Method of and Apparatus for Effecting the Storing Up of Speech or Signals by Magnetically Influencing Magnetisable Bodies.
Year: 1899

page_text: Date of Application, 28th Apr., 1899
Complete Specification Left, 20th Jan., 1900-Accepted, 17th Mar., 1900
PROVISIONAL SPECIFICATION.
Method of and Apparatus for Effecting the Storing Up of Speech or
Signals by Magnetically Influencing Magnetisable Bodies.
I, VALDEMAR POULSEN, of No 17, Alhambravei, Copenhagen, Denmark,
Engineer, do hereby declare the nature of this invention to be as follows:-
According to the present invention messages or signals of all kinds on being
transmitted by electrical means to a distance, are registered and stored up at the
distant station by very simple means based on magnetic action in order there to be
audibly or visibly reproduced at will.
The invention is based upon the fact that when a body made of a magnetisable
material is touched at different points and at different times by an electromagnet
included in a telephonic or telegraphic circuit, its parts are subject to such varied
magnetic influences that conversely by the action of the magnetisable body upon
the electromagnet the same sounds or signs are subsequently given out in the
telephone or recording instrument as those which previously caused the magnetic
action upon the magnetisable body.
The invention is in particular of the greatest importance to the telephonic
transmission of speech, as by the provision of a suitable device in the neighbour-
hood of a telephone, communications transmitted in the absence of the subscriber
at the receiving station, are directly received by the apparatus in order to be
given out thereby to the subscriber whenever required.
By the application of this invention the use of phonographs of known con-
struction is dispensed with, these being replaced by apparatus of much simpler
construction and more effective action.
As is known in phonographs of present construction the vibrations of the air
produced by sounds transmitted to a membrane are utilised for producing by
mechanical means impressions upon a plastic body, which impressions in their
turn impart vibrations to the membrane that reproduces the same vibrations of
the air and consequently also the original sounds.
With this arrangement the necessary mechanical motion of the parts causes
sounds that interfere with those to be reproduced, and this together with the
considerable expense of such apparatus, is the cause of the limited demand for
them at the present day.
According to the present invention, only a magnetic action upon magnetisable
bodies is made use of for storing and reproducing the transmitted sounds, which
are thus not interfered with by other sounds caused by mechanically moving
parts while the said magnetisable bodies can always be used over again, as it is
only necessary to demagnetise them for this purpose.
will describe my invention with reference to the accompanying drawings
which shew by way of example one of a great variety of ways in which it can
be carried into effect.
Fig. 1 shews a front view partly in section of the apparatus to be combined
with a telephone apparatus. Fig. 2 shows a section on line z Fig. 1, Figs. 3

page_text: to 5 shew separate details to an enlarged scale, Fig. 6 shews the connection of
the apparatus with the telephone instrument, Fig. 7 shews a diagram of the
circuit of a telephone station provided with the said apparatus.
A casing a Fig. 1 containing a clockwork mechanism serves as a base to the
bridge shaped frame b whose sides are equidistant from the central vertical
axis c.
This carries a fixed cylinder d which is surrounded by a helically wound
coil of steel wire g Figs. 1 and 3. A stirrup-shaped tubular frame e can rotate
freely on the central axis, round the cylinder d, and on this frame can slide verti-
cally a sleeve f which has a tongue engaging in a longitudinal groove of frame e
so that the magnet holder h shewn in plan at Fig. 3 carried by sleeve f also
receives a corrsponding guided vertical motion. The electromagnet core is
generally not in contact with the steel wire g; but if by the excitation of an
electromagnet 10 Fig. 1 an armature 11 is attracted which ordinarily breaks
the motion of the clockwork in the base a this clock-work in being set in motion,
rotates the frame e through the gearing 12 and 13, and with it the weighted
arm Fig. 3. In consequence of the centrifugal force acting thereon, the
arm p is moved outward, and draws with it the lever k connected thereto by a
spring m lever k being connected to the magnet holder h brings the core i in
contact with the steel wire g. When p is not acted upon by centrifugal force
the spring fixed to sleeve f in pressing upon k keeps the core i out of contact with
the wire coil. The electromagnet can be of horseshoe form, or, preferably, it
consists of two independent contiguous magnets. The core i has either a wedge
shaped notch in order to embrace the wire g and thus insure reliable contact, or
it may slide with a flat surface against two contiguous convolutions of the wire.
