Improvements in Fire Alarm Telegraph Apparatus.
Year: 1899

page_text: Date of Application, 12th Dec., 1899-Accepted, 3rd Feb., 1900
COMPLETE SPECIFICATION.
Improvements in Fire Alarm Telegraph Apparatus.
I, BENJAMIN JOSEPH BARNARD MILLS, of 23, Southampton Buildings, in the
County of London, Patent Agent, do hereby declare, the nature of this inven-
tion (a communication to me from The Gamewell Fire Alarm Telegraph Com-
pany, a Corporation organized and existing under the laws of the State of New
York, United States of America, and having its principal place of business at
No. 19, Barclay Street, in the Borough of Manhattan, in the City, County and
State of New York, U.S.A.) 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 various new and useful improvements in fire alarm
telegraph apparatus, and particularly to an improved system including the central
station and engine house apparatus.
At the present time it is the practice to employ at the central station a so-called
"joker" transmitter, by means of which alarms received at the central station
will be repeated upon one or more joker circuits, each including one or more
engine houses, the joker signal thus sent being transmitted at a high speed
corresponding to that of the street box and being recorded upon a tape. It is
the usual practice also at the present time to succeed the joker signal with a
slower repetition of the alarm, which is sounded upon a heavy, and powerful gong
in each engine house. It thus becomes possible, in the case of alarms received
at night, for the operator at each engine house to observe, by an inspection of
the record produced by the joker signal, whether the alarm is to be responded to
by his station, and if not, it becomes possible by short-circuiting the gong
mechanism, to prevent the gong from being sounded and the firemen from being
awakened.
The objection to the system which has been above outlined is that the joker
transmitter at the central station does not commence to operate until the first
round from the street box has been received, which in the case of some numbers,
such as 685, may be of an objectionable extent. The primary object of this
invention therefore is to provide an apparatus of the same general type now in
use, but by which the signal received at the central office will be sent out by
the joker transmitter immediately upon its receipt and without requiring a com-
plete round of the signal to be first received at the central office.
In this way
the time now lost in this work is avoided.
At the present time, with the apparatus in question, difficulty is experienced by
interference, the reception at the central office of two signals substantially simul-
taneously or at least so closely following each other that the first has not been
transmitted before the second is received, serving to produce aberrations in the
joker transmitter and consequent confusion in the transmission of the joker
signals. A second object of this invention is to produce a non-interference
repeater for a joker system, by means of which the reception at the central office
of two or more signals tending to overlap one another, will not affect the joker
transmitter, and which in consequence will not result in confusion of the joker
signals.

page_text: With the fire alarm telegraph systems of the type now in use, it is the practice
to provide a telegraph apparatus at each engine house and in the central station,
whereby communication between the several engine houses or between the engine
houses and the central station may be carried on over the joker line.. It is
therefore possible, as these systems are now installed, for any engine house to
practically disable the joker line by breaking it at any telegraph key, which,
if done, will prevent the joker signals from being transmitted or received. The
final object of this invention is to provide a system of the character described,
by means of which telegraphic communication between one or more engine
houses, or between any engine house and the central office, may be carried on in
the absence of any joker signals on the line, but which telegraphic apparatus
will be immediately disabled and the joker line placed in condition for the trans-
mission and reception of fire alarm signals upon the receipt of such signals at
the central office, thus making it impossible for anyone either accidently or inten-
tionally to disable the joker line by breaking the circuit at the key.
In order that this invention may be better understood, attention is directed to
the accompanying drawings forming a part of this specification, and in which,
Fig. 1 is a diagram of a convenient embodiment of the improved system,
wherein the non-interference shaft is operated magnetically;
Fig. 2, a section on the line 2-2 of Figure 1;
Fig. 3, a diagram of the main parts of a well known form of repeater, showing
how the same is used in connection with the improyed system and wherein the
non-interference shaft is operated mechanically by mechanism released by the
operation of one or the other of the repeater magnets, and
Fig. 4, a detail view, illustrating the operation of the pole-changer directly
from the non-interference shaft of the device shown in Figure 3.
In each of the above views, corresponding parts are represented by the same
numerals of reference.
The system illustrated is a closed circuit system, and it will be so described,
but, it will be understood that the invention may be applied to open circuit
systems, or to systems employing both open and closed circuits, the necessary
changes for converting it into one or the other being obvious to any one skilled
in the art. A closed circuit system is preferably used on account of the greater
security which is offered thereby.
