Improvements in Musical and other Sound-producing Apparatus.
Year: 1891

page_text: Date of Application, 23rd June, 1891-Accepted, 22nd Aug., 1891
COMPLETE SPECIFICATION.
Improvements in Musical and other Sound-producing Apparatus.
We, EMILE GUERRE and HENRI MARTIN, of 87 Route de Darnètal Rouen in
the Republic of France, Manufacturers, do hereby declare the nature of this inveu-
tion 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 a musical instrument which it is preferred to call
Palsiphone" and in which all the sound producing parts such as metal or crystal
bells, diapasons, metal or catgut strings are set and indefinitely maintained in
vibratory motion by means of an arrangement of electro-magnets and successive
interruptions of the electric current which interruptions take place in the sound
producing bodies themselves by means of light contact breakers preferably of
platinum so as in no way to affect the beauty and harmony of the sounds, which
result is obtained by the rational disposition both of the electro-magnets and
contacts.
In the accompanying drawing
Fig. 1 represents what might be called a musical signalling device in which this
invention is applied to a single bell, the device being more particularly intended for
domestic use and characterized by the absence of the usual hammer.
Underneath the preferably steel bell A retained by a metal support B upon a
plate e also of metal there is arranged the electro-magnet E over which is placed
the platinum switch or contact breaker soldered to the bell. In front of this
there is a small and light plate g also made of platinum secured in a piece of
ebonite which has the property of suppressing false reverberations of sound.
This ebonite piece is connected with a brass bracket G by a steel spring arranged
to be adjusted by a screw H. Above this screw is arranged another set screw i.
The small platinum plate is connected to the steel spring by a thin copper wire.
The case O covering the whole arrangement possesses the property of rendering
more powerful the sound of the bell owing to its peculiar construction and
position.
The operation of this musical bell is as follows ;-
The current from the battery flows to the electro-magnet, thence to the bell
through its metal support, then to the contact piece of the bracket G and finally
returns to the negative pole through the bracket itself. When by pressing the
knob D the circuit is closed the current passing through the electro-magnet E
attracts the bell A and produces vibration. The contacts ƒ and g then separate for
the time being and when the electro-magnet releases the bell they join again. This
alternate making and breaking of circuit will last as long as the finger rests upon
the knob or upon one of the keys (which in the case of a musical instrument may
be one of a series corresponding to a series of bells tuned so as to form the
chromatic gamut).
In Fig. 2 is shown a "Palsiphone" consisting of a diapason or tune-fork the tone
of which is preserved, unaltered and pure, owing to the delicate arrangement of the
mechanism and the position of the contact and electro-magnet. This fork is
intended to indicate the tone or key both to single instruments and orchestras. The
sound which the sonorous casing renders more powerful may be obtained instanta-
neously and kept up as long as desired.
Upon the sonorous casing B is firmly secured the normal tune-fork D at the side
of one of the branches of which is placed an electro-magnet E supported on a metal
bracket G screwed to the casing. At a predetermined point of the tune-fork is
soldered or otherwise suitably secured a light platinum plate c in front of which

page_text: there is another thin plate e of the same metal' tightly fitted in a piece of ebonite f
connected with the preferably brass-bracket H by a steel spring.
To make the instrument readily portable it is, fitted on to a box containing the
electric battery required for its operation, the arrangement of which is the same as
in the case of the single musical.bell.
The circuit is here closed by means of the keys of a key-board instead of by a
commutator placed on one side of the casing of the insulated tune-fork.
In Fig. 3 we represent an ordinary piano provided with our vibrating arrange-
ment. In this instrument the position of the platinum plate fixed by solder or
otherwise to the strings is carefully calculated beforehand so that the purity of the
tones produced by the strings should in no way be affected. Besides the inevitable
spark of the extra current is here prevented from. interfering with or weakening the
sound by the employment of condensers proportionate to the power of the spark.
It will be understood that the instrument is called "Palsiphone" where the electro-
magnet imparts vibration to an instrument specially devised, but that there is
nothing to prevent the application of the same electro-magnetic arrangement to a
piano in. which case the circuit may be opened by operating a pedal.
In the transverse section shown in Fig. 3 it is assumed that a small piece of
platinum F is soldered, to the string C, which platinum, piece is adapted to receive
all the vibrations of the string. Against the bridge forming part of the sounding-
board there is screwed a piece of preferably ebonite O to. which is fixed, a steel
spring carrying, another piece of ebonite B which is to retain in place the thin
platinum plate G forming the circuit breaker.
Another piece of ebonite V. serves to insulate the spring from the metal rod. M.
which. carries the. set-screw I and above this another set screw i..
A copper wire leading from the slot provided. in the piece of ebonite B connects.
the thin platinum plate with the spring. The electro-magnet E is secured; to a
bar Y attached to the sides of the piano between the sounding board and a string
neither of which it should touch.
The operation is as follows;-
The current from the positive pole of the battery P flows to the bar J of.the.
key-board which is throughout its length covered with a metal band..
When a key I which is also provided with a metal contact is pressed down the
current. is allowed to pass into the electro-magnet E and thence into the contact.
breakers G through the metal rod M then to the contact F situated on the string C
and back to the battery. As the current passes through the electro-magnet E. the
string is attracted and the contacts F and G move away from each other and then
join again when the electro magnet releases the string which alternate, operations:
are repeated as long as the key is depressed..
The condensers for the reduction of the spark of the extra current are arranged
underneath or behind an ordinary piano; one of the poles of this condenser being
connected with the strings of the instrument and the other with each of the contact.
plates.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed; we declare that what we
claim is ;-
1. In musical or other tone-producing apparatus the combination with a bell or
gong A of an electric battery an electro-magnet E electric contacts such as f g
adjustable insulating block such as screw H and bracket G substantially as,
described and illustrated in Fig. 1 of the accompanying drawings.
2. The combination and arrangement of parts constituting the complete musical
or. tone-producing apparatus. substantially as described and illustrated in Figure 1
of the accompanying drawings.
3. In musical or other tone-producing apparatus the combination with a fork
such as D of an electro-magnet. E electric contacts such as ce adjustable insulating

page_text: block such as f and bracket H substantially as described and illustrated in Figure 2
of the accompanying drawings.
4. The combination and arrangement of parts constituting the complete musical
or tone-producing apparatus substantially as described and illustrated in Figure 2
of the accompanying drawings.
5. In musical or other tone-producing apparatus the combination with a metal
gut or other wire or string C of an electro magnet E electric contacts such as F G
ebonite or equivalent blocks such as OBV rod or bracket such as M adjustable
insulating block such as B and bar such as J substantially as described and
illustrated in the accompanying drawings.
6. The combination and arrangement of parts constituting the complete musical
or tone-producing apparatus substantially as described and illustrated in Figure 3
of the accompanying drawings.
Dated this 23rd day of June 1891
W. P. THOMPSON & BOULT,
Agents for the Applicants.