Year: 1888

page_text: I, WILLIAM HENRY DUTTON, a citizen of the United States, residing in the City
and County of Philadelphia, in the State of Pennsylvania, United States of America,
Gentleman, 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
-
My invention relates to that class of pianos which are technically known as
"Uprights," and in which the sounding board occupies a vertical or approximately
vertical pline
Heretofore in pianos of the foregoing class the upper or head portion or head of the
frame work, of which head the pin block is a member and constitutes the front face,
has been constructed or framed as a solid, or practically solid, and rigid cross head or
cross frame incapable of vibration
The principal object of my invention, broadly stated, is the construction of an
upright piano, in which piovision is made for rendering the upper part or head of the
frame work of the instrument a sheleton, or box-like, musically-vibratory framing,-
which to such extent is itself a musical instrument, and in which provision is also
made for venting the tone existing to the rear of the sounding board within the casing
directly upward through the skeleton head of the casing, and for, above the top level
of said head, throwing it forward into the apartment within which the instrument is
placed
A further object of my invention is the improvement of the musical quality and
tone of upright pianos in general, first, by the provision of a supplemental or front
sounding board in the form of a sounding dome adapted to encase the action and to
transmit and magnify the musical tone from the vibration of the strings, clarified, or
filtered, so to speak, from the sounds arising from the friction and percussion of the
action and the imperfect tones due to dust or action-noise, and second, by the pro-
Vision of a piano casing adapted to encase the framework, the action, and the above
named supplemental or front sounding board, the front of which casing is virtually
sounding board because the panel portions of said front contain adjustable sounding
and reverberating slats which when closed subserve the purpose of a sounding board
and when open subserve the purpose of a reverberating device, which when gradually
opened and closed produce the effect of an organ swell by gradually at the will of

page_text: and magnify the musical tone from the vibration of the strings, and to afford vent
to the full tone and power of the vibi itions and, by reverberating them, to improve
their quility
The foregoing objects I attain by a construction 1 good form of a convenient :
embodiment of which is represented in the accompanying drawings and described
in this specification, the particular subject-matter claimed as novel being hereinafter
definitely specified
In the accompanying drawings,
Figure 1 is view in perspective, partially sectional or broken way to exhibit
construction, of in upright piano embodying my improvements
Figure 2 is a side sectional elevation of the instrument represented in figure 1
Figure 3 is a view in perspective of the sounding dome removed from the
instrument
Figure 3 is
fragmentary side sectional elevation of the slat pedal and the i
spring catch for maintaining it depressed
Figure 4 is a view in perspective of the instrument represented in figure 1
Figure 5 is a perspective view of the back of the instrument represented in
figures 1, 2 and 4
Figure 6 is a front elevational view of the fixed and sliding slat frames and of 2
convenient devices for moving the one within the other, the panel frame to which
the fixed slat frame and the springs of the sliding slat frame are secured, being, for
clearness, omitted
Figure 7 and Figure 8 are, respectively, sectional plan views of the frame shown
in figure 6, representing in figure 7 the parts in the positions which they occupy
when the fi ames are moved together and the openings between the slats consequently
closed, and in figure 8 the sud parts in the positions which they occupy when the
sliding frame is moved backward to form openings between the slats
Figure 9 is a perspective view from the rear, of the fixed and sliding shat frames and
the devices for moving the one within the other the panel frame to which the fixed a
slat frame and the springs of the sliding slat frame are secured being for clearness
omitted
Similar letters of reference indicate corresponding parts
Referring first to the sheleton head and to the reverberator -In the drawings, A is
the casing, which may be of any usual or preferred character, a ne the sides thereof, a
B is the ordinary sounding board, which occupies a plane slightly inclined from the
verticil, is stepped or fistened at its base in any usuil manner, and as to its upper
portion is connected with the pin bloch C which is an integral portion of and the front
face of the head upper portion or top of the framework of the instrument
Dare the sting D× the iron plate for sud strings and d tuning keys in the pin 4
block with which sud strings are connected
E are the usual vertical fruming studs of the framework, spaced apart such distance
ns is usual, fried it their upper portions between the pin block at the front and,
preferably transverse back board F at the bich, and at their lowest portions framed
to a base block G, or otherwise supported and maintained is convenience of manufacture
may dictite
His the key action, which may be of any preferred character, I are the heys, and
