A New or Improved Automatic Electric Heat Alarm.
Year: 1892

page_text: Date of Application, 12th Jan., 1892-Accepted, 20th Feb., 1892
[Communicated from abroad by THE ELECTRIC HEAT ALARM Cor., of Bangor,
Maine, U.S.A.]
A New or Improved Automatic Electric Heat Alarm.
I, HUGH DONALD FITZPATRICK, of 70 Wellington Street, Glasgow, Registered
Patent Agent, do hereby declare the nature of this invention and in what manner
he same is to be performed, to be particularly described and ascertained in and by
he following statement :-
My invention consists of an automatic electric heat alarm, and is intended for
se chiefly in connection with journals, bearings and other parts of machinery where
njury may occur through overheating by reason of friction or other causes, it being
designed automatically to give an alarm when the heating of the parts begins to be
so great as probably to cause damage.
11
Similar letters refer to corresponding parts throughout the figures.
I provide a metallic cup A having the upper portion of its interior tapped. A
metallic plug B, having a portion of its exterior screw-threaded, is fitted to screw
into the cup A.
From the centre of the plug B is a downwardly extending, thermometric tube b
reaching nearly to the bottom of the cup A. At the upper end of the tube b is
formed a chamber c in the plug B, into which is fitted a conductor wire or spindle C
insulated from the plug B by a ring D of hard rubber or other non-conductor of
electricity fitted into the plug B and supporting said spindle, the spindle being made
vertically adjustable within the insulator D.
The spindle C is connected at its upper end with one of the poles of an electric
battery and the other pole of the battery is connected with the plug B by means
of a set-screw E or other convenient device. A nut F holds the spindle in
position.
In operation the cup A is
are screwed together, and the
bearing of the machine.
partly filled with mercury; the plug B and cup A
whole device set into or upon the journal box or
As the parts become heated the mercury expands and rises in the tube b until it
comes in contact with the spindle C, thus completing an electric circuit and giving
an alarm by means of a bell or other device.
The spindle C, being vertically adjustable in the insulator D and chamber c,
may be so set as to be brought in connection with the mercury at any desired
temperature.
Having now particularly described and ascertained the nature of my said
invention, and in what manner, the same is to be performed, I declare that what
I claim is:
An electric heat alarm consisting of the combination of a hollow metallic
reservoir, a quantity of mercury within said reservoir; a metallic plug partially
filling said reservoir and having a small, downwardly-extending, tubular bore; a
conductor wire or spindle supported and insulated within said plug and extending
to such point as that it may be reached by said mercury when expanded and risen
in said tube-the whole in combination with an electric battery having one of its
[Prine 71

page_text: poles connected with said plug and the other with said insulated conductor wire or
spindle; and a bell or other alarm or indicator connected with and operated by said
electric battery.
Dated this 11th dove of t1000
H. D. FITZPATRICK,
70, Wellington Street, Glasgow.