Aug. 2, 1960
F. L.. LEMM El" AL
2,947,980
ALARM SYSTEM
Original Filed Jan. l0, 1956
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United States Patent 0 ”` f. CC
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Patented Aug. 2, 1960
2
Ifor the unit or device being monitored as such unit or
device becomes inoperative.
A still further object of the present invention is to pro
2,947,980
ALARM SYSTEM
Frederick L. Lemm and Richard H. Jewens, Houston,
Tex., assignors, by direct and mesne assignments, to
Information Systems, Inc., Skokie, Ill., a corporation
of Illinois
Continuation of application Ser. No. 558,218, Jan. 10,
1956. This application Jan. 8, 1957, Ser. No. 633,159
vide an alarm system as above described which, in addi
tion to the centrally located audible alarm above men
tioned, includes a second audible alarm located at the situs
of the point being monitored.
~
In accordance with a preferred form of the invention, in
the case where there are two control relays per point or
alarm light, one to be referred to as an alarm relay and
the other as an acknowledgment relay, both relays are
operated in a normally-energized condition and the alarm
light is connected in series with one of the relays, prefer
13 Claims. (Cl. 340-213) t
This is a continuation of application Serial No. 558,218,
ñled January 10, 1956, now abandoned for an Alarm
System.
ably lbut not necessarily the acknowledgment relay. The
latter relay is designed to operate normally in series with
the alarm light, and the alarm light is substantially de
energized or in dim condition during normal operation of
the system. The alarm relay is associated with a set of
This invention relates to annunciator or alarm systems,
and particularly to an electrical alarm system having visual
sensor contacts, preferably in series with a Inormally closed
and audible alarm means for initially `signalling the failure 20 set of sensor contacts, which sensor contacts are controlled
by a fault-detecting unit, such as a therrnocouple, located
or abnormal condition of a point being monitored.
at the point being monitored. The alarm light is >con
In the interest of safety and eñiciency, it has become
common practice to provide at a central location in indus
trolled by contacts of the alarm relay so that upon opera
tion of the sensor contacts to their trouble-indicating posi
trial plants a panel board containing a maze of alarm
lamps associated with various points in the plant to be 25 tion, the alarm relay will be de-energized and the alarm
light will be energized, that is, it will light brightly. The
monitored. When the point being monitored reaches an
relay with which the alarm light is not directly associated
abnormal state, a sensing device associated with such
is provided with a set of contacts connected preferably
point energizes the circuit controlling the light in ques
in series with the relay which is directly associated with
tion and also an audible alarm for attracting the atten
:tion of an operator to the panel board where he can im 30 the alarm light so that the latter relay will be de-energized
whenever the former relay is de-energized. The trouble
mediately identify the location of the fault in question.
light is associated with the sensor contacts, preferably in
The reliability of such a system, of course, is a function
series therewith, and with a set of contacts controlled by
of the reliability of the alarm system itself and it, accord
one of the relays. The circuit is such that whenever either
ingly, becomes desirable to provide a means for signalling
a fault in the alarm system through visual and audible 35 of said relays are de-energized while the movable sensor
contact is in its normal position, the trouble light will light
means in the same general way as the alarm system signals
brightly thereby signalling most probably a burned out
the abnormal condition of the point or points being
relay or a burned out alarm light, since the relay in series
with the alarm light is ‘de-energized where it is burned out,
It is, accordingly, one of the objects of the present in
vention to provide an alarm system with provision forgiv 40 or the other relay or the alarm lamp is burned out. When
the alarm relay is de-energized for any reason, its contacts
ing preferably both a visual and audible alarm signalling
controlling the alarm light will cause the latter to be
failure of components of the alarm system of a distinguish~
energized.
ing character from the alarm given when a point being
An acknowledgment switch is associated with the ac
monitored becomes abnormal, preferably both with and
without failure of the components so that the operator may 45 knowledgment relay so that upon operation of the ac
knowledgment switch the audible can be silenced as long
at substantially all times have knowledge of the operating
condition of the alarm system as well as the points being . as the `acknowledgment relay is then operative.
In the case where the alarm light is in series with the
monitored.
‘
acknowledgement relay, the audible alarm is controlled
A-n ancillary object of the present invention is to pro«
vide an alarm system wherein there are provided two or 50 by a set of normally-closed contacts of the acknowledge
ment relay so‘that the audible alarm will be sounded whenmore alarm relays for each point to be monitored, an
the acknowledgement relay becomes de-energized due to
‘ alarm light for signalling the abnormal condition of each
point to be monitored and a trouble light which signals
any of the above-mentioned circuit faults. An acknowl
edgement switch is provided which, in cooperation with
the burning ont of any of the relays, and also most pref
erably of the alarm light as well.
55 holding contacts of such relay, re-energize the acknowl
A_nother object of the invention is to provide an alarm
edgement relay when operated, except where the fault
system as above described wherein the size, complexity
exists in the energization circuit thereof, so as to silence
and cost of the alarm apparatus associated with each point
the audible alarm.