1 and 2 represent diagrammatically the transmitting mechanism of two ordinary
street boxes, any number of which can be used. Each box is provided with a
power-driven make-and-break wheel 3 or 31 adapted to be released when the box
is pulled to make its prescribed number of rotations. Co-operating with the
break wheels 3 and 31 are contact springs 4 and 4. Leading from the box 1 is
a closed circuit 5 including a battery 6, and leading from the box 2 is
a closed circuit 7 including a battery S. These circuits 5 and 7 are the usual
street circuits, and lead to the central station, where suitable mechanism. is
placed. Generally a plurality of street boxes are placed in each street circuit,
as will be understood. A key 9 or 91 is placed in each street circuit 5 and 7
respectively, and is located at the central station for the purpose of testing. A
relay 10 or 10¹ is also included in the street circuits 5 and 7 respectively and
placed in the central station. The relay 10 controls a local circuit 11 including
a register 12 for effecting a visual, permanent record on a travelling tape, as is
common, while a local circuit 13 is controlled by the relay 10' and includes a
register 14 similar to the register 12 and recording on a second tape, or if desired
upon the same tape as the register 12. A local battery 15 is common to both
the circuits 11 and 13.
Where more than two street lines are employed, a corresponding number of
street relays will be used, one for each line, each relay controlling a separate
register. The street circuit 5 includes a repeater magnet 16 located at the central
station, and the street circuit 7 includes a repeater magnet 17 located adjacent to
the magnet 16. As many of these repeater magnets will be used as there are

page_text: street circuits leading to the central station. The armatures 18 and 18¹ of the
repeater magnets 16 and 17 respectively will be normally attracted, as shown,
assuming a closed circuit to be used, and when so attracted, the armatures serve
to lock in place levers 19 and 19¹ respectively, each carrying a shutter 20 nor-
mally concealing a number corresponding to and designating each respective
street circuit. The shutter 20 for the repeater magnet 16 is shown as having
been released, the supposition being that the street box 1 is in operation," the
break wheel 3 having completed at least a full turn or having completed its
entire movement. The shutter levers 19 and 191 when released may fall by their
weight, but they are preferably tripped by a spring 21 and are reset by a restor-
ing rod 22 having pins 23, 23 which engage the shutter levers below their pivots,
said restoring rod 22 being mounted in bearings (not shown) so as to slide
sidewise.
Mounted above the repeater magnets 16 and 17 is a non-interference shaft 24,
which is carried in bearings 25, 25 so as to permit of a rocking movement, and
said shaft carries the arms 26, 26 adapted to engage with fingers 27 carried upon
the levers 19 and 191 when the latter are locked in their uppermost position by
means of the armature levers 18 and 18¹. A spring 28, engaging an arm 29 on
the non-interference lever 24, normally withholds the arms 26 from the fingers 27.
The non-interference shaft 24 carries the armature 30 of a non-interference
magnet 31, whereby, when said magnet 31 is energized, the armature 30 will be
attracted, rocking the non-interference shaft and engaging the arms 26 in front
of the fingers 27. Each shutter lever 19 and 191 controls a series of circuit
closers 32, 33, 34, and 321, 331, 34¹.
The circuit closers 32 and 321, and any other corresponding circuit closers
when more than two repeater magnets are used, are included in a normally open
circuit 35 with the non-interference magnet 31. A battery 36 is included in
said circuit. When all the shutter levers are locked in their normal positions,
the circuit closers 32 and 321 will break the circuit 35, and the non-interference
magnet 31 will be de-energized, but upon the release of any of the shutter levers
by the breaking of a line circuit at one of the street boxes, the circuit closer 32
or 321 will close the circuit 35. energizing the non-interference magnet 31;
attracting the armature 30, rocking the shaft 24, and throwing the arm 26 in
front of the finger 27 of the other repeater magnet or magnets than the one which
was operated.
In this way it will be observed, the repeater magnets except the one' first
operated, will be locked by the non-interference mechanism, and they cannot
therefore affect the joker transmitter, as will be hereafter explained. Assuming
the parts to be in the position shown in Fig. 1, it will be seen, however, that
although the repeater magnet 17 is locked against interference and cannot affect
the joker transmitter, yet a signal coming over the street circuit 7 will energize
the relay 101 and operate the register 14, so that the operator at the central office
will know that the street circuit 7 has been energized, and can send out the
proper signals to the engine houses after the restoration of the shutter lever of
the repeater magnet 16. When the message has been received, the restoring
arm 22 is operated to restore the shutter lever, which will be again locked in its
normal position by the armature of the repeater magnet, and in this movement
the pins 37 in the shutter lever will again engage the circuit closers 32, 33, 34,
or 321, 33, 341, to again open the circuits controlled thereby. This restoration,
therefore, effects the breaking of the circuit 35 to de-energize the non-interference
magnet 31 and allow the shaft 24 to be moved to its normal position to free the
shutter levers of all of the repeater magnets.
38 represents the controlling magnet of the joker transmitter, its armature
operating an escapement lever 39, having two oppositely disposed stops or
retents 40 and 41 with which the arm 42 engages. Said arm is carried on a
shaft 43, which is driven by a weight, spring or other motor. A spring 44
opposes the attraction of the magnet 38.

