IMPROVE- MENTS IN AUTOMATIC FIRE AND BURGLAR ALARMS, APPLICABLE TO DWELLINGS AND WAREHOUSES AND IN OTHER PLACES
Year: 1874

page_text: LETTERS PATENT to Frederick Herbert William Higgins, of 17 & 18,
Cornhill, in the City of London, for the Invention of "IMPROVE-
MENTS IN AUTOMATIC FIRE AND BURGLAR ALARMS, APPLICABLE TO DWELLINGS
AND WAREHOUSES AND IN OTHER PLACES.”
Sealed the 5th December 1874, and dated the 6th October 1874.
PROVISIONAL SPECIFICATION left by the said Frederick Herbert
William Higgins at the Office of the Commissioners of Patents,
with his Petition, on the 6th October 1874.
I, FREDERICK HERBERT WILLIAM HIGGINS, of 17 & 18, Cornhill,
in the City of London, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN AUTOMATIC FIRE AND BURGLAR ALARMS,
APPLICABLE TO DWELLINGS AND WAREHOUSES AND IN OTHER PLACES," to be as
follows:-
This Invention has for its object improvements in automatic fire and
burglar alarms applicable to dwellings and warehouses and in other
places.

page_text: The instrument in the dwelling house or other place, by which an
alarm is communicated to a distant station, consists of a train of wheels
driven by a spring, which is wound by a trigger on the face of the instru-
ment. A detent prevents the train running down until it is withdrawn
by an electro-magnet. The liberation of the train causes two revolutions
of a slotted disc, which interrupts an electrical circuit in a pre-determined
manner dependent on the arrangement of the slots. There may be
numerous instruments in one circuit, and the arrangement and number
of the groups of interruptions identifies the instrument giving the alarm
and the locality of the danger. A single line of telegraph is employed.
The current which liberates the alarms is constantly flowing, but cannot
pass through the electro-magnet whose armature liberates the alarm
train because of a shunt or derived circuit which includes a thermostat
or contact breaker. Several may be included in the same shunt or
derived circuit.
The thermostat consists of a metal tube enclosing a compound bar of
zinc and steel. At ordinary temperatures the end of the bar rests upon
a platinized point, and completes the derived circuit through which the
line current flows. With heat the bar deflects, and the contact is broken.
Any interruption of the thermostat circuit causes the current to pass
through the electro-magnet coils of the alarm instrument, liberates the
train, and transmits the signal to a receiving station or place, where there
are instruments and attendants to receive it. The tubes containing the
thermostats are arranged to be placed vertically against the walls of a
building, and are made with a wide open mouth to admit of the upward
flow of currents of heated air, and the top of the tube though open is
protected from dust by a cover placed a short distance above it. Any
rupture, accidental or otherwise, of the derived circuit instantly dis-
charges the alarm, and any rupture of the line circuit is indicated at the
receiving office by an electric trembler bell, the hammer of which is
actuated by a local current, which only passes when a relay provided for
the purpose makes contact upon the line current ceasing to flow.
The burglar alarm is simple and effective, and acts on the same
principle of interrupting a derived circuit. The circuits may be arranged
in warehouses to include thermostats placed under or in piles of goods.
They never require attention, and can therefore be fixed in places
difficult of access. The alarm instrument announces in plain letters on
dial the fact of its having been discharged.

page_text: In order that the signals of the alarm instrument may not be inter-
rupted by the immediate reclosing of the derived circuit after it has
been broken, a contact maker carried by the train cuts out all thermo-
stats and burglar alarms about ¼ second after being liberated. When
discharged each alarm instrument automatically shunts across the coils
of its electro-magnet. The object of this arrangement is to make the
line circuit as short possible.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frederick Herbert William Higgins in the Great
Patent Seal Office on the 6th April 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
HERBERT WILLIAM HIGGINS, of 17 and 18, Cornhill, in the City of
London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixth day of October, in the year
of our Lord One thousand eight hundred and seventy-four, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Frederick Herbert William
Higgins, Her special license that I, the said Frederick Herbert William
Higgins, my executors, administrators, and assigns, or such others as I,
the said Frederick Herbert William Higgins, my executors, adminis-
trators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN AUTOMATIC
FIRE AND BURGLAR ALARMS, APPLICABLE TO DWELLINGS AND WAREHOUSES AND IN
OTHER PLACES," upon the condition (amongst others) that I, the said
Frederick Herbert William Higgins, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands
and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.

page_text: NOW KNOW YE, that I, the said Frederick Herbert William Higgins,
do hereby declare the nature of the said Invention, and in what
manner the same is to be performed, to be particularly described
and ascertained in and by the following statement thereof, that is to
say :-
This Invention has for its object improvements in automatic fire and
burglar alarms, applicable to dwellings and warehouses and in other
places.
The instrument in the dwelling house or other place, by which an alarm
is communicated to a distant station, consists of a train of wheels driven
by a spring, which is wound by a trigger on the face of the instrument.
A detent prevents the train running down until it is withdrawn by
an electro-magnet. The liberation of the train causes two revolutions of
a slotted disc, which interrupts an electrical circuit in a pre-determined
manner dependent on the arrangement of the slots. There may be
numerous instruments in one circuit, and the arrangement and number
of the groups of interruptions identifies the instrument giving the alarm
and the locality of the danger. A single line of telegraph is employed.
The current which liberates the alarms is constantly flowing, but cannot
pass through the electro-magnet, whose armature liberates the alarm
train, because of a shunt or derived circuit which includes a thermostat
or contact breaker. Several may be included in the same shunt or
derived circuit.
The thermostat consists of a metal tube enclosing a compound bar of
zinc and steel. At ordinary temperatures the end of the bar rests upon
a platinized point, and completes the derived circuit through which the
line current flows. With heat the bar deflects, and the contact is broken.
Any interruption of the thermostat circuit causes the current to pass
through the electro-magnet coils of the alarm instrument, liberates the
train, and transmits the signal to a receiving station or place where there
are instruments and attendants to receive it. The tubes containing the
thermostats are arranged to be placed vertically against the walls of a
building, and are made with a wide open mouth to admit of the upward
flow of currents of heated air, and the top of the tube though open
is protected from dust by a cover placed a short distance above it.
Any rupture, accidental or otherwise, of the derived circuit instantly
discharges the alarm, and any rupture of the line circuit is indicated
at the receiving office by an electric trembler bell, the hammer of

page_text: which is actuated by a local current, which only passes when a relay
provided for the purpose makes contact upon the line current ceasing to
flow.
The burglar alarm is simple and effective, and acts on the same
principle of interrupting a derived circuit. The circuits may be arranged
in warehouses to include thermostats placed under or in piles of goods.
They never require attention, and can therefore be fixed in places
difficult of access. The alarm instrument announces in plain letters on
a dial the fact of its having been discharged.
In order that the signals of the alarm instrument may not be inter-
rupted by the immediate reclosing of the derived circuit after it has been
broken, a contact maker carried by the train cuts out all thermostats and
burglar alarms about / second after being liberated. When discharged
each alarm instrument automatically shunts across the coils of its electro-
magnet. The object of this arrangement is to make the line circuit as
short as possible.
Figure 1 is a front view of the instrument by which the alarm is com-
municated to a distant station; Figure 2 is a similar view of the same
instrument, with the case or cover removed; Figure 3 is a side view, with
the case in section.
Figure 4 is a front view of the thermostat, and Figure 5 is a section
of the same.
a, a, is the frame and cover of the transmitting instrument, shewn at
Figures 1, 2, and 3. It is of cast iron, and is arranged to be fixed in an
upright position against any wall which may happen to be conveniently
situate. 6 is an electro-magnet fixed to the frame a. Its armature c is
carried by a lever c¹, having its fulcrum at c³ on a frame a², which carries
the moving parts of the instrument. The frame a' is fixed to the frame a,
and it carries an axis d, on which is the handle or trigger e by which the
instrument is wound or set, the handle being turned for this purpose
about a quarter circle from left to right, and dare two arms fixed

