July 21, 1953
E. D. SMITH
2,646,557"
ALARM AND ANNUNCIATOR DEVICE
'
Filed Aug. 1'7, 1950
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INVENTOR.
Eric D. Smith
BY 2
At’rys.
July 21, 19543
E. D. SMITH
£646,557
ALARMaAND ANNUNCIATOR ‘DEVICE
Filed Aug. 17, 1950 ~
2 Sheets-Sheet 2
FIG 5
NOB/MAL
FIG 6
ALARM
FIG. 7
TROUBLE
INVENTOR.
Eric D. Smith
Patented July 21‘, 1191553;
UNITED
2,646,557
STATES
.
PATENT ' OFFICE
2,646,557
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ALARM AND’ ANNUNCIATOR DEVICE
Eric D. Smith, Chicago,’ Ill.
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Application August r1, 1950, Serial No. 180,049
12 Claims. (Cl. 340—213)
2
1
relays or housing, and can therefore be mounted
singly or in any desired number or arrangement;
It is a further object of the present invention
to provide an annuciator wherein the pointer or
reset key is so constructed that it can be plugged
into or pulled out of the rest of the structure as
machine, or part of a machine.
'
a
maybe necessary in the event of lamp failure
In accordance with the principles of the present
or if a change of color is desired.
invention a number of alarms or annunciator de
It is a still further object of the present inven
vices are connected each to one machine, or one
part of a machine, the annunciators being all 10 tion to provide an alarm device so constructed
mounted adjacent to one another on a switch
that it gives one audible signal when it is en
ergized to its alarm position and 'a different
board or the like. When an abnormal condition
audible signal when it is energized to move from
occurs on any of the machines or places that are
a “trouble” position to a “clear” position.
to be protected a light operates on the particular
This invention relates to annunciators or alarm
devices, particularly such as are adapted for use
in engine rooms, power plants, industrial plants,
and the like, for giving a signal of the existence
of an abnormal condition at a speci?c place or 01
4 annunciator, and an audible alarm is-given. 'The 15
‘In accordance with the principles of the present
invention the visual signal or light is “off” when
the annunciator is in its “normal” position, and
nunciator involved indicates the type of fault or
the light is on when the annunciator is in any
of its off-normal positions. If a fault is one
other condition involved, and the location thereof .»
The present invention is particularly adapted 20 which may remain for some time the operator
for use where certainty of operation is of utmost
then moves the pointer, which includes the lamp,
importance and where signals must indicate not
to‘ the “trouble” position.v ‘In this position the
only momentary alarms which can be reset at
audible signal is discontinued but the visual signal
once, but also must indicate abnormal conditions
is continued, thus indicating the existence of a
which may remain for some time, and once such 25 “trouble” condition which‘must be cleared. If
abnormal conditions have occurred the annun
that trouble condition is then cleared, after the,
ciator must indicate the continuance of the ab
visual signal of the annunciator has been moved
from the “alarm” position to the “trouble” posi
normal condition, and when the abnormal condition has been cleared‘ the annunciator must
tion, the clearance of the trouble then causes the
alarm calls the attendant’s attention to the an
nunciators, and a light on the particular an
affirmatively indicate that'fact.
alarm indicator to move to a fourthv position,
where it remains lighted indicating a “clear”
condition, and a different audible signal is given
to call attention to the fact that the trouble which
previously existed has been cleared. The an
It is a further object of the present invention
to provide an annunciator which includes a lamp
which is mounted on or part of a movable pointer.
The separate positions of the pointer indicate the
respective conditions of the circuit associated with
nunciator can'then be moved from the “clear”
position back to the “normal” position.
that annunciator and the lighted lamp on the
pointer serves to attract the operator’s attention
The attainment of the above and further ob
to the particular annunciator wherein the pointer
jectsof the, present invention will be apparent
from the following speci?cation taken in'conjunc
is moved to the off-normal position. In order to
accomplish the above results each particular an 40 tion with‘ the accompanying drawing forming a
nunciator of the present invention has a number A
v
part thereof.