page_text: Normally the turned-in end 45 of the arm 42 engages the stop 41, whereby
rotation of the shaft 43 will be prevented, but upon the energization of the
magnet 38, the stop 41 will be moved downwards out of engagement with the
end of the arm 42, and said shaft will be permitted to move almost a complete
rotation in the direction of the arrow until the end 45 engages the stop 40.
Upon the de-energization of the magnet 38, the spring 44 will again elevate the
lever 39 to withdraw the detent from the end 45 of the arm 42, and the shaft 43
will be allowed to complete its full rotation to again engage the end of the
arm 42 with the detent 41. Thus a make and break of the circuit including the
magnet 38 permits a complete rotation of the shaft 43, which will result in the
transmission of the signals to the engine house or houses, as will be presently
described. The magnet 38 is included in a normally open circuit 46, which is
broken between the contacts 47 controlled by the armature 18 of the repeater
magnet 16, and also at the circuit closer 34, which it will be remembered, is
normally open, the circuit 46 including also a battery 48. A branch 49 includes
the contacts 50, which are controlled by the armature 18¹ of the repeater
magnet 17, and also includes the circuit closer 34¹.
If more than two repeater magnets are employed, they will be connected in
the same way as the magnet 17. It will be seen that normally the main circuit
of the joker magnet 38, or any branch circuit which may control the said magnet,
will be normally broken, not only at the contacts which are controlled by the
repeater magnets, but also by the circuit closers, which are normally opened by
the several shutter levers.
When, however, one of the street boxes is pulled to break the circuit of any
one of the repeater magnets and to allow its corresponding shutter lever to be
operated, the circuit closer 34 or 34' will close the circuit of the joker magnet 38
at that point, and said magnet will be in condition to be operated by the move-
ments of the repeater magnet. Therefore at each break of the street circuit 5
or 7, permitting the repeater magnet 16 or 17 to be de-energized, the circuit to
the joker magnet 38 will be closed at the contacts 47 or 50, resulting in a com-
plete rotation at each make and break of the shaft 43. If, while the repeater
magnet 16, for example, is thus operating a signal is sent over the circuit 7 to
the repeater magnet 17, the operation of the armature 181 of that magnet to
close the circuit 49 at the contacts 50, will not result in interference at the joker
transmitter magnet 38, because the circuit 49 of the repeater magnet 17 will be
still open at the circuit closer 34¹. The circuit closer 34 or 34¹ for each repeater
magnet therefore supplements in the operation of the non-interference device,
and prevents interference of signals at the joker transmitter, without however
interfering with the proper operation of the street circuit for the recording of the
signals in the central office.
Carried by the shaft 43 is a drum 51 carrying a contact plate 52, with which
contact springs 53 are normally in engagement.
The
The springs 53 connect with a joker circuit 54 leading to one or more engine
houses. It will be understood that by employing more than one of the contact
plates 52 upon the drum 51, the said drum may be employed for the transmis-
sion of messages over a plurality of joker circuits in multiple. The joker
circuit 54 includes in the central station a pole-changer by which
the polarity of the current from a battery 55 impressed on the joker
circuit may be reversed. This pole-changer comprises a pole-changer magnet 56,
which operates a lever 57 against the tension of a restoring spring 58.
lever 57 is pivoted, and is provided with an extension 59 having a contact
device 60 at its end adapted to engage respectively with the spring-pressed elec-
trodes 61 and 62 and force said electrodes out of engagement with the binding
screws 63 and 64. The electrodes 61 and 62 are connected with opposite poles
of the battery 55, and the circuit 54 leads to the armature lever 57 and from
the binding post 63, a branch 65 connecting the binding post 64 with said circuit,
as shown. It will be observed that when the pole-changer 56 is energized to

page_text: attract the armature lever 57, the contact piece 60 will engage the electrode 62
to separate it from the binding screw 64, and will allow the electrode 61 to
engage the binding screw 63. The current from the battery 55 therefore, instead
of passing directly to the extension 59 of the armature lever 57 through the
electrode 61, will pass from the electrode 61 to the binding screw 63, thence
through the circuit 54 in the opposite direction, returning to the battery 55
through the extension 59 of the lever 57, contact device 60 and electrode 62.
When the pole-changer magnet 56 is energized therefore, current will be
impressed upon the joker circuit 54 of opposite polarity to that when the said
magnet is not energized.
The pole-changer magnet 56 is included in a circuit 66 on a battery 67, said
circuit including the circuit closers 33 and 331 of the repeater magnets. Thus
when one of the shutter levers is released as shown, the circuit 66 will be closed
to energize the magnet 56 and change the polarity of the current on the joker
circuit.
The joker circuit 54 at the central station also includes a telegraph key 68,
from the contacts of which the circuit extends through a polarized relay 69 and a
direct relay 70. A shunt 71 extends around the key 68 to the polarized relay 69,
and includes a circuit breaking device 72 by which said shunt circuit will be
broken when the pulverized relay 69 is in its normal condition, i.e. when a fire
alarm signal is not being transmitted. When the shunt circuit 71 is broken
at 72 therefore, the key 68 will control the joker circuit. The front stop 73 of
the polarized relay 69 connects with a circuit 74, which includes a sounder 75 and
leads to the armature 76 of the direct relay 70, the back stop 77 of which connects
with the armature of the polarized relay 69. This local circuit includes a local
battery 78 between the back stop 77 and the armature of the polarized relay.