‘
to 'oe monitored is not substantially different from appara
With the circuit arangement above described, if bo
tus heretofore available without the self-failure signalling 60 the alarm light and trouble light are brightly lighted, then
features above outlined.
the operator knows that the fault is not with the point
Another object of the invention is to` provide an alarm
being monitored but in the energization circuit of the
system as above described having means for testing the
alarm relay, most probably the burning out of the alarm
condition of the trouble light. A related object of the
relay.
And if only the trouble light is lit, then the
invention is to provide an alarm system having a test 65
voperator knows that the trouble is in the'energization
switch` and a trouble or test light which upon depression
circuit of the acknowledgement relay, most probably the
of the test switch will light up if substantially all com
burning out of t‘he acknowledgement relay or the alarm
ponents of the associated alarm circuit are in operating
light. `In the latter situation, the replacement of the alarm
condition.
light willirnmediately indicate the cause of the fault. If
Still another object of the‘present invention is to pro
the audible alarm sounds and both the trouble and alarm
vide an alarm system as above described which automaiimonitored.
>
f
>
cally sets into operation a stand-by means which substitutes
lights are dark, the operator then knows that t'he‘signal
2,947,980
3
4
light-has burned out and the point being monitored is
lighted upon opening of the sensor switch 8. In case of
abnormal.
'
To test the operation of the trouble light, the trouble
light is arranged in a branch circuit preferably -includinga
normally-open test switch, normally-'open contacts of the
relayîinseries with the alarm light, and the sensor con
tactsso that during normal operation of the sensor con
circuit failure in the alarm unit 10, depression of the
push button switch SW-l will have various effects de
pending upon the particular part of the circuit which is
operating abnormally. Inthe preferred form of the inven
tion illustrated in Fig. l, the energization circuits of the
various relays to be described arenormally closed or ener
gized and the circuit fault to be monitored by the trouble
tacts and the relays, depression ofthe test switch will
light T is the open circuiting of such circuits in the pres
light the trouble light if the light is in operating order.
In effect, the lighting of the trouble light under these 10 ence of the closure of the sensor switch 8, which is a
normally closed switch in the embodiment of the invention
circumstances indicates that the relays and the sensor
being described.
contacts are in their normal operating conditions.
Electrical energy for operating -the alarm unit isjpro
-'Other objects, advantages and features of the invention
vided by any suitable-direct current or alternating cur
will become apparent upon making reference to the specifi
15 rent power source 12 Á.from which extend power lines
cation to follow, the claims and the drawings wherein:
' Fig. l is a schematic diagram of the most preferred
Pl-PZ.
form of the invention; and
through the plug and socket terminal connection 1 and
power line Pil connects to the alarm unit 10 Vdirectly
through the plug and socket terminals 3, although most
Fig. 2 is a chart illustrating some of the various light
and horn sequences with the present-invention.
.Power l-ine 4P2 «connects with the alarm unit
Fig. -l shows a schematic diagram of an alarm circuit 20 of the circuits of the alarm nnit l0 connect with the
power line P1 through other units ’located externally of
for monitoring a single point or variable. A condition
.the alarm unit l0, such as the sensor switch 8 and the
responsive unit, not shown, suc‘h as a thermocouple lo
audible alarm H-1. However, all of the circuits of
cated at the situs of the point or variable being monitored,
the alarm -unit iti connect directly with the pow-er line
controls a preferably normally-closed sensor switch 8
which opens when the condition of the point reaches an 25 P2 and the extension of this line within the alarm unit
10 has been identified .by the reference character P2’.
abnormal condition. The switch 8 is electrically con
yEach alarm unit 10, only one being shown in Fig. '1,
nected by a cable g to a central monitoring point in
includes a pair of relays M and A -to be referred to re
the plant involved where a large panel board, not shown,
spectively as the alarm relay and the acknowledgement
is provided containing signal lights, such as light S, for
all the points in the plant being monitored. Control cir 30 relay. The alarm relay M is connected in a circuit
extending from the power line B2.’ and through relay coil
cuits to be described are provided for each sensor switch
M, plug and socket terminals 2 and the sensor switch 8
so that upon opening or” any- sensor switch, the associ
leading to the .power line P1. Since the sensor switch
ated signal light will be lighted and a common audible
is a normally closed switch, the alarm relay will be nor
alarm horn H-l is sounded to attract the operator’s at
tention to the panel board where the location of the fault 35 mally energized.
can immediately be determined by noting the lighted
In describing the position of the contacts of the relays
signal lamp.
of the alarm unit 10», the terms “normally-closed” or
“normally-open” will represent the condition of the con
For the most part, all of the electrical apparatus ex
tacts in `question during the de-energized state of the
elusive to a particular signal lamp are assembled together
as an integral unit generally indicated lby the reference 40 `associated relays. Thus, a set of contacts which are
normally closed will be open during the energized state
numeral 10, there being similar such units associated with
of the relay controlling the same. Also, the contacts
other signal Alights or sensor switches. The unit may be
of the relays will :be identified by a capital letter corre
enclosed in a casing and provided with a socket J into
sponding to the letter used to identify the relay coil
which a plug may be inserted containing terminals for
making all connections to the unit 10. The arrows in Fig. 45 controlling the same together With a number which -dís
tinguishes the contact in question from other >contacts of
l represent plug and socket connections for the unit 1t).
