Year: 1898

page_text: Date of Application, 1st Dec., 1898
Complete Specification Left, 31st Aug., 1899-Accepted, 7th Oct.,
1899
We, WILLIAM GEORGE MUNT and EDWARD MUNT, of St. John's Hill, Battersea,
in the County of Surrey; Pianoforte Manufacturers, do hereby declare the nature
of this invention to be as follows:-
This invention has reference to the improvement of octave or diapason class of
pianofortes wherein a double sound is produced by one finger key and one
concussion from the hammer.
to
we
This invention relates to improvements in the method of constructing bridges
on the belly and wrest plank, also in the construction of the hitches of the
strings,
or wires, which
made fast
are
the iron frame, and
accomplish this by the use of an ordinary piano scaled with one, or more strings
to each note. We add one, or more, strings to each note, either higher or lower,
in pitch to be struck together; forming an octave in sound.
In effecting this we provide a suitable number of bridges; say two or more on
the belly and two or more on the plank or a corresponding arrangement.
The usual way previously employed to enable such extra string to clear the
bridges is to cut out grooves in the bridges to allow the strings which are an
octave lower, or higher and if lower are twice the length of the ordinary scale of
strings by its side making the octave. The cutting of the before mentioned
grooves in bridges requires the scale to be wide in space and the grooving of the
bridges destroys the firmness and induction of tone of the instrument; this will
be noticed in the construction shown in the Specification of Kirkman's Patent of
1816 No. 4068, and in Mark's Patent of 1864 No. 134.
In carrying out our invention, we avoid cutting the belly bridges, but allow
the extra string to vibrate by the side of and above the other note, this we
accomplish by having the second, or lower bridge much higher, thereby to carry
the extra string or strings so much away that it may vibrate freely. The top
bridge or bridges will be made so much lower in height than the ordinary plank
bridge, thereby bringing all the strings to a level in order to secure that the
point of impact of the hammer shall be in correct position and in line.
second bridge is arranged so much the higher that we can make the table for
the hitch pins so much higher to correspond with the high bridge, which makes
the octave, or diapason (this we call the "octave bridge ").
The
We construct this bridge, either with down or up bearing, as may be found more
convenient, using a suitable form of stud or like device, on the ordinary bridge.
The two wrest plank bridges we either form with a suitable form of stud, or
equivalent devices, cast in one with the iron frame, and we may use an ordinary
pressure bar or use the ordinary or other suitable studs.
The damper heads are made in two, or other number of parts, faced with felt for
the two, or more strings, and the part of the head and felt for the octave string,
cr strings, being a little out of level caused by the high diapason string. The arm
damper will be found simple and convenient for use.

page_text: The hammers are made wide enough to strike all the strings when acted upon
by the ordinary shifting pedal.
The invention may be arranged to strike one octave or more, higher or lower.
In place of mounting the diapason bridges upon one sounding board we may
employ a separate sounding board to each of such bridges.
We also sometimes modify the existing form of sound board by dispensing
with the bars thereon.
D
1
1000
Improvements in Pianofortes.
We, WILLIAM GEORGE MUNT and EDWARD MUNT, of St. John's Hill, Battersea,
in the County of Surrey, Pianoforte Manufacturers, do hereby declare the nature
of this invention and in what manner the same is to be performed to be particu-
larly described and ascertained in and by the following statement:-
This invention has reference to the improvement of octave or diapason class of
pianofortes wherein a double sound is produced by one finger key and one
concussion from the hammer.
This invention relates to improvements in the method of constructing bridges
on the belly and wrest plank, also in the construction of the hitches of the
strings, or wires, which are made fast to the iron frame, and we
accomplish this by the use of an ordinary piano scaled with one or more strings
to each note. We add one or more, strings to each note, either higher or lower,
in pitch to be struck together; forming an octave in sound.
In effecting this we provide a suitable number of bridges: say two or more on
the belly and two or more on the plank, or a corresponding arrangement.
The usual way previously employed, to enable such extra strings to clear the
bridge, was to cut out grooves in the bridges, thereby to allow clear passage for
the strings, which are an octave lower or higher, and which strings if lower are
twice the length of the ordinary scale of strings by its side, making the octave.
The cutting of the before mentioned grooves in bridges requires the scale to be
wide, in space, and the grooving of the bridges destroys the firmness and induc-
tion of tone of the instrument; this will be noticed in the construction shewn in
the Specifications of Kirkman's Patent of 1816, No. 4068, and in Mark's Patent
of 1864, No. 134.