The back stop 79 of the polarized relay connects with a circuit 80 including a
bell 81 and leading also to the armature 76 of the direct relay 70. When the
polarized relay is in its normal position with its armature in engagement with
the front stop 73, it will be observed that the de-energization of the direct
relay 70, allowing its armature 76 to engage the back stop 77, will close the
battery 78 on the sounder 75, while, when the armature of the polarized relay is
in contact with the back stop 79, the de-energization of the direct relay 70, allow-
ing its armature 76 to engage the back stop 77 thereof, will close the battery 78
on the bell 81. At each engine house, the arrangement thus described is prac-
tically duplicated, the joker circuit 54 extending to a key 82, thence to a
polarized relay 83, and returning through a direct relay 84. A shunt 85 connects
the polarized relay 83 around the key 82, said shunt having a break device 86
theroin controlled by the armatur lever of the polarized relay. The front
stop 87 of the polarized relay is included in a circuit 88, in which is placed a
sounder 89, said circuit extending to the armature lever 90 of the direct relay 84.
The back stop 91 is connected with a battery 92 to the armature of the polarized
relay 83. The back stop 93 of the polarized relay is connected by a circuit 94
with a register 95 and bell 96, said circuit 94 also extending to the armature 90
of the direct relay 84.
The repeater circuit 46 and its branch 49 are provided each with a switch 97,
whereby either of said circuits may be broken when it is desired to test any one
of the line circuits, so that test signals for the central station will not be trans-
mitted to the engine houses. For instance, if the switch 97 of the repeater cir-
cuit 46 is moved to break said circuit, the breaking of the street circuit 5 in
testing, resulting in the de-energization of the repeater magnet 16 and the closing
of the circuit 46 at the circuit closer 34, will not affect the joker transmitter,
since said circuit will be broken at the switch 97. The operation of this switch
will not, however, disable the joker transmitter from sending signals received by
the repeater magnet 17, since the circuit on the joker transmitter magnet 38
may be still closed through the branch 49, contacts 50 and circuit closer 34¹.
The pole changer circuit 66 is also provided in each of its branches including

page_text: the circuit closers 33 and 331 with switches 98, 98, by means of which the
circuit 66 at each repeater magnet may be broken in testing, so that the operation
of any repeater magnet by the reception of a test signal will not result in the
operation of the pole-changer to disable the telegraphic transmission on the joker
circuit. The operation of either switch 98 or any one of the repeater magnets will
not, however, disable the corresponding switch or the other repeater magnet or
magnets, which may receive alarm signals and transmit them over the joker
circuit. The circuit 35 for each repeater magnet is also provided with a
switch 99 therein, which is also opened in testing, whereby the reception by either
repeater magnet of a test signal will not result in the operation of the non-
interference mechanism and thereby prevent the operation of the other repeater
magnet or magnets.
The operation of a fire alarm telegraph system equipped with the present
improvements and of which the system illustrated in the drawing, is, as stated,
a good embodiment, will be as follows:
With the parts in the position shown, the assumption is that the street circuit 5
is either in process of sending a signal to the central office, or else has sent in
its signal, and the shutter lever 19 awaits restoration by the operation of the
restoring rod 22. In the position of the parts shown therefore, the circuit
closer 32 closes the circuit of the battery 36 on the non-interference magnet 31,
energizing the armature 30 and rocking the shaft 24 to engage the arm 26 with
the finger 27 of the repeater magnet 17, and to similarly lock against movement
any additional repeater magnets which may be used in the system.
When in this condition, the repeater magnet 17 may be energized and de-ener-
gizd in the reception of an alarm signal on the street circuit 7, which signal,
in operating the relay 10', will effect a registration on the tape by the operation
of the register 14. The closing of the branch 49 at the contacts 50 will not
however, affect the joker transmitter 38, since said branch will be open at the
circuit closer 341. Thus all the other repeater magnets than the one first operated
will be disabled and interference avoided. The tripping of the shutter lever 19
also closes the circuit 66 on the pole changer magnet 56, energizing the same
and reversing the polarity of the current from the battery 55 on the joker
c'rcut 54. The reversal of current on the joker circuit energizing the polarized
relays 69 and 83 respectively, will move the armatures of said polarized relays
into contact with the back stops 79 and 93 respectively thereof.