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In the drawing:
7
of separate positions which, for the purpose of
Figure 1 is a diagrammatic view of the annun
description, will be called the “normal,” “alarm,”
“trouble,” and “clear” positions.
. ciator, showing the circuit connections when'the
It is a further object of the present invention 45 parts are in ‘their “normal” positions.
Figures 2, 3 and v4 are diagrammatic views‘cor
to provide an annunciator wherein the pointer
responding to Figure 1 and showing the annun
constitutes a manually reset key which also oper
ciator in the “alarm,” “trouble.” and “clear” posi
ates a spring loading device that controls the
tions, respectively;
.
automatic operation of the annunciator so that
Figures 5, 6, 7 and 8 are diagrammatic views
the automatic ‘operation can be controlled by a 50
solenoid operated trip latch which requires very
of -;the ‘latching and spring arrangements when
little power.
the parts are in their “normal,” “alarm,”
“trouble” and “clear” positions, respectively;
Since the pointer is also the reset key each
Figure 9 is'a longitudinal View of the commu-v
and requiresno additional bell reset, drop reset, 55, tator shaft and key, in partial section;
alarm device or annunciator is a complete unit
3
2,646,557‘
Figures 10, 11 and 12 are sections taken on
Figure 9 along the lines 10-10, H-ll, and
12-12, respectively, and looking in the direction
of the arrows;
Figure 13 is a front view of the pointer; and
Figure 14 is a fragmentary view showing an
alternate location of the control relay.
Reference may now be had more particularly
to the drawings wherein like reference numerals
4
a stationary brush or contact 22 in certain posi
tions of the commutator shaft. The commutator
ring 20 includes a ?at portion 23 that is always
in engagement with the ring l8 and arcuate por
tions 24 and 25 that are adapted to engage
brushes or contacts 25, 21 and 28 in various posi
tions of the shaft l I. The contacts 22 and 26 are
connected to line conductors I’ and l, respec
dicated by the reference character “A,” is
tively, whereas the contacts 2'! and 28 are con
nected to two different audible alarms 29 and 30
which in turn are connected to the line I’. The
audible alarms 29 and 30 are designed so that
adapted to be electrically connected to a power
they give distinctly different sounds.
designate like parts throughout.
The annunciator of the present invention, in
For in
source, indicated by power leads I—-l', which
stance, one may be a bell and the other may be
may be any alternating or direct commercial 15 a buzzer. When conditions are “normal" and the
current source. Figure 1 shows, schematically,
parts are in the positions illustrated in Figure l
the electric diagram and the relative positions of
the circuits for the lamp l3 and for the alarms
the parts when a remote control alarm contact
29 and 3d are open.
2 is open and the device is latched in its “nor
A description will now be given of the opera
mal” position. The remote alarm contact 2 is 20 tion of the device upon the occurrence of an ab
an electric contact located at the place where
normal condition which results in the closure of
trouble is to be detected and is arranged to be
the switch contacts 2. This causes energization
actuated whenever trouble occurs. In the pres
of the winding 4: and consequent attraction of
ent instance it is shown as a normally open con
the armature 6. The armature 6 pivots about
tact arranged to be closed when trouble occurs.
the pivot 1 and withdraws the latch 8- from the
It can equally well be a normally closed contact
path of the latch pin l0. This allows the rotat
arranged to be opened when trouble occurs, in
which event an abnormal condition would be
able commutator shaft H to turn, under the
action of its spring to be hereafter described, to
manifested by the opening of a normally closed
the position illustrated in Figure 2. In this po
circuit, as will be apparent as this description 30 sition a circuit is established for the lamp l3 by
proceeds. The remote alarm contact 2 controls
the engagement of the commutator IS with the
the circuit to the winding of an electromagnetic
contact 22 and engagement of the commutator
coil 4 of the relay type, which in turn controls
28 with the contact 26. At the same time the’
an armature 6. When the coil 4 is not energized
commutator portion 25 engages the contact 28
the armature 6 is held in the position shown in
Figure 1, which is the position away from the
coil. It is held in that position by a spring or
and thus completes a circuit for the audible‘
alarm 30. At this time the contact 27 is free of
the commutator ring 2.4 so that no circuit is es-»
by gravity as is usual in the relay art. The
tablished to the audible alarm 29. The audible
armature-6 is here shown as pivoted at 1 and car
alarm. 30 calls the operatorsv attention to the
rying at one end thereof an armature latch 8 40 annunciator and when there are many side by
which, in the position shown in Figure 1, en
side annunciator devices onthe switchboard the
gages a commutator shaft latch pin ID that is
lighted condition of the particular lamp l3 in
rigid with and extends outwardly from a rotat
forms the operator which annunciator has oper
able commutator shaft II. The shaft is ar
ated, and the position of the pointer key 12 also
ranged to be turned in one direction manually by
indicates which circuit is in trouble.
