A timepiece escapement mechanism including a resonator and an escape wheel arranged to cooperate with this resonator directly or indirectly through a stopper forming part of this escapement mechanism, this escape wheel including a succession of tracks carrying magnetic or electrostatic field potential ramps arranged to cooperate with the resonator or respectively with the stopper, this escapement mechanism comprising a non-return device arranged to oppose the recoil of the escape wheel, and the stopper cooperates, on the one hand, with a plate forming part of the resonator and, on the other, with these magnetic or electrostatic field potential ramps by at least one pole shoe forming part of the stopper and arranged to move in the field corresponding to the magnetic or electrostatic field potential ramps.