The Grand Action

There are two types of action remaining in use: the “English Action” and the “German Action”.

The English Action
Backers successfully built a grand piano employing the English grand action in 1770. The mechanism was a Cristofori’s modification of wing-shaped design and it was constructed on an English harpsichord. However, in 1777, Stodart issued a patent of his new invented sort of instrument or grand forte piano, and this introduces the term “grand piano” to the public the first time.

Explanation on this action’s mechanism:
The construction of a grand action is different from an upright action. There is no immediate lever in this action, and the striking direction of the hammer is upwards rather than forward. On the construction, the hammer rests on top of the hammer rail while the escapement hopper supports the hammer butt. While the comb register is positioned slightly below the hammer butt in order to hold onto the escapement hopper, the set-off screw does the same thing to the escapement hopper. When the key is depressed, the escapement hopper will push away the hammer butt so that the hammer head will hit the strings. A check head is used to help the returning hammer for repetition as well as the hopper retuning its original position.

However, because the escapement hopper is placed at the middle of the key, it results in a slow response.

The “English Action” removed Cristofori’s intermediate lever and applied a screw to regulate the escapement in its structure. Although it enabled Broadwood to achieve maximum tone from his more resonant pianos, the keyboard retained a heavy touch and slow repetition. This action lacked the brilliance and sparkle of the Viennese type.