Improvements in Musical Instruments Actuated by Electricity.
Year: 1891

page_text: Date of Application, 28th Apr., 1891
Complete Specification Left, 29th Feb., 1892-Accepted, 23rd Apr., 1892
PROVISIONAL SPECIFICATION.
Improvements in Musical Instruments Actuated by Electricity.
I PARIS EUGENE SINGER of 6 Victoria Road, Kensington in the County of
Middlesex, Gentleman, do hereby declare the nature of this invention to be as
follows:-
The object of my invention is to produce an instrument which may be of the
piano type, and in which the note produced by the vibrating mass, the string, for
example, may be prolonged by the closing of an electric circuit, and also initiated
by this means, as well as by the ordinary hammer action.
The result which I desire to effect may be attained in two ways, thus :—
(1) Consider, for example, a sounding body, such as a string, making 512 vibra-
tions per second, and thereby producing the note middle C. An electro-magnet is
placed near this, so that when a momentary current passes round its cores, the
string is pulled towards its poles, and by its elasticity recedes immediately. It is
arranged that, by means of a revolving cylinder or oscillating body, such as
momentary current is sent through the coils 256 times per second, so that the
impulses given by the intermittent current agree, and therefore synchronize with
the double vibrations which the string tends to set up, as due to its mass, tension &c.
The revolving cylinder consists of, or carries a toothed wheel or contact breaker,
over which a brush slides, contact being made when a tooth meets the brush. The
number of teeth and speed of the cylinder thus determine the number of impulses
to the string or other sounding mass. The cylinder may be at a convenient distance
from the instrument, or may be enclosed in a vacuous vessel, so that the sound of
contact, if any, may not interfere with the music. Any required number of strings
may be combined to make up the required compass of the instrument, the necessary
contact breakers or toothed wheels being all fixed to one spindle, which is caused
to rotate at a constant speed by any suitable motor.
(2) By making the vibrations of the string or other sounding mass to give
impulses to itself, by causing an intermittent current to pass round the cores of an
electromagnet fixed (as described above) near the vibrating string or mass.
are three ways of effecting the object according to this second mode:-
There
This
(a) The circuit which includes the coils of the electro magnet also includes
two flat conductors, such as plates of platinum or carbon, one of which rests
lightly (being nearly supported by an insulated spring) on the other.
latter is connected by a thread or wire to the vibrating string or mass, or to a
prolongation of the latter, on or beyond the structure known as the "bridge."
When a current is passed through the magnet coils, the flat conductors in circuit
with them tend to separate, according to the known principle, that a current
tends to fracture the conductor which carries it. Simultaneously with this, the
string receives an impulse from the electro-magnet, the joint result being a
cessation or diminution of the current, which lessens or neutralizes the strength
of the electro-magnet, allowing the string, by virtue of its elasticity, to recede
from the poles of the magnet. But this recession of the string, owing to its being
connected by the thread or wire with one of the flat plates, afore mentioned, tends
to complete the circuit, and strengthen the electro-magnet, when another cycle
commences. Each sounding string or sonorous mass of an instrument is connected
with the parts just described, and may therefore be thrown into action, as in (1).
Instead of an electro-magnet, a permanent magnet may be used, but in this case
the momentary current is passed round its poles in such direction that it becomes
neutralized.
An
(b) By the inductive action of a magnetised portion of the vibrating mass.
electro-magnet placed near a string set in motion from any cause, has induced

page_text: currents set up through its coils. These acting on a telephone receiver, cause the
motion of the diaphragm, and this motion is used to operate a relay, which in turn
operates an electro magnet, as in (a). A permanent magnet may in this case also
be used, either alone or in conjunction with an electro magnet.
(c) A permanent magnet with coils round its pole pieces wound in such a manner
that when the circuit is closed. the magnetism is neutralized, is placed with its pole
pieces close to a magnetized portion of the string, which it attracts. When the
current passes, the string recedes from the magnet poles, and this motion of the
magnetized string sets up an induced current in the coils reverse in direction to
the primary current, which allows the permanent magnet to partially regain its
strength, and pull back the magnetized string, when another cycle commences;
thus a pulsating current may be maintained.
Any suitable number of the sounding bodies may be simultaneously operated, for
purposes of harmony or quality, by any of the methods of initiating or sustaining the
vibrations herein described, and for such purposes it is sometimes convenient to
produce several notes related to one another as harmonics, by one contact maker,
and the necessary number of electro magnets joined up in series.
