Lever force F at a point "A" located by the coordinate vector r on the bar. The lever then exerts an output force F at the point "B" located by r. The rotation of the lever about the fulcrum "P" is defined by the rotation angle "θ" in radians. Let the coordinate vector of the point "P" that defines the fulcrum be r, and introduce the lengths which are the distances from the fulcrum to the input point "A" and to the output point "B", respectively. Now introduce the unit vectors e and e from the fulcrum to the point "A"
Lever escapement the exit pallet, which transfers a clockwise impulse to the balance wheel's impulse pin via the lever fork, while pushing the lever up against the left banking pin. The escape wheel drops again until the entrance tooth locks on the entrance pallet now being held in place by the left banking pin via the lever. The balance wheel continues clockwise, again free from interference until it is pulled back by the balance spring to the center position. The cycle then starts again. Each back and forth movement of the balance wheel from and back to its center position corresponds to