Patent ID: 7345235

Claim:
A keyboard musical instrument comprising: a tone generator generating tones, and having self-weight; and plural keys including respective end portions of bars connected to said tone generator so that said self-weight is exerted thereon and other end portions located at opposite sides to said end portions with respect to respective fulcrums of said bars and weighted with resiliently deformed balancers for canceling part of said self-weight, and selectively depressed by a player for specifying the pitch of said tones, wherein each of said plural keys is formed with at least one hole different in cross section from associated one of said resiliently deformed balancers so as to permit said associated one of said resiliently deformed balancers to exert resilient force on part of the inner surface defining said at least one hole in a direction parallel to a longitudinal direction of associated one of said bars, and wherein a cross section of each of said deformed balancers has a major line segment longer than a maximum line segment on a cross section of said at least one hole and a minor line segment shorter than said maximum line segment when said balance is outside of said at least one hole so that said major line segment is shrunk in said at least one hole.