Improvements in the Construction of Pianos.
Year: 1895

page_text: Date of Application, 28th Mar., 1895-Accepted, 4th May, 1895
COMPLETE SPECIFICATION.
Improvements in the Construction of Pianos.
I THOMAS HAVELOCK HUTCHINSON of 1 and 2 Clarence Place, Newport,
Mon. Piano Maker and Dealer 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 improvements in the construction of pianos, and has for
its object to provide a device to be used in connection with the bridgo or frame,
which will give increased brilliancy and volume of tone and will prevent injury to
the sounding board by excess and inequality of pressure, thereby increasing the life
of the piano.
In pianos as commonly constructed, a great strain is put upon the sounding
board by the pressure of the strings on the bridge, and this strain forces the
sounding board out of shape, causing the tone of the instrument to deteriorate
after a time. In many cases the pressure is also unequally distributed, being greater
at some points, than at others, affecting the quality of the notes and rendering it
more uneven. My invention provides a means by which these disadvantages are
obviated, the strain on the sounding board being lessened and equalized. I employ
a secondary bridge for this purpose, fitted to the upper edge of the lower part of
the frame, over which bridge the strings pass before touching the ordinary bridge.
The secondary bridge is made from steel and consists of a strip having the shape
of the edge of the frame to which it is to be fixed, the strip being formed at the
front with a rib at its centre extending for its whole length.
The strip is fitted to the frame by means of screws at intervals of a few inches,
the screws taking into tapped holes in the frame and passing through perforations
in the strip. These screws are provided with large collars situated behind the strip
when fixed in place, and lying in small recesses in the frame. These screws serve
to adjust the position of the strip, permitting the latter to be raised at any point to
regulate and equalize the pressure. Thus if the pressure on the sounding board
caused by any special set of springs is excessive the portion of the steel strip over
which those strings pass is raised by means of the screws, decreasing the angle at
which the strings pass from the bridge and therefore the pressure on the former.
This arrangement owing to the decrease and equalization of the strain on the
sounding board, enables me to construct the same on a principle giving more freedom
and greater brilliancy of tone.
In order that the invention may be more clearly understood, reference is had to
the accompanying sheet of drawings, in which Fig. 1 is a front view of a portion
of the frame of a piano with my invention applied, Fig. 2 is a cross section, showing
the means by which the attachment to the frame is made and Fig. 3 is a similar
view showing the strip slightly raised illustrating the method of adjusting.
A is the frame of the piano to which the strip or secondary bridge B is attached.
The frame may be of any description and shape, the bridge being formed
accordingly. On the upper side of this strip the rib is formed extending
longitudinally.

page_text: Over this rib the strings C pass to the ordinary bridge D at a slight angle,
the angle being reduced by the secondary bridge, thereby relieving the other from
a great part of the strain.
The strip is connected to the frame by the screw pins E, which pass through
the holes a and b¹ in the frame strip, screwing into a which is tapped to receive it.
The end of the screw is formeil with a cross cut to receive a screw driver, the
screw top being exposed through the perforation in the strip.
The screw pin is formed with a collar e alternately at the back and front of the
strip, the collar lying in the recess or rebate a¹. This collar serves to raise the
strip from the frame as shown in Fig. 3 when the screw pin is turned, causing
the strip to take more of the strain from the wire off the ordinary bridge at the
required points, the strip being made of spring metal easily adopts itself to the
desired shape.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what I
claim is
(1.) The secondary bridge for pianos, consisting of a metal strip attached to the
frame, upon which the wires bear before passing to the ordinary bridge adjustable
in position relatively to the frame, at short intervals, substantially as and for the
purposes specified.
(2.) The secondary bridge for pianos consisting of a metal strip with.a. longitudinal
rib, fitted to the frame by screw pins at short intervals, the strip being adjustable
in position relatively to the frame by means of the said screw pins, substantially
as described and for the purposes specified.
(3.) The improved secondary bridge for pianos consisting of a ribbed 'metal
strip attached to the frame by adjusting screws.formed with collars, substantially
as described and shown in the accompanying drawings and 'for the purposes
specified.
Dated this 27th day of March:1899.
of March 1895.
GEO. 'H. RAYNER,
37, Chancery Lane, London, Agent for the Applicant.