The wire coil, which is stationary with the cylinder d, produces a gradual upward
motion of the sleeve f as this revolves with the frame e until on arriving at a
certain height the sleeve comes in contact with a contact piece 14 whereby the
electromagnet 10 is cut out of circuit, and the clockwork is consequently stopped
again. The rotation of the frame e being thus stopped, the weighted arm pis
caused to resume its original position again by the spring 1 thereby effecting the
removal of the core i from the wire coil g. In consequence hereof the sleeve at
once slides by gravity down the frame e to its original position. For insuring
the uniform rotation of the frame e it has on its central stem 15 fly-vanes 16 carried
by a cap 17. In addition, the rotation may be retarded by a brake 18 Fig. 2.
Figs. 4 and 5 shew the connection of the wire leads r leading to the electromagnet.
The two wires are led to the screw clamps 7 which transmit the current by means
of springs to the contact rings s and t.
The connection of the apparatus with the telephone is shewn in the diagram
Fig. 7. A switch apparatus 19 is arranged so that it can establish three different
connections.
In the one position the subscriber being assumed to be on the spot, the above
described registering apparatus is cut out of circuit so that the telephone is
worked in the usual way.
With the second position of the switch the new apparatus is included in the
telephone circuit, so that the subscriber can speak into his own auxiliary ap-
paratus, stating for example the time when he is at home, and every other sub-
scriber in being connected with the first one will then receive from the said
apparatus automatically the message which the first subscriber has spoken into
it, provided the latter, before leaving, has moved his switch into the third
position. When the second subscriber has received the said automatic message
he can speak into the auxiliary apparatus of the first subscriber and the latter
can then, on his return, receive this message if he moves his switch from the third
position back into the second one.
The course of the current is as follows: In the first position of the switch the
.speaking is transmitted in the usual manner through the line wires and the current
passes in the usual manner through the telephone. In the second position of
the switch the subscriber induces by the usual rotation of the inductor crank a

page_text: current in the induction ring R, which current then passes through 20, 21, 22,
23, 24 and 25. The electromagnet then attracts the armature 27 and effects a
contact between 28 and 29 whereby the circuit which includes the battery E is
closed, and the current passes from the battery E through electromagnet 10 con-
tac 28, line wire 30, 31, back to the battery. By the excitation of the electro-
magnet 10 the armature 11 is attracted, and the clockwork being thus started,
frame e is put in rotation, sleeve f rises, breaking contact 23 while the speaking
circuit through 20, 21, core i, lead 32, 33, 29, 24, and 25 is closed.
The subscriber then speaks into the microphone of his telephone apparatus
and the speech is received by the registering apparatus, the currents of varying
strength passing through the coil of electromagnet core i causing this in travelling
over the steel wire g to magnetise different parts of this to a different extent.
When the sleeve f has reached its highest position so as to strike against con-
tact piece 14 the electromagnet 10 is thrown out of action and the clockwork
being arrested, the rotation of the frame e is stopped and the sleeve f slides down
again and closes the contact 23 again.
The course of the current for the third position of the switch will be readily
understood from what has been above described and from the diagram, the action
of the apparatus for giving out the stored message being such that while the
electromagnet core i is made to travel over the same part of the coil g as it did
before, the magnetism of such parts will successively influence the magnet coil
so as to reproduce the same electric currents in the same sequence and thus also
reproduce the same sounds in the subscribers telephone.
The apparatus can also be arranged so that the different subscribers can call
up the exchange and send their messages into the apparatus there placed; the
exchange clerk can then send on the messages at the desired time to the respective
subscribers.
Instead of a cylinder with a helical steel wire there may be used as a receiving
device a steel band, supported if necessary on an insulating material and brought
under the action of an electromagnet. Such an arrangement has the advantage
that a steel band of any desired length may be used. Instead of a cylinder d
there may be used a disc of magnetisable material over which the electromagnet
may be conducted spirally; or a sheet or strip of some insulating material such
as paper may be covered with a magnetisable metallic dust and may be used as
the magnetisable surface. With the aid of such a strip, which may be folded,
a message received at any place provided with the new apparatus may be sent
to another place where it may be repeated by passing the strip through the
apparatus at that place.
