An injection molded wippen or repetition flange bushing for a grand piano action where the bushing has four supports posts or elongated appendages projecting outward from the outer surface of the sleeve member of the injection molded wippen or repetition flange bushing. The four supports posts help reduce or eliminate shrinkage of the sleeve member during the cooling stage in the manufacturing of the injection molded wippen or repetition flange bushing. This occurs because shrinkage occurs in the four support posts and not in the sleeve member portion of the injection molded wippen or repetition flange bushing. The result is a perfectly straight bushing with an extremely precise and accurate bushing surface that produces perfect wippen or repetition rotation.

A keyboard device for a keyboard instrument includes: a swingable key extending in a front-rear direction; an action unit executing a predetermined operation in conjunction with depression of the key; and a hammer rotatably supported by a hammer support shaft of a hammer support and driven upward via the action unit in accordance with depression of the key. The hammer has a backcheck engagement portion protruding downward in front of the hammer support shaft, and the key is provided with a backcheck that stops the hammer by engagement of the backcheck engagement portion when the hammer driven upward with depression of the key rebounds and rotates downward.

A keyboard device for a keyboard instrument includes: a swingable key extending in a front-rear direction; an action unit executing a predetermined operation in conjunction with depression of the key; and a hammer rotatably supported by a hammer support shaft of a hammer support and driven upward via the action unit in accordance with depression of the key. The hammer has a backcheck engagement portion protruding downward in front of the hammer support shaft, and the key is provided with a backcheck that stops the hammer by engagement of the backcheck engagement portion when the hammer driven upward with depression of the key rebounds and rotates downward.