The
In carrying out our invention, we avoid cutting the belly bridges, but allow
the extra string to vibrate by the side of and above the other note, this we
accomplish by having the second, or lower, bridge much higher, thereby to carry
the extra string or strings so much away that it may vibrate freely. The top
bridge, or bridges, will be made so much lower in height than the ordinary plank
bridge, thereby bringing all the strings to a level in order to secure that the
point of impact of the hammer shall be in correct position and in line.
second bridge is arranged so much the higher that we can make the table for
the hitch pins so much higher to correspond with the high bridge which makes
the octave, or diapason (this we call the
struct this bridge, either with down or up bearing, as may be found more
octave bridge"). We con-
convenient, using a suitable form of stud or like device, on the ordinary bridge.
The two wrest plank bridges, we either form with a suitable form of stud, or
equivalent devices, cast in one with the iron frame, and we may use an ordinary

page_text: pressure bar; or use the ordinary or other suitable studs. The damper
heads are made in two, or other number of parts, faced with felt for
the two, or more strings, and the part of the head and felt for the octave string,
or strings, being a little out of level caused by the high diapason string. The arm
damper will be found simple and convenient for use. The hammers are made
wide enough to strike all the strings when acted upon by the ordinary shifting
pedal.
The invention may be arranged to strike one octave, or more, higher or lower.
In place of mounting the diapason bridges upon one sounding board, we may
employ a separate sounding board to each of such bridges.
We also sometimes modify the existing form of sound board by dispensing
with the bars thereon.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 shows a plan view and Fig. 2 a sectional view of a portion of a piano-
forte viz., the ordinary strings, the extra strings, the bridge, the belly and the
diapason, or extra bridge, arranged to carry out this invention. Fig. 3 is a detail.
Fig. 4 shows a plan view, and Fig. 5 a section, of parts similar to Fig. 2, but
with a modification in the arrangement of the dowels for retaining the extra
strings as they pass the extra bridge.
Fig. 6 and Fig. 7 show, by corresponding views to Figs. 1 and 2, another
modification in the arrangement of the diapason or extra bridge with the extra
string secured by an up pull to the iron frame.
Figs. 8 and 9 show, by like views to those last mentioned, the same construc-
tion modified to employ a down pull or bearing bridge.
Fig. 10 shows a plan view, and Fig. 11 a sectional side view, of a further
modification in the construction of the diapason or extra bridge by which it is
formed in two parts and forming an "up pull."
Fig. 12 shows, to an enlarged scale, a portion of the improved stringing, two
bridges and pressure bar in plan view.
Fig. 13 shows a section of the iron frame bridges and pressure bar taken on a
line passing through one of the notches for the ordinary strings to pass through
the diapason bridge.
Fig. 14 shows a similar section to the last, but taken on a line passing through
one of the notches in the ordinary bridge through which the diapason strings
freely pass.
Figs. 15, 16, 17 and 18 show respectively the following details: the underside
of the pressure bar, the front view thereof as viewed from the left hand of
Fig. 12, the form of the notches in the diapason or extra bridge, and the form of
the notches in the top bridge, or wrest plank bridge.
Fig. 19 shows a front view of an improved damper head; and Fig. 20 a cross
section thereof, with adjustable portion for damping the extra or diapason string.
Fig. 21 shows a plan view of portions of a horizontal pianoforte with the
improvements applied in part.
Fig. 22 is portion of Fig. 21 in section, to shew the construction when employ-
ing a down pull to the strings, taken at the treble end.
Fig. 23 shews a portion of a like view to Fig. 21, modified to the use of an
up-pull; and Fig. 24 is a corresponding sectional view.
Fig. 25 shows a corresponding section to Fig. 22, taken at the bass end of
the instrument.
Fig. 26 shows, by an enlarged view of the parts shown to the left hand in
Fig. 22, a modified form of pressure bar, in cross section; and Fig. 27 shows by
front view, a portion of the pressure bar and "cush" bar according to which the
diapason strings are pressed upon by adjustable pins.
Fig. 28 shows a similar sectional view of parts, as in Fig. 26, but with a
notched pressure bar, and Fig. 29 shows a front view of Fig. 28.
Fig. 30 shows, by a corresponding sectional view to Fig. 28, another modi-

page_text: fication in which the solid projections of that figure, to press on the diapason
strings, and the adjustable pins of Fig. 26, are replaced by slotted plates adjust-
ably screwed to the front edge of the pressure bar. Fig. 31 shows a front view
of three of such plates, their screws and a part of the bar carrying them, as they
appear when applied.
Fig. 32 shows a front view, and Fig. 33 shows an edge view, of one of said.
plates separately.