In order to demagnetise the magnetisable surface and thus to prepare the
apparatus for receiving a new message, it is merely necessary to cause the electro-
magnet while it is excited by a current of the same direction as that which
excited it during the sending of the message, or the reverse direction to come in
contact with all the magnetised places of the magnetisable surface.
In the con-
struction shewn in the drawing it is necessary, for the purpose of demagnetising,
to set the clock work in motion and to allow the electromagnet to travel along
the wire coil.
The electromagnet which acts upon the magnetisable surface may be included
directly in the primary circuit of a microtelephone, or it may be connected with
the wires of the secondary coil of a microtelephone circuit, or, finally, it may be
inserted in a tertiary circuit, that is, in a circuit in which a current is induced
by the secondary coil of a microtelephone circuit. In the last named case it is
not necessary, for demagnetising the magnetised surface, to send a current in the
reversed direction through the electromagnet, but it suffices in this case to pass
a current through the magnet which is in the same direction as that of the current
which was used in sending the message or signal.
This invention may be used also with advantage in telegraphy. For this pur-
pose it is merely necessary to cause the current impulses sent along the telegraph

page_text: wires to pass through the electromagnet while this is in contact with the magneti-
sable surface while either the surface moves on the electromagnet, or the latter
moves along the magnetisable surface. By telegraphing in this manner it is
possible to read off the telegram considerably more quickly than it is delivered
and time is thus saved. Moreover, it is possible to include a large number of
apparatus constructed according to this invention in series in a circuit and so to
transmit messages from a central station or call office to a large number of sub-
scribers at the same time. Finally as the above described new method may
obviously be carried out in most diverse ways, it is to be understood that I in
no way limit myself to the arrangements for carrying it out herein described.
With the aid of this invention a message of any kind whatever may be delivered
as quickly as desired, and it is possible to send several messages through one
wire at the same time by telegraph, by telephone or other similar manner.
Dated this 28th day of April 1899.
ABEL & IMRAY,
Agents for the Applicant.
Method of and Apparatus for Effecting the Storing Up of Speech or
Signals by Magnetically Influencing Magnetisable Bodies.
I, VALDEMAR POULSEN of No. 17, Alhambravej, Copenhagen, Denmark,
Engineer, 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:
According to the present invention messages or signals of all kinds on being
transmitted by electrical means to a distance, are registered and stored up at the
distant station by very simple means based on magnetic action in order there to be
audibly or visibly reproduced at will.
The invention is based upon the fact that when a body made of a magnetisable
material is touched at different points and at different times by an electromagnet
included in a telephonic or telegraphic circuit, its parts are subject to such varied
magnetic influences that conversely by the action of the magnetisable body upon
the electromagnet the same sounds or signs are subsequently given out in the
telephone or recording instrument as those which previously caused the magnetic
action upon the magnetisable body.
The invention is in particular of the greatest importance to the telephonic
transmission of speech, as by the provision of a suitable device in the neighbour-
hood of a telephone, communications transmitted in the absence of the subscriber
at the receiving station, are directly received by the apparatus in order to be
given out thereby to the subscriber whenever required.
By the application of this invention the use of phonographs of known con-
struction is dispensed with, these having substituted for them apparatus of much
simpler construction and more effective action.
As is known in phonographs of present construction the vibrations of the air
produced by sounds transmitted to a membrane are utilised for producing by
mechanical means impressions upon a plastic body, which impressions in their
turn impart vibrations to the membrane that reproduces the same vibrations of
the air and consequently also the original sounds.
With this arrangement the necessary mechanical alterations of the plastic
body cause sounds that interfere with those to be reproduced, and this together
with the considerable expense of such apparatus, is the cause of the limited
demand for them at the present day.

page_text: According to the present invention, only a magnetic action upon magnetisable
bodies is made use of for storing and reproducing the transmitted sounds, which
are thus not interfered with by disturbing subsidiary noises, and the said mag-
nctisable bodies can always be used over again, as it is only necessary to demag-
netise them for this purpose.
