Escapement with escape wheel with field ramps and non-return

A timepiece escapement mechanism comprising:

• at least one resonator and at least one escape wheel arranged to cooperate with said resonator through a stopper forming part of said escapement mechanism, wherein said escape wheel comprises a succession of tracks carrying magnetic or electrostatic field potential ramps, and said ramps are arranged to cooperate with said resonator or respectively with said stopper;
• and
• at least one non-return device arranged to oppose a return of said escape wheel,
• wherein said stopper cooperates with a plate forming part of said resonator and with the magnetic or electrostatic field potential ramps by at least one pole shoe forming part of said stopper and arranged to move in a field corresponding to said magnetic or electrostatic field potential ramps, and
• wherein each ramp of the magnetic or electrostatic field potential ramps on a track of said succession of tracks is extended by a magnetic or electrostatic field barrier,
• wherein, immediately following each ramp, said barrier has a first zone of rapid potential growth, a gradient of which is higher than a maximum gradient of each ramp,
• wherein said first zone is followed by a second zone of maximum potential, where a concavity of a potential curve is inverted in relation to said first zone, and said second zone is immediately followed by a third zone of decline in potential where the concavity of the potential curve is inverted in relation to said second zone and said third zone ends at a fourth zone of minimum potential.