Dated this 28th day of April 1891.
NEWTON & SON,
Agents for the Applicant.
.
COMPLETE SPECIFICATION.
Improvements in Musical Instruments Actuated by Electricity.
PARIS EUGENE SINGER of 6 Victoria Road Kensington in the County of
Middlesex, 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 :-
The object of my invention is to produce an instrument which may be of the
piano type, and in which the notes produced by the vibrating bodies, the strings,
for example, may be prolonged by the closing of electric circuits, and also initiated
by this means, as well as by the ordinary hammer action.
The result which I desire to effect may be attained in various ways, some of
which are illustrated in the accompanying diagrams.
Fig. 1 explains the manner of adapting my invention to a grand pianoforte, the
strings being capable of receiving impact from the ordinary hammers, if desired, or
actuated solely by electro-magnets put into circuit by the depression of the playing
keys.
In this figure, a represents one of the ordinary steel pianoforte strings attached,
as usual, by a wrest pin, to the wrest plank b, carried over a bridge c, and made
fast to the metal plate d.
Situate above the string, immediately over the part struck by the hammer, is an
electro-magnet e, pendent from a fixed transverse bar carried by the case.
Each note of the instrument is represented by a magnet e, and each magnet is
separately connected with a battery, or other source of electricity, in a manner
to be presently explained. 9 is the playing key, the depression of which is intended
to put its magnet into circuit, and keep it under the action of the battery, or
other source of electricity, so long as it is desired to sustain a note, and g¹is the
hammer, the use of which provides the player with the means for giving suitable
expression to the music performed.
Underlying the whole row of keys, is a plate , electrically connected with the
battery. Each key is fitted on its underside with an electrically conducting
spring i, connected by a wire to the coil of the electro-magnet which commands
the string represented by the key. The other end of the coil of the magnet
connects with a brush k, of which there is a series, one for each note of the
instrument. These brushes severally bear upon a disc commutator 1, which

page_text: commutators correspond in number with the notes of the instrument, and are
mounted upon one common spindle m, electrically connected with the battery.
Rotary motion, the speed of which must be carefully regulated, is imparted to
this spindle by clockwork or other suitable mechanism, and maintained whilst the
instrument is in use. The commutator discs are so constructed that, say, for one
rotation of their shaft, they shall break and make the circuit in which their
respective magnets are included, at a rate corresponding to the number of pulsations
required to be set up or maintained in their respective sounding strings.
With this preliminary description, my explanation of the action of the apparatus
will be readily followed. Supposing the string to represent the note C, which will
require, when sounded, to make 256 vibrations per second, its electro magnet, when
energised, will attract the string towards its poles, and when the electric circuit is
broken, it will recede by its own elasticity. Now, supposing the commutator / to be
so arranged as to close the circuit 256 times per second, the result will be a series
of attractions of the string corresponding in number to the vibrations pertaining to
the note sounded.
Fig. 2 shews, on an enlarged scale, one of the disc commutators in side view,
and Fig. 3 shows a group of such commutators mounted on their common shaft.
From what has gone before, it will be understood that the rate of making and
breaking the circuit for each note will vary, and consequently the construction of
the commutators for the respective notes of the instrument will vary also, with the
view of maintaining throughout the instrument a proper relation between the
vibration of the strings or sounding bodies, and the make and break of the current
circulating round the respective magnets.
It may be found desirable, instead of placing the commutators within the
instrument, to place them at a distance, or in a vacuum chamber, and thus avoid
the possibility of the sound produced by the rotating commutators interfering with
the music.
I wish here to observe that the magnet e may, if desired, be made to give a
number of impulses less than the absolute speed of vibration of the sounding body.
So long as this speed is one half, one fourth, &c., of the absolute speed, the
sounding body still gives its normal pitch, but with less intensity; but when the
impulses vary in the ratio of, say, one third, one fifth, or one seventh, the sounding
wire will give out a note a third, a. fifth, or a seventh of its fundamental, always,
however, with much less power than when the impulses synchronize with the
sounding body.
I will now describe certain modifications which I have made with a view of
adapting my invention to other sounding bodies than strings, and also for effecting
the regulation of the vibration of such sounding bodies both with and without the
use of a rotating commutator.
Fig. 4 shows a disc of sonorous material as applied to the production of a musical
note. This diaphragm, when not made of magnetic material, is fitted at its centre
with an iron or steel armature, which, like the string in Fig. 1, will be vibrated by
the energized electro-magnet underlying the disc, to produce the sound.
