The escapement includes an escape wheel set (1), a balance roller (3) carrying an impulse pin (4) and a first impulse pallet stone (5). It further includes a pallet assembly (8) fitted with a second impulse pallet stone (11) and first and second locking pallet stone (12, 13). The wheel set (1) includes at least one escape wheel fitted with teeth (6) that mesh directly with the teeth (20) of the first wheel of a gear train (2), the teeth (6) of the wheel (1) cooperating with the impulse pallet stones and locking pallet stones.