I shall describe my invention with reference to the accompanying drawings
of which Figs. 1 to 7 inclusive accompanied my Provisional Specification to shew
by way of example one of a great variety of ways in which my invention can be
carried into effect, with reference also to Figs. 8 to 16 inclusive, which are filed
herewith and which shew a modified arrangement of the apparatus.
Fig. 1 is a front elevation partly in section of an apparatus to be connected
with a telephonic apparatus. Fig. 2 is a section on the line of Fig. 1.
Figs. 3, 3, 4 and 5 are views of details on a larger scale. Fig. 6 illustrates the
connection of the apparatus with a telephonic apparatus. Fig. 7 is a diagram of
connections of a telephone station provided with the new apparatus. Fig. 8
shews the modified form of the apparatus in front elevation. Fig. 9 is a plan
of the same and Figs. 10 to 16 illustrate details hereinafter described.
A clockwork casing a (Fig. 1) serves also as a support or stand to the apparatus
shewn in Figs. 1 to 5. It carries a fixed arched frame b the two arms of which
are arranged at equal distances from the middle axis c. This axis c carries a
stationary cylinder d which has a steel wire g (Fig. 3) wound in a uniform helix
around it. A tube e bent to arch form is arranged to be easily rotated around
the cylinder d. On this tube a sleeve f is fitted to slide up and down being
guided by a tongue engaged in a slot of the tube e and thus the magnet holder h
(Fig. 3) which is carried by the sleeve is suitably guided. The electro magnet
core is normally not in contact with the steel wire g; but when an electro
magnet 10 (Fig. 1) is energised an armature 11, which normally acts as a brake
to the clockwork is attracted and then the tube e is caused to rotate by the gear-
ing 13, 12 driven by the clockwork.
As shewn in Fig. 3 which is a sectional plan, the centrifugal force of the
weight protating with the tube e draws one arm of a lever k by the connecting
spring m away from the cylinder d so that the magnet holder on the other arm
of the same lever brings the magnet core i into contact with the steel wire g,
in opposition to the spring which urges the magnet core away from the wire
before the clockwork is started. The electro magnet may be formed as a horse-
shoe magnet or preferably it may consist of two independent magnet cores
situated side by side, as shewn in the first view Fig. 3. Each magnet core i is
formed either with a wedge-shaped notch to straddle the wire g, thus producing
sure contact, or it may rub with its smooth end always against two adjacent
screw threads. The helical wire which is stationary with the cylinder, by the
travel of the core along it, causes a gradual upward movement of the sleeve f
until it has risen to a stop 14 where it acts to cut the electro magnet 10 out of
circuit, as will now be explained with reference to Fig. 7. The stop 14 consists
of a pivotted lever which is connected by a wire or the like with a block 41 which
carries a contact stud 28. It is only when the armature 27 is attracted by the
electro magnet 22, as will be hereafter described, that the circuit is closed which
includes the battery E that energises the electro magnet 10. While this electro
magnet 10 is energised the clock-work continues in action and drives the re-
volving frame e. But when the block 41 is raised by the stop 14, then the
armature 27 springs back into its position of rest keeping the contacts 28 and
29 broken. In consequence of this, the electro magnet 10 is no longer energised
and the clockwork is stopped by the brake lever 11, so that the frame e stops.
But on the tube frame e coming to rest, the weight p (Fig. 3) is moved back into
its original position by the spring pushing the electro magnet core i away from
the wire g. The consequence of this is that the sleeve f immediately slides down
to its initial position. The tubular frame e carries by wires 15 a cap 17. The
wires are gripped at the upper end of the frame e between a projection 6 and a
в

page_text: to the
nut 7, and are connected by means of a nut S with the boss of the cap 17 which
rests on a pin 9 of the axle c. As the cylinder and its pin 9 are stationary, the
cap 17 can rotate around the pin being carried round by the wires 15, but on the
cap are provided vanes 16 which tend to retard the speed of the cap. The cap
also carries the centrifugal brake 18 as shewn in Fig. 2 which is a plan of the
cap looking from below. On the bottom of the cap 17 the brake levers are
pivotted and when the cap 17 rotates the weights fly outwards, causing the blade
springs to press against the stationary shoulder of the axle and thus produce a
braking action. The cap 17 (Fig. 1) while it is carried round with the frame e,
owing to the resistance of the air to the vanes 16, tends to rotate more slowly
than e.
