Improvements in Alarm Thermometers.
Year: 1890

page_text: te of Application, 8th Apr., 1890-Accepted, 7th June, 1890
COMPLETE SPECIFICATION.
Improvements in Alarm Thermometers.
I, EDWIN MARSHAL Fox, of 543A Lexington Avenue, Brooklyn, County of Kings,
and State of New York, United States of America, Attorney and Counsellor at Law,
do hereby declare the nature of my invention for IMPROVEMENTS IN ALARM THER-
MOMETERS and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
The object of my invention is to provide devices in the nature of thermometers,
which shall give automatically a signal or alarm of any corresponding nature when-
ever the temperature of the surrounding medium reaches one or more predetermined
points, and to use the same, either as a single thermometer which will be chiefly
useful in sick rooms. green houses, Turkish baths, or other similar places where it is
desired that an attendant should obtain knowledge of a limit of temperature being
reached without personal examination of the thermometer, or as a simple system of
fire alarm devices by which the increase of temperature caused by a fire, automaticall
operates the whole system of alarms, and is more particularly adapted to dwelling
houses, hotels, ships, or other places where many persons are likely to remain for
hours either asleep or awake in more or less isolated apartments. I am aware that
thermometers and kindred devices have been used to give an automatic alarm when
the metal, woodwork or other substance upon which they are fastened, reaches a given
temperature, but the warning thus given, in case of fire is apt to be delayed from the
fact that a fire starting at some distance from the thermometers has a chance to
acquire considerable headway before the temperature of the thermometers is
sufficiently affected to produce the change necessary for the automatic giving of an
alarm.
Another difficulty in procuring adequate protection by the systems of automatic
fire alarms now in use is that the alarm is given at but one place, and thus the
effectiveness of the alarm is made to depend upon the wakefulness or attention of the
watchman there situated. It is one of the results aimed at by my improved system
of fire alarms that the fact that a fire has broken out in one of the apartments of a
dwelling house, vessel, or hotel is instantly communicated automatically to every
other apartment in which one or more persons may be sleeping or at work, and a
special alarm indicating the exact locality of the fire is at the same time communicated
to the apartment in which works or sleeps the person upon whom the responsibility of
watching the hotel, vessel or house rests.
The other main result accomplished by my improved system is that the delay
caused by the necessity of transmitting the increase of temperature caused by the fire,
to the metal or wood work upon which the thermometers is mounted is done away
with.
To accomplish these results I place one or more thermometers which may be single
or double tube mercury thermometers or metallic thermometers if preferred, which
may be hung in any part of the room or apartment from which an alarm is to be
given, and I place these thermometers in an electric circuit in such a way that the
column of mercury or metallic pointer becomes a circuit closer for the circuit, which
is normally open. This closing of the circuit enables the current from a battery
within the circuit to ring a bell or otherwise give an alarm or indication that the
circuit is closed, which is synonymous with indicating that the predetermined limit of
temperature has been reached, thus if it is desired that the temperature of a Turkish
bath room should not exceed 110° Fahrenheit, one of my thermometers placed in that
room would act like an ordinary thermometer for all temperatures lower than 110 but
when the column of mercury reached that point the circuit of which the column of

page_text: mercury is a part would be closed and an alarm given electrically either at the
thermometer itself, or at any desired distance therefrom, whether in the same building
or not.
This feature of my invention consists of an alarm thermometer composed of an
electric circuit, an alarm, situated in said circuit, and a mercury thermometer pierced
at one or more fixed points by the line forming said circuit and in which the column
of mercury when reaching said fixed point acts to complete said circuit and operate
said alarm.
When used as an alarm system in distinction from a single temperature thermo-
meter, I place an alarm bell in each apartment through which said circuit passes and
I place also an ordinary hotel indicator or other suitable contrivance for indicating
the source of the alarm, together with an alarm bell in what I will call for
convenience the main apartment by which I indicate that apartment where is the
person responsible for the care of the whole series of apartments. In this way any
chang of temperature in any apartment sufficient to raise the column of mercury to
the predetermined point will give an aların in every apartment which is provided
with a bell and will also, in the main apartment, throw down a figure or give somo
other indication corresponding to the apartment in which such increase in temperature
takes place.
The fixed point at which the alarm should be given should naturally be selected
only slightly above the temperature to which the air of the apartment is normally
allowed or expected to go and for the temperate zone 100° Fahrenheit may well be
selected as the aların point, as the atmospheric temperature does not normally reach
that point except in the hottest days in summer. It is obvious that the lower the
temperature selected for the alarm point, the nearer simultaneous will be the giving
of the alarm with the breaking out of the fire.
This feature of my invention therefore consists in a series of alarm bells arranged
with a number of independent thermometers in an electric circuit, which is closed to
operate all of said alarm bells by the action of the mercury rising in any one of said
independent thermometers to a point corresponding to a predetermined degree of
temperature.
My invention may be applied in its simplest form to an ordinary single column
thermometer, in which case the fixed points for the introduction of the line wire
would be two in number, the upper being at the predetermined limit to which the
temperature should be allowed to rise and the lower being at any convenient point
lower down on the tube or in the bulb.
One form of my invention is shown in the accompanying drawing in which some
of the thermometers are single tube and some double tube.
A represents an indicator of ordinary construction such as used in hotels
elevators etc., and is shown with four signals marked 1, 2, 3, 4, of course any
number of signals either by display figures, pointers or other suitable contrivances
may be employed-this indicator is to be placed in the most convenient position to
suit the person upon whom rests the care of the house, ship or other place to be
protected, as for example, the sleeping room of the occupant of the house, the state
room of the captain, or in the janitor's office.
The large gong B, may be placed in the same room as the indicator or in a main
hall or other position to act as a general aların as desired. The small alarm bells, C,
C, C, C, marked respectively, 4, 3, 2, 1, are placed, one-each, in each of the rooms,-
corresponding to the display figures on the indicator-from which an alarm is
desired as for example, cabins, staterooms, offices or sleeping rooms.
Each apartment from which a signal is desired is provided with a thermometer of
ordinary construction, D, D, D', D¹, and a battery E, is placed in whatever part of
the house, ship or botel is most convenient.
These devices are arranged as an automatic fire alarm system as follows:
The main battery wire a, connected with one pole of the battery, leads to the base
of the mercury column of each and every thermometer, D, D, D', D', in the system,