'Ille unit-10 may carry the alarm light S, and, in accord
ance with the present invention, a trouble or test light T.
the same relay. Additionally, the positions of the con
tacts shown in Fig. l represent the normalrpositions
thereof, that is their lposition during the de-energized
The alarm unit 10 also hasa push button switch assembly
mounted on the exterior thereof including push button 50 state of the associated relay coils.
The acknowledgement relay coil A is in a circuit ex
switches SW-î and SW-2. The switches are ganged to
tending from the power line P2’ and through the’vñlarnent
gether so that depression of one switch will automatically
of the alarm or signal light S, .the normally-open section
depress the other.
of a Vsingle-pole double throw switch comprising mov
The lightS, which will be sometimes referred to as an
alarm light, is arranged to be normally dimly lighted and 55 able contact M-Z’ .and stationary contacts M-Z and M412",
relay coil A, a parallel vcircuit including normally-open
to -be brightly lighted when the associated sensor switch 8
holding contacts A-5 of the acknowledgement relay A
opens to thereby signal an »abnormal condition of the
point being monitored thereby. The ytrouble light T is
in parallel with Inormally-open contacts M-3 of .the alarm
relay M, and plug yand socket terminals 3 which connect
arranged to be automatically lighted brightly whenever
any of the relays to be described in the alarm unit l0 or 60 with the power line 'PL The acknowledgement relay
coil A is designed to operate in series with or in parallel
their associated circuits become open due, for example, to
with the signal light S. The alarm or signal lamp S
the burning out ofthe relay coils, or whenever the signal
normally receives a small amount of current through
or alarm lamp S burns out. Simultaneously with the
.the circuit including the relay coil A so that the light
lighting of either the alarm light S` or lthe trouble light T,
the audible alarm- H-l is sounded to attract the attention 65 bur-ns dimly. However, when the alarm relay M is in
of lthe operator to the panel board. In a manner to be
a Vde-energized state, the alarm light S is directly Vcon
explained, the push button switch S'W-Z acts as a test
nected to the power line ïPl so ¿as 'to burn brightly by
switch and if the Vtest light T lights upon depression of.
means, of a branch 14 connected in parallel with the
the push button switch then this indicates that the trouble
relay A and its holding contacts A-S, which branch in
light is operating properly and also that the relay coils of 70 cludes a normally-closed set of contacts M-S which are
the unit are in normal operating-condition.
closed under the condition in question to couple the full
The operation of the push button switch `SW-l, in the
line voltage te the alarm light S.
-
'
Y
Upon the de-energization of the alarm relay coílM
anaeknowledgement switch by theoperator to silence the
due, :for example, tov ,the opening of the sensor switch
audible alarm H-l when the alarm light S is initially 75 8 or to the .burning .out of _the coil M, the acknowledge
absence of any circuit failure in alarm .unit 10, is used as
ffj
2,947,980
6
ment relay A is also de-energized due to the movement
of the movable contact M«2’ of the above-mentioned sin
gle pole double-throw switch from the stationary con
tact M-2 to the stationary contact M-Z”, the latter being
ment relay A re-energizes, this'silences the audible alarm
H-l. If the audible alarm H-l cannotbe silencedby
depression of the push button switch SW-l, and the
alarm light S is de-energized, then the operator has a
further indication that the >fault is probably in the burning
connected to a line 16 extending directly to the power
line yP2'. Before the movable contact M-Z' reaches the
out of the acknowledgement relay coil A or theV burn'
stationary contact M~ ", the relay coil A is de-energized
so that itsholding contacts A-S are open.
ing out of the alarm light S. Since the alarm light Scan
When the
movable contact M-Z' reaches the stationary contact
M-«2", the acknowledgement relay A remains cie-ener 10
gized because at that moment its holding contacts are
open and `the contacts M~3 in parallel therewith are open
be quickly replaced by a new alarm light, the‘operator can
quickly determine whether the fault is with the relay A
or the alarm light S.
'
-
-
In order to test for the operation of the alarm light T,
a push button switch SW-Zis connected in a test branch
because of the de-energized condition of the alarm relay.
extending from the bottom terminal of the trouble light
This does not eifect the lighting of the alarm light S
T and through the switch SW-Z to itself, a normally-`
because of the above-mentioned parallel branch 14.
