An Improved Complete Iron Framed Pianoforte.
Year: 1893

page_text: Date of Application, 10th May, 1893
Complete Specification Left, 9th Feb., 1894-Accepted, 9th June, 1894
PROVISIONAL SPECIFICATION
An Improved Complete Iron Framed Pianoforte.
THOMAS FIRTH, THOMAS WILLIAM FIRTH HARRY MARCUS WALLHEAD
FIRTH and EDWARD MARMADUKE FIRTH No. 2, Frederick Terrace, Lower
Fore Street, Edmonton Dealers in all kinds of Musical Instruments do hereby
declare the nature of this invention to be as follows:-
An improved iron framed pianoforte in which wood bracings are not required,
the frame casting having uprights at back, to which the wrest plank is bolted. The
top and bottom bridges are cast as part of the frame, the bottom bridge being so
arranged as to allow a complete regular action, the frame having notches cast below
the bottom bridge replacing hitch pins and avoiding boring, and also projecting
studs cast on the outer edge, or any part of the extreme back of the frame for the
purpose of attaching soundboard, avoiding boring holes in the casting. Raised
letters cast in a direct line from right to left of the extreme top front of frame
securing a correct & definite register of the distance of one note from another. The
frame casting extended at sides for attaching wood or other case material as
required with arrangements for carrying and easily ajusting keyboard & action with
movement for soft pedal which enables a subdued sound to be produced at will
without altering the original touch or the purity of tone. The casting extended at
foot to carry and attach pedal action & castors, making a complete iron framed
skeleton pianoforte without the need of or before any portion of the outside frame
is attached.
Dated this 9th day of May 1893
THOMAS FIRTH.
THOMAS WILLIAM FIRTH.
HARRY M. W. FIRTH.
EDWARD M. FIRTH.
An Improved Complete Iron Framed Pianoforte.
THOMAS FIRTH, THOMAS WILLIAM FIRTH, HARRY MARCUS WALLHEAD
FIRTH and EDWARD MARMADUKE FIRTH, (trading as Firth Bros.) of
2 Frederick Terrace, Lower Fore Street, Edmonton, Musical Instrument Dealers,
do hereby declare the nature of this invention and in what manner the
Bame is to be performed, to be particularly described and ascertained in and by
the following statement :-
A metal frame, forming a complete front and back elevation of a cottage piano
without case (Sheet 1), consisting of uprights (A, Sheet 1) which shall carry the
full tension of the strings, doing away entirely with, and superseding wood bracings,
with a plate (B, Sheet 1, A Sheet 2) so cast on to the uprights as to secure a
correct and definite register and position of the bottom bridge (C, Sheet 1,
D, Sheet 2), which bottom bridge shall be cast on the frame or separately as desired
without prejudicing the register in any way. The said bottom bridge to be either
such that by a simple arrangement it will, together with raised studs cast on the
plate substituting bitchpins (B, Sheet 2) secure to the strings (C, Sheet 2) a side
tension, such tension being equally divided both ways, right and left, or a front and

page_text: back tension equally divided, thus relieving the soundboard of all such tension or
pressure from the strings and thereby securing to it its maximum vibration. The
said bottom bridge to be cast with small feet so arranged as to form a surface to
which the soundboard shall be screwed. The frame to have similar feet or flanges
cast on its outer edge (D, Sheet 1,) to which the soundboard may be firmly
fixed.
The top bridge (E, Sheet 1,) to be also cast on the frame, the bass end being so
cast as to secure its proper register, and commencing a gradient which is continued
to the treble end of the frame, the upper surface forming a bed upon which the
wrestplank shall rest. The tenor and treble portion of the bridge branching away
in such form as to secure its correct and permanent register with the bottom
bridge.
The extreme top of the frame to be cast in the form of a shelf, the under surface
of which forms a couterpart of the upper surface of the wrestplank bed, thus
forming together two sides of a box in which the wrestplank (G, Sheet 1) is held.
The said two sides being held together by stays at the back, (F, Sheet 1,) forming
the third side to the said box, being also in turn directly connected with the
uprights. The box having ridges (H, Sheet 1,) cast on the front edge of the top
and bottom surfaces so arranged as to hold the wrestplank securely in position
without the aid of bolts. The two ends of the said box being left open so as to
admit the wrestplank which we insert in the form of a wedge (G, Sheet 1, showing
wrestplank half-inserted).
Letters (I, Sheet 1) being cast on the front edge of the extreme top permanently
denoting the position of the wrestpins.
The frame also having chairs so arranged and cast on the two end uprights to
which we easily adjust that portion of the frame (J, Sheet 1,) which carries the
keyboard and action. The two end uprights having projections (K, Sheet 1,) at
intervals, to which the outside case may be attached. Also with further extensions
at the bottoms forming feet (L, Sheet 1,) upon which the whole stands thus enabling
us to complete the instrument before any portion of the outer case is attached.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is -
--
1. A metal framed piano which does away with a wood bottom bridge, the boring
for, and fixing of bridgepins, and the boring for, and fixing of hitchpins.
2. An arrangement for holding the wrestplank in position without fastenings of
any kind, and for inserting the same end wise, and in the form of a wedge.
3. The idea of arranging the soundboard to form the extreme back of piano,
together with the feet or flanges to which it is attached.
4. The idea of a definite and permanent register of the bridges and all other
parts of the frame, so that, with patterns once perfectly adjusted, each frame must
be an exact repitition of the same register requiring no further adjustment in the
inanufacture of the piano.
5. The idea of the uprights, in conjunction with the hitchpin plate, being cast in
such a form as centralize the strain, securing the maximum of power with the
minimum of weight.
6. The idea and design of our frame including uprights with projections and
extensions.