Thus the telegraph keys at the central station and at the several engine houses
will be prevented from breaking the joker circuit by the closure of the shunts 71
and 85 through the contact devices 72 and 86 respectively. As soon, therefore, as
one of the repeater magnets is operated to actuate the pole-changer, the polarized
relays will be operated on the joker circuit to prevent the disablement of that
circuit by any one of the signaling keys, and it thus becomes impossible for a
person, either accidentally or intentionally, to disable the joker circuit by the
manipulation of one of such keys. The reversal of the current by the pole-
changer, throwing the armature of the polarized relay 69 into contact with the
back stop 79 thereof, places the bell 81 in condition for signaling upon the ener-
gization and de-energization of the direct relay 70, while the corresponding move-
ment of the armature of the polarized relay 83 places the register 95 and bell 96
in condition for operation when the direct relay S4 is affected. The movements
which have been described take place immediately after the breaking of the line
circuit to one of the repeater magnets, for example magnet. 16, so that at the
first release of said magnet, the closing of the repeater circuit 46 at the contacts 47
and circuit closer 34, will energize the repeater magnet 38 to move the detent 41
out of engagement with the turned-in end 45 of the arm 42, thus allowing the
shaft 43 to turn almost a complete rotation, and breaking the joker circuit
between the contact springs 53, 53. The breaking of this circuit allows the
direct relays 70 and 84 to close the local circuits 80 and 94 respectively on the
bell 81, at the central station, and upon the register 95 and bell 96 at each engine

page_text: house. Upon the completion of the line circuit 5 to again energize the repeater
magnet 16, the repeater circuit 46 will be broken at the contacts 47 to de-ener-
gize the joker transmitter magnet 38, allowing the detent 40 to be withdrawn
from engagement with the turned-in end 45, and permitting said end to again
engage the detent 41, whereby the shaft 43 will have completed its full turn, the
contact 52 will be brought again into engagement with the springs 53, and the
joker circuit will be again completed, energizing the direct relays 70 and 84 and
breaking the local circuits through the bell and register. Thus each make and
break in the line circuit will be transmitted over the joker circuit and received
at the engine house, and this result will take place during the first and each
succeeding round of the street box signal, instead of only at the commencement
of the second round of said signal, as at the present time. During the normal
condition of the joker circuit, when the pole-changer circuit 66 is broken at the
several repeater magnets, the armatures of the polarized relays 69 and 83 respec-
tively will be in engagement with their front stops.
The shunts 71 and 85 are therefore broken at the contacts 72 and 86 respec-
tively, so that the joker circuit can be controlled from the telegraph keys. The
breaking of the circuit at one of the telegraph keys will therefore result in the
de-energization of the direct relays 70 and 84 respectively, closing the battery 78
at the central station on the sounder 75 through the front stop 73 and circuit 74,
and closing the sounder 89 at the engine house on the battery 92 through the
front stop 87 and circuit 88. Ordinary telegraphic communication can in this way
be established, but the moment a signal is received at the central station to
operate the pole-changer, the movement of the armatures of both polarized relays
will complete the shunt around each key, throw out the sounder, and connect in
the bell at the central station and the register and bell at the engine house.
It thus becomes possible, during the normal condition of the joker circuit, to
establish communication between any two engine houses or between an engine
house and the central station, but such communication will be automatically
interrupted immediately a signal is received at the central station.
In Fig. 3, the main parts of a well known form of repeater are shown, in which
one or more repeater magnets are employed, each connected with a particular
street circuit, generally normally closed. The armatures of these magnets, when
released, operate a rock shaft with which is connected a tripping mechanism to
permit a power driven joker transmitter shaft to partake of a single revolution to
transmit an impulse over one or more joker circuits. The armatures of the
repeater magnets are restored either magnetically, upon the reclosure of the
circuit, or positively from the joker transmitter shaft. In order that interference
may be avoided, the repeater is provided with non-interference mechanism
operated from a non-interference shaft, which is actuated at the commencement
of movement of the first rotation of the joker transmitter shaft to lock the arma-
tures of all the other repeater magnets except the one in active operation, whereby
the operation of any one of such other repeater magnets will not result in aberra-
tions in the repeating mechanism. After a signal has been received, the non-
interference mechanism is automatically released, and the apparatus placed in
position for re-operation.
In applying the present improvements to a repeating apparatus of this char-
acter, a circuit-closing device is arranged on the non-interference shaft to close
the circuit 66 for the pole-changer magnet 56 when the non-interference shaft
partakes of its movement and before the joker transmitter shaft operates to
transmit impulses over the joker circuit.
With this form of device, the two repeater magnets 16 and 17 are provided
with the armatures 18 and 18¹, as before. These armatures are adapted, when
released, to slightly rock a shaft 100 connected by a link 101 with a lever 102.
The said lever carries a stop 103, with which an arm 104 normally engages, said
arm being mounted on the joker transmitter shaft 43. A cam 105 engages a
lever 106 to return the stop 103 into the path of the arm 104 at each rotation of

page_text: the shaft 43. 24 is a non-interference shaft, which is driven by gears 108 and 109
from a power shaft 110. The latter shaft is normally locked against rotation by
a stop mechanism controlled by a lever 111, said lever being actuated by a cam 112.