Fig. 34 indicates by a plan view, and
Fig. 35. by a vertical section, another construction in which although we have
cut the diapason or extra belly bridge the long bridge c is left intact and
unweakened, the ordinary strings passing clear over it.
Fig. 36 shows a detail view of the front of the diapason bridge b the better
to indicate the form of the cut away parts for the passage of the ordinary strings
therethrough on their way to the iron frame.
d
Referring to Figs. 1, 2 and 3, and generally throughout the figures where the
same parts occur, a is the iron frame, b is the diapason bridge, c is the belly
bridge, sometimes called long bridge for the usual strings and of ordinary
construction,
are the diapason strings which, by means of our
improved construction, are enabled to be carried above and clear of the belly
bridge c as shown, and in a line well clear of and above the strings e which we
have throughout called the usual strings. f indicates the sound board. The
pressure bar g (see Figs. 11, 12, 13, 14, 15, 16 and other of the figures) is not
shown in the smaller general views. h are the wrest pins for the usual strings,
and the like for the diapason strings. is the usual bridge, and the
additional, or diapason, string bridge. k (Figs. 19 and 20) is the usual damper
head and is the additional part. Each damper is provided on its face next
the usual strings e with suitable felt and the additional part 1 to each head is
similarly provided on its face next the string d. This part is slotted and fitted
so that its relative position to the part k may be screw adjusted so that those
combined parts may properly contact with their strings d and e respectively, and
proper allowance be made for the distance out of line of the strings d and e.
is the screw.
In the arrangement Figs. 1 and 2, the diapason string d is passed through a
notch or slot 62 in the dowell, or pin, b' which is affixed in the bridge b. The
form of one of these dowels b', and the shape of the notch 62, will be best seen
by reference to Fig. 3, wherein the dowel is seen, in side view and cross section,
on the line of the notch. This arrangement employs the up pull.
In Figs. 4 and 5 the " down-pull" is employed; and to effect the proper sup-
port, or bearing of the string d, that string passes through the notch of the
dowell and then over the head of a shorter dowell 63 shown to the left of b¹; so
that the strings d are slightly cranked on their way to the hitch pins a¹ of the
lower ledge of iron frame «. By the use of these two sets of dowels a grip is had
both on and into the dowels, and, in all the illustrated forms it will be clearly
seen that the strings d are carried higher than, and over, the bridge c, as already
stated; so as to vibrate unimpeded, whilst the slotting or cutting with inevitable
weakening of that bridge is avoided.
66
In a modification shown by Figs. 6 and 7, with the use of the "up-pull" on the
strings to the hitch pins a² on the upper ledge of the iron frame, and in the
corresponding arrangement employing the common down-pull" to the hitch
pins a on the lower ledge, we use a divided, or double belly-the dowells b¹
being affixed in the second or inner belly, or sound board, f¹; and passing into
a bridge fat back thereof. The dowells 61 pass through openings f³ in the first,
or outer belly, or sound board, f. Said holes, to provide for movement or tilting
of the dowels b¹, we make oval or of equivalent greater diameter in the direction
of the pull of the strings.
Although we prefer to use a dowel of the form shown by Fig. 3, other equiva-
lent forms of dowels may be substituted, or metal hooks, or holding devices, for
the wires d used.

page_text: In Figs. 10 and 11, we have shown a modification in which the diapason bridge
is modified in form, and used in conjunction with the "up-pull method of
stringing. The lower portion of the bridge rests on the sound board f, whilst
the upper portion 6 of said bridge is separated from the lower part, it being held
connected thereto by means of screws, b, whose heads prevent the strains of
the wires, lifting the part 6, in their stretch from the hitch pins to the wrest
pins. By this method of holding down the strings d by the upper bridge b*, com-
bined with their passage aslant from one side of one screw to the other side of the
opposite screw, and the use of the "up-pull" from the iron frame a most efficient
contact, or induction, with the sound board f is obtained, whilst ready means of
regulation of distance between the two parts 6 and 6, to regulate strength of
bearing upon the string d, can be attained by turning screws 5 in one, or other
direction.
The improved construction of bridges i, j, shown more clearly by Figs. 12, 13,
14, 17 and 18, enable those parts to be cast in one with the iron frame. The
diapason bridge (Fig. 17) has notches so formed as to afford free passage and
area for vibration to the usual strings, whilst the top or wrest plank bridge is
notched at to afford free passage to the diapason strings d.
