ENTRY

In theSwiss lever escapement, the entry refers to the shorter of the two arms of thePallets (lever) and thePallet stone it carries. It is the entry pallet stone that a tooth of theEscape wheel meets first, depending on the wheel’s direction of rotation; the second pallet stone, carried by the longer arm, is called the exit. At both entry and exit, the pallet stone — a small prism ofRuby / Jewel — first receives the tooth on its resting plane (rest phase), then on itsImpulse plane (phase during which energy is transmitted to the lever). The geometry, inclination, andRegulation / Adjustment of the entry and exit pallet stones determine the proper functioning of the Escapement: rest, Unlocking (drop angle), Drop (impact) and impulse must be balanced between the two. The entry/exit distinction is therefore fundamental to describing and adjusting the escapement, the component that counts and distributes energy to the oscillator, at the heart of the watch’s precision.