Patent ID: 8294009
Filing Date: 2012-10-23
Classification: G10C

Abstract:
1. An upright piano type action comprising: a jack moving in response to a depression and a release of a key; a butt having a surface pushed up by the jack in response to the depression of the key; and a swinging member extending from the butt and swinging forward and backward in response to the depression and the release of the key respectively to perform a hitting activity; wherein the surface of the butt is provided with a flat portion which is situated forward and has a small inclination angle with respect to a horizontal plane, and a slanting pressure receiving portion which is situated backward and has a large inclination angle with respect to the horizontal plane as areas pushed up by the jack, so that the flat portion and the slanting pressure receiving portion form an escapement portion having an obtuse angle between the flat portion and the slanting pressure receiving portion; the escapement portion is provided to correspond to a position of the jack placed immediately after start of swinging caused by contact of the jack with a regulating member in some point during the depression of the key; and the angle of inclination of the slanting pressure receiving portion is determined such that when the key is depressed to a full stroke position so slowly that the swinging member will not perform the hitting activity, the jack is to continue pushing up the butt whereas in a stage where the key starts returning from the full stroke position, a position at which the butt is in contact with the jack is to be kept with the butt swinging backward.