Patent ID: 8529122

Claim:
A Swiss lever escapement comprising: an escape wheel having teeth, and a lever, wherein the lever comprises (i) an entry pallet and an exit pallet that engage alternately with the teeth of the escape wheel, and (ii) a fork that engages periodically with an impulse pin on a roller mounted on the staff of a regulator balance wheel, wherein the relative width Lpl of each of said pallets, expressed as a percentage of the sum of the lengths of arc of one of said teeth and one of said pallets, measured at the circumference of the escape wheel, is: Lpl = ( Ls Ls + d ⁢ ⁢ or ⁢ ⁢ Le Le + d ) ≤ 60 ⁢ % where Ls and Le are the lengths of arc of the exit pallet and entry pallet, respectively, and d is the length of arc of one escape wheel tooth.