Patent ID: 6965070

Claim:
An upright keyboard instrument comprising: a plurality of keys; a plurality of actions interlocked with the plurality of keys respectively; a plurality of hammer assemblies respectively driven by the plurality of actions in connection with the plurality of keys; at least one plate spring, which is arranged in proximity to a whippen included in the action, wherein the whippen is forced to rotate upon depression of the key and is normally regulated in rotation by the plate spring, which is brought into contact with the whippen upon depression of the key, wherein elasticity of the plate spring causes resistive force to push up a portion of the whippen in order to simulate a key depression feeling associated with a damper in acoustic upright pianos even in absence of a damper; and a loud pedal unit including a loud pedal interlocked with the plate spring, so that when the loud pedal is depressed, the plate spring is moved to depart from the whippen so as not to regulate rotation of the whippen, thereby actualizing a key-touch feeling that simulates a key touch feeling realized when depressing a key while depressing a loud pedal in acoustic upright pianos.