Improvements in Planofortes.
Year: 1893

page_text: Date of Application, 6th Mar., 1893
Complete Specification Left, -6th Dec., 1893--Accepted, 27th Jan., 1884
.
PROVISIONAL SPECIFICATION.
Improvements in Planofortes.
I, GEORGE PROWSE, of 27 Warner Place, Hackney Road, in the County of
Middlesex, Pianoforte Manufacturer, do horeby declare the nature of this inven-
tion to be as follows:-
"
This invention relates to inprovements in the iron frames of pianofortes its
object being to afford a better means of securing the wrest pins to the same in
cases where the wooden wrest plank is not employed. In some cases this is sought
to be accomplished by the employment of what is known as "bushed frames
i.e. those in which the holes for the wrest pins are made very much too large and
are each filled with a wooden plug or bush into which the wrest pin takes its
bearings. These plugs are secured by means of glue to a piece of board placed
at the back of the iron frame.
The disadvantages of this arrangement are that the fixed position of the holos
in the frame do not allow of the adjustment of the relative position of the
wrest pins as when the wooden wrest plank is employed, the result being that
in many cases the string passing from one of the upper wrest pins lies too close
to one of the lower pins against which it rattles and jars when the instrumont
is played, again frames cast for trichord instruments cannot possibly be altered
or converted to bichord frames as they cap where this invention is adopted.
Furthermore the glue used to secure the wooden bushes to the backboard
in many cases get squeezed back through the opening in the bush when the
same is insorted and becomes hardened and forms an obstacle which prevents
the wrest pin being pressed well home, the consequence being that the string
connected to the pin cannot be kept in tune.
Furthermore the bush often fails to make a joint with the back board in which
case it is found to revolve with the pin which cannot be kept tight.
In carrying this invention, which is designed to overcome these difficulties, into
effect I form the upper part of the frame with a number of diagonal slots into
each of which I drivo a strip of any hard wood or other suitable substance. These
slots are of greater width on their face than they are at the back surface in order
that the casting may readily withdraw from the mould in which it is cast and also
for the purpose of preventing the strips of wood or other substance which aro also
made slightly taper in section from being driven right through the frame. It is
on these strips of wood or other substance that I mark the positions of the wrest
pins for which they are drilled. It will be roadily understood that the positions
of any of these holes may be varied sufficiently to prevent the string coming in
contact with any of the pins in the manner hereinbefore referred to, it is also
obvious that the pieces of wood or other substance cannot rotate with the pins and
that the same frame may be employed for either bichord or trichord stringing.
Such strips of wood or other substance may be secured in position by being glued
to a board placed at the back of the frame.
1652

page_text: Improvements in Pianofortes.
I, GEORGE PROWSE, of 27 Warner Placo, Hackney Road, in the County of
Middlesex, Pianoforte Manufacturer, 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 iron frames of pianofortes, its
object being to afford a better means of securing the wrost pins to the same in
cases whore the wooden wrest plank is not employed. In some cases this is sought
to be accomplished by the employment of what is known as "bushed frames"
i.e. those in which the holes for the wrest pins are made very much too large and
are each filled with a wooden plug or bush into which the wrest pin takes its
bearings. These plugs are secured by means of glue to a piece of board placed at
the back of the iron frame.
The disadvantages of this arrangement are that the fixed position of the holes in
the frame do not allow of the adjustment of the rolative position of the wrest pins
as when the wooden wrest plank is employed, the result being that in many cases
the string passing from one of the upper wrest pins lies too close to one of the
lower pins against which it rattles and jars when the instrument is played, again
frames cast for trichord instruments cannot possibly be altered or converted to
bichord frames as they can where this invention is adopted. Furthermore the glue
used to secure the wooden bushes to the back-board. in many cases gets squeezed
back through the opening in the bush when the same is inserted and becomes
hardened and forms an obstacle which prevents the wreat pin being pressed
well home, the consequence being that the string connected to the pin cannot be
kept in tune.
Furthermore the bush often fails to make a joint with the back-board in which
case it is found to revolve with the pin which cannot be kept tight.
In carrying this invention, which is designed to overcome these difficulties, into
effect I form the upper part of the frame with a number of diagonal slots into each
of which I drive a strip of any hard wood or other suitable substance. These slots
are of greater width on their face than they are at the back surface in order that
the casting may readily withdraw from the mould in which it is cast and also for
the purpose of preventing the strips of wood or other substance which are also
made slightly taper in section from being driven right through the frame. It is on
theso strips of wood or other substance that I mark the position of the wrest pins
for which they are drilled. It will be readily understood that the positions of any
of these holes may be varied sufficiently to prevent the string coming in contact
with any of the pins in the manner hereinbefore referred to, it is also obvious that
the pieces of wood or other substance cannot rotate with the pins and that the same
frame may be employed for either bichord or trichord stringing. Such strip of
wood or other substance may be secured in position by being glued to a board
placed at the back of the frame.
And in order that my invention may be more fully understood and carried into
practice I will now proceed to describe the same with reference to the accompanying
drawings of which Fig. 1 is a front elevation of an iron pianoforte frame con
structed according to my inventiou, Fig. 2 an enlarged portion thereof and Fig. 3
section on line A B Fig. 2.
The iron frame a is cast with oblong slots b preferably tapered in the direction
of their depth. In these slots bare secured by glueing or in any other manner
correspondingly shaped strips of wood or other material c holes in which are for the
reception of the wrest pins d.

page_text: It will thus be seen that the strips or bushes e will be prevented owing to their
shape from turning with the wrest pins as is often the case with the circular bushes
as at present used, whilst the holes in said strips for the reception of the wrest pins
may be altered to onable the instrument to be converted from a bichord to a
trichord one or vice versa.
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 :-
Metal frames of pianofortes with slots and bushes for the wrest pins scoured
therein, substantially as and for the purpose hereinbefore described and illustrated
in the accompanying drawings.
Dated this 4th day of December 1893.
66
CASTLE SMITH,
Invention" Office, 64, Fleet Street, Loudon, E.C.,
Agent for the Applicant.