Natural escapement for horological movement and horological movement comprising such an escapement

A natural escapement for horological movement carrying out a succession of operating cycles each including a first and of a second alternation of a balance that comprises a balance wheel on an arbor of which is adjusted a balance plate, the natural escapement comprising:

• a first escape wheel set having a first toothing, the first escape wheel set, arranged to be driven by a wheel set of a train of the horological movement, driving in turn a second escape wheel set having a second toothing, the first and second escape wheel sets forming a kinematic chain arranged to cooperate with an anchor capable of pivoting about an anchor-staff, the balance plate carrying a second impulse pallet-stone through which the balance plate receives a direct and tangential driving impulse from the first escape wheel set during the first alternation, and a first impulse pallet-stone through which the balance plate receives a direct and tangential driving impulse from the second escape wheel set during the second alternation, the balance plate also carrying a first safety tooth arranged to cooperate with the first toothing or the second toothing so as to lock the first or the escape wheel set when the first or second escape wheel set escapes to the second impulse pallet-stone or to the first impulse pallet-stone, respectively.