J the key bottom upon which sud keys are mounted
A back to the casing may be used and serve to inclose or hound the interspaces and
open spaces existing between the sounding board and the framing studs
5
Each framing stud 19, from the base block or basal support throughout its extent to
the top level of the back board and pin block, independent of and disconnected from
every other framing stud, so that between said studs and the pin block and the back
board, or other bick, tre formed continuous interspaces, channels, passage ways, or
openings, which I term "tone conductors" L, and which extend completely through 5
the framed box like structure which constitutes the upper portion or head of the
frame work of the instrument

page_text: By virtue of the foregoing construction the entire upper portion or head of the
piano framework is formed into a horizontal, skeleton, vibrating frame, which is
bounded by the pin block in front, the backboard, back to casing, or rear wall, at the
back, and the outside framing studs at the sides or ends, and in which exist transverse
divisions formed by the upper portions of the framing studs, between which divisions
and the aforesaid bounding members of said vibrating frame the tone conductors exist
and extend from the rear of the sounding board entirely through the upper portion,
top platform, or head of the framework of the instrument
The precise form of the tone conductors, as such, is, of course, immaterial, but it is
preferable, for simplicity and economy of construction, that they should be rectangular
chambers or openings substantially of the character represented It is no disadvantage
that a back to the casing or a back board should be employed, but it is not essential,
especially where it is intended to place the instrument against a wall
The upper portion or head of the frame work 19 surmounted by a longitudinally-
extending reverberator or tone-deflector M, which may be of any preferred con-
struction, but the office of which is to turn, deflect, or overbei ite, the tone which rises
through the tone conductors above the top of the pin block, forward to the front of
the instrument, and into the apartinent within which it is placed
To this end therefore the said reverberator is well made as to its deflecting surface
of cucular or parabolic cross-section, it extending longitudinally across and from the
extreme back edges of the openings or mouths of the tone conductors upward and
forward more or less directly over said several openings or mouths
Either in connection with, or without, the reverberator, I contemplate in some
instances employing valve or lid for the tone conductors, hinged upon the upper
surface to the head of the frame work, which when dropped will close the top
openings of the tone conductors, and which when raised and lowered will serve as
swell to said tone conductors This lid may be operated by a draw stop, by a knee
or elbow lever, or by a pedal as desired
It will now be understood that the gist of my improvement so far as already
described, resides in making the head, upper portion, or top of the framework of the
instrument instead of a solid mass of inateriil, sheleton, a framed-together, or a
box-like structure, capable of vibration and therefore itself musical instrument,-
such result being most readily secured by the removal or omission of the filling pieces
between the studs, and being accompanied by the concomitant result that the openings
so produced by the removal of the aforesaid filling pieces, constitute ducts, or
channels, which pass up through the top of the frame-work, ina, being in communica-
tion below with the interspaces and open spaces existing to the rear of the sounding board
between the studs and sides of the casing, serve as tone conductors to vent the tone
existing within the casing to the rear of the sounding board out through the top of
the instrument and against the reverberator or deflector superimposed above sud
ducts, and acting to deflect said tone forward or to the front of the instrument ind
into the apartment within which it is placed
It will he apparent that the pin block itself is preserved intact, and that it and
the back-board, or other back, when framed in with the studs form i framework of
entirely sufficient strength
The dome or action tone chest may, if desired, be omitted although, when
employed, it serves to insure against the escape of the tone except through the
tone conductors Considered simply as a hollow skeleton or framed box, the skeleton
head which I employ gives better musical results than have heretofore been possible
with upright instruments as ordinarily made
I have herein spoken of the tone conductors as being "in communic ition” with the
spaces to the rear of the sounding board By this statement, however, I am not to be
understood as meaning that the communication is necessarily a physical one, and that, for
instance, a ball dropped into a tone-conductor would necessarily fall to the base of the
instrument behind the sounding-board, because musical tone, consisting of vibrations,
and being increased and enhanced, rather than diminished or deteriorated, by the
interposition of a thin piece of wood,-would be emitted through the tone conductors

page_text: notwithstanding the interposition of transverse thin pieces of wood, in the form,
for instance, of a bottom to the box-like structure which constitutes the skeleton head
of the framework
Referring, second, to the sounding dome in front of the action, this dome S 18
composed of such thin wood is sounding boards are usually made of, and is preferably
of the form represented in the drawings, that is to say having a front wall 8, a
bevelled roofs, and cheek or side pieces which, being connected with both, serve
to retain the relative angular position of the wall and roof
Form, however, is not of the essence of this device, and the only requirement of the
dome, so far as its form is concerned, is that it should encase the action and extend from
the pin block as the point of its upper attachment completely or practically across the
breadth of the framework, from side to side of the casing, and down close to
the keys
The mode of attachment is likewise immaterial, but the attachment must be of such
character that the dome, although preferably capable of removal, 13 yet, while
attached, a permanent fixture within the instrument, having such connection with the
pin block and sides of the casing as to readily receive and transinit the vibrations of the
pin block, sides of the casing, and instrument is in entirety
To the foregoing end I prefer to provide the 100f or upper portion of the dome
with a single flanges, or with a series of flingus, conforming to the plane of the
front fice of the pin block, and to provide other flanges sit the sides, through
holes in which, by the aid of wooden thumb screws, the desired attachment may
effectuated
be
Buttons may be employed as a substitute for the thumb screws, and other and
entirely different means for effecting retention may, of course, be resorted to
The dome serves to transmit and magnify the vibrations it receives from the
members with which it is connected, and in so doing incidentally serves to confine the
noises of percussion and friction of the action which, unlike purc musical tones, do
not readily pass through sound-board wood, while being to the front of the
instrument and close to the player it supplements the action of the main sounding
board, augmenting the volume of tone and distributing it, so to speak, throughout the
apartment
Referring, third, to the uljustable sounding and reverberating slats, a³ is the upper
panel frume of the front of the casing, ind a the lower panel frame of said front
which lies below the key bottom Each of these panel frames is preferably formed
with continuous rails of thin wood, and with end stiles but no mullions
Each frame is adapted to contain a panel composed entirely of a series of suitably,
but preferably vertically, disposed sounding and reverberating slits w and
The construction, application, and means for operating the slats, being the same in
both panel frames, I limit my description to the upper frame
Within the aforesaid panel frame is contained i fixed slat fiame W, which fills the
panel opening of said frame, and is rearwudly extended therefrom to a desired depth
The region of joinder between the aforesaid two frames may be ornamented by beads,
chamfers, or otherwise at will
V is a sliding slat frame conformed to snugly fit and have a telescopic, or in and
out, movement of a predetermined extent within said fixed slat frame
Each of the slat frames is provided with series of parallel slats w and v, spaced a
given distance part The slats composing the series of one frame are in their
mounting within their frame alternated with respect to the mounting of the sluts
composing the series of the other frame, so that the openings between the slats of.
either frame register with the slats of the other frame, and, when the sliding frame is
moved or closed up within the fixed frame, the edges of the slats of the respective
frames meet or lap and close the openings
The form of the slats is not material I prefer, however, to make them of semi-
cylindric form, the convexity of the slats of the outer frame and the concavity of the
slats of the inner frame facing toward the front of the instrument
All of the slats of both series are preferably parallel, but the general direction or

page_text: trend of the slats is not important In the drawings I show them as vertically
disposed, and the slats of the respective series as semi-cylinders, of the same diameter,
and so staggered or disposed that their longitudinal edges, when the frames are
closed in, are adapted to meet and abut together, the double series in such position
presenting from above, or viewed sectionally as in figure 4, a continuous and regular
serpentine line
The slits are each made of thin material, preferably sounding-board wood, so as to
be thoroughly resonant
When the sliding frame is slid in to close the openings between the slats of the
respective series, the slat-composed panel shown in the drawings presents from the
front the appearance of a uniformly corrugated surface composed of crests and
hollows, and constitutes a sounding face to the casing
While, as stated, I prefer the semi-cylindric form of slat, I do not confine myself to
such form, and contemplate using slats which are, sectionally considered, either flat,
slightly curved, angular, semi-elliptic, or semi-polygonal
I do not moreover confine myself to mounting the slats within slat frames or within
a panel frame strictly as such, because, while such a mounting as that which I have
described is conven.ent, it is apparent that the invention is broad enough to cover
any such application of the slats to the front face of the casing as a cabinet maker
would naturally resort to
The object of this invention, so far as the mounting and moving of the slats 1s
concerned, being to most cheaply and readily occasion the movement of one sories
of slats toward and from the other series, it is obvious that I can resort to many
constructions for securing this result, each series being, if desired, mounted in a
movable fiume, and the two frimus being both relatively movable, or either one
fixed and the other relatively movable I prefer, however, the construction which
I have represented and described, and in which the inside and innermost frame
moves
1
Many mechanical devices operated by pedal, a draw-stop, or a hand, knee, or
elbow lever, may obviously be adapted to effectuate the movement of either or both
slat frames I find it convenient to employ a pedal and lever connection, operative
only upon the inner slat frame, and of the following construction
-
Tis a slat-pedal, being a supplemental pedal conveniently disposed between the
loud and soft pedals of the action, and operating upon a horizontal first-order pedal
lever t, connected with a vertical pedal rod t*, suitably housed or stayed, in the form
of application represented, just inside of the right side of the casing This pedal rod
rises in pline parallel with and adjacent to the plane of the inside face of the pedal
frames, and its upper extremity comes immediately beneath the horizontal arm of a
vertically disposed right angular crank, which I term the rocker bell-crank t2,
fulcrummed against the inside fice of the upper panel frame, the vertical arm of
which crank bears agunst a lug ux projecting radially forward from a vertically
disposed rock shaft U suitably housed or journalled, conveniently, within extended
extremities to* of the flat upper and lower rails of the fixed slit-frame The
roch shaft extends beyond both of its bearings wx, being suitably stepped with
respect thereto, ind, is to its extended extremities, is fixedly equipped with two
right angular bell crank levers, which I term frame-cranks u, which lie, in a
horizontal plane parallel respectively with the planes of the upper and lower rails
of the fixed slat-frame, immediately against the respective outside faces of said ruls,
and the longitudinally extending arms of which frame-cranks bear against the
cheeh-pieces *, or hindred abutments, connected with or being a part of the near
end of the sliding slit-frame The transversely extending arms of the frame-cranks u¹
are, at their outer extremities, provided with links Z which extend longitudinally along
the respective upper and lower rails of the fixed slat-frame, and are pivotally connected
at their far extremities to the transverse members of counter-frame-cranks =, con-
veniently fulcrummed upon the aforesaid upper and lower ruls of the fixed slat-frame,
and engaging by their longitudinal arms counter-cheek-pieces upon the far end
of the sliding slat-frame The duplication of the frame-cranks and cheek-pieces, by

page_text: the connection with them, through the links, of counter-frame-crinks and counter-
cheek-pieces, is simply for the purpose of equalizing thrust upon the sliding frame
and preventing its binding within the fixed slat-frame
✗ are a series of frame springs, being preferably flat springs respectively secured
at one extremity to the inside face of the panel frame, and as to the other extremity
bearing upon the back of the sliding frame The office of these springs is to
maintain the sliding frame normally within the fixed frame and the respective scries
of slats closed together
Such being a preferred contrivance for occasioning the moving of the sliding slat
frame its operation will be readily understood
Depression of the pedal is attended, through the pedal lever, with an elevation of
the pedal rod, accompanied, in turn, by a right hand deflection of the rocker bell-
crank, by a partial oscillation of the rock shaft, and by such a throw of the frame-
cranks ind counter-frame-cranks as to occasion, by the thrust of sud cranks gunst
the cheek-pieces, in inward movement of the sliding frame sufficiently strong to,
for the time being, overcome the resisting stress of the frame-springs
In order to conveniently operate the slats of the lower panel, I provide the pedal
lever with a supplement il pedal rod t³, which acts upon supplement il rocker bell-
crank t* co-operating with set of devices, applied to the aforesaid lower panel for
occasioning the movement of its frame, entirely similar to the set above described
in connection with the upper pinel
In order without continued foot pressure to maint un the pedal depressed against
the stress of the frame strings, and the slats in consequence open, it is convenient
to provide the pedal with a spring-actuated retaining catch t, figure 3, the hooked
extremity of which is by spring to, sccured to the catch, ind, icting gunst the
face of the casing, retained in notch a in sud casing, when once by the depression
of the pedal, engaged therein Any other contrivance operative to the same purpose
can, however, be substituted for the spring catch
Such being description of a convenient embodiment of my improvements, it is
only necessary to add that the slats, when closed, transmit and magnity the vibrations
of the instrument, giving forth, after the manner of a sounding board as such, pure
tone only, and, when open, afford vent to the tone existing within the instrument,
it being, however, augmented in volume and improved in quility by reverberating
upon and from their surfaces
It is apparent that the slits may be employed solely in the upper panel frame, the
lower pinel frame being filled by a solid or open pinel of any preferred construction,
or may be employed solely in the lower panel frame and not in the upper
Having now described the several improvements which constitute my invention, it
is proper to stite that the skeleton head either with or without the reverberator can be
employed without the sounding dome or without the reverberating slats, or without
both, and that either the slats alone or the sounding dome alone or both together may
be applied to an upright piano the head of which is not skeletonized The best results,
however, flow from an instrument in the construction of which all of the foregoing
improvements are combined
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the sime is to be performed, I declare what I claim is
-
1 An upright piano, the upper portion or head of the framework of which is of
skeleton or box-like structure, in order to runder said upper portion of said framework
a musically vibratory framing, substantially as set forth
2 An upright piano, the upper portion or head of the framework of which is a
skeleton or box-like structure the component members of which are so joined or
framed together is to embody between them openings or tone conductors which both
render said head a musically vibratory framing and afford top channels of egress for
the tone which exists to the rear of the sounding board within the casing of the
instrument, substantially as set forth
3 An upright piano, the upper portion or head of the framework of which is

page_text: channeled or provided with openings or tone conductors which render said bend a
musically vibratory framing, and afford top channels of egress for the tone which
exists to the rear of the sounding board within the casing of the instrument,-and
which is as to its said head provided with a reverberator, or other suitable tone-
deflecting device, which serves to deflect the tone escaping from the openings or tone
conductors forward or to the front of the instrument, substantially as and for the
purposes set forth
4 An improved framework for an upright piano, consisting of a pin block, if
desired back-board and a series of vertical framing studs disposed between said
pin block and back-board at given intervals and without intermediate filling blocks,
in such manner as to constitute the head of the framework a skeleton or vibratory
framing, and to form in it a series of vertical passages or tone conductors, sub-
stantially as set forth
5 An upright piano having sounding dome or sounding board in front of the
action, substantially as and for the purposes set forth
6 In an upright piano, a sounding board in front of the action, formed as a dome
and secured to the pin block at its upper portion and to the sides of the casing at its
sides, substantially as set forth
7 An upright piano the front of the casing of which contains or embodies a
sounding board surface composed of slats, for the purposes set forth
8 An upright piano, the front face of the casing of which contains a sounding-
board-surface consisting, essentially, of two series of alternating slats respectively
disposed in parallel planes, substantially as set forth
9 An upright piano, the front face of the casing of which contains a sounding-
board-eurf ice consisting, essentially, of two series of alternating slats respectively
disposed in parallel planes, and which is provided with suitable means for occasioning
the approach or recession of the respective series of slats, substantially as set forth
10 An upright piano, the front face of the casing of which contains panel of
slats, the said panel consisting of two series of semi-cylindric, reverberating, alter-
nating, slats lying in parallel planes, and, by series, reversely disposed in order that,
when the slats of one series are brought into contact with the slats of the other series,
the said slats may register edge to edge and constitute a corrugated panel surface,
substantially as set forth
11 The combination, to form the front face of the casing of an upright piano, of a
panel frame, shat frame contained within said panel frame and having a series of
separated slats and 1 second slat frame, containing a corresponding series of sepirited
slats alternately disposed with respect to the slits of the first series, and which is
movable with respect to the slat frame first referred to, in order to occasion the
meeting or lapping of the edges of the slats, and thereby to provide, or to close,
openings between the slats of the respective series, substantially is set forth
12 The combination, in an upright piano, of a panel frame for its front face,-a
slut frane cont uned within said panel frame and having a series of separated slats,-
1 second slat frame, contuning corresponding series of separated slats alternately
disposed with respect to the slats of the first series, and which is movable with respect
to the slit frame first referred to, in order to occasion the meeting or lapping of the
edges of the slats, and thereby to provide, or to close, openings between the slits of
the respective series, and suitable means, under the control of the player for
occasioning the relative approach or separation of the slats of the aforesaid respective
series, substantially as set forth
Dated this Floyenth day of May A 1) 1888