The conducting wires r which are attached as shewn in the elevation
Fig. 4 and sectional plan Fig. 5, lead to the electro magnet of the sleeve f. Two
wires are led to clips q from which the current is led by contact springs
contact rings s and t. From the contact rings s and t the wires r lead to the
interior of the cap 17 and then out through an opening in its shell. At this
opening the wires are fixed to the cap and lead thence through a bent tubular
projection 5 into the interior of the tube e and thence to the electro magnet
on f, as shewn in Fig. 3. When the frame e and with it the cap 17 rotates, the
wires become wound upon the outer surface of the cap 17. When the sleeve f
ascends and strikes the lever 14 and the current is thereby cut off, then the
sleeve slides down again along the tube e. This descent however takes place
gently, because the wires have to uncoil themselves from the cap 17, the
rotation of which is retarded as described above. The connections of the
apparatus at a telephonic station is shewn in the diagram Fig. 7. It is to be
noted that the apparatus thus described is intended only for two purposes. It
is designed to act as a phonograph and to send a message by means of a telephonic
apparatus to a subscriber who calls it. The subscriber at whose telephone station
the apparatus is situated is able to speak a message to the apparatus, for example
"I am not at home and shall not return till three o'clock. Call me again at
that time."
If then the telephonic station is called up, the person who calls hears the
message which has been retained in the apparatus, but in order to transmit a
conversation directly from a distant point it is necessary to use the second modi-
fication of the apparatus which is hereafter described in more detail. Referring
to the diagram of connections Fig. 7, there is provided a switch 19, which can be
moved to three different positions. In the one position shewn in Fig. 7 the
subscriber is at home and the new apparatus is entirely cut out, so that the
telephone can be worked in the usual manner. One line wire 35 leads to the
conductor 36, which is connected to the telephone. From the telephone the
second wire 37 is led back to the contact 38 which as shewn, is connected to the
contact 39 so that the current passes by 40 to the line wire. The current by
passing by 35, 36, 37, 38, 39, 40, thus takes its usual course like that in other
telephone apparatus, just as if the new apparatus did not exist. If now, the
switch lever be put to the middle position so as to connect the two middle con-
tacts, then the secondary winding of the induction coil R is connected to the
microphone. The current comes from the telephone wire 36 to the secondary
winding of the induction coil R by the contact of 19 to the right of 38, then by
38 and 37 back to the telephone. The subscriber first turns the crank handle of
his induction coil, whereupon when the line wire is cut out, the current does not
pass to the central station as usual, but it induces in the primary winding of the
induction coil R a current which takes its course by 20, 21, the electro magnet 22,
contact 23, conductors 24 and 25. The electro magnet 22 in this case attracts
the armature 27 and thereby releases the block 41, whereby the contacts 28, 29
and 34 are closed. By the contacts 28 and 29 the circuit from the battery E
is closed through the electro magnet 10, contact 28, 29, 30, 31, back to the
battery E, so that the clockwork is released and the frame e begins to rotate.
As the sleeve f moves upwards, the electro magnet core being in contact

page_text: with the steel wire g as above described, the subscriber can speak to his own
apparatus. For this he has in the usual way taken down the telephone receiver
which is connected to the switch hook, and when he speaks to his microphone he
produces currents in the secondary winding of the induction coil R corresponding
with the vibrations of the sounds." These currents induce in the primary winding
currents which are transmitted from 20 by 21, the magnet i, conductors 32, 33,
24. 25. But the currents can no longer flow by 22 and 24, because the contact 23
is interrupted as soon as the apparatus enters into communication (Fig. 1), since
as soon as the sleeve is raised away from the contact, the contact screw is lifted
off from the two stationary contact rings by means of a blade spring 23 (Fig. 1).
The two stationary contact rings are employed for the reason that the contact 23
car be closed in all positions of the tube e as it turns. Having thus in the central
position of the switch lever of 19 caused, by the calling up current, the frame e to
rotate, the words for example "I am not at home and shall not return till three
o'clock, call me up again at that time," are simply spoken to the apparatus, and
the message fixed on the steel wire g can be reproduced audibly to the sub-
scriber who called by putting the switch lever of 19 to its third position, that is
to say, when the two right-hand contacts are connected. Then the line current
coming by 35 and 40 cannot pass into the telephone apparatus, but takes the
following course :-
From 35, first to the secondary winding of the induction coil R, by the right-
band contact of 19 to the contact 39 and thence to the line wire 40. But as
when the calling up current was sent over the line wire 35 and 40, a correspond-
ing current is produced in the line 20, 21, 22, 23, 24, 25, the armature 27 is attracted
and by energising the electro magnet 10 the apparatus is again started and as
soon as it has started the contact 23 is again broken as above described.
caller-up who is holding his telephone receiver to his ears now hears the message
which was fixed on the steel wire g, the course of the current being as follows:-
From the electro magnet by the line 21, 20 to the induction coil R by 25,
24. 34, 33, 32, back to the magnet i.
The
There is thus produced in the secondary winding of the induction coil Ra
current which corresponds to the magnetic vibrations that proceed from the
electro magnet i. But the secondary winding is now connected with the line
wires 35 and 40, so that the currents take their course in the usual manner
through the receiving apparatus of the person who called. He therefore hears
that the particular subscriber is not at home and that therefore he must call
again later.
As soon as the apparatus comes into operation, the frame e rotates until the
lever 14 is moved.
If the subscriber wishes to wipe out the message fixed on his wire g, he reverses
the contacts 30 and 33, for which a special key is provided, in such a manner that
they are brought into connection with the two extreme contact pieces, and he then
starts the apparatus. Then from the battery E there passes a current by 10, 28,
29. 30, 33, 34, 24, 25, induction coil R. 20, 21, electro magnet 32, 31, back to
the battery E. The electro magnet being then supplied with a continuous
current the previously fixed message is wiped out.
In order to fix a message from a distance, the strip apparatus shewn in Figs. 8
to 16, is preferably employed. This strip apparatus operates on the same prin-
ciple as the wire apparatus, but, instead of a wire. a steel strip is employed
which is wound off one drum on to another, travelling in contact with an electro
magnet situated between the two drums. By the strip apparatus, several
messages of considerable length can be received. Fig. 8 shews the strip apparatus
in front elevation partially in section. Fig. 9 is a plan. Figs. 10 to 15 shew
various details and Fig. 16 is a diagram of the electrical connections.
In the frame 42 there are mounted two drums 43 and 44, their axlesbeing
centred on pointed screws 45 so as to be easily rotated. The strip 80 is wound
on the one or the other drum, according to the direction of rotation of the appara-
tus, which may be driven by a hand from an electric motor rotating the pulley 47.

page_text: In order to reduce the speed, the pulley 47 has on its axle a small friction
wheel 48 which is brought into contact with the one or the other of the two large
friction wheels 49 and 50 by a shifting lever having head 52.
arm 57
By means of a handle 54 the spring catch 53 is raised out of a notch 55 and then
on moving over the lever 51 the catch 53 is engaged in the other notch 50. In
this manner not only is the driving effected of the one drum 43 or the other 44
as required, but at the same time the electric motor, which is suitably connected
up, has the direction of its rotation changed, thereby producing at the same time
the reversal of the direction of the motion of the drum. On considering the
friction disc 48 in Fig. 8, it will be seen that it is not sufficient to put the disc
alternately in contact with the pulleys 49 or 50 in order to produce a forward or
a rearward travel of the steel strip 80, for in the position shewn the drum 44
would rotate in the direction of the hands of a clock, and the strip would be
wound upon this drum. When, by reversing the arm 51, the pulley 48 is pressed
against the pulley 50 without at the same time altering the direction of
rotation of the motor, then the pulley 50 and the drum 43 would still rotate in
the direction of the hands of a clock, and therefore the strip 80 would still be
wound on to the drum 44. But as, on reversing the lever 51, it is desired at
the same time to cause the strip 80 to be wound upon the drum 43, the motor
must also be reversed at the same time. The frame 42 carries an
on which is screwed a blade spring 59 carrying the electromagnet 58. This
electromagnet 58 operates in the same way as the magnet in the apparatus
first described. that is to say, the coils of the electro magnet 58 being connected
with one winding of a microphone bobbin, when the microphone is spoken
to, whilst the steel strip 80 travels past the electro magnet 58, then the
steel strip experiences a magnetic influence corresponding to the words spoken.
and these words can be reproduced in an audible manner when the electromagnet
coils are connected to a telephone receiver and the steel strip is again moved past
the electro magnet. In order to prevent the strip 80 from being wound too far on
to the drum 43 or the drum 44. there are provided feeler-levers 60 pivotted at 61.
When the drum is nearly filled up with the strip, this moves the feeler-lever 60
outwards so as to cause it to break a contact 81 which is in the circuit of the motor
which is thus at once automatically arrested, whatever be the direction of its
rotation, as there is feeler-lever and contact 81 at each side of the apparatus.
In order that neither drum 43 nor 44 may rotate too rapidly, producing slack-
ness of the strip 80. the brake 62 is connected with the lever 51. In the position
shewn in Fig. 8, while the strip is running on to the drum 44. the brake 62 acts
upon the drum 43 and thereby prevents it from rotating in the direction of the
hands of a clock when the apparatus is stopped. But if the strip runs on to the
drum 43, then conversely, the brake 62 at the right side prevents the drum 44
from rotating in the direction opposite to that of the hands of a clock. When
the strip apparatus is set in operation by the line currents the apparatus must
only work for a time approximately proportional to the length of the message.
The following arrangement is provided for this purpose. First the line current
energises the weak current electro magnet 72 (Figs. 8, 9, 12 and 16) which works
as a relay and closes the contact 73. By this means the local or strong current
is put in circuit and takes its course through an electro magnet 67 (Figs. 8, 10,
12; 14. 15 and 16) which then attracts an armature 69 (Figs. 8, 10 and 15) carry-
ing a pivotted pawl 71, which is acted on by a spring 70 tending to turn it towards
the right hand as shewn in Fig. 14. When the electro magnet 67 is not ener-
gised, the pawl assumes the position shown in Fig. 13. But if the armature 69
(which is pirotted at 90, Figs. 8 10 and 16) is attracted and the pawl 71 is thereby
lifted out of the teeth of the wheel 68 which is driven by a clockwork, then the
spring 70 presses the pawl 71 to the right hand, as shewn in Fig. 14. The pawl
then rests upon one of the teeth of the wheel 68 which is rotated by the clockwork
in the direction of the arrow (Fig. 14), and it is not till the wheel 68 is rotated

page_text: so far as to allow the pawl 71 to fall into the next space beyond the tooth, that
the armature 69 is caused by a spring or weight to move again into its initial
position. Thus, a momentary energising of the magnet 67 is sufficient to attract
the armature 69 and to keep it in its depressed position until the pawl 71 engages
in the next space of the wheel 68. As this wheel 68 is driven by clockwork, it
can easily be arranged such that the armature 69 will remain after each attraction
in its depressed position until the duration for a message expires. Probably a
period of three minutes may suffice.
When it is desired to stop the clockwork a lever 64 which is pivotted at 63,
as shewn in plan Fig. 10, and has an arm 65 is brought to bear against the escape
wheel 66 of the clockwork. Usually the lever 64 is in such position that when
the electro-magnet 67 is energised the clockwork works and the small wheel 68
rotates. The operation of the apparatus may be understood on reference to the
diagram of connections of Fig. 16. The wires 91 and 92 can be branched off
from points 21 and 24 of Fig. 7, and consequently connected with the line con-
ductor, unless the switch lever is in the position shewn on Fig. 7, in which case
only the telephone apparatus is put in circuit whilst the new apparatus is quite
cut out of circuit. If the switch lever occupies the position, in which, as de-
scribed above, the apparatus driven by the clockwork gives an answer to the
subscriber who is calling, then the strip apparatus is placed in circuit at the same
time. The course of the current for this is as follows, with reference to Fig. 16:
First the calling current passes by 91, magnet 58, to the electro magnet 72 and
by 92 back to the inducing coil R. The calling current energises the electro
magnet 72 for a moment and thereby closes the contact 73, whereupon the strong
current which can be generated by a local battery or be sent from an electric
central station, takes the following course:-By 93, 73, electro magnet 67, and
by 94, back to the battery or central station. Thus the electro magnet 67 is
energised and attracts the armature 69, by which the contact 73 is again broken.
But the armature 69 is retained by the pawl 71 in the depressed position until
the pawl 71 engages in the next space of the wheel 68. In the meantime, the
electric motor 97 is working, being supplied with current from the battery or
central station which passes through motor 97 and the contact 95, 96, which is
closed by the depression of the arinature 69. Whilst the motor 97 is working,
the strip 80 is wound for example from off the drum 43 on to the drum 44, and
the magnet 58 fixes upon the strip 80 the messages sent by the calling subscriber
through the line wire. The apparatus moves simultaneously with the wire
apparatus which first makes a communication to the calling subscriber.
When the apparatus has fulfilled this office and has come to rest, the strip
apparatus can receive the desired message. The messages which are sent over
the line wire induce in the induction coil R currents which can no longer act
upon the wire apparatus after it has stopped. But these induced currents, com-
ing from the induction coil R, act upon the magnet 58 of the strip apparatus,
for the armature 69 closes, not only the motor contact 95. but also a contact 98,
so that the induced currents from the coil R take their course by 91, 58, 99, 98,
100 and 92, back to the induction coil. But this current does not energise the
electro magnet 72 in such a manner as to cause it to again close the contacts 72
and 7, because the electro magnet 72 has a sufficiently high resistance to cause
the current to take the course just described.
When the strip apparatus has received the message and when it has come to
rest after the expiration of the period allowed for the conversation, then the
subscriber can on his return hear the conversation that has been retained by
reversing the lever 51 (Fig. 8) so as to cause the motor first to run backwards
corresponding to the period of conversation, and then reversing the current again
in order to cause the strip 80 to pass again past the electro magnet 58 in the same
direction as it passed when receiving the conversation. The electro magnet has
then to be connected to the telephone receiver. For this purpose there is pro-
vided a separate switch which is also adapted to connect, when desired, the electro

page_text: magnet 58 to the poles of a battery, in order to wipe out the conversation con-
tained on the strip. As the construction of a switch of this kind does not com-
prise any novel features, it needs only to be mentioned without special description.
Instead of speech, telegraphic signals such for instance as those of the Morse code
may be stored and reproduced in the following manner. The telegraph trans-
mitter such as that employed, for sending dots and dashes, into the line, is con-
nected to the coil of an electromagnet which is moved along a steel wire or strip
or has the wire or strip moved along it. The wire or strip is thus influenced
in such a manner that when the coil of the electromagnet is connected to a tele-
phone receiver and moved along the wire or strip or has the wire or strip moved
along it, the dots or dashes may be heard as short and longer sounds in the order
in which they were first transmitted.
The apparatus above described are intended merely to serve as examples of
construction, for they might be constructed in many ways without departing from
the fundamental principle set forth above.
Having now particularly described and ascertained the nature of this in-
vention and in what manner the same is to be performed, I declare that what I
claim is:
1. The herein described method of receiving, storing and reproducing messages,
signals or the like by subjecting a magnetisable body such as a steel wire or
strip, to the action of an electromagnet which moves along it, or along which
it is moved, the coil of this magnet being first in connection with a transmitter
so that the wire or strip is influenced in a manner corresponding to the signals
transmitted, and the coil being then in connection with a telephone receiver by
which the signals which influenced the wire or strip are reproduced.
2. For operating as set forth above,, apparatus comprising a steel wire wound
, helically on a cylinder, an electromagnet caused to travel along the wire and
suitable electric connections, substantially as described with reference to Figs. 1
to 7 inclusive.
3. The modified form of apparatus comprising a steel strip wound on and off
a pair of drums so as to pass along a stationary electromagnet, and suitable
electric connections, substantially as described with reference to Figs. 8 to 16
inclusive.
Dated this 20th day of January 1900.
ABEL & IMRAY,
Agents for the Applicant.