Patent ID: 7897860

Claim:
A keyboard apparatus comprising: a frame having key supports and hammer supports and integrally formed by resin, said frame being adapted to be supported on a musical instrument main body; a plurality of keys mutually juxtaposed and each supported by a corresponding one of the key supports for pivotal motion when depressed; a plurality of hammers mutually juxtaposed so as to correspond to respective ones of said keys, each of said hammers being supported by a corresponding one of the hammer supports at a location below the corresponding key so as to pivot about the hammer support in conjunction with the corresponding key and impart inertia to a pivotal motion of the key; a plurality of key guides provided on said frame integrally therewith or separately therefrom so as to correspond to respective ones of said keys, each of said key guides being adapted to guide a pivotal motion of the corresponding key; key-guide mounting portions provided on said frame integrally therewith and mounted with said key guides; an initial stopper provided on said frame integrally therewith or separately therefrom, said initial stopper being adapted for contact with said hammers to restrict key depression initial positions of said keys in a key depression forward stroke; an initial-stopper mounting portion formed on said frame integrally therewith and mounted with said initial stopper; a front-side contact portion formed on said frame integrally therewith at a location beneath the hammer supports, said front-side contact portion being adapted to be in contact with the musical instrument main body to support said frame on the musical instrument main body; and a rear-side contact portion formed on said frame integrally therewith at a location rearward of the front-side contact portion and downward of the key supports, said rear-side contact portions being adapted to be in contact with the musical instrument main body to support said frame on the musical instrument main body, wherein at least one of said key-guide mounting portions and said initial-stopper mounting portion is positioned forward and upward of the hammer supports, the initial-stopper mounting portion, the key-guide mounting portions, and the front-side contact portion are connected with the rear-side contact portion by means of a vertical rib, and a lower edge of the vertical rib becomes higher at a position closer to said key-guide mounting portions or said initial-stopper mounting portion, whichever positioned forward, in a longitudinal region between the key supports and said key-guide mounting portions or said initial-stopper mounting portion, whichever positioned forward.