a pointer or key I2, shown more particularly in
If the alarm is av momentary type alarm the
Figure 9, against the action of one or more
contact 2 opens at once-and deenergizes the coil
springs which serve to restore the shaft under
control of the armature 6 acting through its
tion of Figure l.
the “normal” position, the shaft is spring biased
position and leave it there because: as soon. as
4 allowing the armature-5 to return to the posi
The operator can then manu
latch- 8 and another latch to be later described.
ally turn the key l2 back to “normal,” thus load
50
It is su?icient here to state that the pointer or
ing the return spring; and latch in the “normal"
key I2 is located at the front of the annunciator
position as shown in Figure i. If the alarm is
and carries a visible signal in the form of an,
a maintainedtype alarm the contact 2. remains
electric lamp I3 which may be of the glow dis
closed and the coil 4 remains. energized. so that
charge type or any other type as desired. It is
the armature 6 remains pulled towards the. coil
sufficient here to state that when the parts are 55 4, as shown in Figures 2 and 3. The-operator
in the position illustrated in Figure 1, which is
cannot then turn the key hack to the. “normal”
to urge it to turn to the “alarm” position of Fig
ure 2, but is held by the armature latch 8 against
the operator releases the key iZ‘there is immedi
ate restoration of the’ shaft H to the. alarmpo
turning to that position. The key I2 is releasably 60 sition of Figure 2‘. The operator can, however,
secured to the shaft H to turn therewith and
turn the key !2 from the “alarm” position on
is adapted to turn he shaft H under control of
ward to the “trouble?” position indicated in;Figthearmature 6. The key l2v includes a. tip con
ure 3, where the latch pin l6 engages an arma
tact l4 and a ring contact. [8 that are adapted
65 ture latch, 31 at that’ end ofLthe armature 6-0p
to engage commutator rings I 6‘ and 20,.respec
posite where the latch 31 is located. This latches
tively, on the commutator shaft II. The tip [4
the shaft in the “trouble‘f’ position. At this time
is- connected to one side of the lamp by a conduc
the contacts 27' and 28 are free and clear of the
tor l5 while the other side of the lamp I3 is per
commutator ring, 29. so that thecircuits'for both
manently connected through a resistor ll to the 70 audible alarms; 29 and. so. are open.- The lamp
ring 18. The commutator ring [6 which is
I3 is now in its, “trouble.” position and remains
mounted on the commutator shaft ll includes
lighted by reason of the fact that the contact
a flat portion l9 that is in contact with the tip
26 is in engagement with the portion 24 of the
H. in all rotatable positions. of the shaft H, and
commutator ring 28 which completesan operat—
a circular portion 2| that is adapted to. engage. 76 ingcircuitior the lamp. [3. The rotatable com
2,646,557
6
mutator shaft | i "-is held in the ‘.‘trouble” position
by the latch ‘3| so long. as" the armature 6 re-.
mains attracted to the‘ core of the relay .by the
energization of the winding 4. The operator can
now tell both by'the position of. the key |2 and
the lighted lamp that a “maintained” trouble ex
ists on a particular circuit. - 1
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tion counter-clockwise, as seen in Figure 6, from‘
the position of Figure 6 towards the position of
Figure. '7. In the movement of the shaft II from
the position of Figure 6 towards the position of
Figure '7 the projecting, pin 36 ?rst engages the
spring end 35 and tensions the spring. At this
time the end 330i the spring remains in contact
When the trouble has cleared on the particular
circuit involved the contact 2 opens, thus deener
gizing the winding 2 and permitting the armature <
with‘ the stop pin 32. Loading of ‘the spring con
tinues until the positioning cam 44 engages the
3- to'restcre to its normal position. This-moves
shaft causes thepositioning cam 44 to move the
stop pin 32. Therefore continued turning of the
the latch 35 free of the latch pin [9 on the arma
stop pin v32inthe slot 39, thus causing the two
ture shaft | l and the shaft ’ therefore rotates
ends 33-35 of the. spring both to move together,
under its spring loading'from the positioniillus-x
the end 33 of the spring following the stop pin 32.
trated in Figure. 3 to the position illustrated in 15 This condition continues until the “trouble” post
Figure ll. In this positionthe circuit for the lamp.
,tion of Figure 7 is reached at which time the stop
I3 ‘remains closed ‘because of engagement of the
pin lilrides over the latch 3|. If the “trouble”
contact 26 with the portion 24 of the commutator
is a maintained trouble the latch 3| is in'its latch
ring 2!). At this time also the portion 25 of the
ing position so that when the shaft reaches the
commutator ring'iil engages the contact 2‘! and 20 position. of Figure '7 and the operator releases the
establishes a circuit for the audible alarm 29. i
key |2,'the pin it; is latched ‘by thelatch 3|. At
This alarm, being different in sound from that
this time the spring end 35 is in engagement with
of the alarm 3i}; informs the operator that the
the projection 36 on the pin IB and urges the
previously existing trouble has been cleared. The
shaft i l in a direction clockwise as seen in Figure
lighted condition of the signal lamp and the'posi-i 26 7,. towards the position of Figure 8, being kept
from moving to that. position by the latch 3|.
tion of the key- l2 indicate the particular location
where the trouble has been cleared. The opera
When the trouble clears and the coil 2 is deener
torv can then turn the key l2 from the “clear”
gized the latch 38 swings‘out of position and thus
position of Figure 4 to the “normal” positionof
permits the spring end 35 to rotate the shaft i|
Figure l to restore normal conditions of the
until the spring end comes in contact with the
annunciator “A.” When the operator has turned
stop pin 32. This is the “clear” position illus
the key i2‘ and therefore the shaft I | tothe “nor
trated in Figures- 4 and 8. The operator can then
mal” position, while thearmature 6 and its latch
turn the shaft l | in a direction clockwise as seen
are in their deenergized position asillustrated in
in Figure '8, back to ‘the “normal” position by
Figures 1 or ii, the latch pin it] rides over the 35 turning of the key l2. When the shaft is turned
curved back of the latch 8 and then engages the
clockwise from the position of Figure 8 to the
latch which thereupon acts‘on the pin to ‘hold
position of Figure 5 the stop pin 32 ?rst holds the
the shaft ii against return rotation by its load
spring end 35 While the projection 36 moves ‘with
ing spring.
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the spring end 33 to load the spring.‘ This con~
Reference may now be had more particularly 40 tinues until‘ the positioning cam 4-3 engages the
to Figures o'through Qwhich show the mechani
cal‘ arrangement for‘ biasing and actuating the
commutator shaft H, The commutator shaft
laitch'pin it is- rigidly secured‘to the shaft and
stop pin 32. Thereafter continued turning of the
shaft causes the stop pin 32- to move With the
has a projection 35- against which an end of a
projection 36, maintaining the loaded condition
of the spring, until the stop pin it rides under
and is engaged by the latch 53, at which time the
coiledspring It? bears. In the “normal” position
shaft | I is in its “normal” position and a release
one end of the springbears against the projec
tion :35 and the other end bears against-a stop
pin 32 that is carried by a'lstationary plate '38,
of the key i2 leaves the shaft ii latched in the
“normal” position.
' Reference may now he had more particularly
said pin projecting‘at right angles to the plate
to Figures 9, 10, ll and 12 which show the con~
and extending through an arcuate slot 39 in the
struction of the key i2 and the rotatable com
plate, in which slot it ‘is slidable, being held ‘in
mutator shaft. The key ?ts into the hollow end
its adjusted position by a spring Washer 40 that
of the shaft ! I and is held thereby friction and
is pressed against the bearing plate 38 lby a pair
may be inserted or withdrawn at will. The com
of lock nuts iii-4| on the pin 32. Two p-in posi
mutator shaft | | comprises a cylindrical insulat
tioning cams 43-434 are mounted on the shaft 55 ing stud 50 which extends through a circular hole
in a plate 5| on which the cams lit-44 are
H to rotate therewith. These cams engage the
stop pin‘ 32 and move it from one position to the
formed. The plate 5| is secured to a plastic tubu
other in the slot 35), depending upon the position
lar sleeve 52 in any desired manner as, for
and movement of the shaft H, ‘by the manual
instance, by a set screw 54. The cylindrical stud
60
turning of the key i2.
.
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. 5i] ?ts into the s1eeve'52 and is secured thereto
When the annunciator is in the normal position
as by a set screw 56.’ The stud 53, plate ‘5|, and
the spring urges the shaft H in a direction
sleeve 52 thus constitute one unit which is the
counter-clockwise as seen in Figure 5, which
commutator shaft i i. The end of the stud within
motion of the shaft is prevented by the latch 8.
the sleeve has a longitudinal key slot 57 therein
When the latch B is retracted by energizaticn of 65 for receiving a flat shank which constitutes the
the coil ii and consequent movement of the arma
ture 6 (Fig. l) the shaft || moves to the “alarm”
tip of the key i2, as will ‘be hereinafter explained.
The commutator rings 56 and 29 are mounted on
the plastic tubular sleeve 52 and to that effect the
ment the positioning cam 43 moves away from 70 ‘sleeve is slotted, as indicated at 58 and 59.
The key l2 comprises a molded body of in
the stop'pin 32 and the spring arm 33' moves-up
position‘ illustrated in Figure 6.‘ In this move
to engagement'with the stop pin 32. This limits
the extent of rotation of the shaft ill to the
sulationi'in which is embedded the lamp H, the
resistor H, the tip, terminal l4 and the ring i8.
‘falarm”position illustrated .in Figure‘ 6. '
Thertip ‘terminal l4 comprises‘ a copper rod 60
The operator can then turn the key in a" direc? 75 one end of which'is ?attened. as indicated at'62,
a?
8.
saidimember. so that the position of the key in“
dicates the position ofthe. rotatable member, an
electric signal light carried by said key, and
to constitute a key that ?ts into the slot 51 of
the stud 50. A body of plastic 65 is molded
around the rod, the lamp [3, the resistor I1 and
also holds the ring (8. One terminal of the
lamp is connected directly to the rod 60 and the
opposite terminal of the lamp connects through
the resistors H, from which a copper conductor
extends from the other terminal of the resistor
to the ring I 8, that conductor also being em
bedded in the plastic 65. The plastic 65 is pref
erably clear transparent plastic, although it. is
within the purview of this invention to use a
colored transparent plastic. The key assembly
may be inserted into and removed from the an
nunciator by a simple plug in or pull out action.
contact means controlled by the turning, of said
member for controlling said signal light.
3.. In- an electric‘ alarm device a rotatable
member having two stop positions and manually
movable. from one stop position to the. other,
spring means and meansfor loading the spring
means upon rotation of the member in one direc
tionfrom one stop position and in the other di
rection from the other stop position, means for
latching the member in positions reached upon
rotation in one direction from one stop posi
15 tion and in theopposite‘ direction fromthe op
When that is done the tip portion 62 engages the
?at part IQ of the commutator l6 and flexes it
outwardly a very slight amount. The ?at key
part 62 has a pair of slight notches therein so
that the ?at portion I9 of the commutator spring. ~
18 engages one of those notches and resiliently
posite'stop position,,and electromagnetic meansv
for releasing, the latch means whereby thero-v
tatable spring loaded member returnsto thecor
responding, stop position.
4. In an electric alarm device‘ a rotatable
member having two stop positions and manually
movable from one stop position to the other,
At the same
springmeans and means for loading the spring
time the ?attened end 62 enters the key slot 51
means upon rotation of the member in one di
in the stud 50 so that by turning of the key the
operator can turn the shaft l l which includes 25 rection from one stop position and in the'other
direction from the other stop position, means for
the stud 50 and the plate 5i and the tubular
latching the member in positions reached upon
sleeve 52.
rotation in one direction‘ from one stop position
In some annunciators it is desirable to have
and in the opposite direction from the opposite
the annunciator indicate normal conditions upon
stop position, electromagnetic means for re
the existence of a closed circuit and indicate ab
leasing the latch means whereby the rotatable
normal conditions when that circuit is open.
spring loaded member returnsto thecorrespond
This result can be obtained with the annuncia
ing stop position, and plug-in key means for r0
tor of the present invention by shifting the posi
tating therotatable-member from one stop posi
tion of the relay 4, as indicated in Figure 14-.
When this is done the relay is connected in cir 35 tion to the: other and from either stop position
to either spring loaded latched position, said key
cuit with normal closed switch contacts 2’ that
means being insertable into said rotatable mem
are located on the machine or part of the ma
ber and being rotatable thereby so that the posichine to be protected. The armature 6 of the re
lay is therefore normally attracted by the mag
tion of the key means indicates the position of
netic action of the winding 4 in a closed circuit. 40 the rotatable member.
When the winding 4 is open circuited, as by
5. In an electric alarm device a rotatable mem-v
her-having two stop positions and manually mov
opening of the switch 2’, the armature 6 is moved
to its alternative position, namely, the position
able from one stop position to the other, spring
of Figure 2, by a spring or the like.
means and means for loading the spring: means
In compliance with the requirements of the’
upon rotation. of the member in one direction
patent statutes I have here shown and described
from one stop position and in the other direc
a preferred embodiment of my invention. It is,
tion from the other stop position, means for
latching the member inpositions reached upon
however, to be understood that the invention is
not limited to the precise construction here
rotation in onev direction from one stop position
shown, the same being merely illustrative of the
and in the opposite direction from the opposite
principles of the invention. What I consider 50 stop position, electromagnetic means for releas
holds the plug in the sleeve 52.
ing the latch means‘whereby the rotatable spring
loaded member returns to the corresponding stop
loaded rotatable member, latch means for latch
position, plug-in key means for rotating the
ing said member in either of two positions, elec~
55 rotatable member from one stop position to the
tromagnetic latch means, means effective upon
other and from either stop position to either
actuation of the latch means for stopping res—
spring loaded latched position, said key means
toration of the member under its spring load
being insertable into said rotatable member and
ing in either of two different positions depend
being, rotatable thereby so that the position of
ing upon the position in which the member had
60 the key means indicates the position of the rotat
last been latched, and a removable key ?tting
able member, and signal circuits controlled from
said rotatable member for turning it and being
'di?erent positions of the member.
also turned by said member so that the position
6. In an electric alarm device a rotatable mem
of the key indicates the position of the rotatable
her having two stop. positions and manually mov
member.
65 able from onestop position to the other, spring
new and desire to secure by Letters Patent is:
1. An electric alarm device comprising a spring
2. An electric alarm device comprising a spring
loaded rotatable member, latch means for latch
ing said member in either of two positions, elec
means and. means for loading, the spring means‘
upon rotation of the member in one direction
from one stop position and in the'other direction
tromagnetic latch means, means effective upon
from the other stop position, means for latch
actuation of the latch means for stopping restora 70 ing the member in positions reached upon rota
tion in one direction from one stop position and
tion of the member under its spring loading in
either of two di?erent positions depending upon
the position in which the member had last been
latched, a removable key ?tting said rotatable
member for turning it and being also turned by
in the opposite direction from the opposite stop
‘position, electromagnetic means for releasing the
latch means whereby the rotatable spring loaded
member. returns to the corresponding stop posi
2,646,557
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either stop position, electromagnetic means for
releasing the latch means whereby the rotatable
spring loaded member returns to the corre
sponding stop position, and plug-in key means
for rotating the rotatable member from one stop
tion, and signal circuits controlled from differ
ent positions of the member.
'7. In combination with a number of similar
electric alarm devices each including a rotatable
member having a stop position, spring means and
position to the other and from either stop posi
means for loading the spring means upon rota
tion to either spring loaded latched position, said
tion of the member from the stop position, means
key means being insertable into said rotatable
for latching the member in its spring loaded posi
member and being rotatable thereby so that the
tion, electromagnetic means for releasing the
latch means whereby the rotatable spring loaded 10 position of the key means indicates the position
member returns to the stop position, plug-in key
of the rotatable member.
11. In an electric alarm device a rotatable
means for rotating the rotatable member from
member having two stop positions and manually
movable from. one stop position to the other,
position, said key means being insertable into said
rotatable member and being rotatable thereby 15 spring means and means for loading the spring
means upon rotation of the member from either
so that the position of the key means indicates
stop position, means for latching the member in
the position of the rotatable member; and signal
different positions reached upon rotation from
circuits common to all of said devices and con
either stop position, electromagnetic means for
trolled by rotation of the member of any of said
devices, whereby the operation of a signal circuit 20 releasing the latch means whereby the rotatable
spring loaded member returns to the correspond
indicates the operation of an alarm device and
the stop position to the spring loaded latched
the position of the rotatable member on one of
ing stop position, and signal circuits controlled
the devices indicates which device has operated.
from different positions of the member.
12. In an electric alarm device a rotatable
8. In an electric alarm device a rotatable mem
ber having a stop position, spring means and 25 member having two stop positions and manually
movable from one stop position to the other,
means for loading the spring means upon rota
spring means and means for loading the spring
tion of the member from the stop position, means
means upon rotation of the member from either
for latching the member in its spring loaded posi
stop position, means for latching the member in
tion, electromagnetic means for releasing the
latch means whereby the rotatable spring loaded 30 di?erent positions reached upon rotation from
either stop position, electromagnetic means for
member returns to the stop position, plug-in key
releasing the latch means whereby the rotatable
means for rotating the rotatable member from
spring loaded member returns to the corre
the stop position to the spring loaded latched
sponding stop position, plug-in key means for ro
position, said key means being insertable into
said rotatable member and being rotatable there 35 tating the rotatable member from one stop posi
tion to the other and from either stop position
by so that the position of the key means indi
to either, spring loaded latched position, said key
cates the position of the rotatable member, sig
means being insertable into said rotatable mem
nal circuits controlled by rotation of the mem
ber and being rotatable thereby so that the posi
ber, and a signal light mounted on the key and
connected in one of the circuits.
40 tion of the key means indicates the position of
the rotatable member, and signal circuits con
9. In an electric alarm device a rotatable
trolled from different positions of the member.
member having two stop positions and manually
movable from one stop position to the other,
ERIC D. SMITH.
spring means and means for loading the spring
means upon rotation of the member from either
stop position, means for latching the member in 45
References Cited in the ?le of this patent
di?erent positions reached upon rotation from
either stop position, and electromagnetic means
for releasing the latch means whereby the
rotatable spring loaded member returns to the
Number
UNITED STATES PATENTS
Name
Date
350,450
1,083,566
1,142,102
1,510,587
1,554,048
Tucker ___________ __ Oct. 5,
Stone ____________ __ Jan. 6,
Kettering ________ __ June 8,
Diegel ____________ __ Oct. 7,
Thomas _________ __ Sept. 15,
spring means and means for loading the spring
means upon rotation of the member from either 55
1,576,276
Hedges et al _______ __ Mar. 9, 1926
1,664,215
Hunt ___________ __ Mar. 27, 1928
stop position, means for latching the member in
2,116,947
2,434,065
Ketay ___________ __ May 10, 1938
Courtney __________ __ Jan. 6, 1948
corresponding stop position.
50
10. In an electric alarm device a rotatable
member having two stop positions and manually
movable from one stop position to the other,
di?erent positions reached upon rotation from
1886
1914
1915
1924
1925