page_text: on the axis d, which in conjunction with the stop a* fixed on the frame a
limit the motion of the axis d. f is a ratchet wheel with five teeth fixed
on the axis d. g is a pawl which falls into the teeth of this ratchet; it
works on a centre at g¹ on the face of the spur wheel h. When the
axis d is turned to wind or set the instrument one tooth of the ratchet f
passes beneath the pawl, and the spring i then causes the pawl to drop
into the next space between the teeth. k is a coiled main spring, one
end of which is attached to the frame a¹ and the other to the axis d.
This spring when the instrument is set tends to rotate the spur wheel 7,
which gears with a pinion on the axis m.
l
The axis m also carries the
escapement wheel n, and o is an anchor escapement engaging with the
escapement wheel; it has a short pendulum p attached to it. Whenever
(the spring having been wound) the pendulum p is set free the train
will run down at a regular speed, which the pendulum controls. q is a
.break contact wheel fixed on the axis m. The notches in it are cut
differently in every instrument included in the circuit. is an insulated
spring making contact against the wheel q. 8 is a detent attached to
the armature c; it prevents the pendulum p vibrating except when the
armature is depressed by the attraction of the electro-magnet b. t is a
spring, which at other times sustains the armature c. u is an arc fixed
on the axis d, which serves to prevent the lever c¹ rising when the circuit
is broken by the break wheel q. v¹, v³, v³, are three binding screws to
receive the coupling wires. The binding screw v¹ is insulated from the
frame a, and is coupled with one extremity of the line wire, and also
with one terminal of the shunt or circuit in which the thermostats and
burglar alarms are included; in addition it is coupled within the instru-
ment to the insulated contact spring w. The binding screw * is insulated
from the frame a, and is coupled with the thermostats and burglar
alarms, and within the instrument with the spring contact piece x. The
arm & carries a pin, which comes against the springs w and x. The
binding screw ³ is coupled with the line circuit.
The thermostat consists of a cast-iron tube A, on which is mounted the
vulcanite block B carrying the compound blade C of iron and zinc. D is
a contact screw, which is set just in contact with the blade C, and there
secured by the lock nut E. F is a moveable cover to exclude dust from
the tube A. G and H are binding screws, by which the instrument is
coupled in circuit. When the blade C is heated it bends, and breaks
contact with the screw D. By experiment the temperature at which
contact will be broken can be adjusted with great accuracy.

page_text: Burglar alarm contact breakers of any convenient construction may
be arranged in circuit in such manner that metallic contact is broken by
the opening of doors, windows, and such like, the instruments being
coupled and set as they are shown at Figures 2 and 4.
The flow of the current may be traced as follows:-From the line
wire to the binding screw v¹, thence to G and through the thermostat
to H, and so to ², thence to w and by the arm d to the frame a, and so
by the binding screw to the continuation of the line wire. When
contact is broken in the thermostat or in the burglar alarm, as the case
may be, the current being no longer able to pass by the route just
followed is forced to passes from ' through the coils of the electro-magnet
to the spring r, and thence through the wheel q to the frame, and to the
binding screw v³ in connection with the line wire. The electro-magnet
now attracts its armature and the train runs, causing the wheel q to
produce a number of breaks in the electric circuit, which are suitably
recorded and observed in the central receiving station.
When the instrument has run down, an easier course is provided for
the electric current than through the electro-magnet; it then passes
from v¹ to x, and by the arm & to the frame, and so to the binding
screw ³ and to the line wire. Thus it is only whilst the instrument is
actually signalling that the current has to traverse the coils of the
electro-magnet, at all other times an easier path is provided: This
is of great importance where many instruments are included in one
circuit.
Having thus described the nature of my said Invention, and the
manner of performing the same, I would have it understood that I claim
the construction and combination of apparatus constituting automatic
fire and burglar alarms substantially as described.
In witness whereof, I, the said Frederick Herbert William Higgins,
have hereunto set my hand and seal, this Second day of April, in
the year of our Lord One thousand eight hundred and seventy-
five
F. H. W. HIGGINS. (L.S.)