Improvements in Apparatus for Effecting Electrical Communication between a Number of Separate Stations or Apartments with a Central Station or Apartment.
Year: 1893

page_text: Date of Application, 7th June, 1893
Complete Specification Left, 9th Apr., 1894-Accepted, 12th May, 1894
PROVISIONAL SPECIFICATION.
[Communicated from abroad by F. E. MORGAN and H. E. WALTER, of
New Haven, Connecticut, in the United States of America, Electrical
Engineers.]
Improvements in Apparatus for Effecting Electrical Communication
between a Number of Separate Stations or Apartments with a
Central Station or Apartment.
We, SIEMENS BROTHERS & Co. LIMITED, of 12 Queen Anne's Gate,
Westminster, in the County of Middlesex, Electrical Engineers, do. hereby declare
the nature of this invention to be as follows:-
:-
This invention relates to apparatus for effecting electrical communication between
a number of separate stations such as lamp posts or fire alarm posts with a central
station such as a police or fire station, or it might be between a number of separáte
apartments in a hotel or other establishment and a central apartment occupied by
an official. At each of the separate stations there is a magneto or other suitable
call instrument and switch by which the operator can send an electric current by
a conductor to the central station. Each conductor at the central station branches
into two, the first branch leading through a suitable resistance and through the
coil of an electro magnet to earth; the first branches from all the conductors. join
into the coil of this magnet each after passing through a resistance suited to its
length and other conditions. The second branch of each conductor is connected
to an insulated plate of a commutator which has as many plates as there are
conductors, arranged preferably in a circle or an arc of a circle in the centre of
which is pivotted a radial arm carrying at its end a brush or rubber, which, as the
arm revolves rubs over the successive plates. This arm when it is free, is caused
to revolve by a weight spring or clockwork with speed moderated by a pendulum
or flyer, and it is always in electrical connection with the coil of a second electro-
magnet, a battery and earth. The arm is held either in the position where it last
stopped or at a zero position (when its brush does not bear on any of the plates
connected to the conductors) by a catch on the spring armature of the magnet first
mentioned.
When a call current is transmitted from any station this magnet is excited and
attracts its armature which closes a local circuit whereby another magnet is excited,
Or when the
and its armature releases the clockwork that drives the radial arm.
radial arm stops on zero the magnet first mentioned releases the catch holding the
arm which thereupon moves over the successive plates. As soon as its brush bears
upon the plate belonging to the station whence the call came, the circuit is closed
through the second magnet which attracts its armature and stops the farther move-
ment of the radial arm. The distant station and the central station now remaining
in electrical communication, messages can be sent from the one to the other by
telegraph or telephone, but in cases where certain important messages have to be
transmitted without risk of mistake as for instance in communicating with police
or fire stations, the apparatus is modified in the following manner.
At the distant station there is provided a dial having marked on it a number of
important messages, and at the central station there is a corresponding dial. Each
dial has an index having connected to its axis by a ratchet and pawl an escapement
wheel, urged by clockwork and governed by an anchor on the spring armature of
an electro magnet. The operator at the distant station moves his index round in
the direction permitted by the ratchet and pawl, to some message on his dial
which he desires to transmit. At the central station the second magnet or another

page_text: magnet excited by the current which excites the second magnet in stopping the
movement of the radial arm also removes a detent from a make and break toothed
wheel which is caused to revolve by clockwork, and which has bearing against its
teeth a spring brush electrically connected through the coil of another magnet at
the central station and through the coil of the second magnet above mentioned
with the radial arm, and through it to the conductor and electromagnet of the
distant station.
As the toothed wheel at the central station revolves, alternately making and
breaking contact, the armature anchors at the central and distant stations are
caused to reciprocate allowing their respective engagement wheels to turn step by
step, the one at the central station forwards, the one at the distant station back-
wards. When the index of the latter has been moved quite back to its zero
position, contact with the conductor to the central station is broken and con-
sequently the escapement then ceases to move, but its index having been moved
through the same number of. divisions forwards as the index at the distant station
is moved back, points to the same division on the station dial as that on the distant
dial to which the operator there had set his index.
