Piano escapement action

摘要

An escapement action for a piano includes a hammershank having a first end mounted to pivot relative to the piano and a second end carrying a hammer to strike a tensioned string of the piano, with a knuckle disposed therealong between the first and second ends. A repetition support bearing against a key of the piano is mounted to pivot relative to the piano in response to depression of the key. A jack has a first portion extending from a pivot connection with the repetition support and defines a jack surface disposed for engagement with a knuckle surface, the jack arranged for escape of the jack surface from engagement with the knuckle surface during depression of the key. A spring urges the jack toward an "at rest" position with the jack surface in engagement with the knuckle surface. A jack retainer assembly dependent from the hammershank between the second end and the knuckle includes a cushion surface positioned to retain the jack in "at rest" position in opposition to force of the spring.