page_text: making contact through the glass with the mercury. A point on the thermometer,
corresponding to some desired temperature, say 100° Fahrenheit, is selected as the
alarm point, and a fine wire is here introduced into the tube, to make contact with the
mercury column whenever the temperature of the surrounding air is high enough to
expand the mercury to that point,at other times the circuit remains broken at this
point.
:
These wires i lead independently to the corresponding signal or display number of
the indicator A, from which the bell wire b, as shown in dotted lines, connects all the
display numbers, runs to the series of bells, C, C, passing through each in turn, so
that when a current passes over the wire, each and every bell is made to ring, and
thence to the main gong or bell B, from which the return wire r, runs to the other
pole of the battery.
It is obvious that when the temperature of all the thermometers is below the alarm
point, the circuit is open, but as soon as the temperature in any apartment rises by
means of fire or any other cause to the alarm point, the inercury in that thermometer
rises in the tube to the alarm point, and thus closes the circuit at that point, the
column of mercury itself forming thus a part of the circuit. The current then
passing along the main wire a, throngh the mercury to the indicator i, to the
indicator A, dropping the appropriate display number, thence by bell wire b, through
all the bells C, 0, C, C, ringing then, to the bell B, and ringing it, returns to the
battery by the return wire r.
Should the temperature in more than one room rise to the alarm point at the same
time the alarms will be given in the same way, all the corresponding display numbers
being dropped together.
The advantage of using the ordinary two legged thermometer, D¹, D', in preference
to the single tube thermometer, D, D, is that an alarm can be given in the right hand
tube by a rising temperature, and from the left hand tube by a falling temperature, so
that the system can be relied upon to regulate the temperature of the rooms in
addition to giving a fire alarm.
The construction of both these single and double tube thermometers is well known,
both being common articles in the market, and the connection in both cases to the
line wire is made by connecting the same with fine platinum wire inserted through
the glass tube during the process of manufacture, in the path of the rising or falling
mercury without affecting the vacuum or liquid in which the mercury works.
It is obvious that an ordinary metallic thermometer may be substituted for the
mercury thermometer, by making the circuit through the pointer which travels over
the face of the thermometer, placing isolated contact points at such temperatures as
desired.
One of the most convenient forms in which my improved Alarm Thermometer can
be used where the signal is desired more especially in the room where the thermometer
is situated, which I have described as being the first feature of my invention, is to
have the battery, the alarm, and the glass tube or tubes containing the mercury and
the wires forming the electric circuit, all mounted upon the same base, and associated
together in a compact and convenient form, and I have shown at F, in the drawing,
such an association of parts, which 1 claim as a new article of manufacture, consisting
of a thermometer, an alarm bell and a small battery connected by electric wires, all
mounted and associated together upon the same base. The battery E' is inserted in
or attached to the base G in any convenient manner above or below the glass tube D11
containing the mercury, the bell C' is also mounted on the base, either above or below
the glass tubes, but preferably as near the battery E' as practicable for convenience
and economy of space, and the wires to make the circuit a¹, i i¹, and r¹ are preferably
sunk in grooves cut in the base G for that purpose. Thus a compact easily portable
alarm thermometer is produced which can be as readily hung as any other thermo-
meter, by means of a ring at the top or otherwise, and if at any time it is
desired to use said thermometer in connection with the alarm system this may be
easily done by simply running the wires in the manner above described in explaining
said system.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare what I
claim is:
1. A series of alarm bells arranged with a number of independent thermometers in
an electric circuit which is closed to operate all of said alarm bells by the action of
the mercury rising in any one of said independent thermometers to a point
corresponding to a predetermined degree of temperature, substantially as and for
the purposes specified.
2. A series of alarm bells and a general alarm or indicator arranged with a number
of independent thermometers in an electric circuit which is closed to operate all of
said alarm bells and said indicator by the action of the mercury rising in any one of
said independent thermometers to a point corresponding to a predetermined degree
of temperature, substantially as and for the purposes specified.
3. An alarm thermometer which consists of an electric circuit, an alarm situated in
said circuit, and a mercury thermometer pierced by the line forming said circuit at
fixed points and in which the column of mercury when reaching said fixed points acts
to complete said circuit and operate said alarm substantially as and for the purpose
specified.
4. As a new article of manufacture an alarm thermometer which consists of an
alarm bell, a battery, and an ordinary thermometer all mounted upon the same base,
and line wires also secured to said base, and connecting said battery, said bell, and said
ordinary thermometer in an electric circuit, substantially as and for the purposes
specified.
Dated at New York United States of Amerion this 27th day of March 1900
at New York, United States of Amerion, this 27th
7th day of March 1800
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.