A New and Improved Upright Piano Action.
Year: 1894

page_text: Date of Application, 13th July, 1894-Accepted, 10th Nov., 1894
COMPLETE SPECIFICATION.
A New and Improved Upright Piano Action.
I, ROBERT BURN, of 186 Aldersgate Street, London, in the County of Middlesex,
Secretary, a communication from Frederick Edmund Wood, of 729 Amsterdam
Avenue, New York City, U.S.A., do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
This invention relates to an improved action for upright pianos by which great
rapidity of motion and facility of repetition is obtained; and the invention consists
of an upright piano-action in which the rubbing or friction of the jack upon the
butt of the hammer, which rubbing or friction is imparted by a spring interposed
between the heel of the jack and the jack-lever, is relieved by a spring interposed
between the top of the jack-lever and the bottom of the hammer-rail, as will as fully
described hereinafter and finally pointed out in the claims.
In the accompanying drawing,
Fig. 1 is a side-elevation of my improved upright piano-action, partly in section,
through the supporting-rails of the action and
Fig. 2 is a portion of the action, drawn on a larger scale.
Similar letters of reference indicate corresponding parts.
Referring to said drawing, A represents a hammer-rail, to which the hammer A'
is pivoted in the usual manner. Below the hammer-rail are fulcrumed the jack-
levers B to which the jacks C are applied in the usual manner. The jack C is
acted upon by the helical spring F, which is interposed between its lower end or
heel and the jack-lever B and which serves to push the jack against the hammer-
butt. The upper end of the jack C rubs against the hammer-butt before it comes
back to renew its action thereon.
For the purpose of exerting a slight but constant downward pressure on the
jack-lever B, a helical spring D is interposed between the bottom of the hammer-
rail A and the top of the jack-lever, in front of its pivot, the end of said spring
being secured in suitable recesses or sockets in said parts as shown in dotted lines.
These springs are subjected to compression and act by expansion so as to assist in
the return of the jack-levers to their initial positions. The spring D counteracts
the rubbing or friction of the jack C with the hammer-butt, which is produced
by the spring F, and acts to bring the jack quickly back into position for repeating,
so that a great rapidity in the movement of the parts of the action is obtained,
which cannot be obtained without the use of this spring-action on the jack-lever.
The action of the spring D on the jack-lever in connection with the spring F
renders the entire action more sensitive and better adapted for repetition, and
permits the keys to be worked as easily as before, so as to supply a superior action
for upright-pianos.
The remaining accessories of the action are the same as in the well-known piano-
action.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
:-
An upright piano-action, comprising a hammer and its rail, a jack engaging the
butt of the hammer, a jack-lever to which the jack is pivoted, said jack-lever being
pivoted to said hammer-rail, an expansion-spring interposed between the jack-lever

page_text: and the jack, and a counteracting expansion-spring interposed between the hammer-
rail and jack-lever in front of the pivot-connection of the latter with said rail,
substantially as set forth.
ROBERT BURN.