IMPROVEMENTS IN THE CONSTRUCTION OF THE FRAMES AND TUNING PINS OF PIANOFORTES
Year: 1881

page_text: LETTERS PATENT to Thomas James Brinsmead, of the Firm of John Brinsmead.
50
and Sons, of Wigmore Street, Cavendish Square, in the County of Middlesex,
for an Invention of IMPROVEMENTS IN THE CONSTRUCTION OF THE FRAMES
AND TUNING PINS OF PIANOFORTES."
PROVISIONAL SPECIFICATION left by the said Thomas James Brinsmead at
the Office of the Commissioners of Patents on the 21st May 1881.
THOMAS JAMES BRINSMEAD, of the Firm of John Brinsmead and Sons, of
"IMPROVEMENTS
Wigmore Street, Cavendish Square, in the County of Middlesex.
IN THE CONSTRUCTION OF THE FRAMES AND TUNING PINS OF PIANOFORTES."
The object of my Invention is, first, to secure an easier method of tuning
pianofortes, and by an improved method to dispense with the old system of tuning
by pins simply driven into wood, and also with the necessity of using any wood in
the frame (back) and wrest plank.
In carrying the first portion of my Invention into effect I employ metal screwed
tuning pins, which, running parallel with the strings, pass through a metal plate
secured in the further side by metal nuts, which, when moved by a tuning key,
increases or decreases the tension of the strings.
The second portion of my Invention consists in constructing that portion of a
piano which takes the strain of the strings in one solid piece of metal, thus ensuring
the instrument remaining in perfect tune in any climate for a much longer period
than those built in the ordinary manner, and ensuring the frame never giving way
through exposure to damp nor extreme heat.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas James Brinsmead in the Great Seal Patent Office on the
21st November 1881.
THOMAS JAMES BRINSMEAD, of the Firm of John Brinsmead and Sons, of
Wigmore Street, Cavendish Square, in the County of Middlesex. "IMPROVEMENTS
IN THE CONSTRUCTION OF THE FRAMES AND TUNING PINS OF PIANOFORTES."
The object af my Invention is, first, to secure an easier method of tuning
pianofortes, and by an improved method to dispense with the old system of tuning
by pins simply driven into wood, and also with the necessity of using any wood in
the frame (back) and wrest plank.
In carrying the first portion of my Invention into effect I employ metal screwed
tuning pins, which, runuing parallel with the strings, pass through a metal plate
secured on the further side by metal nuts, which, when moved by a tuning key,
increases or decreases the tension on the strings.
The second portion of my Invention consists in constructing that portion of a
piano which takes the strain of the strings in one solid piece of metal, thus ensuring
the instrument remaining in perfect tune in any climate for a much longer period
than those built in the ordinary manner, and ensuring the frame never giving way
through exposure to damp nor extreme heat.
My Invention is clearly represented in the annexed Sheet of Drawings. Figure 1
is a detached view of one of my improved wrest pins A with a hook B at one end,
the other end C being formed with a screw thread, over and on which a nut D can
be turned to tighten the string or wire to obtain the necessary tension when turned
by a key. The pin A has a fat portion formed along its stem, as seen in the
sectional view, Figure 2. The part of the wrest plank, through which the pin A
passes is shaped to correspond to prevent the pin and the wire being twisted when
the nut D is acted upon.
Figures 3 and 4 are modifications of the hook end B of my improved pins A.
Instead of the hook engaging in a loop of the string or wire, as for Figure 1, the
end of the string or wire can be passed through the hole a and secured to it by
twisting the end over and over, or to coil it on.
In pianos, in which my improved pins A are employed, I fit a bar or strip of
metal on the "back," the bar or strip having holes in it corresponding with the
sectional shape of the pins, as before mentioned.
Figures 5 and 6 represent the second part of my Invention, which consists in
constructing the "wrest plank" E in a piece, with or as part of the "top frame" F,
and also of the "lower frame " G in metal, preferably cast, to which the "lower
frame" G, the ordinary hitch pins H, H, are secured.
Just above the bridge I, which is also part of the casting, I affix a pressure bar J
under which the strings or wires K, K, are passed as shown.
The upper portion of the casting is made hollow at L, and the back of it has one
or more wing bars M, which enable the casting to be of light weight without
interfering with its strength. N is the sounding board bridge. Figure 7 is another
arrangement of the pins A. in the wrest plank E.
I prefer to make my improved pins A of phosphor bronze.
Having now described the nature of my said Invention and in what manner the
same is to be performed, I declare that I claim,―
First. The pin shown at Figure 1, and its modifications, Figures 3 and 4, for
connecting the strings or wires of pianofortes, and for facilitating the tuning and
straining thereof.

page_text: Secondly. I claim the construction of pianoforte frames in metal, as described
and as shown in Figures 5 and 6 of the annexed Drawings.
Thirdly. I claim the combination of my improved pins A and metal back frame
as hereinbefore described and as shown at Figures 5 and 6.
In witness whereof, I, the said Thomas James Brinsmead, have bereunto set
my hand and seal, this Twenty first day of November, in the year of our
Lord One thousand eight hundred and eighty one.
THOMAS JAMES BRINSMEAD. (L.S.)