IMPROVEMENTS IN PIANOFORTES
Year: 1858

page_text: application for Letters Patent was not given within the time prescribed
by the Act.)
PROVISIONAL SPECIFICATION left by Richard Sharp at the Office of
the Commissioners of Patents, with his Petition, on the 5th May 1858.
I, RICHARD SHARP, of Lowther Street, Liverpool, in the County of
Lancaster, Pianoforte Manufacturer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN PIANOFORTES," to be as follows:-
My Invention of improvements in pianos relates, first, to a peculiar appli-
cation of tension braces to the ordinary braces or framework that sustain the
tension of the strings, which render such braces less liable to warp or give by
reason of such tension, whereby the number of wood braces may be reduced,
or they may contain a less amount of wood than usual.
In upright pianos I secure these tension braces to the upper part of the
wrest plank by a jointed metal strap, which is turned partly down in front of
the wrest plank where it is bolted. The joint of this strap is at the back part
of the wrest plank, and in a position central with the vertical central line of the
wood braces, and rests on a metal plate secured to the back part of the wrest
plank; from this joint a link depends, to the lower end of which a tension rod
placed at the back of the instrument is connected; the upper end of this
tension rod bears against a block placed on the back of the wrest plank near
the bottom, which block is of sufficient size to keep the tension rod at a
distance behind the central vertical line of the braces, equal to the distance of
the strings in front of such central line, or nearly so. On the lower end of the

page_text: tension rod I place a nut or screw, or other contrivance to connect it with a
short lever, which I mount on a fulcrum fixed to the foot plank, such fulcrum
being also in the central vertical line of the wood braces. The back end of
this lever, as before mentioned, is connected with the tension rod, while the
front end takes a bearing on the string plate. The string plate is applied and
fixed in the usual way, being carried under the foot plank; the fulcrum of the
lever being fixed through that plank, also passes through and is secured to the
plate. By means of the screw on the rod, any strain can be applied to buckle
or bend the braces in a backward or opposite direction to that produced by the
tension of the strings, and whereby the sum of the forces applied to the wood
braces is a direct thrust, and not calculated to deflect the braces from their
original position. At the bent side of the instrument I interpose blocks of
wood between the braces, to which I fix the fulcrum of the lever at the bottom
of the tension rod, that rod being connected to the lever, and with the fore end
of the lever bearing on a horizontal surface formed on or notched into the bent
part of the string plate, the effect of which is all as before mentioned.
In bracing grand pianos according to my Invention I dispose the tension
rods at the back, or rather under the wood braces, and apply a short lever at
either end, one to take a bearing on the string plate, while the other lever
takes a bearing on the edge of the wrest plank near the strings. The fulcrum
of such additional lever is placed in the central line of the braces, and firmly
secured to the wrest plank. The effect produced is the same as that before
mentioned. with reference to upright pianos.
The second part of my. Invention relates to a check action for upright
pianos, and also to. a particular application of the dampers.
I apply the check to the head of the hammer, and mount it on a wire stem
raised from a short jointed lever or arm disposed horizontally at about the
same level as the hammer butt. The under side of this lever carries an
inclined surface, on which the upper end of a lever placed vertically takes
effect. The lower and short end of this vertical lever is acted on by an
inclined surface placed in front of the hopper, which surface takes effect by a
sliding contact with the lever, while at the same time the upper end is caused
to slide on the incline of the check lever, producing a considerable amount of
motion in the check, which takes effect on the hammer head immediately it
falls off the strings, and may. be regulated so as to check the hammer at any s
suitable distance, say, a quarter of an inch, more or less, and which I regulate
by means of a screw in the upright lever. This regulation and disposition of
the check action lever also takes effect on the hopper, and prevents it falling
out beyond a certain distance, which with the check greatly enhances the

page_text: capabilities of the instrument for repetition. The back part of the hammer
head on which the check takes effect is curved, as also the check head, which
is so disposed and presented at an angle as readily and securely to effect the
grip of the hammer.
The improvement in the dampers is in affixing a heel piece thereto on the
opposite side of the fulcrum from that on which the sticker rod acts, and on
which a slight spring takes effect to throw the damper quickly up to the strings,
when it is released by the key.