In some cases a make and break wheel may be provided at the distant station to
be moved by clockwork there and to operate escapement wheels and indices as above
described, so that the operator at the central station can send any one of a number
of messages on his dial to the distant station.
After an operation is completed the parts are restored to their normal or zero
condition by a movement which makes and breaks the necessary contacts and winds
up the clockwork.
At any time the operator at the central station can transmit a current to any
station that may have its index in position to complete circuit, in which case the
clockwork at the central station is released and the message is received. In cases
where the telephone is to be employed, the conductors from all the stations are
connected to suitable jacks on a switch board.
Dated this 7th day of June 1893.
ABEL & IMRAY,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Effecting Electrical Communication
between a Number of Separate Stations or Apartments with a
Central Station or Apartment.
We, SIEMENS BROTHERS & CO. LIMITED, of 12 Queen Anne's Gate, West-
minster, in the County of Middlesex, Electrical Engineers, 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 :-
This invention relates to electric apparatus for effecting communication between
a number of separate stations or apartments and a central station or office. The
central station may be an office in a hotel, factory or other large establishment with
which apartments may communicate; or the central station may be a police or fire
station, communicating with lamp posts or fire alarm posts.
When the invention is applied indoors as in a hotel or factory the communication,
when once it is opened by a suitable signal, may be effected simply by telephone, but
when it is applied out of doors, where telephonic communication might be liable to
interruption, besides the telephone there is provided an independent system of
signalling a number of messages, suitable apparatus for their transmission to the
central station and for their reception from the central station being provided
in places accessible only to the policeman or other official or authorised person in the
district.

page_text: A convenient place for this apparatus is presented in a lamp post where it is
accommodated in a locked chamber of which the policeman or official or other
authorised person have keys.
As the apparatus according to this invention, in its most complete form, is adapted
for communicating between a central police station or office and a number of lamp
posts in the district of which the office is the centre, we shall describe apparatus
suited for this purpose, referring to the accompanying drawings.
Fig. 1 is an external front view of the apparatus at the central station or
office.
Fig. 2 shows the interior, the front being removed.
Fig. 3 is an external front view of the apparatus situated in the chamber of a
lamp post.
Fig. 4 is an internal view the front being removed.
Fig. 5 is an external and Fig. 6 an internal view of the apparatus at the office for
transmitting messages to the distant stations or lamp posts.
Referring first to Figs. 1 and 2, the larger index 11 points to oue or other of the
numbered divisions 1, 2, 3, etc. on the dial, each of which corresponds to one of the
distant stations, shewing which of these stations is in communication with the office.
When no station is in communication I¹ points to the star. The smaller index I*
points to any one of a number of messages written on the divisions of the smaller
dial, shewing, for instance, that "Fire" is signalled from Station 7.
A is a circular are on which are fixed a number of segments insulated from each
other. A conducting wire (W1 W2 &c.) from each of the distant stations is led to
one of the segments on A. Each of these wires also has a branch w¹ w² &c. leading
through a suitable resistance (rl 2 &c.) to a common conductor C a current through
which operates a relay c¹ bringing a battery into circuit with the coil of an electro-
magnet E through the segment O of the arc A. The armature e¹ of the electro
magnet E has its end formed as a latch hook which holds the end of an arm A¹
centered at a and having a spring rubber A' which when released from e' can sweep
over all the segments of A. making contact with them successively.
A heavy segment S¹ has teeth at its periphery which gear with a pinion on the
axis which is the axis of the index I', so that when the segment $¹ descends it
causes the index I' to turn, the complete descent of S¹ causing I¹ to make a complete
revolution. Instead of the pinion being caused to revolve by the descent of the
segment S it may be actuated by suitable clockwork. A pinion D' on the axis ¿¹
gears with a wheel D² of twice the diameter on the axis a so that when I makes a
complete revolution A' makes half a revolution sweeping quite over the arc A which
is a semicircle. Obviously the arc A may be made as a complete circle in which case
the pinion D' and the wheel D² would be made of equal size or it might be a
segment of a circle in which case the pinion D' and wheel D' would be made
of proportionate size to enable the arm A³ to sweep the segment.