15 open set of contacts A-3 of the acknowledgment relay,
In the `de-energized state of the acknowledgement re
plug and socket terminals S, and the normally-closed
lay A, an energization circuit for the audible alarm H-1
sensor switch 8. Therefore, if the depression of the-push
is completed through a set of normally-closed contacts
button switch SW-Z‘results in the lighting of the trouble
A-l of the -acknowledgment relay which contacts are
or test light T, the operator knows that the trouble light
in a branch extending from the power line P2' and 20 T is operating properly, that the acknowledgement and
through the contacts A~1, plug and socket terminals
alarm relay coils A and M are energized and' that th
4 and the >audible alarm H-1 leading «to the power line
sensor switch 8 is closed.
.
- p
P1. Depression of the push button switch SVV-1, which
In order to alert a workman in the vicinity of the
is connected in parallel rwith the holding contacts A-S
point being monitored of the abnormal condition of such
of the acknowledgement relay, will re-energize the ac 25 point, an auxiliary emergency audible alarm or bell H-2
knowledgement relay A which will lock-in through its
may be provided in the vicinity of the point being moni
holding contacts A-S thereby silencing the audible alarm
tored which operates simultaneously with the above-men
H-l lupon the consequent opening of the normally-closed
tioned audible alarm H~1. Accordingly, Vthe auxiliary
contacts A-«1. The alarm light S remains lighted as long
audible alarm H~2 is located in a circuit extending from
as the alarm relay M remains de-energized. If the alarm 30 the power line P2' and through a set of normally-closed
light S was lighted' because of the open condition of
contacts A-4, plug and socket terminals 6 and the audible
the sensor switch S, upon closure of the sensor switch
alarm H-Z leading to the power line P1.
`
8 the `alarm relay M will become re-energized and the
If
the‘point
being
monitored
is
a
particularly
critical
alarm light S will become de-energized, that is become
point, making‘desirable the immediate substitution of a
dimly lighted.
35 stand-by unit for the unit which has become defective,- a
As above explained, the trouble (or test) light T iS
stand-by unit 16 in Fig. l is associated with the alarm unit
provided to signal the burning out of the relay coils M
10 so that it may be automatically inserted into the point
or A or the alarm light S. The trouble light T is in
of the system being monitored upon the existence of a
a circuit extending from the power line PZ’ and through
fault at such point. Accordingly, the stand-by unit 16
the @lament of this light, a set of normally-closed con 40
includes an electrically controlled element (not shown)
tacts A-«Z of acknowledgement relay A, plug and socket
which is in an energization circuit extending from the
terminals 5, line 16 and the sensor switch 8 leading to
power line P2’ and through a set of normally-closed con
the power line P1. Thus, trouble light T will light when
tacts M-1, plug and socket terminals 7 and the above
the acknowledgement relay A is de»energized which, as
above explained, occurs if the alarm relay M is de 45 mentioned control element of the stand-by unit 16 lead
ing to the power line P1. Thus, when the sensor switch
energized, if the acknowledgement relay coil A >burns out,`
S opens the alarm relay M is accordingly de-energized,
or Iif the alarm -light S burns out, in the presence of
the normally-closed contacts M-1 will close to energize
a closed condition of a sensor switch S. The audible
the control unit for the stand-by unit 16 which substi
alarm H-1 will simultaneously sound upon the lighting
of the trouble light T since the normally-.closed contacts 50 tutes the stand-by unit for the defective unit.
The present invention has thus provided an alarm
A-1 associated with the audible alarm will then be closed.
or _annunciator system, which in addition to the normal
If the sensor switch is in its abnormal open position and
alarm light, is provided with a trouble light which lights
the A relay burns out, then the trouble light T will be
up
when the relays burn out, and, most preferably, also
out and the alarm light will be on. If depression of the
when the alarm light burns out. Moreover, means are
switch SW-«l does not silence the horn, then the opera
provided for testing for the proper operation of Athe
tor knows that the acknowledgement relay has burned
trouble light in the form of» a manual test switch. If de
out and that the point -being monitored is abnormal.
pression of the test switch results in the lighting of the
If the 4fault which caused the trouble light T to light
trouble light, the operator knows not only that the
was the burning out of the alarm relay coil M, then the
consequent closure of the normally-closed contacts M-S 60 trouble light is operating but that the circuits associated
with the relay coils in the circuit are energized as they
in the 'branch 14 leading -to the alarm light S will cause
should be. Furthermore, it indicates that the sensor
the alarm light S also to light up. The alarm light S
switch 8 is closed. All of these advantages are obtained
will not light up simultaneously with the trouble light T
if the fault was the burning out of the A relay coil or
by means of a circuit which does not require additional
the alarm light S itself. Also, if the audible alarm 65 relays over that acquired for a circuit not having such
features, and the additional contacts and circuitry are
sounds .and both the alarm and trouble lights are out7
such that the resultant unit can be made to sell for
this indicates that .the alarm light is burned out and the
not too much more than a conventional system.
i
point being monitored is abnormal.
