An Improvement in and relating to Pianoforte Frames.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
An Improvement in and relating to Pianoforte Frames.
We, HERBERT MELCHOR GREENWOOD, of 32, Garlies Road, Forest Hill, S.E.,
Gentleman, and FREDRICK RICKARDS BENNETT, of 6, Beaconsfield Road, Willesden
Green, Pianoforte Tuner, do hereby declare the nature of this invention to be
as follows:-
The object of the present invention is to produce a pianoforte frame in which,
the usual front iron frame being dispensed with, there will be no danger of the
wrest plank bending or buckling under the stress of the wiring.
According to our invention, we arrange an iron truss rod or bar at the back
of the wrest plank which bears at each end against abutments provided at or near
the extremities of the latter, or upon the uprights of the frame. The stress of
said truss rod is regulated by a screw bolt which passes through the centre thereof
and screws into the wrest plank.
If considered necessary two or more truss rods may be employed.
1000
E. P. ALEXANDER & SON,
Chartered Patent Agents,
19, Southampton Buildings, Chancery Lane, London, W.C.,
Agents.
An Improvement in and relating to Pianoforte Frames.
We, HERBERT MELCHOR GREENWOOD, of 32, Garlies Road, Forest Hill, S.E.,
Gentleman, and FREDRICK RICKARDS BENNETT, of 6, Beaconsfield Road, Willesden
Green, Pianoforte Tuner, 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:-
The object of the present invention, which relates to pianoforte frames, is to
improve the tone of the instrument by dispensing with the ordinary braced iron
frame which supports the lower front edge of the wrest, plank and is placed in
front of the soundboard obstructing the latter with its braces. The removal of
the usual front iron frame, however whilst leaving the soundboard free and
unobstructed, necessarily entails loss of support to the lower front edge of the
wrest plank, rendering the latter liable to buckle, bulge or pull over under
the stress of the wiring, and our invention provides means for overcoming this
difficulty.
"

page_text: According to our invention, the bent side to which the wires are hitched, and
which is usually cast integral with the braced front iron frame aforesaid, is
either a separate casting or part secured in front and clear of the soundboard in
any suitable manner, or it may be cast integral with a light iron frame of novel
construction which leaves the face of the soundboard absolutely unobstructed as
will hereinafter be described. To compensate for the loss of the support afforded
to the wrest plank by the ordinary braced iron frame, we stiffen the former by
applying a truss device to the back thereof as will be hereinafter described.
We will now fully describe our invention and the manner of performing the
same having reference to the annexed drawings in which similar letters refer to
like parts in all the figures and wherein:-
Figure 1 is a front elevation of a pianoforte frame constructed in accordancs
with our invention.
is
Figure 2 is an end view, and Figure 3 a plan of rigure 1.
Figure 4 is a transverse vertical section on line a
Figure 1.
Figure 5 is a transverse vertical section on line y-y Figure 1, and Figure 6
a detail.
The frame comprises the usual base plank a from which extend upwards the
vertical braces upon which the wrest plank is supported in the ordinary
manner. To the front faces of the outer braces are bolted metal plates & the
upper ends of which fit into rebates in the extremities of the wrest plank and thus
assist to some extent to hold the same in place. e is the bent side to which the
wires are hitched, the same, with its extension e, being secured to the plates &
aforesaid, the latter and the bent side and extension being preferably one casting
and forming a light iron frame which in no way obstructs the soundboard.
ff are bent metal straps, preferably cast on the bent side, which pass beneath the
Frame and up the rear faces of the wood braces to which they are bolted adding
greatly to the strength of the frame. In the drawings these straps f are repre-
sented as separate parts secured in place by bolts traversing the frame (see
Figs. 4 and 5). is the usual soundboard, which it will be noted is absolutely
unobstructed by the iron portion of the frame. The tone of the instrument is
in consequence greatly improved but at the same time the wrest plank is deprived
of the support to its lower front edge afforded by the ordinary construction of
braced iron frame. Now to compensate for this loss of support and prevent all
risk of the wrest plank e buckling or bulging under the stress of the wiring we
apply a truss device as before stated to the back of the wrest plank, and will
now describe in detail the particular arrangement illustrated in the drawings.
Along the upper edge of the front face of the wrest plank is bolted the metal
strap and along the upper edge of the rear face of the wrest plank is bolted a
similar strap at each end of which latter projections are formed which con-
stitute abutments for the ends of the curved metal truss rod or bar m to bear
against. The stress of this truss rod or bar (which is preferably of wrought iron)
is regulated by the screw bolt which passes through the wrest plank and the
straps, and screws into the truss bar m. The said truss bar effectually stiffens the
wrest plank and enables it to withstand the stress of the wiring without buckling
or bulging, and as security against any liability to pull over, the bolt a is caused
to engage a hole in an extension f¹ of one of the straps f as illustrated (Figure 4):
or the extremity of this extension f¹ may be bent over and engage the upper
edge of the truss bar m for the same purpose (Figure 6).
Although we have illustrated an upright frame in the drawings, it is clear
that with obvious slight modifications our invention may be equally well applied
to horizontal frames.
In conclusion we would observe that we do not confine or limit ourselves to
the precise constructional details of the frame as above described and illustrated
in the drawings, as the same may be obviously somewhat modified without in
any way departing from our invention as set forth.
Y

page_text: Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. A pianoforte frame wherein the usual braced iron frame in front of the sound-
board is dispensed with and the wrest plank has a truss device applied thereto to
compensate for the consequent loss of support to its lower front edge, substantially
as described.
2. A pianoforte frame constructed without a front iron frame substantially as
set-forth and having a wrest plank to the back of which a truss device is applied,
the latter being engaged by a part of the frame so that risk of "pulling over"
is obviated, substantially as described.
"2
3. The combination with a pianoforte wrest plank of abutments at or near
either end thereof, a curved truss bar m bearing against said abutments, and
means for regulating the stress of said truss bar, substantially as and for the
purpose described.
4. The combination with a pianoforte wrest plank of the metal straps k
extending longitudinally of the front and rear faces thereof, abutments at cach
end of the rear strap, a curved metal bar m bearing against said abutments and
a screw passed through the straps and wrest plank and engaging said bar m
whereby the stress thereof is regulated, as described and for the purpose set
forth.
01 F coruary 1900.
E. P. ALEXANDER & SON,
Chartered Patent Agents,
19, Southampton Buildings, Chancery Lane, London, W.C.