The action of the jack is the same in all types.
Action of the Grand Piano.
After thoroughly going over the details of the action of the square and upright pianos, there remains very little to describe in the action of the grand.
The grand action partakes of the characteristics of both the upright and the square, and is somewhat more complicated than either.
The bottom and extension are almost identical with those of the upright; the extension, however, is necessarily very short.
The wippen is of different construction, and somewhat more complicated in the grand.
The flange rail in the grand is made also to serve the purpose of regulating rail, as the hammer rail is made to do in the square.
The back check is identical with that of the square.
The dampers are the same in their working principles as those of the square, but are generally different in construction; yet, some squares have the same arrangement of dampers as those shown in the cut of the grand action.