ENGLISH DIRECT LEVER GRAND ACTION, DEVELOPED BY BROADWOOD FROM BACKERS (1884).

DOUBLE REPETITION ACTION OF SEBASTIAN ERARD AS USED BY S. & P. ERARD, PARIS.

Shortly before the general adoption of the Broadwood model, however, there was brought forward a new type of grand action, which was destined in its turn entirely to supersede the then favorite English type. This was the invention of Sebastian Erard, of Paris, founder of the still existing house of S. & P. Erard. His new action was termed the “double repetition action,” and it fully deserves the name. By the use of this device the leverage that exists between the hammer and the key is so manipulated that the very slightest touch upon the keys is sufficient to cause the hammer to deliver a blow. It will be observed by reference to the cut that the Erard action differs very largely from that of Broadwood. In the first place, we observe that the hammer heel is no longer provided with a notch in which the jack works, but that this heel is reduced to the smallest dimensions and acts merely as a pivot. Upon the shank of the hammer is fastened a felt-covered roller. The jack acts upon this roller. Between the jack and the roller, however, we observe a long lever, one end of which has a slot through which the jack passes, while the other end is pivoted on to a rail projecting from the wippen. This is the “escapement” or repetition lever, and forms the main improvement of Erard. It will be observed that the repetition lever bears against the roller, and indeed lifts it before the jack can come into engagement with it. The jack, working through the slotted portion of the lever, is not brought into play until the lever has raised the hammer a little way. The long, double spring that acts both upon the lever and the jack gives them their motions, and the result of the depression of the key is that the repetition lever is always in engagement, and when the angular key-motion is not sufficient to bring the jack into play, the work will be done by aid of the lever. Furthermore, the lever operates to maintain the hammer-shank in precisely the proper position for striking, at all times, and without reference to the angular position of the key.

It can easily be understood that such a vital change in action mechanism did not become popular at once. Many pianists objected to double escapement. Notable among these were Chopin and Kalkbrenner; these two being the greatest pianists of their day in Paris. Chopin preferred pianofortes fitted with the Broadwood action.