels and transmits these pulses to the plate on the balance wheel, driving the balance wheel to swing. It also locks the first and the second escape wheels alternately. Thus, the lever fulfills a dual function: transmits the force to the balance wheel and locks the escape wheels alternately.

Demonstration Video

The safety phase that occurs before the first shock. Note that the lever is in contact to both escape wheels creating the lock. At the same time, the balance wheel is reaching its limit position and is about to swing clockwise. The unlocking phase, at which the first shock occurs when the plate on the balance wheel contacts the upper left horn of the lever causing it pivoting counter clockwise. This releases the two escape wheels. The second and the third shocks occur almost at the same time. First, Escape wheel 1 contacts the first recess of the lever causing the second shock. Then, the upper right horn of the lever catches the plate of the balance wheel causing the third shock. At this time, the lever is in contact to both escape wheels creating the lock. Another safety phase occurs, in which the balance wheel continues to swing, while the lever and the two escape wheels remain locked.