This
inagnet is connected with a battery, or other source of electricity, through a com-
mutator, as in Fig. 1. Provision, consisting of an adjustable pad, is made for
tuning" the disc, as indicated in the drawing.
61
In Fig. 5, in place of the sonorous disc, a free reed a is used; in other respects,
the arrangements in the two diagrams are alike.
In Fig. 6, the fitting of the free reed so as to produce a powerful tone is more
fully indicated. The electro-magnet e in this case overlies the free reed «<, and the
system of intermitted currents is employed, as in Fig. 1. The free reed is made
fast to a block, and overlies a bridge c, carried by the sound board o. For sounding
the free reed a hammer may be provided, as indicated in Fig. 6, and a damper is
also employed for arresting the sound.
The manner in which I provide for the rapid making and breaking of the circuit

page_text: of the electro-magnet without the use of the commutator, is shewn in Fig 7, where
a reed is used for making and breaking contact. This reed is in direct connection
with one pole of a battery or other source of electricity, and the other pole connects,
as in the arrangement Fig. 1, through a wire, with one end of the coil of an
electro-magnet e*, the other end of the magnet coil is connected to a flat spring,
which bears on the back of the reed I, and is so regulated that it cannot follow the
reed beyond the half of its vibrations. On closing the circuit by the depression of
the key, as in Fig. 1, the current will pass round the magnet e, through the flat
spring, to the reed ; thence back to the source of electricity. By the
attraction thus created in the magnet, the reed will be drawn down clear of the
spring 1³, and breaking the circuit at *, the reed will spring back, and the circuit
will be again completed. By tuning the reed to its work, its vibrations will be
caused to control the vibrations of the sounding body, according to the note that
body is designed to emit. As this reed form of commutator is calculated to create
a buzzing noise, I propose to place the reeds and their connections at a distance
from the instrument, in, say, an adjacent apartment, giving the conducting wires a
suitable extension for that purpose.
In Fig. 8, I have shown an arrangement for working the reed (as a substitute
for a rotary commutator) by means of one electrical current, and producing the
vibration of a sounding string by means of a second current. The reed is
actuated in precisely the same manner as in Fig. 7. Overlying it are two elastic
terminals and of a second circuit, in which is situate the electro-magnet e,
which causes the vibration of the sounding body, in this case a string a.
When,
by the depression of a key, the electro magnete is caused to attract the reed l,
the current will be broken, as explained with reference to Fig. 7, but on the
release of the reed ', it will recoil and strike the terminal 1, and move it into
contact with the terminal P, and thus establish the circuit, which energizes the
electro-magnet e and actuates the string a, as before explained.
Fig. 9 shews an arrangement for causing the reed to make and break the
circuit which it controls, twice for every complete vibration.
This is done by duplicating the terminals 21, and placing the reed / between
them, so as to act on both pairs of terminals alternately. The two terminals are
united so as to become practically one, and the same remark applies to the
terminals. Thus, when one pair is in action, the other is open, and no current
passes in that direction. The operation of the other parts is substantially the same
as in Fig. 8, only, as a result, the number of vibrations per second in the string a
is doubled.
A further modification of my invention consists in making the string or other
sounding body, when set in vibration, create its own impulses, by causing an
intermittent current to pass through the coils of an electro magnet fixed near the
string or body to be vibrated.
One way in which I propose to carry out this part of my invention, is illustrated
by the diagram Fig. 10, where a represents the string or sounding body, and e the
electro magnet situated and operated as in Fig. 1. The circuit. which includes the
electro-magnet e also includes two platinum or carbon conductors n, n', one of
which, n, rests lightly on the other, it being in part supported by an insulated
spring. The conductor n is connected by a thread p to the vibrating string a.
When a current is passed through the coils of the magnet e by the closing of
the circuit on the depression of a key, the conductors n and n' naturally tend to
separate. Simultaneously with this action, the string receives an impulse from its
electro-magnete, the joint effect of which two actions will be the cessation or
diminution of the current which neutralizes or lessens the strength of the electro-
maguet, allowing the string, by virtue of its elasticity, to recede from the poles of
the magnet, but this recession of the string, owing to its connection, through the
thread 7, with the conductor n, tends to complete the circuit, and strengthen the
electro-magnet, when another cycle commences.