A wheel D³ on the axis a through a pinion D* drives gearing having an escapement
or flyer contained within a casing D³ this serving to moderate the speed with
which A revolves as the segment S¹ descends. The casing D is pivotted at d so
that it can be raised out of gear with D³ leaving A' free to be moved rapidly back
to the position where its rubber A2 would be over the segment O, the index I¹ being
then at the star. The gearing in D' can be stopped by an arm D engaging one of
its toothed wheels, and when it is stopped the arm A¹ and index I¹ are stopped at
some part of their respective courses.
F is a case containing spring clockwork which can be wound up by raising
a lever F and which drives a wheel F2 having contact teeth and spaces between, a
contact spring F3 bearing on these teeth. The wheel is prevented from turning by
a stop engaging its teeth, this stop being on the spring armature F' of an electro
magnet E2. A third electro magnet E³ the coil of which is in connection with the
contact spring F³ through the coil of E2 has a spring armature G terminating in an
anchor G engaging the teeth of an escapement wheel G2 which is on a sleeve on
which is fixed the index 12. A lever H which can be raised by turning an

page_text: eccentric H¹ by an external handle serves to raise through a spring / the segment S'
a second segment S2 geared to a pinion on the sleeve of 12, also to raise the lever F¹
for winding the clockwork F and a rod S³ which lifts D out of gear with D³
the apparatus being thus put in condition for operating as will presently be
described.
Referring now to Figs. 3 and 4, I is an index which can be turned by the local
operator to any one of a number of messages written on the divisions on the right
hand side of the dial which is the sending side, some of these with other
messages being written on the left half of the dial which is the receiving half. H' is
a handle or push which when depressed by the operator moves a magneto electric
machine like an ordinary telephone call, thus sending by his line wire a current to
the central station or office. There is also provided a telephone T which is brought
into connection with the line wire by turning down the hinged door T2 and thus
making contacts by springs T³. The operator can speak into the opening T and
can hear by applying the tubes T to his ears in the usual way.
By turning an external handle H³ the operator turns an internal pulley H* from
which a cord or chain passes up the lamp post to suspend over the light a cylinder
of red or colored glass or talc. Usually this is held quite above the light, but
when a communication comes from the central station, a detent is released as will
presently be described allowing the pulley H to revolve in the direction of the
arrow and thus to let the coloured screen descend and enclose the light. The
policeman or other authorised person can then even if he is at a distance, see
that he has to receive a communication and, on proceeding to the lamp post,
he can open the chamber and operate. Within the chamber there is an
electromagnet E of high resistance with spring armature which acts as a detent
to hold an arm H³, and on the boss of this arm is a stud which acts as a detent to
hold an arm H* fixed on the pulley H*. When a current from the central station
excites the magnet E the detents are released allowing the pulley H* to revolve
in the direction of the arrow for the descent of the coloured screen as
above mentioned. Another electromagnet E' of low resistance has its spring
armature F arranged to operate an anchor on the teeth of the wheel F' which is
fixed on the axis of the index 13. On the same axis is fixed a conducting
semicircle F against which a contact spring F' bears only during the revolution
of I³ over the right half of its dial. When the index points to the star or to any
of the left hand divisions the spring F° does not make contact.
The apparatus so far described operates in the following manner. The index [¹
being on the star also I' on its star, the arm A¹ being in such position that its
rubber A² is on the segment O of A, and the lamp post apparatus being in the
condition shewn in Figs. 3 and 4, the operator at one of the lamp posts say No. 7
wishes to signal, say "Fire" to the office. He first puts the index 13 to "Fire,"
then calls the office by pushing down the handle H whereby a current is sent to
the relay bringing into circuit with the battery the magnet El causing it to
attract its armature, thus releasing the arm A¹. The segment S' then descends at
a speed moderated by the clockwork gearing in D turning the arm A¹ until its
rubber A² comes on the segment 7 the index I' pointing to 7. A current from
one terminal of the battery now passes through earth to the axis of index 13 the
contact spring F, the coil of E the line wire W the 7th segment of A, the
rubber A², arm Al and the wheel F2 spring F³ the magnets E³Ë³ and a cut out
switch B to the other terminal of the battery. The armature F5 being thus
attracted releases the wheel F2 and also by moving De stops the gearing D³ thus
causing the arin A' to remain stationary. The wheel F2 being released is turned
round by the clockwork alternately making and breaking contact whereby a series
of intermittent currents are transmitted to the electro magnets E' E' at the lamp
post 7, the electro magnets E and E³ being similarly actuated. As the
magnet E is of high resistance the currents do not sensibly affect it. The anchor
armature moved by the magnet E' thus causes the wheel F' to move tooth by
tooth in the direction of the arrow while the wheel G' is simultaneously moved

page_text: tooth by tooth. This goes on until the index I reaches the star, when the contact
spring F being off the semicircle F the circuit is opened and the movement of
the wheels F and G2 ceases, the index 12 having thus been moved forward over
as many divisions of its dial as the index 13 was moved backwards, and
consequently 12 now points to the " Fire" signal, and the operator at lamp post 7
by finding his index I³ at the star knows that his message has been received.
When the operator at the central station desires to send a message to any lamp.
post say No. 7 he turns his index I' to the particular message which he desires to
send say for instance "Fire." He then by means of a plug or otherwise connects.
a strong battery to No. 7 line wire, at the same time winding by handle K
(see Figs. 5 and 6) clockwork to drive a make and break wheel K. The first
current exciting the magnet E' releases the detent allowing the coloured screen to.
fall so as to call the attention of the policeman or other authorised person. The
intermittent impulses excite a magnet E at the station as well as E at the
lamp post. By means of the anchor armatures of the magnets E and E³.
the escapement wheels F' at the lamp post and K2 at the central station are turned
to the left tooth by tooth, until a spring K³ bears on an insulated part of a boss.
upon K, the index 1' being thus turned back to zero while the index I³ has been
turned to the message sent.
The arm A' at the central station may have a boss with which can be put in
contact either of two conducting springs, the one for the circuit of the
magnets E E³, the other for the magnets E E. Then on putting the arm A¹ in
such a position that its rubber bears on any segment such as 7 and on switching in
the magnets E E' the communication can be made as above described to the lamp.
post 7.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. Electrical apparatus at a central station or office consisting of a number of
contact segments circularly arranged, each connected by a conducting wire to a
distant station or apartment, a rubber which when released by the armature of an
electromagnet excited by a current from one of these stations is caused by a weight
or clockwork to travel over the segments until it reaches that corresponding to the
station whence the current came, at which point it brings into circuit electro.
magnets which stop the rubber and release mechanism to drive a make and break
wheel whereby successive electrical impulses acting on one of the magnets at the
office and on an electromagnet at the said distant station cause an index at each of
these places to turn equally round until the distant index reaches its zero position,
the index at the office being thus made to point to a division on its dial corresponding
to that at which the distant index had been set substantially as described.
2. At each lamp post constituting one of the distant stations above referred to,.
an electro magnet which when excited by a current from the office releases a
detent allowing a coloured screen to descend and enclose the light thus giving a
visible signal that a communication is made from the office, substantially as
described.
3. At the office a make and break wheel by which successive currents are caused
to excite an electromagnet at the office and an electromagnet at the distant station
the former moving an index at the office to its zero position and the latter moving
an index at the distant station to a division on its dial corresponding to that to.
which the index at the office had been set, substantially as described.
Dated this 6th day of April 1894.
ABEL & IMRAY,
Agents for the Applicants.