The present invention relates to an
escapement mechanism (1) arranged to supply mechanical impulses from a driving source to an oscillating
regulator (2) of a
clock movement via a
leaf spring (6) operating in buckling around an inflection point (I). The mechanism comprises a winding rocker (10), a release rocker (12), and a locking rocker (14). The
leaf spring (6), in normal operation, is capable of accumulating energy from the driving source transmitted by winding elements (40a, 40b) during a winding phase, remaining in a wound state during a locking phase, and then releasing the accumulated energy to the oscillating
regulator (2) during a pulse phase preceded by a release phase. The locking rocker (14) comprises two locking arms (56a, 56b), each equipped with a locking member. (58a, 58b) arranged to cooperate with a locking member (46a,46b) respective complement of the cocking lever (10) to block said cocking lever (10) during the locking phase. Each locking arm (56a, 56b) of said locking rocker (14) has, at its free end, an inclined plane (66a, 66b) configured to cooperate with the starting inclined plane (61a, 61b) provided correspondingly on the arming rocker (10) during a self-start phase during which an activation of the drive source causes the arming rocker (10) to move, the free passage of which is permitted by the locking rocker (14) which was previously positioned by the
detent rocker (12) under the influence of the oscillating
regulator (2) at rest, said angular movement of the arming rocker causing a displacement of the locking rocker (14) by pushing one of the starting inclined planes (61a, 61b) on the corresponding inclined plane (66a, 66b) of the locking rocker (10),so that said locking lever (14) rotates the oscillating regulator (2) out of the lifting angle, the
escapement mechanism (1) positioning itself in a position corresponding to a locking phase ready to be followed by an unlocking phase and a pulse phase of normal operation.