Improvements in Electric Fire-alarm System.
Year: 1890

page_text: Date of Application, 8th July, 1890-Accepted, 30th Aug.. 1890
COMPLETE SPECIFICATION.
Improvements in Electric Fire-alarm System.
I, PETER JENSEN, Fellow of the Institute of Patent Agents. of 77, Chancery Lane,
in the County of London, do hereby declare the nature of this invention, which has
been communicated to me from abroad, by The European Fire Service and Motor
Company, located in the City of Milwaukee, in the County of Milwaukee, and State
of Wisconsin, United States of America, 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 automatically operated electric fire alarms, and it consists
in certain peculiarities of construction and combination of parts as will be fully
described hereinafter, constituting an automatic electric system adapted for use in
buildings of all descriptions to instantly give the alarm in the event of fire breaking
out anywhere.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a diagrammatic view of the complete system.
Figures 2, 3, 4, 5 and 6 are details illustrating the preferred forms of construction
of various portions of the apparatus used in said system.
A is a pinion that is driven by any suitable motor, and B is a break wheel which
has cog teeth a on its hub that mesh with like teeth on pinion A, and break pins B' B¹
arranged in series on its outer face; and on its face adjacent to break wheel B the
pinion A is provided with two triangular projections, b and c, one of which, b, is
nearer the periphery of the pinion than the other, c.
A lever C is pivoted at d to a suitable support on the box (not shown) and carries
the armature D of a differentially wound electro magnet E and is also provided with
a lug g that projecting downward, has a beveled finger, h, projecting from it at right
angles and the face of this finger h is designed for engagement with lug c when
core E¹ of magnet E is de-energized and lever is in the position shown in Figure 1,
or to engage with lug b when the core is energized and the lever () is lifted.
Wires and G form what is called the main circuit of the apparatus. Wire F
starting from battery X and passing through relay H' to a core E of a magnet E
about which it forms a helix and then to binding post L; and wire G starting from
battery X and joining wire F at binding post L. A inake and break spring H and
binding post His interposed between two sections of wire G, and the free end of this
spring lies in the path of the break pins B₁ so that when the wheel B revolves these
pins will make and break the circuit successively and cause the bell in local circuit P
to sound a corresponding number of strokes.
The line F tapped at g by a wire G' and this wire after being wound about a
core M is carried on to core E' and wound over the helix formed by wire F in an
opposite direction thereto and thence passes to a thermostat I one end of which
projects between posts i j³ which are connected by a wire G³ with another thermostat I',
one end of which similarly projects between another set of posts K K¹ which are
connected by wire G*, with another thermostat I², one end of which projects between
posts K K which posts are connected, by wire G³, with the binding-post L, already
named, and other thermostatic connections may be included, the illustration given
being designed to represent thermostat I in the third floor, thermostat I¹ in the second
floor, and thermostat I' in the first floor of a building. It will also be understood that
a switch for manual operation may be interposed at any point desired on the wires of
any or each floor, and switches are shown in Figure 1, at L' L L. Below these
switches are shown annunciator drops, numbered 1, 2, and 3, (to correspond to the
first, second, and third floors) and whose magnets O O O₁ are wound to much
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page_text: "
greater resistance than the main line magnet, the said annunciator magnets 011 01013
being wired to the wires G G G G³ by wires o' o², o³ of, and of o. On account of
this higher resistance, at this point, the current will normally pass through the closed
circuit G G G G³ (instead of through the short circuit G¹‍¹ O¹ o³ G¹³ O²º¹ G² 0³
030 G³), but if a break occurs in the former circuit (say in the first floor, by the
thermostat I rising from the post K³) then the current would pass through a portion
of the described short circuit of higher resistance, and cause the annunciator drop
(1, in this instance) to fall, at once indicating on which floor the break in the circuit
had occurred. In Figures 5 and 6 are shown details of the preferred construction of
the annunciator drops and connections. O¹ shows one of the magnets, and 1 is the
corresponding annunciator drop, which is pivoted on a pin or stud r to the adjacent
framework P, and which drop has on its inner side a longitudinal projection s. P¹ is
the magnet-support, and to the same are pivotally secured, as shown at p the preferably
bent armature levers P2, the upper arms of which are normally held upright (with
their armatures Q free from contact with the magnets 01, 0, 0³) by means of
springs Q¹ extending from the magnet-support P¹ to the lower ends of said levers P².
These levers P' carry detent rods P (projecting through slots p³ in the framework P)
which normally support the annunciator drops 1, 2, 3, in a raised position by means
of the described projections son said drops resting on the ends of said detent rods.
A screw or other stop R projects through or from the inner side of the framework P
and limits the outward movement of the upper arms of the armature levers P' against
the force of the springs Q¹.
Now, when the described break occurs in any part of the closed circuit G¹ G* G* G³
from fire, or any other cause, the current, as stated, will pass through the corresponding
part of the described short circuit of higher resistance, and if, (as first stated) this
break is supposed to occur in the first floor, then the current will pass from G¹ to G
through oo, and in so passing will so increase the energy of the magnet ¹ as to
draw the adjacent armature Q and its lever P2 thereto, overcoming the resistance of
the spring Q, and thereby withdrawing the detent rod P³ from beneath the projection &
of annunciator drop 1, and permitting the latter to fall, by gravity, at once indicating
the floor on which the break occurred, the alarm meanwhile sounding, and calling
attention to the fact.
A swinging lever N carries the armature N¹ of core M and the lower end of this
lever is hooked or offset as shown, that it may, when core E¹ is energized and lever C
is lifted, engage the end of said lever and support it in position to be out of the
path of lug c.
mm are limiting pins for the lever C. p is a spring for retracting lever C and p¹ a
like spring for retracting lever N.
The operation of the device is as follows:
When the parts are in the position shown in Figure 1 as there are two currents
passing around core E' which neutralize each other the core is practically de-mag-
netized and the armature D and lever C are drawn away from by spring p and the
lug g lies in front of lug c on the pinion A. to prevent the latter from revolving. Now
if by a slight rise of temperature above normal the thermostat I (or I¹ or 12) be warped
away from its lower contact post, or a break from any cause occurs in loop G¹G
GG the wire G³ will be cut out, destroying the neutrality in the helices of core E¹,
which becoming energized will lift armature D and lever C and as core M is also
de-magnetized by the cutting out of wire G³, the lever N will be released, and as it is
drawn away from core M its lower hooked end will engage lever C in its raised
position so that the finger h of lug y will be out of the path of lug c and in the path of
lug 6 of pinion A. Just as soon as lug c is released the pinion A will start and make
a quarter revolution when lug 6 coming in contact with finger of lug g will stop the
pinion, but during this quarter revolution of pinion A it will, through the teeth a on
the bub of the wheel B, revolve the latter once, causing the pins B₁ to make (in this
instance) nine successive breaks in the loop F G by depressing and releasing
spring H.
Now if there is not a sufficient rise in temperature to cause the thermostat effected

page_text: to make connection with the other post this signal which merely means danger or a
broken line will be all that is sent in; but if upper contact is made then the cutting
in of loop G G G G will energize core M which by attracting armature N will
cause it to release lever C which, as core E' is de-energized, will drop and permit the
lug b to pass over finger of lug g, thus releasing pinion A and permitting it to
complete its revolution and in so doing revolve the wheel B three times; this gives
the alarm 3 3 3 three times and indicates fire.
To prevent the re-establishment of contact between the thermostat I (or I¹ or I³)
with its lower post after it has once been broken and before the apparatus is re-adjusted
any convenient means may be provided, for instance, as shown in Figure 4, the under-
side of the thermostat bar I (or I' or I2) may be provided with rack teeth, which, as
the bar rises, will be engaged by a spring pawl, which pawl will support the bar in
any position it may rise to, until it is disengaged by hand.
It is obvious that simple switches may be used instead of thermostats without
departing from the spirit of this invention."
Having now particularly described and ascertained the nature of this invention
as communicated to me by my foreign correspondent and in what manner the same
is to be performed, I declare that what I claim is :-
1. The combination with a single motor of a main circuit and a branch circuit, a
magnet wound differentially by the wires of the two circuits and another magnet
in the branch circuit, a lever controlled by the differential magnet and a detent for
said lever controlled by the magnet in the branch circuit, connections between the lever
aforesaid and the motor; and thermostats, all arranged substantially as set forth.
2. The combination with normally closed main and branch-circuits, a magnet wound
differentially by the wires of said two circuits, another magnet in the branch circuit,
armatures for said magnets, a signal motor controlled by the magnets and switches in
the branch circuits, and connections substantially as described, whereby the first named
magnet is energized and the other magnet de-energized by a break in the branch
circuit, all arranged substantially as set forth.
3. The combination with normally closed main and branch circuits, a magnet wound
differentially by the wires of the said two circuits, another magnet in the branch
circuit, a signal motor, a lever carrying an armature actuated by the differential
magnet to start said motor, when said magnet is energized by a break in the branch
circuit, and the other magnet thereby de-energized, and a lever provided with a detent
for said first named lever, and carrying an armature actuated by the magnet in the
branch circuit when said magnet is re-energized by the reclosing of said branch
circuit, all arranged substantially as set forth.
Dated this 8th day of Jul 1900
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.