Improvements relating to Telegraphic, Telephonic,. and like Systems, and to Automatic Switching Apparatus therefor.
Year: 1899

page_text: Date of Application (in United Kingdom), 6th Apr., 1899
Complete Specification Left, 24th Nov., 1899-Accepted, 5th May,
1900
Improvements relating to Telegraphic, Telephonic,. and like Systems,
and to Automatic Switching Apparatus therefor.
I, LÉON JOSEPH MATHURIN DARDEAU, of 5, Rue Louis Rolland, Montrouge,
(Seine), in the Republic of France, Electrician, do hereby declare the nature of
this invention to be as follows:
METHOD OF CALLING UP GENERALLY EMPLOYED IN TELEGRAPHY AND IN
TELEPHONY. ITS DISADVANTAGES.
In the existing telegraphic and telephonic installations, one wire, in the case
of telegraphy, or two wires, in the case of telephony, start from one end of the
network and terminate at the extreme station passing through all the inter-
mediate stations, that is, the line is divided into as many sections as there are
intermediate stations between the extreme stations.
It results, from this arrangement, that in order to communicate from, one
extreme station to the other, it is necessary to successively call up all the inter-
mediate stations and ask each of them for communication with the next station.
Take, for example, a line with 10 stations: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. If
station 1 requires to communicate with station 10, it has first to call up station 2,
enter into communication therewith and ask for station 3; station 2 has then to
insulate itself in order to enable 1 to be in direct communication with 3.
When has replied, it will do the same as 2 to establish communication
between 1 and 4 and so on up to the last.
This method offers the following disadvantages: -
1. Of requiring all the employees to be permanently at their post.
2. Of rendering the line idle during a very long time to produce the calls,
thus bringing about considerable delays in the transmission of messages.
3. The necessity of insulating each intermediate station is liable to cause
mistakes; in fact, if voluntarily or involuntarily an employee places his station
in shunt, he will interfere with the transmission and can also receive the message.
4. It is not possible to let the intermediate stations know when the line is
free.
CONDITIONS TO BE FULFILLED TO SATISFY THE REQUIREMENTS OF TELEGRAPH
AND TELEPHONE LINES WHICH ARE RAPIDLY WORKED.
1
L
IT
1:
J 11
11

page_text: 1. All the stations should be put in circuit on the same wire in such a manner
as to produce a direct line from one end of the network to the other and,
inversely, between all the stations, connected onto the route.
2. The employment of more than two line wires should not be necessary.
3. To operate without distinction with the same apparatus, either with a
single or double wire line.
4. To directly effect the release of the alarm at the desired station without
affecting the others.
5. To enable the calling station to stop the alarm at the called station in the
case of absence of the attendant at the latter station.
6. To enable the attendant at the called station to advise the calling station of
his presence, by starting the alarm at the latter station..
7. To also permit any number of stations connected onto the route to enter
into communication and to correspond collectively together whatever be the
order of these stations.
8. To moreover permit any station, in case of need to call up, at a single
stroke all the other stations and to transmit orders to them all at once.
9. To ensure the absolute secrecy of the correspondence between the com-
municating stations.
10. To indicate, at all the stations whether the line is free or occupied.
11. In the case of prolonged occupation of the line, to enable the attendant
at any station, in case of need, to advise the communicating stations, by means
of an arranged signal, that there is need to give up the line to him and if need be
to interrupt them, in the case of absolute necessity, and call up the desired
station.
12. To only employ very weak and, consequently, inexpensive currents on
the line.
13. The apparatus employed for the calls, except the local alarms, should be
capable of operating without distinction according to each particular case or to
distance, either with the current from a local battery or directly with the line
current; this for economical reasons in having, as far as possible, only a single
battery working at a time, that is to say, the battery of the calling station.
14. The manipulation of the apparatus should be very simple and not require,
for calling, replying, entering into communication or indicating that the line
is free, any switches, commutators or connections operated by hand and capable
of being left in place.
15. The stoppage or throwing out of action of one or more apparatus should
not interfere with the operation of the others.
16. It should be possible, for reasons of economy, to utilise existing telegraphic
or telephonic apparatus as well as the relays in use serving to actuate them.
17. The combination should be such that it has absolute security in calling
without any chance of possible error.
18. The apparatus should be all identical so as to enable them to be distributed
without distinction over the network and to be interchanged reciprocally.
19. The number of stations to be intercalated in the circuit should not be
limited.
20. Finally the proposed apparatus above all should be of as simple a con-
fruction as possible so that its moderate price will permit its coming into
general use.
DESCRIPTION OF THE APPARATUS TERMED "DARDEAU'S UNIVERSAL AUTOMATIC
COMMUTATOR."
The new apparatus which I am about to describe, to which I give the name
of automatic universal commutator, gives a perfect solution of the problem which
was set me and which is stated above.
The accompanying drawings represent, by way of example, an apparatus con-
structed according to my system.
1

page_text: Figure 3 a side view thereof.
Figure 4 shows the dial.
Figure shows details of the relays employed in the commutator.
Figure 6 is a diagram representing the connections of the different parts
between themselves and with the main and local circuits.
Figure 7 shows the operating buttons.
My apparatus is composed of a number of parts hereinafter mentioned, viz. :-
I. A special telegraphic instrument with a clock-work movement represented
in different positions by Figures 1, 2 and 3.
Figure 4 shows the dial A serving to indicate by means of letters, figures or
other inscriptions, according to the applications, the position of cams making
the desired connections in the interior of the apparatus. The reading of the
dial is effected by means of a pointer B moving in front of the dial A and follow-
ing the divisions of the latter.
This pointer is fixed onto the prolongation C of the arbor D. On the opposite
prolongation C are fixed, so as to correspond to the indications of the pointer,
the connecting cams E and E¹.
The arbor D bears, in the middle, an escapement-wheel F having as many
teeth as there are divisions on the dial.
An escapement-fork G controlled by an electromagnet H allows the wheel F
to advance one tooth at each passage of the current and thus causes the pointer.
to move through one division of the dial enabling the corresponding position of
the cams E and E¹ to be read off and, consequently, the predetermined con-
nections in the interior of the apparatus.
The arbor D is driven by the clockwork movement which, in this case, serves
as a motor and is arranged so as to produce 4450 rotations of the arbor D, conse-
quently effect 4400 connections, and accordingly, the exchange of an equal
number of messages, without requiring to be rewound.
To satisfy all requirements, it is possible to considerably increase the number
of rotations of the arbor D, in two different ways, viz. :-
1. By increasing the force of the spring and by intercalating an additional
wheel in the clockwork movement. If, in fact, this wheel is geared with the
pinion on the arbor D, in the ratio of 1 to 10, there will be obtained, in this
manner, 44000 revolutions of D and consequently, 44000 connections, before the
spring, requires to be rewound.
2. By entirely suppressing the clockwork movement and replacing it by an
electromagnet attracting an armature which acts by means of a pawl on a ratchet-
wheel keyed onto the arbor D, instead and in place of the escapement-wheel F.
and having the same number of teeth as the latter, in such a manner that, at
each passage of the current, the pointer is caused to move over one division
of the dial.
The operation of the apparatus will be the same as with the clockwork move-
ment, the different commutating parts remaining the same in the two cases.
II. The accessory apparatus shown in Figure 5 serving to control the operation
of the telegraphic apparatus above described.
This comprises two solenoidal electromagnets I, the cores J of which, consist-
ing preferably of a bundle of iron wires and supported by the elastic strip K,
are placed vertically in the interior of the bobbins I and are subjected to the
action of a magnet L which attracts them towards one or other of its poles.
There is thus obtained a system in unstable equilibrium, which permits the
cores J to oscillate from one position to the other according to the direction
of the current which is sent through the coils I and to allow their tongues or
extensions M to strike against the contact-plates N or stops N¹ fixed by means

page_text: omne prates themselves secured in position by nuts on the
poles of the magnets L.
The nuts are supported on the screws P¹ which pass through the ebonite
plate and serve to fix in a suitable position the polar extensions Q acting on the
cores J.
R is a sleeve passing into the bobbins I and serving as a support for the
core and the elastic strip K.
The whole is arranged as. indicated in Figure 5, which shows these two
apparatus, which operate similarly to relays and serve as commutators, as fol-
lows!:
One of them, 1, Figure 5, to send the current from the local battery into the
electromagnet H, controlling the escapement or to interrupt the current from the
line in this electromagnet if the apparatus is to operate directly by the current in
the line.
The other, 2, Figure 5, to send the current from the local battery into the
releasing electromagnet T or to the alarm S to set it in operation or to withdraw
it, to interrupt its operation.
These apparatus can be mounted on each side of the telegraph and on the same
frame (Figures 1, 2, 3) or be separated therefrom and be quite distinct. More-
over, one or more of these relays or both together can be replaced by other
relays of any suitable pattern selected from existing relays or a combination of
the latter suitably arranged for this purpose.
AQ is the opposing spring of the escapement-fork G and AR the pivots
on which it oscillates. A S are screws which limit its travel in each direction.
A T the tension strip or plate for the spring, and A U the regulating screw
therefor.
MANIPULATION AND OPERATION OF THE APPARATUS.
To easily understand the function of the different parts composing the
apparatus, it is indispensable to follow them on the figures of the drawing, which
shows them in their respective places, by means of letters of reference which are
assigned to them and to then refer to the diagram, Figure 6, where these same
letters of reference are retained. It can thus be seen what happens from an
electrical point of view.
-
3+ acting on
This diagram, Figure 6, represents all the connections of the different parts,
between themselves, and with the main and local circuits.
The manipulating arrangement consists of three buttons 10 2
the spring strips 4, 5, 6, 7 which serve to send the current into the line by
means of a battery U and contacts 8 and 9 connected in pairs, each pair to one of
the poles of the battery U, and at the same time to send a current into the
several apparatus by means of a battery V and contacts 10, 11.
On each button is engraved the sign of the current which it sends into the line.
These three buttons are placed in the following order 2 lo and 3+.
-
3, marked with the sign +, serves to actuate the electromagnet H which, by
acting on the fork G, Figures 1 and 3, allows the wheel F to advance one tooth
at each passage of the current.
To ensure synchronism and perfect concordance between the pointers at all
the stations, the wheel F bears a pin X which, at each revolution, abuts against
the nose of the lever Y and comes to rest in this position.
If currents of the same sign continue to be sent, the escapement-fork G
will continue to oscillate between two teeth of the wheel F which is thus en-
gaged by the pin X and no new effect is produced at the stations, which permits
an apparatus accidentally left behind to continue to advance until it is also
stopped in the same manner. From this moment, agreement is re-established
between all the stations and all the pointers are then stopped in front of the
cross which is the sign indicating that the line is free.
It is thus necessary to now effect the release of the wheel F in order to permit
it to respond to the fork G and thus make a fresh revolution.

page_text: For this purpose, the lever Y is put into communication by its axis Z with
the end of the wire of the electromagnet T, the other end of which is connected
by the wire 12 to the pole of + sign of the battery V.
The wheel is in communication, through the base of the apparatus, with
the wire 13 and the contact N.
The wire 14 is connected to the pole of
core of the relay 2, Figure 5.
sign of the battery V and to the
The wheel F having been brought into contact with Y by means of the but-
ton 3 marked with the + sign, the current has passed in the desired direction
in order that the tongue M of the relay 2 has taken the position indicated in
dotted lines. The circuit of the battery V is then broken between M and N in
the relay 2; the wheel F thus remains engaged.
If now it is desired to call up any station, it is only necessary to press on the
button 2, marked with the sign, to send into the line a current which will
pass through all the stations in an opposite direction to that sent by the
button 3+. It will result therefrom that, in all the stations, the tongue M of
the relay 2 will leave the position indicated in dotted lines in order to occupy
that marked in full lines. M will engage N and the circuit of the battery V
will be closed in all the stations at the same time. The electromagnet T will
raise the lever Y. The pin X being no longer held back, the wheel F will
respond to the propulsion of the clockwork train, and will rotate through a half-
division and be again stopped by the escapement-fork G which is now in engage-
ment with a tooth of the wheel, which was held away therefrom by reason of
the engagement of the pin X with X which had stopped it in its motion in the
middle of a division corresponding to the cross +. The pointers of all the
stations having advanced through the same amount, they are now opposite the
word déclanchment" (release).
By reason of this advance of the wheel, the pin X is no longer in contact with Y
since it has passed it and the circuit of the battery V is again interrupted in all
the stations."
If currents of the same sign continue to be sent into the line by means of
the button 2, no new effect is produced at the stations since all the local circuits
are interrupted in each apparatus and the wheel F cannot advance under the
action of a current of this sign by reason of the arrangement given to the
relay 1.
In fact, in this apparatus, the core J is very much limited in its travel by the
contact- and stop-plates N and N¹, Figure 5. One of the polar extensions Q,
that corresponding to the contact N,. is advanced very near to the core J in such
a manner as to keep the tongue M resting against the contact N which is con-
nected by a wire to one end of one of the bobbins of the electro-magnet H. The
core J is connected to the end of the other bobbin.
This arrangement is designed to form a bridge between the two ends of the
wire of the electromagnet H and to permit the current to pass through this
bridge without traversing the electromagnet H which thus remains inactive and,
consequently, no longer attracts the armature A. G of the escapement-fork.
The above mentioned operations having been effected, the pointer of the
calling station indicates that the release of all the apparatus is effected. If
it is wished to communicate with station 7, for example, the button 3 + down
is pressed 7 times. The current sent over the line will then pass in the desired
direction for the tongue M of the relay 2 to again take up the position N
indicated in dotted lines, and the tongue M of the relay 1 to move away from N
so as to allow the current to pass through the electromagnet H which will then
attract the armature A C of the escapement-fork and will advance the wheel F
one tooth.
This action is repeated each time that the button 3 + is pressed. On ceasing
to press the said button, the current also ceases to pass and the tongue M. of the
relay returns to touch N under the attraction of the nearer extension Q,

page_text: If the button 3 + be again
pressed, the same result will be obtained as before. The relay 2 will not move
as long as the direction of the current is not changed by pressing the button 2.
When the pointer has reached the Figure 7 corresponding to the desired
station, the communications at this station will be re-established in the follow-
ing manner: —
which here replaces the spring for returning it.
The cam E driven with the arbor D and the wheel F, will be in contact with
the lever of the alarm A 1); at the same time it will move away from the
screw A E with which it is maintained in contact by a spring A F.
The bridge A G, which prevents the line current from traversing the tele-
phonic receivers or the telegraphic relays A V, is now open; the station is in
communication. There only remains to give notice thereof by the alarmı by
pressing on the button 2
-
The tongue M of the relay 2 will then leave the position indicated in dotted
lines and will touch the contact N to complete the circuit in the following
manner; The wire 15 connected to the + pole of the battery V, the alarm S,
the axle 16 of the lever A D), the cam E, the arbor D, the wire 13, the con-
tact N, the tongue M and the core J connected by the wire 14 to the
battery V.
-
pole of the
If the employee at the station which is called up is present, he will press the
button 1, marked with the sign o, to cause his alarm to stop at the same time
as he presses on the button 2, to start the alarm of the calling station and
advise the attendant there of his presence.
The pressure on the button lo acts to close the circuit of the battery V on the
contact 11 and to cause a current to pass through a double winding indicated in
dotted lines in the bobbin of the relay 2, in such a direction that the tongue M.
and the core occupy the position indicated in dotted lines and thus interrupt
the circuit of the alarm.
If, on the contrary, the employee at the called station is absent, it is only
necessary, in order to stop the alarm, to bring back, by means of the button 3 +,
the pointers to their starting point or even to call up the next station, if that
be required.
In this manner, the alarm stops in the station 7 which is just called up and
re-establishes at the same time the bridge on the receivers or the telegraphic
relays AV by means of the shunt A G by means of the lever A D which, being
no longer retained by the cam E, comes to rest on the screw A E with which it
makes contact.
As will be seen from the above description, the stations are only in com-
munication when their pointers are on the figure for which they have been
adjusted.
But, as this condition is no longer fulfilled by the calling station, I have over-
come the difficulty in a very simple manner, by means of a small electro-
magnet A H which is traversed by the current from the battery V every time that
the button 3+ is pressed, which closes the circuit of the battery V by means of
the strip 6 and the contact 10.
It follows that once the apparatus is released by the fact of displacing the
pointer one division by means of the button 3 + the circuit of the electro-
magnet A H has thus been closed, which then attracts the lever A D and causes
it to engage with a pin A I fixed on a piece A J, visible on Figures 2 and 3,
and supported by its arbor A L.
The
It remains in this position until the pointers have reached the cross +. At
this moment a cam E fixed on the shaft D raises the piece A J, Figure 2, and
releases the lever A D which returns onto the contact of the screw A E.
bridge A G is re-established and all the local circuits of the apparatus are broken.
The apparatus can now operate in the called station if it is called up by an-
other station in the network. In this station, matters take place as has just been
mentioned.

page_text: This arrangement has the advantage of permitting a subscriber to enter into
communication, at the same time, with any number of stations which can com-
municate collectively together by calling them one after another in such a
manner that each station called becomes in its turn the calling station in order
to enable it to remain in communication with the others.
It may also be useful for all the stations to be called at the same time by
any station of a network to receive similar orders or a message interesting to
them all collectively.
For this purpose, there is arranged symmetrically in all the apparatus, a con-
tact-strip AM which the stop-pin X touches when the pointer corresponds to
the collective sector, by causing the point of attachment of this strip to com-
municate with the wire 17.
-
It will be only necessary to press the button 2 in order that the tongue M
and the core J of the relay 2 shall leave the position indicated in dotted lines
and engage with the contact N. The circuit is then closed through the electro-
magnet A H which attracts the lever of the alarm A D and thus opens the
bridge A G A D engages with AI and the alarm starts. The same effect
takes place in all the stations at once.
When the pointers are returned to the cross +, the cain E, Figures 2 and 3,
will again raise the piece A J; the piece A D will again fall onto A E and all
the stations will be again ready for receiving a call.
To make Figure 6 of the drawing clearer, I have not shown the connection
of A M with 17, in order to enable me to show another application which can
be easily carried into practice with the apparatus forming the object of my said
invention.
It relates to the setting to time of the clocks on railway lines.
For this purpose, the strip A M is put into connection with the end of the
wire of an electromagnet A N placed in the clock to be regulated; the other end
of this wire is connected to the pole of + sign of the battery V. The circuit is
closed in the same manner as mentioned above for the calls of the alarm.
Suppose that A. O be the regulator and A P the clock at the station, which it
is required to regulate, it will be seen at once that the said clock is two minutes
fast. The regulation is effected in the following manner: either by hand
with the buttons 2 and 3; or automatically with a rotary controller which is
released by the regulator A O at the desired moment.
This controller, actuated by a clockwork movement, makes a complete revolu-
tion each time that it is released. This release can take place once every 24
hours at a suitable time when the traffic of the line is stopped.
Suppose, on the other hand, that it could not be so, and that it was to be feared
that at the moment of the passage of the hour, two stations would be in com-
munication with each other. In this case, in admitting, by way of example,
that an installation for 9 stations is being dealt with, the dial being divided like
that shown in Figure 4, the controller will send into the line the current of +
sign, 12 times to bring back if necessary the pointers to the cross +, in the
case where two stations would be at work, afterwards once the current of
sign to effect the release of the apparatus and again the current of + sign 11
'clocks."
times to bring the pointers onto the sector:
A current of sign
will be again passed to effect the setting to time, then followed by another of
+ sign to bring back the pointers to the cross.
66
-
This operation has required a very short time: 12 to 15 seconds to do the work:
and the stations which have been able to be cut out, have only to call back
to put themselves into, communication.
. EMPLOYMENT OF THE APPARATUS FOR SIGNALS ON RAILWAY TRACKS AND FOR
VARIOUS DOMESTIC, COMMERCIAL, INDUSTRIAL AND OTHER PURPOSES.
As it is very easy to see, the working of my apparatus is both very simple
and very sure, which enables it to be employed for many purposes, for all cases

page_text: where it is required to establish communication to a distance such, for example
as to open and shut doors, water, air or gas cocks; to operate signal dises on
railways, or to cause any desired signal or indication to appear.
It can also be employed in a very advantageous manner as an automatic
station; thus a single apparatus placed with the lodge keeper of an estate will
enable a dozen apparatus placed at different points to be served by means of
two wires only passing to the central office in such a manner that the said
central office can call up any one of the points or subscribers connected to the
automatic station, without interfering with the others, this being effected by
causing to appear at the latter a small signal indicating that the line is not free.
Any subscriber connected to the automatic station can, if the line is free,
directly call up the central office without interfering with the others, by causing
to appear at each a small signal indicating that the line is not free and the
central office replys to this subscriber as if it were connected directly therewith
by means of a special line.
This is effected by arranging the apparatus serving the automatic station,
in such a manner that it is provided with as many contact blades or strips as
there are stations to be connected and in such a manner that each blade or
strip corresponds to a given station. The cam E, keyed onto the shaft D, will
be arranged in such a manner as not to touch any of the blades when the
pointer is at the cross +.
SPECIAL ARRANGEMENTS OF THE APPARATUS FOR SPECIAL PURPOSES.
It is obvious that, according to the applications for which it is designed, the
apparatus can be varied in form and dimensions whilst retaining the same
principle and the same method of operation which forms the subject of my
invention.
:
In the same way, the arrangement for doing away with the clockwork move-
ment indicated in the description of the apparatus can be applied whatever be
the dimensions of the apparatus and the use for which it is designed.
My improved apparatus can be modified so as to utilise, for its operation,
currents alternately reversed produced by the "magnetic calls" at present cm-
ployed on telephone lines.
It is also possible, without inconvenience, in order to put in motion apparatus
such as is described above, without changing in any way its operation, to
utilise continuous or rectified currents produced by a small magneto-electric
machine operated by hand and which would thus replace the calling battery U,
Figure 6.
It should be noted that the apparatus is arranged in such a manner that if
there is added to the network a larger number of stations than that for which
it has been designed, it is only necessary to change the dial for another having a
larger number of divisions and to also change the escapement wheel for another
having a larger number of teeth.
This modification would not necessitate the removal of the apparatus and
their replacement by others which are more suitable. For this purpose, the
escapement wheel is secured by means of screws between two plates fixed to the
arbor D which permits the change to be made in a few minutes and at very little
cost.
Datal
en
1000

page_text: Improvements relating to Telegraphic, Telephonic, and like Systems,
and to Automatic Switching Apparatus therefor.
I, LÉON JOSEPH MATHURIN DARDEAU, of 5, Rue Louis Rolland, Montrouge,
(Seine), in the Republic of France, Electrician, 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:-
METHOD OF CALLING UP GENERALLY EMPLOYED IN TELEGRAPHY AND IN
TELEPHONY. ITS DISADVANTAGES.
In the existing delegraphic and telephonic installations, one wire, in the case
of telegraphy, or two wires, in the case of telephony, start from one end of the
network and terminate at the extreme station passing through all the inter-
mediate stations, that is, the line is divided into as many sections as there are
intermediate stations between the extreme stations.
It results, from this arrangement, that in order to communicate from one
extreme station to the other, it is necessary to successively call up all the inter-
mediate stations and ask each of them for communication with the next station.
Take for example, a line with 10 stations: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. If
station 1 requires to communicate with station 10, it has first to call up station 2,
enter into communication therewith and ask for station 3; station 2 has then to
insulate itself in order to enable station 1 to be in direct communication with 3.
When 3 has replied, it will do the same as 2 to establish communication
between 1 and 4 and so on up to the last.
This method offers the following disadvantages:
1. Of requiring all the employees to be permanently at their post.
2. Of rendering the line idle during a very long time occupied to produce the
calls, thus bringing about considerable delays in the transmission of messages.
3. That the necessity of insulating each intermediate station is liable to cause
mistakes; in fact, if voluntarily or involuntarily an employee places his station
in shunt. he will interfere with the transmission and can also receive the message.
4. It is not possible to let the intermediate stations know when the line is
free.
CONDITIONS TO BE FULFILLED TO SATISFY THE REQUIREMENTS OF TELEGRAPH
AND TELEPHONE LINES WHICH ARE RAPIDLY WORKED.
To obviate the disadvantages above mentioned, the problem to be solved con-
sists in satisfying, in a practical manner, the following conditions:-
1. All the stations should be put in circuit on the same wire in such a manner
as to produce a direct line from one end of the network to the other and,
inversely, between all the stations, connected onto the route.
2. The employment of more than two line wires should not be necessary.
3. To operate without distinction with the same apparatus, either with a
single or double wire line.
4. To directly effect the release of the alarm at the desired station without
affecting the others.
5. To enable the calling station to stop the alarm at the called station in the
case of absence of the attendant at the latter station.
6. To enable the attendant at the called station to advise the calling station of
his presence, by starting the alarm at the latter station.
7. To also permit any number of stations connected onto the route to enter
into communication and to correspond collectively together whatever be the
order of these stations.

page_text: 8. To moreover permit any station, in case of need to call up at a single
stroke all the other stations and to transmit orders to them all at once.
9. To ensure the absolute secrecy of the correspondence between the com-
municating stations.
10. To indicate, at all the stations whether the line is free or occupied.
11. In the case of prolonged occupation of the line to enable the attendant
at any station, in case of need, to advise the communicating stations, by means
of an arranged signal that there is need to give up the line to him and,
in case of absolute necessity, to interrupt them, and call up the desired station.
12. To only employ very weak and, consequently, inexpensive currents on
the line.
13. The apparatus employed for the calls, except the local alarms, should be
capable of operating without distinction according to each particular case or to
distance, either with the current from a local battery or directly with the line
current; this for economical reasons in having, as far as possible, only a single
battery working at a time, that is to say the battery of the calling station.
14. The manipulation of the apparatus should be very simple and not require,
for calling, replying, entering into communication or indicating that the line
is free, any commutators or connections operated by hand and capable of being
left in place.
15. The stoppage or throwing out of action of one or more apparatus should
not interfere with the operation of the others.
16. It should be possible, for reasons of economy, to utilize existing tele-
graphic or telephonic apparatus, as well as the relays in use serving to actuate
them.
17. The combination should be such that it has absolute security in calling
without any chance of possible error.
18. The apparatus at the several stations should be all identical so as to enable
them to be distributed without distinction over the network and to be inter-
changed reciprocally.
19. The number of stations to be intercalated in the circuit should not he
limited.
20. Finally, the proposed apparatus, above all, should be of as simple a con-
struction as possible so that its moderate price will permit its coming into
general use.
DESCRIPTION OF THE APPARATUS TERMED "DARDEAU'S UNIVERSAL AUTOMATIC
COMMUTATOR."
The new apparatus which I am about to describe, to which I give the name
of automatic universal commutator, gives a perfect solution of the problem which
was set me and which is stated above.
In the drawings accompanying my Provisional Specification, is represented,
by way of example, an apparatus constructed according to my system.
Figure 1 is a front view, the dial and the plate being removed to permit the
movement to be seen.
Figure 2 is a rear view, and
Figure 3 a side view thereof.
Figure 4 shows the dial.
Figure 5 is a detail view to show the form of the relays employed.
Figure 6 is a diagram of the connections between the different parts of the
apparatus, and with the main and local circuits.
Figure 7 shows the operating buttons.
My apparatus comprises the parts hereinafter mentioned, riz.:
I. A special telegraphic instrument with a clockwork movement, viewed in
different directions in Figures 1, 2 and 3.
Figure 4 shows the dial A serving to indicate by means of letters, figures or
other inscriptions, according to the applications, the positions of the cams making

page_text: the desired connection in the interior of the apparatus. The reading of the
dial is effected by means of a pointer B moving in front of the dial A and follow-
ing the divisions of the latter.
This pointer is fixed onto the prolongation C of the arbor D. On the opposite
prolongation C are fixed, so as to correspond to the indications of the pointer,
the connecting cams E and E¹.
The arbor D bears, in the middle, an escapement-wheel F having as many
teeth as there are divisions on the dial.
An escapement-fork G controlled by an electro-magnet H, allows the wheel F
to advance one tooth at each passage of the current and thus causes the pointer
to move through one division of the dial, enabling the corresponding position of
the cams E and E' to be read off and, consequently, the predetermined con-
nection in the interior of the apparatus.
The arbor D is driven by the clockwork movement which, in this case, serves
as a motor and is arranged to rotate the arbor D, so as to effect 4400 connections
and accordingly, the exchange of an equal number of messages without requiring
to be rewound.
To satisfy all requirements, it is possible to considerably increase the number
of rotations of the arbor D, in two different ways, viz.:
1. By increasing the force of the spring, and by intercalating an additional
wheel in the clockwork movement.
If, in fact, this wheel is geared with the pinion on the arbor D, in the ratio
of 1 to 10, there will be obtained, in this manner, 44000 connections before the
spring requires to be rewound.
2. By entirely suppressing the clockwork movement and replacing it by an
electromagnet attracting an armature which acts by means of a pawl on a ratchet
wheel keyed onto the arbor D, instead and in place of the escapement wheel F,
and having the same number of teeth as the latter, in such a manner that, at
each passage of the current, the pointer is caused to move over one division
of the dial.
The operation of the apparatus will be the same as with the clockwork move-
ment, the different commutating parts remaining the same in the two cases.
II. The accessory apparatus shown in Figure 5 serving to control the operatión
of the telegraphic apparatus above described.
This comprises two solenoidal electromagnets I, the cores J of which, consist-
ing preferably of a bundle of iron wires and supported by the elastic strip K,
are placed vertically in the interior of the bobbins I and are subjected to the
action of a magnet L which attracts them towards one or other of its poles.
There is thus obtained a system in unstable equilibrium which permits the
cores J to oscillate from one position to the other according to the direction
of the current which is sent through the coils I and to allow their tongues of
extensions M to strike against the contact plates N or stops N¹ fixed by means
of screws onto ebonite plates themselves, secured in position by nuts P on the
poles of the magnets L.
The nuts Pare supported on the screws P which pass through the ebonite
plate and serve to fix in a suitable position the polar extensions Q acting on the
cores J.
R is a sleeve passing into the bobbins I and serving as a support for the
core and the elastic strip K.
The whole is arranged as indicated in Figure 5, which shows these two
apparatus, which operate similarly to relays and serve as commutators, as fol-
lows:-
One of them, (Figure 5), to send the current from the local battery into the
electromagnet H, controlling the escapement or to interrupt the current from the
line in this electromagnet if the apparatus is to operate directly by the current in
the line.
The other, 2 (Figure 5), to send the current from the local battery into the

page_text: releasing electromagnet T or to the alarm S to set it in operation or to withdraw
it, to interrupt its operation:
More-
These apparatus can be mounted on each side of the telegraph and on the same
frame (Figures 1, 2, 3) or be separate therefrom and be quite distinct.
over, one or other of these relays or both together can be replaced by other
relays of any suitable pattern selected from existing relays or a combination of
the latter suitably arranged for this purpose.
AQ is the opposing spring of the escapement-fork G and AR the pivots
on which it oscillates. A S are the screws which limit its travel in each direction.
A T the tension strip or plate for the spring, and A U the regulating screw
therefor.
MANIPULATION AND OPERATION OF THE APPARATUS.
To easily understand the function of the different parts composing the
apparatus, it is indispensible to follow them on the figures of the drawing, which
show them in their respective places, by means of letters of reference which are
assigned to them and to then refer to the diagram, Figure 6, where these same
letters of reference are retained. It can thus be seen what happens from an
electrical point of view.
This diagram, Figure 6, represents all the connections of the different parts,
between themselves and with the main and local circuits.
The manipulating arrangement consists of three buttons to 2- 3+ acting on
the spring strips 4, 5, 6, 7 which serve to send the current into the line by
means of a battery U and contacts 8 and 9 connected in pairs, each pair to one of
the poles of the battery U, and at the same time to send a current into the
several apparatus by means of a battery V and contacts 10, 11.
On each button is engraved the sign of the current which it sends into the line.
These three buttons are placed in the following order 2-lo and 3+.
3, marked with the sign +, serves to actuate the electromagnet H which, by
acting on the fork G, Figures 1 and 3, allows the wheel F to advance one tooth
at each passage of the current.
To ensure synchronism and perfect concordance between the pointers at all
the stations, the wheel F bears a pin X which, at each revolution, abuts against
the nose of the lever Y and comes to rest in this position.
If currents of the same sign continue to be sent, the escapement-fork G
will continue to oscillate between two teeth of the wheel F which is thus en-
gaged by the pin X and no new effect is produced at the stations which permits
an apparatus accidentally left behind, for example, by reason of the escapement
fork G making an incomplete oscillation, to continue to advance until it is
also stopped in the same manner.
-
The stopping device can only be operated by means of a current of
sign
(according to the diagram, Figure 6), it follows therefore that, if currents of
+sign continue to be sent, this stopping device is not operated. This permits
the wheel F to rotate until is meets the stop abutment; therefore, for example,
if an apparatus is in advance, the said apparatus would not be able to pass this
abutment. This permits the other apparatus to recover the delay by also suc-
cessively coming to rest in the same manner. At a given moment, by sending
an additional number of current emissions sufficient to cause a complete rotation
of the wheel F, the synchronism of the apparatus at the several stations will be
certainly reestablished since all will have arrived at the stop abutment and it
will then be necessary to send a current of sign to again release each one of the
said apparatus.
-
From this moment, agreement is reestablished between all the stations and
all the pointers are then stopped in front of the cross + which is the sign
indicating that the line is free.
It is thus necessary to now effect the release of the wheel F in order to permit
it to respond to the fork G and thus make a fresh revolution.

page_text: purposes
το μαν
the end of the wire of the electromagnet T, the other end of which is connected
by the wire 12 to the pole of sign of the battery V.
-
The wheel is in communication, through the base of the apparatus, with
the wire 13 and the contact N.
The wire 14 is connected to the pole of
core J of the relay 2, Figure 5.
sign of the battery V and to the
The wheel F having been brought into. contact with Y by means of the but-
ton 3 marked with the sign, the current has passed in the desired direction
in order that the tongue M of the relay 2 has taken the position indicated in
dotted lines. The circuit of the battery V is then broken between M and N in
the relay 2 the wheel thus remains engaged.
-
If now it is desired to call up any station, it is only necessary to press on the
button 2, marked with the sign, to send into the line a current which will
pass through all the stations in an opposite direction to that sent b the
button 3+. It will result therefrom that, in all the stations, the tongue M of
the relay 2 will leave the position indicated in dotted lines in order to occupy
that marked in full lines. M will engage N and the circuit of the battery V
will be closed in all the stations at the same time. The electromagnet T will
raise the lever Y. The pin X being no longer held back, the wheel F will
respond to the propulsion of the clockwork train, and will turn through a half-
division and be again stopped by the escapement-fork G which is now in engage-
ment with a tooth of the wheel, which was held away therefrom by reason of
the engagement of the pin X with Y which has stopped it in its motion in the
middle of a division corresponding to the cross +. The pointers of all the
stations having advanced through the same amount, they are now opposite the
word déclanchment" (release).
By reason of this advance of the wheel, the pin X is no longer in contact with Y
since it has passed it and the circuit of the battery V is again interrupted in all
the stations.
.
If currents of the same sign continue to be sent into the line by means of
the button 2, no new effect is produced at the stations since all the local circuits
are interrupted in each apparatus and the wheel F cannot advance under the
action of a current of this sign by reason of the arrangement given to the
relay 1.
In fact, in this apparatus, the core J is very much limited in its travel by the
contact- and stop-plates N and N₁, Figure 5. One of the polar extensions Q,
that corresponding to the contact N, is advanced very near to the core J in such
a manner as to keep the tongue M resting against the contact N which is con-
nected by a wire to one end of one of the bobbins of the electro-magnet H. The
core is connected to the end of the other bobbin.
This arrangement is designed to form a bridge between the two ends of the
wire of the electromagnet H and to permit the current to pass through this
bridge without traversing the electro-magnet H which thus remains inactive and,
consequently, no longer attracts the armature A C of the escapement-fork.
The above-mentioned operations having been effected, the pointers of the
calling station indicates that the release of all the apparatus is effected. If
it is wished to communicate with station 7, for example, the button + is pressed
down 7 times. The current sent over the line will then pass in the desired
direction for the tongue M of the relay to again take up the position N¹
indicated in dotted lines, and the tongue M of the relay 1 to move away from N
so as to allow the current to pass through the electromagnet H which will then
attract the armature A C of the escapement-fork and will advance the wheel F
one tooth.
This action is repeated each time that the button 3+ is pressed. On ceasing
to press the said button, the current also ceases to pass and the tongue M of the
relay returns to touch N under the attraction of the nearer extension Q,

page_text: which here replaces the springs for returning it. If the button 3 + be again
pressed, the same result will be obtained as before. The relay 2 will not move
as long as the direction of the current is not changed by pressing the button 2.
When the pointer has reached the Figures 7 corresponding to the desired
station, the communications at this station will be re-established in the follow-
ing manner-
The cam E driven with the arbor D and wheel F will be in contact with
the alarm lever A D; at the same time the latter will move away from the
screw A E with which it is maintained in contact by a spring A F.
The bridge AG, which prevents the line current from traversing the tele-
phonic receivers or the telegraphic relays A V, is now open; the station is in
communication. There only remains, to give notice thereof by the alarm by
pressing on the button 2
The tongue M of the relay 2 will then leave the position indicated in dotted
lines and will touch the contact N to complete the circuit in the following
manner: The wire 15 connected to the sign pole of the battery V, the alarm S,
the axle 16 of the lever A D, the cam E, the arbor D, the wire 13, the con-
tact N, the tongue M, and the core J connected by the wire 14 to the
battery V.
-
pole of the
If the employee at the station which is called up is present, he will press the
button 1 marked with the sign o, to cause his alarm to stop at the same time
as he presses on the button 2 -
to start the alarm of the calling station and
advise the attendant there of his presence.
The pressure on the button lo acts to close the circuit of the battery V on the
contact 11 and to cause a current to pass through a double winding indicated in
dotted lines in the bobbin of the relay 2, in such a direction that the tongue M
and the core occupy the position indicated in dotted lines and thus interrupt
the circuit of the alarm.
If, on the contrary, the employee at the called station is absent, it is only
necessary, in order to stop the alarm, to bring back, by means of the button 3 +
the pointers to their starting point or even to call up the next station if that
be required.
In this manner, the alarm stops in the station 7 which is just called up and
re-establishes at the same time the bridge on the receivers or the telegraphic
relays A V by means of the shunt A G by means of the lever A D which, being
no longer retained by the cam E, comes to rest on the screw A E with which it
makes contact.
F
As will be seen from the above description, the stations are only in com-
munication when the pointers are on the figure for which they have been
adjusted.
But, as this condition is no longer fulfilled by the calling station, I have over-
come the difficulty in a very simple manner, by means of a small electro-
magnet A H which is traversed by the current from the battery V every time that
the button 3+ is pressed, which closes the circuit of the battery V by means of
the strip 6 and the contact 10.
It follows that once the apparatus is released by the fact of displacing the
pointer one division by means of the button 3+, the circuit of the electro-
magnet A H has thus been closed, which then attracts the lever A D and causes
it to engage with a pin A. I fixed on a piece A J, visible on Figures 2 and 3,
and supported by its arbor A L.
The
It remains in this position until the pointers have reached the cross +. At
this moment a cam El fixed on the shaft D raises the piece A J, Figure 2, and
releases the lever A D which returns onto the contact of the screw A E.
bridge A G is re-established and all the local circuits of the apparatus are broken.
The apparatus can now operate in the called station if it is called up by an-
other station in the network. In this station, matters take place as has just been
mentioned.

page_text: This arrangement has the advantage of permitting a subscriber to enter into
communication, at the same time, with any number of stations which can com
municate collectively together by calling them one after another in such a
manner that each station called becomes in its turn the calling station in order
to enable it to remain in communication with the others.
It may also be useful for all the stations to be called at the same time by
any station of a network to receive similar orders or a message interesting to
them all, collectively.
For this purpose, there is arranged symmetrically in each apparatus, a con-
tact-strip AM which the stop pin X touches when the pointer corresponds to
the collective sector, by causing the point of attachment of this strip to com-
municate with the wire 17. This connection has not been shown on the draw-
ing in order that it may not be confused with the blade A M which serves to
illustrate another application, as will be hereinafter set forth.
It will be only necessary to press the button 2 in order that the tongue M
and the core J of the relay 2 shall leave the position indicated in dotted lines
and engage with the contact N. The circuit is then closed through the electro-
magnet A H which attracts the lever A D of the alarm and thus opens the
bridge A G A D engages with A I and the alarm starts. The same effect
takes place in all the stations at once.
This passage is very clear if the connection between 17 and the blade A Mis
take into consideration. This connection has not been shown on the drawing
for the reason above mentioned.
When the pointers are returned to the cross + the cam E, Figures 2 and 3,
will again raise the piece A J; the piece A D will again fall onto A E and all
the stations will be again ready for receiving a call.
To make Figure 6 of the drawing clearer, I have not shown the connection
A M with 17, in order to enable me to show another application which can
be easily carried into practice with the apparatus forming the object of my said
invention.
It relates to the setting to time of the clocks on railway lines.
For this purpose, the strip A M is put into connection with the end of the
wire of an electromagnet A N placed in the clock to be regulated; the other end
of this wire is connected to the pole of + sign of the battery V. The circuit is
closed in the same manner as above mentioned for the sending of a current
through the alarm circuit.
fast.
Suppose that A O be the regulator and A. P the clock at the station, which it
is required to regulate, it will be seen at once that the said clock is two minutes
The regulation is effected in the following manner: either by hand with
the buttons 2 and 3: or automatically with a rotary controller which is released
by the regulator A O at the desired moment.
This controller, actuated by a clockwork movement makes a complete revolu-
tion each time that it is released. This release can take place once every 24
hours at a suitable time when the traffic of the line is stopped.
This controller, actuated by a clockwork movement, can be of any suitable
construction; for instance, it may comprise a cylinder provided with projections
(of the kind or class employed as the cylinder in a musical box) the said pro-
jections making contact in passing or any other convenient arrangement which
will yield the desired result. This, however, is an auxiliary device which may or
may not be dispensed with, as desired.
at
Suppose, on the other hand, that it was to be feared that
the moment of the passage of the hour, two stations would be in com-
munication with each other. In this case, in admitting, by way of example,
that an installation for 9 stations is being dealt with, the dial being divided like.
that shown in Figure 4. the controller will send into the line the current of +
sign 12 times to bring back if necessary, the pointers to the cross +, in the
case where two stations would be at work, afterwards once the current of
-

page_text: sign to effect the release of the apparatus and again the current of + sign 11
times to bring the pointers onto the sector (horloges) "clocks." A current of sign
-
will be again passed to effect the setting to time, then followed by another of
+sign to bring back the pointer to the cross.
This operation has required a very short time; 12 to 15 seconds to do the work,
and the stations which have been able to be cut out, have only to call back
to put themselves into communication.
EMPLOYMENT OF THE APPARATUS FOR SIGNALS ON RAILWAY TRACKS AND For
DOMESTIC, COMMERCIAL, INDUSTRIAL AND OTHER PURPOSES.
As it is very easy to see, the working of my apparatus is both very simple
and very sure, which enables it to be employed for many purposes, for all cases
where it is required to establish communication to a distance such, for example
as to open and shut doors, water-, air- or gas-cocks; to operate signal discs on
railways, or to cause any desired signal or indication to appear.
It can also be employed in a very advantageous manner as an automatic exchange
station thus a single apparatus placed with the lodge-keeper of an estate will
enable a dozen apparatus placed at different points to be easily served by means of
two wires only passing to the central office in such a manner that the said
central office can call up any one of the points or subscribers connected to the
automatic station, without interfering with the others, this being effected by
causing to appear at the latter a small signal indicating that the line is not free.
Any subscriber connected to the automatic station can, if the line is free,
directly call up the central office without interfering with the others, by causing
to appear at each a small signal indicating that the line is not free and the
central office replys to this subscriber as if it were connected directly therewith
by means of a special line.
This is effected by arranging the apparatus serving as the automatic station,
in such a manner that it is provided with as many contact blades or strips as
there are stations to be connected and in such a manner that each blade or
strip corresponds to a given station. The cam E, keyed onto the shaft D, will
be arranged in such a manner as not to touch any of the blades when the
pointer is at the cross +.
PARTICULAR ARRANGEMENTS OF THE APPARATUS FOR SPECIAL PURPOSES.
It is obvious that, according to the applications for which it is designed, the
apparatus can be varied in form and dimensions whilst retaining the same
principle and the same method of operation which forms the subject of my
invention.
In the same way, the arrangement for doing away with the clockwork move-
ment indicated in the description of the apparatus can be applied whatever be
the dimensions of the apparatus and the use for which it is designed.
My improved apparatus can be modified to utilise, for its operation, currents
alternately reversed produced by the magnetic calls" at present employed on
telephone lines.
It is also possible, without inconvenience, in order to put in motion apparatus
such as is described above without changing in any way its operation, to
utilise continuous or rectified currents produced by a small magneto-electric
machine operated by hand and which would thus replace the calling battery U,
Figure 6.
It should be noted that the apparatus is arranged in such a manner that if
there is added to the network a larger number of stations than that for which
it has been designed, it is only necessary to change the dial for another having a
larger number of divisions and to also change the escapement wheel for another
having a larger number of teeth.
This modification would not necessitate the removal of the apparatus and
their replacement by others which are more suitable. For this purpose, the
escapement wheel is secured by means of screws between two plates fixed to the

page_text: arbor which permits the change to be made in a few minutes and at very nute
cost.
I can, if preferred, modify the form and arrangement given to the pieces and
parts forming my improved apparatus, according to the conditions prevailing
when putting the same to practical use, without departing from the nature of my
said invention.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. An improved automatic switching device for telegraphic, telephonic or
like exchange systems comprising an arbor actuated by clockwork and having
an arm and an escapement-wheel the detents of which are controlled by separate
electro-magnets, the said arbor also bearing a pointer inoving over a dial and
two suitably-arranged cams, one of which cams serves to close the bell-circuit
by coming into contact with the oscillating armature of a third electro-magnet
so as to permit the said armature to be locked in this position, and also serves
to break the "telephonic bridge," the other cam serving to re-establish the
telephonic bridge" by raising the locking lever of the said armature when
the pointer reaches a predetermined position on the dial, substantially as de-
scribed
«
2. In combination with an automatic switching apparatus such as is hercin-
before described, a polarised relay controlling, by the aid of a local battery, the
different operative parts of the apparatus in such a manner that only one station
can be called when a sufficient number of current impulses are sent into the line
to bring the needles in all the stations opposite the number or mark of the
station to be called and, if a current in the contrary direction is afterwards sent
through the line, to release the bell of this station, the cam of which is then
in position to close the bell circuit and open the telephonic bridge, substantially
as described.
3. In apparatus of the kind or class claimed in Claim 1, an arresting device
comprising a pin X fixed on the arbor of the escapement wheel F, which pin,
at each complete rotation of the escapement wheel makes contact with a stop-
pin Y which can be released by means of a special electro-magnet T energised
by means of the polarised relay on sending into the line a single current-impulse
in a contrary direction to that which causes the telegraph to advance, substantially
as described.
4. In apparatus such as is herein before described, the employment, in order
to permit the simultaneous calling of all the stations, of a spring A M which
makes contact with the stop-pin X fixed on the escapement wheel arbor when
the pointer moves from the number of the last station to the mark indicating a
general call, substantially as described.
"
5. In combination with the apparatus hereinbefore described, an arrangement
for assuring secrecy of communication, characterised by a "telephonic bridge'
for short circuiting the line terminals of the telegraphic or telephonic apparatus,
this bridge being opened: in the called station, by the contact of the cam E with
the bell-contact strip A D and, in the calling station, by the electro-magnet A H,
substantially as described.
6. The improved system of electrical communication, constructed, arranged and
operating substantially as hereinbefore described with reference to the accom-
panying drawings, for the purposes specified.
Dated the 24th da November 1900.
KATYva
A
D. YOUNG & C.,
11 and 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.