The non-interference shaft 24, in making a half rotation, operates the
fingers 113 and 113 to engage one or the other of the armatures 18 or 18¹ to
hold the same from operation, while the other armature is free to operate to pro-
vide for oscillations of the shaft 100 and consequent rotations of the joker trans-
mitter shaft 43. Carried upon the non-interference shaft 24 is an insulated
sleeve 114 supporting a contact plate 115, with which two contact fingers 116
and 117 engage. The contact plate 115 is brought into position to electrically
connect said contact fingers when the non-interference shaft 24 is turned to the
position to lock one or the other of the armatures of the repeater magnets from
operation. The joker transmitter shaft 43 carries the drum 51 having the contact
plate 52 thereon, with which the contact springs 53, 53, engage, as in the device
shown in Fig. 1, said contact springs being in the joker transmitter circuit 54,
whereby an impulse will be transmitted over the joker transmitter circuit at
each rotation of the joker transmitter shaft. The contact fingers 116 and 117
are placed in the circuit 66 of the pole-changer magnet 56, so that upon movement
of the non-interference shaft 24, the circuit 66 will be closed to operate the pole
changer and disable the telegraph instruments in the joker circuit, as with the
device shown in Fig. 1.
With the device shown in Fig. 3, the breaking of any one of the street circuits
results in the de-magnetization of the corresponding repeater magnet 16 or 17,
whereby the armature thereof will be released to rock the shaft 100 and elevate
the stop 103 from out of engagement with the arm 104. The joker trans-
mitter shaft, therefore, is permitted to make a single turn, when it will be again
arrested by the stop 103. For each break of the street circuit, therefore, the joker
transmitter shaft will make a complete turn, thereby repeating over the joker
transmitter circuit or circuits the same signal received at the central station from
the street circuit. The engagement of the cam 112 with the arm 111 serves at
the commencement of the movement of the joker transmitter shaft to release the
non-interference mechanism, and the shaft 24 will thereupon make a half turn
to cause the fingers 113 to engage with the armatures of all the repeater magnets
except the one in direct operation, thereby preventing interference. This rota-
tion of the shaft 24 also, either electrically or mechanically, actuates the pole-
changer to reverse the polarity of the current from the battery 55 on the joker
circuit 54. With the device shown in Fig. 3, this is effected by
the engagement of the contact fingers 116 and 117 with the contact
plate 115, so as to close the circuit 66 on the pole-changer magnet 56.
It will be understood, however (see Fig. 4) that the non-interference shaft 24
may be provided with a cam 118 thereon, which in turning will directly elevate
mechanically the pole changer lever 57. The reversal of current on the joker
circuit energizes the polarized relays 69 and 83, so that the operations described
in connection with the system shown in Fig. 1 will take place on the joker
circuit. Upon the completion of the street circuit to again energize the repeater
magnet 16 or 17, the armature thereof will either be restored by the attraction of
said magnet or mechanically by connections from the joker shaft. This restora-
tion of the armature of the operating repeater magnet 16 or 17 does not, however,
affect the non-interference shaft 24, which still remains in its locked condition
and stays in that condition until sufficient time has elapsed after the reception,
of a signal at the central station to allow the arm 111 to be moved down to its
full limit to release the non-inteference shaft.
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 repeater system for use in connection with a fire alarm telegranh system

page_text: comprising the street circuits which connect with two or more repeater magnets
at a central station, a joker system which is brought into operation by the opera-
tion of any one of said repeater magnets, telegraph apparatus for use on the joker
system, and a pole-changer for the joker system adapted to be operated from one
of the repeater magnets so as to disable the telegraphing apparatus, substantially
as set forth.
2. In a fire alarm telegraphic system, the combination of a street circuit, a
repeater magnet controlled thereby, a joker transmitter magnet operated from
the repeater magnet, a joker transmitting apparatus under the control of the
joker magnet, and a joker circuit controlled by said transmitting apparatus, sub-
stantially as set forth.
3. In a fire alarm telegraph system, the combination of a street circuit, a
repeater magnet controlled by said circuit, a repeater circuit controlled by the
arinature of said repeater magnet, a joker magnet in said repeater circuit, a joker
transmitter controlled by the joker magnet, and a joker circuit extending to an
engine house and controlled by said joker transmitter, substantially as set forth.
4. In a fire alarm telegraph system, the combination of a plurality of street
circuits, a repeater magnet for each circuit, a joker transmitter magnet, repeater
circuits controlled by the repeater magnets and including said joker transmitter
magnet, a joker transmitter controlled by the joker magnet, and a joker circuit
controlled by the joker transmitter, substantially as set forth.
5. In a fire alarm telegraph system, the combination of a plurality of street
circuits, a repeater magnet for each circuit, a joker transmitter magnet, repeater
circuits controlled by the repeater magnets and including said joker transmitter
magnet, a joker transmitter controlled by the joker magnet, a joker circuit con-
trolled by the joker transmitter, and a non-interference mechanism for locking the
armature of the inactive repeater magnet, substantially as set forth.
