The wippen is the part of the action that comes into direct contact with the key. It is responsible for transmitting the motion of the key to the hammer.When the wippen is at rest, the wippen heel (1) rests on the capstan screw attached to the back of the key. The wippen is set in motion when the pianist depresses the key. The capstan screw pushes up on the wippen heel cushion (2), a felt pad attached to the heel, which causes the wippen body (3) to rotate. The wippen body rotates on the wippen flange (4), which is supported by the wippen flange rail (5). The hammer shank rest post (6) is located at the end of the wippen that is closest to the hammer head. The post is topped by the rest cushion (7), a felt pad that the hammer shank sits on when at rest. On the other end of the wippen, the jack flange (8) is built into the wippen body. The jack is attached to the end of the wippen and rotates in the flange. The spoon (9) is a metal support that holds the jack in the proper position. The jack regulating button rests against the spoon, and can be adjusted to fine-tune the position of the jack.