page_text: In Fig. 10, I have shewn this part of my invention adapted to a sonorous disc,.
which takes the place of the vibrating string of Fig. 10, and when set in action,.
produces the like result.
Another mode whereby the vibrations of the sounding body are utilised to.
regulate the impulses of the electro-magnet e is shewn in Fig. 11, where e¹ is a
permanent magnet surrounded with coils of wire, and placed over a magnetised
string u. When this string is set in vibration, induced currents are set up in the
magnet e', the coils of which are connected with a magnet e³ underlying a metal
disc, as in Fig. 4.
Connected with the centre of this disc is a rock lever y, the longer limb of which
carries on its underside a contact plate y', which overlies an adjustably fixed contact
plate 9, forming one terminal of the circuit connected electrically with one pole of
a battery or other source of electricity; the other pole of the battery connects with
the coils of the electro magnet e, which coils also connect electrically with the
lever 9.
When, therefore, an induced current is set up in the coils of the magnet e¹ by the
vibrations of the string a, they will energize the magnet e, and cause the disc to
vibrate synchronously with the string, and through its connection with the rock
lever (which, with the contact plates 7 and 93, constitute a relay), alternately
make and break the circuit in which the electro magnet e is situate. By this.
means the impulses of the electro magnet e imparted to the sounding string will be
synchronous with the vibrations of the latter.
In order to introduce into my new instruments, facilities for playing which are
afforded to the organist, it will only be necessary to adopt some such arrangement
as that shown in Figs. 12 and 12, which will enable the player, by the depression
of one key, to sound several notes for the purposes of harmony, or several kinds of
sounding bodies for variation of quality of tone, whichever of the methods herein
described of initiating or sustaining the vibrations is selected.
In Fig. 12 I have shewn, in diagram, the means for bringing into circuit, at the
pleasure of the player, four qualities of sounding bodies, corresponding to four stops
of an organ.
In this figure, sss are four switch rods, the construction of
which is best shown at Fig. 12ª, their object being to throw into circuit the
magnets e', ell, ell, ell of the several sets of sounding bodies to which the switch
rods respectively belong.
The switch rods are made of wood or other non conducting material, partially
surrounded by metallic bands, one for each note of the instrument. These bands
are severally embraced by a pair of contact springs t t¹, the springs t being con--
nected with their respective magnets e¹, e¹¹, e¹li, elit, and the springs t' with the
key 9.
The object of these switch rods, it will be understood, is, by introducing a third
break into the circuit (one break being at the key and another at the commutator,
as before explained), to bring into circuit or throw out of circuit, at pleasure, the
magnets of the severed so-called stops or series of sounding bodies contained in the
instrument. The switch rods will receive an axial motion from the player (to
throw the stops into or out of use) by any one of the well known devices employed
by organ builders for the like purposes.
From this illustration it will be readily understood how harmonics and octaves.
may be obtained by the introduction of switch rods that will couple up electrically
the notes intended to be sounded by the depression of one key.
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
1. Sounding strings or other sonorous bodies constituting the compass of a
musical instrument, by means of electro-magnets in close proximity to the strings
or other sonorous bodies, and maintaining the vibrations of such strings or sonorous

page_text: bodies during the pleasure of the performer, through the intermitted action of such
electro-magnets, as herein before described.
2. The means described with reference to Figs. 1, 2, and 3, for determining the
number of impulses to be given to the sounding strings or bodies, and making them
synchronize with the vibrations respectively due to the strings or bodies sounded.
3. The modified forms of commutator described with reference to Figs. 7, 8,
and 9 of the drawings, for regulating the electrical impulses imparted to the
sounding strings or bodies.
4. The arrangement described with reference to Figs. 10 and 104, whereby the
sounding string, or other sounding body, is caused to regulate the electrical
impulses required to sustain its own vibrations.
5. The application to musical instruments of the means described with reference
to Fig. 11 of the drawings, for initiating and sustaining the vibrations of a
sounding magnetic body, by utilizing the current induced in the coils of a proximate
permanent magnet, for actuating a relay and closing the circuit in which the
electro-magnet employed to vibrate the sounding body is situate.
6. The means described herein for simultaneously operating two or more strings
or other sounding bodies on the depression of one key, which will temporarily join
up the corresponding magnet coils either in series or in parallel.
Ten this with Any of
HOTAN This 76th A
EX49
NEWTON & SON,
Agents for the Applicant.
NEWTON & SON,
Agents for the Applicant.