6. In a fire alarm telegraph system, the combination of a plurality of street
circuits, a repeater magnet for each of said circuits, a joker circuit controlled
by said repeater magnets, a non-interference device for locking the armatures of
the repeater magnets in an inactive position, a non-interferonce magnet con-
trolling said device, and a circuit controlling device actuated upon the operation
of one of said repeater magnets to allow the non-interference magnet to effect the
locking of the armatures of the non-actuated repeater magnets, substantially as
eet forth.
7. In a fire alarm telegraph system, the combination of a plurality of street
circuits, a repeater magnet for each of said circuits, a joker circuit controlled by
said repeater magnets, a non-interference device for disabling the repeater
magnets to prevent them from actuating the joker circuit, and means controlled
by the operation of one of said repeater magnets to cause the non-interference
device to lock the other repeater magnets, substantially as set forth.
8. In a fire alarm telegraph system, the combination of a plurality of street
circuits, a repeater magnet for cach of said circuits, a joker circuit controlled
from the armatures of said repeater magnets, a non-interference device, a shutter
lever locked against movement by the armature of each repeater magnet, a non-
interference device, and a circuit controlling mechanism operated by the shutter
levers of the repeater magnets to actuate said non-interference device, substan-
tially as set forth.
9. In a fire alarm telegraph system, the combination of a plurality of street
circuits, a repeater magnet in each circuit, a shutter lever controlled by each
repeater magnet, a non-interference shaft mounted above said repeater magnets,
arms on said shaft to engage the shutter levers, a magnet for operating said
shaft, and circuit controlling devices operated by the shutter levers for effecting
the operation of the non-interference inagnet, substantially as set forth.
10. In a fire alarm telegraph system, the combination of a plurality of street
circuits, a repeater magnet in each circuit, a shutter lever controlled by cach

page_text: magnet, and a restoring rod for restoring the shutter levers, substantially as set
forth.
11. In a fire alarm telegraph system, the combination of a plurality of street
circuits, a repeater magnet in each circuit, a repeater circuit controlled by the
armatures of said repeater magnets, a joker magnet in said repeater circuit, and
a circuit controlling device for making the repeater circuit operative controlled
from the operation of any one of said repeater magnets, substantially as set forth.
12. In a fire alarm telegraph system, the combination of a plurality of street
circuits, a repeater magnet in each circuit, a repeater circuit controlled by said
repeater magnets, a joker magnet in said repeater circuit, a joker circuit con-
trolled by the joker magnet, and circuit controlling devices for completing the
repeater circuit, said devices being under the control of the respective repeater
magnets, substantially as set forth.
13. In a fire alarm telegraph system, the combination of a plurality
of street circuits, a repeater magnet in each circuit, a shutter lever
controlled by each magnet, a repeater circuit controlled by said magnets,
a joker magnet in said circuit, a joker circuit controlled by the joker
magnet, and a circuit closing device operated by each shutter lever for closing
the repeater circuit at each repeater magnet, substantially as set forth.
14. In a fire alarm telegraph system, the combination of a street circuit, a
repeater magnet in said circuit, a repeater circuit controlled by the armature of
said repeater magnet, a joker magnet in said repeater circuit, an escapement
device actuated by said joker magnet, a joker transmitter controlled by said
escapement device, and a joker circuit controlled by said transmitter, sãostan-
tially as set forth.
15. In a fire alarm telegraph system, the combination of a street circuit, a
repeater magnet controlled by said circuit, a repeater circuit controlled by said
repeater magnet, a joker magnet in said repeater circuit, a joker circuit controlled
by said joker magnet, telegraphic apparatus in the joker circuit, a polarized relay
for disabling said telegraphic apparatus, a pole-changer for reversing the current
in the joker circuit, and a circuit controlling device under the control of the
repeater magnet for actuating said pole-changer, substantially as set forth.
16. In a fire alarm telegraph system, the combination with a street circuit and
a repeater magnet controlled thereby, of a joker circuit, a joker transmitter con-
trolled by the repeater magnet, a polarized relay in the joker circuit, a telegraph
key connected to said relay, a shunt around said key adapted to be broken by
reversal of current in the relay, and a pole-changer in the joker circuit controlled
by the repeater magnet, substantially as set forth.
17. In a fire alarm telegraph system, the combination with a street circuit and
a repeater magnet controlled thereby, of a joker circuit, a joker transmitter con-
trolled by the repeater magnet, a polarized relay in the joker circuit, a telegraph
key connected to said relay, a shunt around said key adapted to be broken by
reversal of current in the relay, a pole-changer in the joker circuit controlled by
the repeater magnet, a sounder connected to the front stop of said polarized relay,
and a bell connected to the back stop of said polarized relay, substantially as set
forth.