Although the drawings show practically all of the sets
Depression of the push button switch SW-1, upon the
of relay contacts as individual sets of contacts, it should
occurrence of any of the above-mentioned circuit faults, 70 be
understood that, in accordance with the usual prac
will re-energize the acknowledgement relay A in all cases
tice, contacts of the same relay are combined wherever
except a situation where the acknowledgement lrelay coil
possible into single-pole, double-throw units. This is the
has burned out or an open circuit has developed in the
case,'for example, whenever two sets of contacts of the
energization circuit thereof, as for example, due to the
same relay have a common terminal connection and one
burning out of the alarm light S. When the acknowledge
75 set is normally-open and the other is normally closedl
2,947,986
8
A’ The `term “sensor” used in the claims refers to a de
vice including control means usually contacts, which is
responsive to the condition of a variable being monitored
Y
trouble indicating means including means responsive to the
de-energization of said other control means when the
sensor` means is in its normal condition _for energiza
tion said visual-trouble indicating means, and an energiza
by closing or opening such contacts whenever the vari
able ireaches a value which is considered actually or U! tion circuit for said audible alarm including means re
sponsive to the de-energization of said other control means
potentially abnormal, >requiring the alerting of an oper
for energizing the audible alarm.
ator.
4. In an electrical alarm system including Íirst control
It'should be understood that numerous modifications
means which is energized during the normal operating
may -be made of the most preferred formof the inven
conditions oi the point being momîtored, sensor means
tion illustrated in the drawings without deviating from
responsive to the abnormal condition of said point by ef
the broader aspects of the invention.
fecting the de-energization of said first control means, sec
We claim as _our invention:
ond control means which is energized during the normal
1. In an alarmv unit including` at least two normally
operating condition of said point, visual alarm means re~
energized relaysrand `a visual alarm means connected in
sponsive to the de-energization of said Íìrst control means
circuit ‘withrar condition-responsive sensor switch means
for signalling the abnormal condition of said point, and
so that-operation of said sensor switch to a position in
audible alarm means to be initially energized simul
dicating anv abnormal condition of the point being
taneously with said visual alarm means, the improvement
monitored will de~energize at least one of said relays
comprising visual-trouble indicating means for signalling
and will operate the visual alarm means, the improve
ment comprising a visual trouble-indicating means, an 20 the burning ont of any of said control means and said
energization circuit `for said trouble-indicating means in
cluding said sensor switch means, contacts of at least one
of said relays, and circuit means connected to said trouble
indicating means, sensor switch means and said contacts
of said one relay for preventing energization of said
trouble-indicating means by operation of said last-men
tioned contacts when said sensor switch means is in its
position indicating the abnormality of the point being
monitored, land energizing said trouble-indicating means
when either of said relays become de-energized and said
iirst visual alarm means, said visual-alarm means being
connected in series circuit relationship with one of said
control means, the latter control means being in an oper
able energized state when so connected in series with said
visual alarm means but being normally de-energized when
said Visual alarm means has burned out, said visual
alarm means being normally in a substantially de-ener
gized state when so operated in series with said control
means, means responsive to the de-energization of the
other of said control means for eíïecting the de-energiza
an operator when either said visual trouble~indicating
tion of said one control means, an energization circuit for
said visual-trouble indicating means including means re*
sponsive to the de-energization of said one control means
means or said visual alarm means is energized.
when the sensor means is in its normal condition for en
sensor switch means is in its normal position, and au
dible alarm means for signalling an alarm condition to
2. In an alarm unit including normally energized relays 35 ergization said visual~trouble indicating means, and an
energization circuit for said audible alarm including means
which are all normally energized and a visual alarm
responsive to the deaenergization of said one control
means, one of the relays being connected in series with
a. normally closed condition~responsive sensor switch
means so that opening of said sensor switch will de-ener~
means.
5. In an electrical alarm system including an alarm
gize at least _one relay and will operate the visual alarm 40 relay which is energized during the normal operating con
ditions of the point being monitored, sensor switch means
means, the Vimprovement comprising a visual trouble-indi
responsive to the abnormal condition of said point by ef
cating means, an energization circuit for said trouble
Íecting the de-energization of said alarm relay, an ac
indicating means including said trouble-indicating means,
knowledgement relay which is energized during the nor
normally» closed contacts of .at least one of said relays
mal operating condition of said point, manually oper~
and said sensor switch means `all being in mutual series
able acknowledgement switch means for changing the
relationship, Said sensor switch means being thus ar
state of energization of said acknowledgement relay from
ranged toprevent energization of said trouble-indicating
the condition thereof when said sensor switch is in its
means by operation of said last-mentioned contacts when
abnormal-indicating position, visual alarm means respon
said sensor switch means is in its position indicating the
abnormality of the point being monitored, said last-men 50 sive to the de-energization of said alarm relay for sig
nalling the abnormal condition' of said point, and audible
tioned contacts >and relays being arranged to energize said
alarm means to be initially energized simultaneously with
trouble-indicating means when either of said relays be
said visual alarm means and to be normally de-energized
come de-energized and said sensor switch means is in
upon said operation of said acknowledgement switch
its normal position, audible alarm means, and an ener
means, the improvement comprising visual-trouble indi
gization circuit for said audible alarm including contacts
cating means for signalling the burning out of any of said
of at least one of said relays arranged Vto sound said
relays, means responsive to the de-energization of one of
audible alarm means when any of said relays become de
said relays for eiïecting the cie-energization of the other of
energized under any condition of said sensor switch
said relays, an energization circuit for said visual-trouble
means.
Y
l 3. In an electrical alarmisystem including ñrst control 60 indicating means including means responsive to the de
energization of said other relay when the sensor switch
means vwhich is energized during the normal operating
means is in its Vnormal condition >for energization said
conditions of the point being monitored, sensor means
visual-trouble indicating means, and an energization cir
responsive to the abnormal condition ,of said point by ef
cuit for said audible alarm including means responsive to
fecting the de-energization of said tirst control means,
the de-energization of said other relay for energizing the
second control means which is energized during the nor
audible alarm, said acknowledgement switch means when
mal operating condition of said point, visual -aiarm means
operated dez-energizing said audible alarm except during
responsive to _the (le-energization `ot said first kcontrol
failure of said acknowledgement relay.
i
means for signalling the abnormal condition of said point,
6. ln Ian electrical alarm system including an alarm
and audible alarm `means to 4be initially energized simul
taneously with -said visual alarm means, the improvement 70 relay which is energized during the normal operating
conditions of the point being monitored, sensor switch
comprising visualtrouble indicating means for signalling
means responsive to the abnormal condition of said point
the burning out Yof _any of said control means, means Vre
by eifecting »the deenergization of said alarm relay, an
sponsive _to the Vde-energization vof one of said control
acknowledgement >relay which is >energized `during the'nor
means for effecting ,the >de-energization „of the other of
>said control means, an energization circuit for said visual 75 mal operating condition of said point,`manually operable
9
2,947,980
lt)
acknowledgement switch means for changing the state
9. In an alarm unit including at least two relays and a
of energization of said acknowledgement relay from
visual alarm means connected in circuit with a condition
responsive sensor switch means so that operation of said
the condition thereof when said sensor switch is in its
abnormal-indicating position, visual alarm means re
sensor switch to a position indicating an abnormal condi
sponsive to the de-energization of said alarm relay for
signalling the abnormal condition of said point, and audi
ble alarm means to be initially energized simultaneously
tion of the point being monitored will operate at least
one of said relays and will energize the Visual alarm
means, the improvement comprising visual test means, an
energization circuit for said visual test means including
said sensor switch means, a manually-operable test switch
with said visual alarm means and to be normally de-en
ergized upon said operation of said acknowledgement
switch means, the improvement comprising visual-trou 10 and contacts of at least one of said relays, energization
ble indicating means for signalling the burning out of
circuit including circuit connection for preventing ener
lany of said relays and said 'visual alarm means, said
visual alarm means being connected in series circuit
gization of said test means by operation olf said test switch
and said last-mentioned contacts when said sensor is in its
-relationship with one of said relays, the latter relay being
position indicating the abnormality of the point being
15 monitored, said test switch and said last-mentioned con
ries with said visual alarm means but being normally
tacts being arranged to operate said test means to indi
in an operable energized state when so connected in se
de-energized when said visual alarm means has burned
cate positively the proper normal operation `of said relays
out, the visual alarm means being normally in a sub
aswell as proper operation of said test means and the
stantially de-energized state when operated in series
sensor switch means when the sensor switch means is in
with said relay, means responsive to the de-energization 20 its normal position, and a second energization circuit for
of the other of said relays for effecting the de-energiza
said test light including said sensor switch means and
contacts of at least one of said relays, said contacts being
tion of said one relay, an energization circuit for said
arranged to operate said test means to indicate the abnor
visual-trouble indicating means including means respon
mal condition of either of said relays when said sensor
sive to the de-encrgization of said one relay when the
sensor switch means is in its normal condition for ener- . 25 switch means is in its normal position.
l0. An annunciator system comprising: a source of
gizing said visual trouble-indicating means, and an en
energizing potential, an alarm relay having sets of both
ergization circuit for said audible alarm including means
normally-open and normally-closed contacts, an acknowl
responsive to the de-energization of said one relay for
energizing the audible alarm, said acknowledgement
edgement relay having sets of both normally-open and
switch means when operated de-energizing said audible
alarm except during failure of said alarm light or ac
normally-closed contacts, a normally-closed sensor switch
which opens when the variable to be monitored becomes
knowledgement relay.
abnormal,- a normally-open acknowledgement switch, a
normally-open test switch, an alarm light, a trouble-indi
7. In an alarm unit including -at least -two relays and
cating light, means connecting said alarm relay and said
a visual alarm means connected in circuit with a condi
tion-responsive sensor switch means so that operation 35 sensor switch in series across said‘source of energizing
potential, the alarm relay thereby being normally ener
of said sensor switch to a position indicating an abnormal
gized,4 an energization circuit for said acknowledgement
condition of the point being monitored will operate at
least one of said relays and will energize the visual
relay between said acknowledgement relay and said
source of energizing potential and including a parallel cir
alarm means, the improvement comprising visual test
40 cuit arrangement of said acknowledgement switch, a set
means, an energization circuit for visual test means in
of normally-open contacts of said alarm relay and a -set
cluding said sensor switch means, a manually-operable
test switch and contacts of at least one of said relays,
of normally-open contacts of said acknowledgement relay
in series circuit relation with said acknowledgement relay,
a-nd circuit connecting for preventing energization of said
whereby» closure of any of said-parallel connected ele
visual test means by operation of said test switch and
said last-mentioned contacts when said sensor switch 45 ments will energize said acknowledgement relay, said er1
ergization circuit further including ñrst and second alter
nate branch circuits in series with said acknowledgement
relay and said parallel circuit, one of said branch circuits
test means to indicate positively the proper normal op 50 including normally-open contacts of said alarm relay in
series with said alarm light which, when the variable
eration of said relays as well as proper operation of said ,
means is in its position indicating the abnormality of
the point being monitored, and said test switch and said
last-mentioned contacts being arranged to operate said
test means and the sensor switch means when the sensor
switch means is in its normal position.
8. In an alarm unit including at least two normally
energized relays and a visual alarm means connected in 55
circuit with a normally closed condition-responsive sensor
being monitored is abnormal, eifect Athe energization of
the- acknowledgement relay and the dim lighting of said
alarm light, and, when said Variable is abnormal or said
alarm light burns out, effect the de-energization of said
acknowledgement relay, the other branch circuit including
normally-closed contacts of said alarm relay effecting
switch means so that opening of said sensor switch to a
energization of the acknowledgement relay when an ab
position indicating an abnormal condition of the point
normal condition of the variable has been acknowledged
being monitored will de-energize at least one of said
relays and will energize the visual alarm means, the im 60 by momentary closure of said normally-open acknowl
edgement switch, an energization circuit for said alarm
provement comprising visual test means, an energization
circuit for said Visual test means including said sensor
switch means, a normally-open manually-operable test
switch and normally-open ‘contacts of at least- one of
said relays all in series with one another, energization 65
circuit including connection for preventing energization
of said test means by operation of said test switch and
position indicating the abnormality of the point being »
monitored, andA said test switch and said last-mentioned
as proper operation of said test means and the sensor
switch means when the sensor switch means is in its
normal position.
said alarm relay which connects »the alarm light to said
source of energizing potential to light the same brightly
when the alarm relay becomes de-energized as the vari
able being monitored becomes abnormal, an energization
circuit for said trouble-indicating lightincluding said sen
sor switch, a set ofßnormally-closed contacts of `said ac
said last-mentioned contacts when said sensor is in its
contact being arranged to operate said‘test meansto in
dicatefpbsitively the energization of` said relays as 'well
light including normally-closed contacts controlled by
70
knowledgement relay and circuit connections connecting
said sensor switch, trouble-indicating light and saidlatter
contacts to said source of energizing potential for lighting
brightly t» said trouble-indicating` light when -the sensor
switch is closed indicating a normal variable, and said
acknowledgement relay is de-energized, and a test circuit
connected in parallel with said normally-closed contacts
75 of said acknowledgement relay comprising said normally
2,947,986
12
energization circuit further including ñrst and second
open test switch and a'set of normally-open contacts of
said _acknowledgement relay, whereby the trouble-indicat
alternate branch circuits in series with said acknowledge
ment relay and said parallel circuit, one of said branch
circuits including normally-,open contacts of said alarm
gized.
5 relay in series withsaid alarm light which, when the
l1. An annunciator >system comprising: a source of
variable being monitored is abnormal, effect the ener
gization of the acknowledgement relay and the dim
energizing potential, an alarm relay having sets of both
lighting of said alarm light, and, when said variable is
normally-open and normally-closed contacts, an acknowl
edgement relay having sets of both normally-open and
abnormal or said alarm light burns out, effect the de
energization of said acknowledgement relay, the other
normally-closed contacts, a normally-closed sensor switch
branch circuit including normally-closed contacts of said
which opensV when the variable to be monitored becomes
alarm relay effecting energization of the acknowledge
abnormal, a normally-open acknowledgement switch, an
alarm light, a Vtrouble-indicating light, means connecting
ment relay when an abnormal condition of the variable
inglight will also become energized upon closure of said
test switch provided said acknowledgement relay is ener
has been acknowledged by momentary closure of said Y
said alarm relay and said sensor switch in series across
said source of energizing potential, the alarm relay there 15 normally-open acknowledgement switch, `and an ener
by being normally energized, an energization circuit for
gization circuit for said alarm light including normally'
said acknowledgement relay between said acknowledge
closed contacts controlled said alarm relay which connect
the alarm light to said source of energizing potential to
ment relay and said source of energizing potential and in
light the same brightly when the alarm relay becomes
cluding a parallel circuit arrangement of said acknowl
edgement switch, a set of normally-open contacts of said 20 cle-energized as the variable being monitored becomes
alarm relay and a set of normally-open contacts of said
abnormal.
13. An annunciator system comprising: a source of
acknowledgement relay in series circuit relation with said
energizing potential, an alarm relay, an acknowledgement
acknowledgement relay, whereby closure of any of said
relay, a normally-closed sensor switch which opens when
parallel connected elements will energize said acknowl
edgement relay, said energization circuit further including 25 the variable to be monitored becomes abnormal, an
acknowledgement switch, a normally-open test switch,
ñrst and second alternate branch circuits in series with
said acknowledgementrelay and said parallel circuit, one
of said branch circuits including normally-open contacts
of said alarm relay in series with said alarm light which,
an alarm light, a test light, means connecting said alarm
relay and said sensor switch in series across said source
of energizing potential, the alarm relay thereby being
when the variable being monitored is abnormal, effect 30 normally energized, an energization circuit for said ac
knowledgement relay between said acknowledgement
the energization of the acknowledgement relay and the
relay and said source of energizing potential and including
dim lighting of said alarm light, and, when said variable
a parallel circuit arrangement of said acknowledgement
is abnormal or said alarm light burns out, effect the de
energization of said acknowledgement relay, the other
switch, a set of normally-open contacts of said alarm
branch circuit including normally-closed contacts of said 35 relay and a set of normally-open contacts of said ac
alarm relay effecting energization ofthe acknowledgement
knowledgement relay in series circuit relation with said
acknowledgement relay, whereby closure of any of said
relay when an abnormal condition of the variable has
been acknowledged by momentary closure of said nor
parallel connected elements will energize said acknowl
edgement relay, said energization circuit further including
mally-open acknowledgement switch, an energization cir
cuit for said alarm light including normally-closed con
lirst and second alternate branch circuits in series with
tacts controlled by said alarm relay which connect the
said acknowledgement relay and said parallel circuit,
alarm light to said source of energizing potential to light
one of said branch circuits including normally-open con
the same brightly when the alarm relay becomes de-ener
tacts of said alarm relay which, when the variable being
gized as the variable being monitored becomes abnormal,
monitored is abnormal, eñects the energization of the
and an energization circuit for said trouble-indicating
acknowledgement relay, and, when said variable is ab
light includingsaid sensor switch, a set of normally-closed
normal or said alarm light burns out, effects the de
contacts of said acknowledgement relay and circuit con
energization of said acknowledgment relay, the other
nections connecting said sensor switch, trouble-indicating
branch circuit including normally-closed contacts of said
light and said latter contacts to .said source of energizing
alarm relay effecting energization of the acknowledge
potential for lighting brightly said trouble-indicating light
50 ment relay when an abnormal condition of the variable
when the sensor switch is closed indicating a normal vari
has been acknowledged lby momentary closure of said
able and said acknowledgement relay is de-energized.
normally-open acknowledgement switch, an energization
12. An Vannunciator system comprising: a source of
circuit for said alarm light including contacts controlled
energizing potential, an alarm relay having sets of both
said alarm relay which connect the alarm light to said
normally-open and normally-.closed contacts, an acknowl 55 source of energizing potential to light' the same brightly
edgement relay having sets of both normally-open and
when the alarm relay becomes de-energized as the vari
normally-closed contacts, a normally-.closed sensor switch
able being monitored becomes abnormal, andan vener
which `opens when the variable, to be monitored becomes
gization circuit for said test light comprising a series
abnormal, a normally-open acknowledgement switch, an
circuit of said sensor switch, normally-open test switch,
alarm light, means connecting said alarm relay and said 60 a set ’of normally-open contacts ofv said acknowledge
sensor switch in `series across said 4source of energizing
ment relay, and 'said source of energizing potential,
potential, the alarmrelay thereby being normally ener
gized, an energization circuit for said acknowledgement
relay between said acknowledgement relay and said
whereby the test light will become energized upon closure
of said test switch provided'said acknowledgement relay
is energized.
source of energizing potential and including a parallel 65
circuit arrangement of said acknowledgement switch, a
set of normally-open contacts .of said alarm relay and
a set of normally-open contacts of said acknowledgement
relay in seriescircuit relation with said acknowledgement
relay, wherebyfclosureof any of said parallel connected
elements will energize said acknowledgement relay, said
70
‘
'
References Cited in the file of this> patent ' ‘
'
UNITED >STATES PATENTS.,
1,580,313
Mclntire ________ .__-____ Apr. 13, v1936
2,709,250
2,730,702
Marmorstone ________ __ May 24, 1955
Marmorstone ________ __ Jan; 10, 1956
u