Mechanical regulator for horology comprising a semi-detached self-starting escapement with low lift angle

A mechanical regulator for horology comprising an escapement collaborating with an oscillator provided with an inertial element oscillating in an oscillation plane by virtue of a restoring force element;

• the escapement comprising a pin rigidly connected to the inertial element, an anchor and an escape wheel comprising a plurality of teeth;
• the anchor comprising a fork configured to collaborate with the pin, an entry pallet-stone and an exit pallet-stone, each of the pallet-stones being configured to collaborate with teeth of the escape wheel;
• the escapement being configured such that, during an unlocking phase, the pin pushes the fork in order to release the escape wheel from one of the pallet-stones and, during an impulse phase, the fork pushes the pin in order to transmit to the inertial element a torque of the escape wheel that is in contact with one of the pallet-stones;
• wherein the regulator is configured such that the unlocking phase is preceded by a first frictional locking phase, the first frictional locking phase being preceded by a first free-oscillation phase, and the impulse phase is followed by a second frictional locking phase, the second frictional locking phase being followed by a second free-oscillation phase;
• wherein during each of the free-oscillation phases, the inertial element oscillates freely with no contact between the pin and the fork;
• wherein during the first frictional locking phase and the second frictional locking phase, the pin is in contact with the fork so as to push the fork, and one of the teeth of the escape wheel is in rubbing contact with one of the pallet-stones;
• wherein each pallet-stone is provided with an unlocking face that comes into contact with a tooth during the unlocking phase, and with an impulse face that comes into contact with said one of the teeth during the impulse phase;
• wherein each of the pallet-stones is further provided with a pallet frictional locking face configured to come into rubbing contact with said one of the teeth, during the first and second frictional locking phase;
• and
• wherein a lift angle, corresponding to the portion of oscillation of the inertial element between the start of the unlocking phase and the end of the impulse phase, is at most 6°;
• wherein the escapement is configured to allow the pin in contact with the fork to push the fork when the angular position of the inertial element with respect to a center line is smaller than a frictional locking half-angle and greater than lift half-angle;
• wherein the center line is the angular position of the inertial element at equilibrium without the escapement;
• and
• wherein the lift half-angle is the angle between the center line and the angular position the of inertial element at the end of the impulse phase;
• and
• wherein the frictional locking angle corresponds to the portion of oscillation from the angular position of the inertial element at the start of the first frictional locking phase to the angular position at the end of the second frictional locking phase.