The pressure bar g is of improved construction; and is so formed that it can
take a separate bearing on each set of strings, by its opposite parts or edges g¹, I²,
such separate bearings being each approximately equal in extent and being
designed to equalize the strains imparted to the two bridges i and j. It will be
seen that whilst the edge gl (Fig. 13) rests on the usual strings e, the opposite
edge is clear of them, and said strings pass from the wrest pins to the edge g¹
and thence, over the bridge j, to rest on the bridge i, and thence away to the
belly bridge c. Now the edge g² of bar y rests on the strings & in their passage
from their wrest pins, under the notched edge g¹ and clear thereof, to the bridge j,
said strings resting thereon, and passing over bridge to the bridge d before
described.
The construction of the iron frame a, with upper and lower ledges for up-pull
or down-pull respectively, and the facility afforded for the application of the
hitch pins in series, on either upper or lower ledges, is of importance; whilst
the pins for the ordinary strings are kept clear and below (see particularly Figs. 22
and 24).
In the modified form of our improved pressure bar g, shown by Figs. 26
and 27, the solid and relatively fixed part g rests at its bottom edge on the
strings e and the adjustable pins or screws g², (the equivalents of the edge g²,
Fig. 25) rest on the strings d. These screws are carried in tapped holes in the
slotted bar g, the projecting lip g of which bar embraces the lower rear edge
of bar g', forming an abutment to prevent upward relative movement of these
parts, whilst screws y passing through holes in g³, are secured in tapped holes in
bar gl. Adjustment of the pressure of the pins g is regulated by screwing them
up or down in the taps in the bar g³.
In the modified construction shown by Figs. 28
presses on the strings e and the projecting parts
The bar g rest on the strings d, whilst the
interstices.
and 29; the bar, by its edge g¹,
of the removable portion of
strings e pass free through the
In Figs. 26, 27, 28 and 29, a modified construction of bridges resting on the
iron frame is shown, in place of casting the bridges and iron frame in one.
Herein the diapason strings & pass over and rest on the bridge j, thence under
the pressure bar as described and through apertures cut in the 'cush"
bridge i, upon which cush the ordinary strings bear, in their passage to and under
the other edge g¹ of the bar g.
66
or
The forms of the notches, or apertures, cut in the "cush" bar or bridge i can
be seen at, in the lower halves of Figs. 27 and 29. The description of the
preceding Figures 20 to 29 may be applied to Figs. 30 to 33, substituting the

page_text: series of slotted and tooth provided plates g², for the screws or projections g²
therein described.
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 :-
In a pianoforte in which extra strings are provided adapted to give a double
sound, or diapason tone, when desired;
1. The construction or arrangement of the bridges and parts cooperating there-
with, substantially as and for the purpose set forth.
2. The constructions and arrangements of parts for supporting and adjusting the
extra or diapason strings relatively to the usual strings, whereby the strings pro-
ducing the extra tone or sound are carried over the belly bridge without neces-
sitating injurious cutting or weakening of that bridge, substantially as and for
the purpose set forth and shown by the drawings.
3. The construction or arrangement of the parts of the bridges for the extra
strings for the diapason tone in combination with the means for obtaining an
up-bearing, or down-pull, or draught, on the said "strings, substantially as set
forth and shown in the drawings.
4. The construction of iron frame and co-operating parts for attaining the up-
pull or bearing for the series of extra or diapason strings, as set forth.
5. The construction and use of two metal bridges supported on the wrest plank
in combination with the pressure bar, substantially as and for the purpose set
forth.
6. The construction and use of a pressure bar designed to equalize the strains
on the respective sets of strings, borne upon by its opposite bearing surfaces,
substantially as set forth and shown by the drawings.
7. The construction and arrangement of the parts so as to enable a divided,
or second, sound board to be used, substantially as described and shown with
reference to Figures 6 and 7; 8 and 9.
8. The construction of damper head, adapted to be regulated to act on the
ordinary and the additional strings, as described and shewn by the drawings
Figs. 19 and 20.
9. The various constructions of pressure bars and iron-frame parts for support-
ing and regulating the tension of the extra or diapason strings, substantially as
described and shown with reference to Figures 21, 22, 23, 24, 25, 26, 27, 28
and 29.
10. The construction of bridge, in adjustable parts, for the regulation of the
tension and support of the extra or diapason tone strings, substantially as set
forth with reference to Figs. 10 and 11.
11. The construction and use of "cushi" bars for the support of the ordinary
strings and the passage therethrough of the extra or diapason strings, as set forth.
12. The various constructions of parts adjustably attachable to the pressure
bars for obtaining a bearing upon the extra or diapason strings, substantially
as described and shown by Figs. 26, 27, 30, 31, 32 and 33.
13. The general arrangement and combination of the strings, ordinary and
extra, for diapason tone with the parts for straining and supporting the same in
proper relative positions, substantially in the manner and for the purpose set
forth, and as shown by the drawings.
n
WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicants.