Improvements in Electrical Attachments for Pianos.
Year: 1892

page_text: Date of Application, 8th Mar., 1892-Accepted, 2nd July, 1892
CUMI DI DI ECIFICATION.
Improvements in Electrical Attachments for Pianos.
We, FRITZ ANTON FELDKAMP, Electrician, JACOB SCHOENHAAR, Engraver,
and EMIL EDUARD LEIR, Butcher, all of 277, Springfield Avenue, in the City
of Newark, County of Essex, and State of New Jersey, in the United States of
America, do hereby declare the nature of our 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 an attachment intended for use in connection with pianos
controlled by an electric current and a contact making and breaking apparatus used
in connection with a perforated sheet of paper, whereby, by means of these several
devices and the electrical system, a piano can be made to reproduce automatically
any piece or composition, in exact accordance with the intentions of the composer,
not only as to rythm and melody but also as to expression, as each and every single
note can be played either in its normal strength, "piano," "forte," or "fortissimo,'
as marked by the composer, and the "crescendo" and "decrescendo" can be exactly
reproduced.
3.
The primary object of the present invention is to provide a piano with an
apparatus connected with the action of the piano for operating the same by means
of an electrical current, and whereby any music from the simplest air to the most
complicated symphony can be played with exactness and feeling, either by means of
electricity or by hand, as may be desired, without first removing, arranging or
rearranging the apparatus or any part of it.
The invention consists, generally, in the organization of the following systems of
apparatus, and combining in one instrument all or any of the specific features as
may be desired for the particular purpose, embracing therein, first, a contact making
and breaking apparatus, into which is fed a perforated sheet, through the per-
forations of which electrical contact is made by means of contact arms or levers
with suitable mechanism, and a motor for driving the apparatus; secondly, suitable
mechanism connected with the action of the piano, consisting of electro-magnets
which are put into and cut out of circuit according to the contact made by the
contact arms or levers in the contact making or breaking apparatus, whereby any
one or more actions in the piano can be operated and the corresponding strings are
caused to vibrate; and finally, the organizatious of the electrical circuits for
operating the contact making and breaking apparatus and the electro-magnets for
working the actions in the piano.
The contact making and breaking roll or cylinder in the contact making or
breaking apparatus is also the paper or sheet-carrying roll in which holes or per-
forations of the necessary lengths are made, the paper or sheet traversing upon
said roll beneath the points of the contact arins or levers, so that when one or more
holes in the sheet have been brought under one or more of the contact points of the
arms or levers, said contact points drop upon the metallic surface of the cylinder or
roll and an electrical current is established and is free to pass through a line of wire
connected therewith and with the proper magnet connected with an action in the
piano, thereby rendering the invention essentially valuable in places where there
are no players to perform on the keys of the same.
Another object of the invention is to provide a contact making and breaking
device, which by means of its construction and the number and arrangement of the
contact arms will automatically cause the piano to perform in imitation of the
nimbleness and dexterity of the human fingers and thereby give feeling and expression
which is so very essential to give life to the language of music.

page_text: The invention further consists of certain arrangements and combinations of parts,
such as will be hereinafter more fully set forth and finally embodied in the clauses
of the claim.
In the accompanying drawings,
Figure 1 is a diagrammatic view showing the arrangement of the electrical
circuits and operative mechanism embodying the invention.
Figure 2 is a plan view of the contact making and breaking apparatus, and
Figure 3 is a front view of the same, both views showing in connection with the
apparatus, a small electrical motor and intermediately arranged clock-work for
operating and regulating the speed of the contact cylinder over which the perforated
sheet is fed, and a comb, having teeth of non-conducting material, which project
down between the contact arms and thereby insulate one from the other.
Figure 4 is an enlarged vertical cross-section of the contact cylinder.
Figure 5 is a view of the contact cylinder and a modified form of contact arm, in
this instance being a spring-arm.
Figure 6 is a plan view of several of such spring-arms and part of the contact
cylinder.
Figure 7 is a part of such perforated sheet.
Figure 8 is a side view of a piano-action which is of any well-known construction,
and an electro-magnet connecting with said action for causing the hammer thereof
to strike a string and vibrate the same, when the armature has been attracted by the
magnet, the several parts of mechanism in said view being shown in their inoperative
positions.
Figure 9 is a similar view of the several parts of mechanism in their operative
positions.
Figure 10 is
levers, and
4
front view of the several electro-magnets and their connecting
Figure 11 is a vertical section of one of these magnets.
In said drawings, A is the contact making and breaking apparatus secured to a
base a for securing the same in any suitable position to the piano. Said contact
making and breaking apparatus consists essentially of a cylinder a provided with
guiding shoulders a for retaining the perforated sheet in its proper position upon
the periphery of the cylinder. Said cylinder is provided on its ends with journals a³
and within bearings a secured to a support a are pointed adjusting screws a
which extend into indentations in the ends of the journals, as shown in Figures 2
and 3.
The cylinder rotates upon said adjusting screws, and can be made to run perfectly
true. The table a is supported by means of columns a secured to the base a.
Upon one of the journals is secured a gear wheel a³, which projects through said
table and meshes with a pinion of clock work mechanism C, upon the main arbor
of which is arranged a suitable motor C¹.
As will be seen from Figures 2 and 4, upon the upper side of the table a³ and on
opposite sides of an opening a therein, through which the periphery of the
cylinder al projects, are arranged binding posts d, and each post is secured to the
table as by means of a screw d', as shown in Figure 4. To each post dis pivoted
by means of a pin d² a contact arm d³ having a contact point d and preferably
provided with a tension spring d³ for normally holding each contact point of the
levers down upon the periphery of the cylinder a or the paper thereon.
prefer to use four of such contact arms to each action in the piano, and these are
connected with each other, either at the top as in Figure 2, or at the bottom as in
Figure 4, by means of resistance coils o, o and o² and from one of the arms ³
extends a wire which connects with an electro-magnet in connection with the battery
or other source for deriving electrical current.
We
Above the table a secured thereto by means of a post a¹0 at one end and to the
housing of the clock-work C at the other end is an insulating device which consists
of a bar e laving insulating strips e¹ of non-conducting material, which extend
between two adjacent contact arms, thereby completely insulating them one from

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to vibrate.
In lieu of the contact arms shown in Figure 4, we can use spring-contacts do,
each provided with a pin d for making contact through one of the perforations bi
in the sheet b. The action of each of these arms is similar to that illustrated in
Figure 4.
In the drawing, Figure 1, as aforesaid, represents a theoretical diagrammatic view
of the principal operative devices and circuits.
The main circuit wire y, in which is arranged any suitable battery (or other
electric current-deriving source, is attached to one of the adjusting screws a",
whereby a complete circuit can be established through said wire, through the
journal a³ and cylinder a', through any one of the perforations in the sheet b, and
one of the contact arms d³, through any one of the branches g', ², 93, 9ª, 9³, 9°; etc.,
connected with said arms ³, magnetizing the proper one of the electro-magnets h',
h², h³, hª, 15, 1º, etc., and back through the main wire k to the battery or other
electrical source. A resistance K can be placed in this circuit to vary the strength
of the current, as the occasion may require.
When the end of the wire has been connected with the cylinder in this manner,
a second circuit is established through the wire g, the gear wheel as, through the
clock-work C through the main arbor c', the motor C', the wire i, to the resistance i',
which can be dispensed with, if desirable, and back through the wire to the
battery.
In this manner the same current which operates the magnets connected with the
actions in the piano, controlled by means of the contact making and breaking
apparatus, also magnetizes the magnets in the motor, sets the same in motion,
rotates the arbor e of the clock-work, which operates the gear wheel a³ and in turn
rotates the cylinder a' of the contact making and breaking device. The speed of
the motor Ci and that of the cylinder can be controlled by a resistance i con-
nected with the motor or shunt circuit, shown in Figures 1 and 2.
Suppose the current from the electrical source has been turned on, and the
prepared sheet moves upon the cylinder a', then the motor by means of the inter-
mediately placed. clock-work revolves said cylinder and with it the sheet passes
beneath the contact points of the arms and when any one of said points extend
through any one of the perforations in the sheet, a complete circuit is
established.
Suppose the contact point on the contact arm ³ at I, (see Figure 1) has made
contact in this manner with the cylinder a¹, then the current passes through the
line to the magnet which attracts its armature arranged on a lever j',
pivotally secured to a post, and upon the upper end of said lever is a forked
arm, which is pivotally connected with the action of the piano, as shown. When
the armature j is attracted by its magnet then the arm ³ lifts a rod / of the action
and causes the hammer to strike the string 12, as indicated in Figure 9.
The several magnets, each one of which is connected by means of a system of
lever just described with an action, are arranged upon a fixed support J secured in
the piano, and the forked end of each arm engages with a pin m in the fastening
plate msecured to the arm of the action, as clearly shown.
As bas been stated, there are four contact arms and four correspondingly arranged
perforations in the sheet for each action in the piano.
When the arm d* at I makes contact, then the armature jis attracted with great
force, causing the hammer to strike violently and playing "fortissimo." The
same hammer can be made to act with less force and play "forte," when contact is
made with the arm dat II (see Figure 1), the current passing from said cylinder
through said arm on the post at II, through a resistance coil o to the post d at 1,
and through the wire g to the magnet, the current being weakened by the
resistance o and hence the magnet is attracted with less force and the string
produces a "forte" tone. When contact is made with the arm d³ at III, two
resistance coils o and ol are thrown in, as will be evident from Figure 1, and the

page_text: tone of the string will be normal; the current and hence the attractive force of the
magnet having been decreased. When it is desired to have the string vibrate with
a piano" effect, then arm d³ at IV is caused to make contact and three
resistances o, o¹ and o² are thrown into line.
$6
In the same manner contact is made at V, VI, VII and VIII, and the current
passes through the line g² to another magnet 12, and so on, contact can be made
with any one of the contact arms, or several arms d³ can make contact at one time
causing a piece to be produced with great expression.
In Figure 7, at 1, 2, 3 and 4, is shown the perforations for the contact arins d³
at I, II, III, IV in Figure 1, and at 1", 2", 3" and 4" in said Figure 7, those for the
contact arms at V, VI, VII and VIII, in Figure 1.
Of course it will be evident that the strength of the current and hence that of
the tone can be greatly modified by using more than four contact arms for one
action, but for ordinary purposes four contact arms are preferable. If desirable a
smaller number of such contact arms may be employed.
In order to operate either the loud or soft pedals connected with the piano, two
of the contact arms, as at Y and Z, Fig. 2, are respectively connected by means of
wires Gland G² connecting with electro-magnets, which, when contact is established
through a perforation by means of either of these contact arms, causes an electro-
magnet (not shown in the drawing) to raise the arm 13, shown to the left of Fig. 8,
and thereby raise the pedal rod, as will be clearly understood.
The advantages of this arrangement of the contact arms and the different
resistance coils is that any music from the simplest air to the most complicated
symphony or rhapsody can be played by the instrument with precision, the "forte"
and "pianissimo," and the "crescendo" and "decrescendo," as marked by the
composer being exactly reproduced.
The quantity of electricity necessary to work the piano is exceedingly small, and
can be drawn from any electric light or other conductor, or from a storage battery
or accumulator, which latter needs charging only at intervals of several weeks.
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. The combination, in a piano, of the action thereof, electro-magnets attached to
a fixed support, and mechanism connected with said magnets for electrically con-
trolling the action, consisting essentially of an arm provided with an armature j,
and pivoted to a post, a second arm ³ connected with a rod. of the action for
operating the same, when the armature has been attracted by its magnets, and an
electrical circuit connected with said magnets, a contact making and breaking
device in said circuit provided with contact arms and contact points, for making
and breaking the circuit, and causing said magnets to operate the mechanism con-
nected with the action, as set forth.
2. The combination, in a piano, of the action thereof, electro-magnets attached to
a fixed support, and mechanisin connected with said magnets for electrically con-
trolling the action, consisting essentially of an arm, provided with an armature j
and pivoted to a post, a second arm connected with a rod of the action, for
operating the same, when the armature j has been attracted by its magnet,
substantially as and for the purposes set forth.
3. The combination, in a piano, of the action thereof, electro magnets attached to
a fixed support, and mechanism connected with said magnets for electrically con-
trolling the action, local circuits in which said magnets are placed, a main circuit,
a contact cylinder connected at one end with the main circuit, a series of contact
arms or levers connected with said local circuits for establishing electrical contact
with the periphery of said cylinder, substantially as and for the purposes set
forth.
4. The combination, in a piano, of the action thereof, electro-magnets attached
to a fixed support, and mechanism connected with said magnets for electrically

page_text: controlling the action, local circuits in which said magnets are arranged, a main
circuit, a contact cylinder for carrying a perforated sheet, held in bearings and
provided with journals; one of which is connected with said main circuit, a series of
contact arms connected with said local circuits, adapted to make contact through
the perforations in the sheet with said contact cylinder and said arms being con-
nected with said local circuits, a gear wheel a on one of said journals on said
cylinder, a clock-work mechanism, a motor connected therewith, and a local circuit
between said motor and the main circuit, substantially as set forth.
5. The combination, in a piano, of the action thereof, electro-magnets attached
to a fixed support, and mechanism connected with said magnets for electrically
controlling the action, local circuits in which said magnets are arranged, a main
circuit, a contact cylinder for carrying a perforated sheet, held in bearings provided
with journals, one of which is connected with said main circuit, a series of contact
arms connected with said local circuits, adapted to make contact through the
perforations in the sheet with the contact cylinder and said arms being connected
with said local circuits, a gear wheel a on one of said journals on said cylinder, a
clock-work mechanism, a motor connected therewith, and a local circuit between
said motor and the main circuit, and a resistance in said circuit, substantially as
set forth.
6. The herein described contact making and breaking device, consisting
essentially of a table-support, a sheet-carrying contact cylinder arranged in
bearings, and posts d on said support, provided with pivoted contact arms and
contact points for establishing contact with the periphery of said cylinder and
resistance coils between some of said posts, substantially as set forth.
7. The herein described contact making and breaking device, consisting
essentially of a table-support, a sheet-carrying contact cylinder arranged in
bearings, and posts don said support, provided with pivoted contact arms and
contact points for establishing contact with the periphery of said cylinder, and
resistance coils between some of said posts, and an insulating device e provided
with teeth of a non-conducting material arranged between said contact arms,
substantially as set forth.
8. The herein described contact making and breaking device, consisting
essentially of a table-support, a sheet-carrying contact cylinder arranged in
bearings, and contact posts d on said support, provided with pivoted contact arms
and contact points for establishing contact with the periphery of said cylinder,
resistance coils between some of said posts, a gear wheel as on one journal of said
cylinder, a clock-work mechanism, and a motor on the clock-work arbor, operating
to drive the contact cylinder, substantially as set forth.
9. In the herein described contact making and breaking device, a contact cylinder,
and contact arms d³ pivoted in posts d, every fourth post being connected with a
line wire, and resistance coils o connecting said intermediate posts with each other.
and with said post connected with the line wire, as set forth.
Namank NI Walruary 5th 1800
FRITZ ANTON FELDKAMP.
JACOB SCHOENHAAR.
EMIL EDUARD LEHR.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicants..