Improvements in Apparatus for Automatically Connecting any Two of a Number of Electric Circuits Branching from a Central Station.
Year: 1899

page_text: Date of Application, 11th Oct., 1899-Accepted, 6th Oct., 1900
Improvements in Apparatus for Automatically Connecting any Two
of a Number of Electric Circuits Branching from a Central Station.
I, Dr. LUIGI CEREBOTANI, of No. 63, Sendlinger Strasse, in the City of
Munich, in the Kingdom of Bavaria and German Empire, Professor, do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
The subject of the present invention is an apparatus in and through which
the current from a distant station can exercise its effect in any one branch out
of the many which start here.
The effect of the electric current arriving here may be such that through it
a second electrical effect may be excited in the desired direction (for the purpose
of effecting mechanical operations or the like); secondly, that it may continue in
the desired direction to a definite place (telegraphy, telephony etc); lastly, that
the connection of the first conductor with one of a number of branches may
be an exclusive one, that is to say may be such that no third line of those
which meet here can be connected after the said first connection has been made.
The new auto-communicator is so constructed that these three effects can take
place and the manner in which they are brought about is explained in the
present specification.
The use of two kinds of currents (plus and minus) by means of one line is
not a new feature in electrotechnics. In the present case, however, there is so
far novelty in that firstly, the results of the two kinds of currents are more
than two fold; secondly, in that the polarized magnets which are employed
are of peculiar construction, so that not only do current intensities of any desired
degree act, but act uniformly as already mentioned in the specifications of the
multiplex and printing telegraph apparatus, described in British Patents
No. 12241, May 31st 1898 and No. 10040, May 12th 1899.
The manner in which these two kinds of currents arrive at and operate the
new auto-communicator may be explained in general as follows. At the trans-
mitting station are, for instance, two contact buttons, which so connect up the
circuits of two different batteries and transmit the current along the line to the
communicator, that from the one button positive and from the other negative
current arrive. At the communicator two polarised stationary electromagnets
are arranged. The one polarised, for instance, plus, through the oscillations
of its armature effects the motion of one coordinate (i.e. the motion of a contact
in the direction of one coordinate), the second electromagnet, polarised for in-
stance minus, effects the motion of the second coordinate (i.e. of the same contact
piece in the direction of the second coordinate). The contact piece endeavours
to make the contact on a checked plane with that wire through which the desired
electric effect is to take place; but in such manner that this effect only takes
place when the contact is complete. The wire from the two contact buttons
branches at at the auto-communicator in such manner that the one branch encircles
the one polarised electromagnet and then passes to earth, the other encircles the

page_text: second electromagnet and then passes to earth, whilst the third runs to the said
contact piece. If now, current impulses from the one, for instance, plus contac
button arrive, the armature of the plus polarised magnet will oscillate and the
contact piece advances a distance so that it cannot again make metallic connec
tion. If, however, impulses of current arrive from the minus contact button
the minus polarised magnet acts and the contact piece will move in the
direction of the second coordinate, so that, firstly, although it travels over the
squares occupied by the terminals of the individual wires and therefore com
municates a minus current to the wires in question, nevertheless the latter
current does not operate, because usually the receiver only responds to plus; and
so that secondly, through the first stage of this movement the connection of the
transmitting line with the branch leading to the first plus polarised relay is
broken. The result of this is, that after the contact piece through these two co-
ordinate movements has made contact with the desired wire of the square,
plus current impulses can be sent from the transmitting station, which, firstly,
have no influence on the contact piece, so that the latter remains undisplaced,
in connection with the square-wire; secondly, these plus current impulses are
reproduced at the corresponding receiving apparatus.
Naturally the latter (plus current impulses) will now no longer be sent from
the one or other transmitting button, but from a transmitter, according to the
character of the electric effect to be produced. The said contact piece returns
to its first position when the transmitting button again sends minus current
impulses, whereby the contact piece reaches a second stage by which the latter
automatically returns to the original position. As regards the above mentioned
effects, it suffices here to remark that these are in connection with an arrange-
ment of relays and polarised magnets as will be explained below.
The accompanying drawings show one form of the arrangement by which the
invention may be carried into effect.
Fig. 1 is a plan view of the auto-communicator in connection with a trans-
mitting station, the course of the current being also indicated.
Fig. 2 is a detail view showing in plan a part of Fig. 1.
Fig. 3 is a plan view corresponding to Fig. 1, the auto-communicator being
shown in action, instead of in the position of rest.
Fig. A is a cross section on the line -, Fig. 1, seen from the right hand.
Fig. 5 is a cross section on the line zz, Fig. 1.
Fig. 6 shows a detail view of a kind of escapement wheel without wheel work.
Fig. shows in elevation the contact piece in connection with a polarised
electromagnet and
Figs. 8 and 9 show a combination of polarised electromagnets for the purpose
of attaining exclusive connection as already referred to.
The whole apparatus rests upon a base or frame, one side of which is indicated
with the letter A (Fig. 1). The field F, represented as a series of small checks
or squares showing the ends of the various conductors (Figs. 13 and 4) lies
on the ground and is surrounded on three sides by non-conducting courses b.
It is of such construction that a contact piece C can travel over it in uniform
manner. This contact piece C is rigidly connected by means of an arm d with
a plate P (Figs. 1, 3 and 4). The plate P is provided with straight grooves some
running longitudinally, the remainder transversely, a deeper channel t being left
between the two sets of grooves (Figs. 1, 2, 3, and 5). This plate P slides in
a straight line in a second plate Q in the direction of the length of the latter
(Figs. 2, 3 and 4). The lower plate Q is provided with rollers v, v and runs
on rails m n, m³ n¹. E is a spiral spring by means of which the plate Q is
drawn against the stops and can only move by overcoming the force of said
spring. Similarly the plate P is acted upon by a spiral spring e secured to the
plate Q, whereby the plate P is always drawn upon towards the right.
Above and to the left of these plates are electromagnets mounted in suitable
bearings (not shown on the drawing) so as to occupy positions as shown in

page_text: Figs. 4 and 5. These electromagnets are polarised and consist each of two
magnet pairs D D and B B. The polarisation is such that one pair D B is
encircled by the winding of a local circuit W, and both pairs D D¹ and B B¹
also encircled by the line current L. The result is, that if the line current on
the one side, for instance at D D¹, runs in an opposite direction to the local
current, the electromagnetic pair D' which is only encircled by the line winding,
will exercise a magnetic force which is greater than that of the other magnetic
pair D, and the armature g (which without a line current, or with a line.
current in the same direction as the local current is attracted by the electro-
magnet D) is now attracted. by the electromagnet D. Suppose now that at D D¹
the direction opposite to the local current is minus and at B B plus, the magnet.
arrangements are thus differently polarised and D D₁ will respond only to minus.
and B B only to plus. As already mentioned, the impulses of current from the
transmitting station have the sole purpose of effecting attraction alternately of.
the armature by the one or other magnet pair, that is to say of the armature g.
if the current impulses are minus and of the armature g¹, if plus.
The movement of these armatures g g either results in the oscillation of an.
escapement on the escapement-wheel (Figs. 4 and 5)-in which case a small
train influencing the latter can be provided at the communicator; or there
results the up and down motion of a ratchet pawl device 5, 5 (Fig. 6), which
operates the said wheel directly. The axle of each escapement wheel carries.
rigidly mounted on it a toothed wheel hand respectively, the teeth of.
which engage in the grooves of the plate C, (Figs. 4 and 5), the wheels turning
in the direction of the arrows. From this it is clear that every current impulse
arriving causes an upward advance of the complete system PQ, if the current
impulse is plus, and a movement of the said plate P towards the left if the.
impulse is minus.
If the auto-communicator is in the position of rest, as shown in Fig. 1, and
plus impulses of current arrive, the magnet system B B' will respond, and PQ.
and therefore the contact piece C on the non-conducting path b moves upwards.
If minus impulses of current arrive, the magnet system D D' will respond, and
the plate and contact piece C will move towards the left (Fig. 3). The teeth
of the wheel h are so spaced that when it is outside the plate P and the latter
commences to rise the teeth engage at once
in the grooves. The two
wheels h h perform a two-fold duty; firstly, to move the plates upwards or
sideways, and secondly to hold these plates by means of the ridges of the grooves
in the position they have attained against the action of the springs E and e,
that is to say, the wheel h during the operation of the wheel (viz. during
sliding of the complete system PQ) and h¹ during the lateral sliding of P, the
teeth of sliding along the ridges of the grooves. If, therefore, first through
a number of plus impulses of current and then of minus impulses of current,
the contact piece C is brought into connection with a square (that is, with the
terminal of a wire in the field F), the contact piece remains there immovable, as
long as the teeth of the wheels engage in the grooves. As mentioned, how-
ever, the plate l' is provided in the centre with a channel t, so that when the
plate l' is moved towards the left until the teeth of h¹ pass out of the grooves and
into the channel t (the wheel h¹ being somewhat drawn downwards under the
action of a suitable spring), the spiral spring E will be free to exert its force
and draw down the complete system P Q. Since during the action the teeth of h
engage in the grooves, the spring e will only act when the teeth of h pass out
of the grooves. In this moment the spring e comes into action and the original
position is immediately restored.
If the course of the current from the transmitting station is followed, likewise "
the operations at the communicator, the following will be seen to result. At the
transmitting station in addition to the transmitter S (for instance a transmitter
for the Morse alphabet, or one of my printing telegraphs) are two contact
buttons kk. Through a minus current is caused to flow; through k and S

page_text: a plus current. The current (from k k or S) takes the following course: L to 0:
at the conductor branches, one branch i running to the contact piece C, the
other to the magnet pair D), to D¹ to earth. The contact piece during its
upward motion slides along the metal rail m¹ n', so that the first branch i is
continued over this rail m n¹. From this rail runs a wire u to the electro-
magnet pair B, then to B, and to earth. Suppose then that the communicator
is in the position of rest Fig. 1, and it is desired to connect the contact piece
of the the transmitting station with some wire of the field F. The two coordinates
which correspond to the wire in question being ascertained from a table (that is,
the numbers of the vertical and horizontal lines of the checked field being
known) it is only necessary to send through the button ka number of plus
current impulses corresponding to the first number, and through a number
of minus impulses corresponding to the second number. The result of the plus
current impulses, which act only at B B', and run over Li, C m¹, n¹, u through
B B to earth, is that the contact piece C moves along the rail m¹ n' and over the
non-conducting path 6 (the plus current, now not being able to continue its
course) to the first of the said rows. The result of the minus impulses (from ¹)
which act only at D D (coming over L 7 to D D¹ and thence to earth) is that
the branch circuit to the electromagnet B B is interrupted through the contact
piece being separated from the rail m¹ ; furthermore, that the lateral
sliding of the contact piece C over the squares of the said row to the desired
square; and finally the non-response during this process of the receiving appara-
tus, which are in the circuit of the wire terminals travelled over, since these
are so arranged that they only react to a plus current. If now the contact
piece C is in connection with the wire of the field F through which an electrical
effect is to be produced at a receiver or the like, use is made of the transmitter S
(Fig. 1) and the plus current sent according to the effect desired. The precise
construction of the transmitter need not be here described, since it may be varied
according to the effects desired. Since, as already stated, the electromagnets B B¹
are now out of circuit, the contact piece C cannot make any further movement
by reason of the plus current, and the latter will thus only act in the conductor
with which the contact piece is in connection, i.c. in the apparatus connected
up in it, which only operate to plus. When the desired electrical effect is
finished and it is wished from the transmitting station to restore the auto-
communicator to its original position-that is, restore the contact piece C to
its first position, the button must be again operated and a number of minus
impulses of current sent, which as explained, only impart a lateral motion
towards the left, until the left path b is reached. What now occurs has been
described above. In this moment, namely, the wheel h will be in the channel t,
the spring E will at once act, the contact piece C runs down the insulated left
hand course (the teeth of h preventing the retreat of the plate P towards
the right) and finally when the teeth of h pass out of the grooves, whereby the
spring e immediately acts, reaches its original position, passing along the lower,
likewise insulated course b.
As regards the operation at the apparatus which are inserted in the conductors
running from the contact piece C (for telegraphy, operation of mechanical pro-
cesses, lighting and the like) this may be effected from the transmitting source
of electricity itself, or one from a source near or not far from the communicator.
In the first case the contact piece C is nothing more than a device for connecting
the conductor L, with one of the wires y, y (Figs. 7 and 4); in the second case;
on the other hand, a small polarised magnet 4 is arranged, in connection with
the contact piece C, which magnet acts as a relay. The conductor (Figs. 1 and 7)
encircles 4 and then passes to earth. This relay only responds to plus. During
the ascent of the right-hand course b (Figs. 1 and 3) any response remains ob-
viously without effect. If now, minus current impulses arrive in order to move C
laterally to the desired square, the relay 4 does not respond, and the local circuit 7
(Fig. 7) .e. the circuit from the source mentioned, remains open. When, how-

page_text: ever, a plus current again arrives, the relay responds, and the circuit from 7.
is closed at 3, the current passing through the conductor y and operating the
apparatus R (telegraphy, wheelwork, lamp or the like). There is a third case to
be considered, viz. that of a radial telegraphic system, whereby a large number
of stations are mutually connected for telegraphic communication, so that each
station by means of the auto-communicator arranged in a central station, so
comes into connection with another station (one of the many which likewise havo
their auto-communicators in the said central station) that this connection is an
exclusive one; that is, such that none of the other stations can make a like
connection at the same time. Figs. 8 and 9 show how this is attained. From
each transmitting and receiving station two conductors run to a central station
(for instance, from the one transmitting station J. 14, 15, Fig. 8). The one
(the transmitting line) runs to the auto-communicator I (i.e. to its contact
piece C) and to the electromagnets D D¹, B B, Figs. 1 and 3. The other (the
receiver line) divides at the central station into as many branches as there are
auto-communicators (say 20) for the remaining stations. At the place where the
receiver conductor branches, the following arrangement is made:-
The line receiving wire of the distant station VI (16 Fig. 9) as long as there
is no current passing is at 8 in contact with a contact piece 9. From this contact
piece the conductor branches and each branch encircles first a small electro-
magnet 6, 6 (Fig. 9) and then passes to the square of one of the (say 20) remain-
ing auto-communicators I, II, III, (Fig. 8). These electromagnets 6, 6 are so con-
structed firstly, that their armatures 13 rock between the poles, secondly, that
their cores are steel-magnetic, i.e. exercise a permanent magnetism. The result
is firstly, that the armature at the one or other pole remains attracted even
when there is no current: secondly, that as soon as a current flows through
the coils 6, 6 the action of which is opposed to the steel magnet, the armature
tips.
The course of the current at each of these magnets, as soon as it has to transmit
the current from the communicator to the receiving line, is as follows:-
As long as the particular receiving line is not being used by any of the auto-
communicators the armatures 13. 13 etc. take up the position shown in Fig. 9
and and the piece 9 is in connection with 8. so that the branching at this place
undergoes no interruption. These armatures, however, are connected by means
of a cord 19, 19 with the device 9 in such manner that if the one or the other
is tipped, the piece 9 separates from S. Supposing then that through the trans-
mitter wire 14 from the distant station J (Fig. 8) the contact piece Cat at the par-
ticular communicator I is brought into connecton with the conductor 16 for the
distant station VI, the following will be the procedure:-From the communi-
cator I the wire 16 passes to one of the electromagnets 6, then through 20
and 9 to 8 and further. If now an operator telegraphs from 14 as already ex-
plained, the first impulse goes through the described path, 16, 20, 9, 8. At the
first impulse the procedure will resnond and its armature 13 at once tip. This
is so, since all the magnets are so arranged that they respond (i.e. their armatures
tip) as soon as the receiver current flows through the receiver line. thus, in the
above case, when a plus current flows. When this has occurred the current
cannot longer flow in the path 16. 6, 20. 9, 8 since this circuit is interrupted at 9.
Another way is now open for it, however, viz. that through the piece 21 and wire
connection 22, viz. 16, 6, 21, 22, S, and further, so that telegraphing may be
continued. Since, however, the other branches to the button 8 from the same
receiver wire (that is, from the different auto-communicators) are here broken,
since the only way to the latter in the position of the corresponding armature is
the contact piece 9, no other of the remaining (say 20) transmitting stations can
make a connection with the receiver wire 16 (i.c. with the distant station VI)
as long as the transmitter wire 14 (i.e. the transmitting station J. Fig. 8) is in
connection with the receiver wire 16. It need scarcely be further explained after
the above, that the connection between 8 and 9 is effected so that all the

page_text: magnets 6, 6, 6 are again in position to respond as soon as the connection of
the transmitter wire, e.g. 14 with the receiver wire, e.g. 16, is broken. The con-
nection is broken, as already explained, when the transmitter button k¹ (Fig. 1)
again transmits minus current impulses, whereby the first position is again
restored. The minus current impulses, however, now exercise on the electro-
magnet 6 (Fig. 9) an effect opposite to that of the plus impulses, so that its arma-
ture again tips, and the piece 9 comes into connection with 8, and so on.
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. A process and apparatus for automatically effecting at a central station,
between the line from a distant station and any one second line of a number
of other lines meeting at said central station, for the purpose of telegraphic
or telephonic communication, or of effecting mechanical processes and the like at
a second distant station, in such manner that during the said connection no
third distant station can be connected with the second distant station, charac-
terised by the arrangement of two plates (P Q) one sliding within the other, the
former having suitable grooves in which toothed wheels (h h¹) engage, wheel h
sliding the plate P over Q, and the wheel h sliding both plateś simultaneously
along the rails (m n, m¹ n¹) whereby a device (C) which effects the connection
between a conductor of one distant station and a conductor of a second distant
station, is caused to travel over a field F divided into squares and make contact
with the terminal of the required conductor, substantially as described.
2. In an apparatus as claimed in Claim 1, the employment of two different
currents, through one and the same line, in such manner that whereas the
one current (e.g. the minus) only operates in one direction (L, ) and exercises
its action at the minus polarised electromagnet (I D¹), which operates to rotate
the toothed wheel h, either through an escapement wheel and train, or through
a ratchet-paul 55 or the like, the other (plus) current first takes the course Li
Cmn to the plus polarised electromagnet B 13' (the operation of which rotates
the wheel ¹) and then no longer takes the course indicated (and so thus cannot
pass to 13 B) but passes through Cy and acts at the receiving apparatus inserted
in the line y, which only reacts to plus currents, substantially as described.
3. In an apparatus as claimed in Claims 1 and 2, the arrangement of a polarised
relay 4 at the contact piece C, whereby a circuit containing a generator near
the central station is closed, the current taking the desired direction through the
line y substantially as described.
4. In an apparatus as claimed in'Claims 1, 2 and 3 the combination of polarised
electromagnets 6, 6 provided with lever armatures 13, with the parts 8, 9, 19, 21
and the wire connections 16, 20, 21 and 22, in such manner that after tipping
of the armatures the exclusive connection of a distant station with the receiving
wire of a second distant station is made, substantially as described.
Dated this 11th day of October 1899.
BOULT, WADE & KILBURN,
Agents for the Applicant.