18. In a fire alarm telegraph system, the combination with a street circuit and
a repeater magnet controlled thereby, of a joker circuit, a joker transmitter con-
trolled by the repeater magnet, a polarized relay in the joker circuit, a telegraph
key connected to said relay, a shunt around said key adapted to be broken by
reversal of current in the relay, a pole-changer in the joker circuit controlled by
the repeater magnet, a sounder connected to the front stop of said polarized relay,
and a bell and register connected to the back stop of said polarized relay, sub-
stantially as set forth.
19. In a fire alarm telegraph system the combination with a street circuit and
a repeater magnet controlled thereby, of a joker circuit, a joker transmitter con-
trolled by the repeater magnet, a polarized relay in the joker circuit, a telegraph

page_text: key connected to said relay, a shunt around said key adapted to be broken by
reversal of current in the relay, a pole-changer in the joker circuit controlled by
the repeater magnet, a sounder connected to the front stop of said polarized relay,
a bell connected to the back stop of said polarized relay, and a direct relay in
the joker circuit for actuating said sounder, substantially as set forth.
20. In a fire alarm telegraph system the combination with a street circuit and
a repeater magnet controlled thereby, of a joker circuit, a joker transmitter con-
trolled by the repeater magnet, a polarized relay in the joker circuit, a telegraph
key connected to said relay, a shunt around said key adapted to be broken by
reversal of current in the relay, a pole-changer in the joker circuit controlled by
the repeater magnet, a sounder connected to the front stop of said polarized relay,
a bell connected to the back stop of said polarized relay, and a dircet relay in said
joker circuit for actuating the sounder and bell, substantially as set forth.
21. In a fire alarm telegraph system, the combination of a street circuit, a
repeater magnet controlled by said circuit, a joker circuit controlled by said
repeater magnet, telegraphic apparatus in the joker circuit, a polarized relay
for disabling said telegraphic apparatus, a pole-changer for reversing the current
in the joker circuit, and a non-interference mechanism for the repeater magnet,
said mechanism controlling the pole changer, substantially as set forth.
22. In a fire alarm telegraph system the combination with a street circuit and
a repeater magnet controlled thereby, of a joker circuit, a joker transmitter con-
trolled by the repeater magnet, a polarized relay in the joker circuit, a telegraph
key connected to said relay, a shunt around said key adapted to bd broken by
reversal of current in the relay, a pole-changer in the joker circuit, and non-
interference mechanism for the repeater magnet controlling said pole-changer,
substantially as set forth.
23. In a fire alarm telegraph system, the combination with a street circuit and
a repeater magnet controlled thereby, of a joker circuit, a joker transmitter con-
trolled by the repeater magnet, a polarized relay in the joker circuit, a telegraph
key connected to said relay, a shunt around said key adapted to be broken by a
reversal of current in the relay, a pole-changer in the joker circuit, non-interfer-
ence mechanism for the repeater magnet controlling said pole-changer, a sounder
connected to the front stop of said polarized relay, and a bell connected to the
back stop of said polarized relay, substantially as set forth.
24. In a fire alarm telegraph system the combination with a street circuit and
a repeater magnet controlled thereby, of a joker circuit, a joker transmitter con-
trolled by the repeater magnet, a polarized relay in the joker circuit, a telegraph
key connected to said relay, a shunt around said key adapted to be broken by
reversal of current in the relay, a pole-changer in the joker circuit, non-interfer-
ence mechanism for the repeater magnet controlling said pole-changer, a sounder
connected to the front stop of said polarized relay, and a bell and register con-
nected to the back stop of said polarized relay, substantially as set forth.
25. In a fire alarm telegraph system, the combination with a street circuit and
a repeater magnet controlled thereby, of a joker circuit, a joker transmitter con-
trolled by the repeater magnet, a polarized relay in the joker circuit, a telegraph
key connected to said relay, a shunt around said key adapted to be broken by
reversal of current in the relay, a pole-changer in the joker circuit, non-interfer-
ence mechanism for the repeater magnet controlling said pole-changer, a sounder
connected to the front stop of said polarized relay, a bell connected to the back
stop of said polarized relay, and a direct relay in said joker circuit for actuating
said sounder, substantially as set forth.
26. In a fire alarm telegraph system, the combination with a street circuit and
a repeater magnet controlled thereby, of a joker circuit, a joker transmitter con-
trolled by the repeater magnet, a polarized relay in the joker circuit, a telegraph
key connected to said relay, a shunt around said key adapted to be broken by
reversal of current in the relay, a pole-changer in the joker circuit, non interfer-
epçe mechanism for the repeater magnet controlling said pole-changer, a sounder

page_text: connected to the front stop of said polarized relay, a bell connected to the back
stop of said polarized relay, and a direct relay in said joker circuit for actuating
the sounder and bell, substantially as set forth.
Dated this 12th day of December 1899.
HARRIS & MILLS,
23, Southampton Buildings, London, W.C., Agents.