Echappement naturel...

... a Detached Escapement, thought off by Abraham Louis Breguet. Its main features are that this escapement runs without any oil, the balance swings free to its greatest possible extent, the impulse is produced close to the dead point, two opposite running escape wheels are to be found, two escape wheels exist, that are contra rotating and are compulsively coupled via gearing. A disadvantage are the relatively high rates that want to speeded up during the impulse phase - the inevitable back-lash in the teeth of the coupling wheels and the risen friction (of the pivots) due to the additional escape wheel.