Improvements in Alarm-thermometers, and in Apparatus connected therewith, for the Automatic Transmission to a Distance of Signals Indicating Deviations or Fluctuations of Temperature Beyond Predetermined Limits.
Year: 1895

page_text: Date of Application, 16th July, 1895-Accepted, 14th Dec., 1895
COMPLETE SPECIFICATION.
Improvements in Alarm-thermometers, and in Apparatus connected
therewith, for the Automatic Transmission to a Distance of
Signals Indicating Deviations or Fluctuations of Temperature
Beyond Predetermined Limits.
I, EMIL TEMPEL of No. 7, Rosenkranz, Bremen, in the German Empire,
Merchant, do hereby declare the nature of this invention 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 electrical apparatus whereby when the temperature in
a room or apartment rises above a predetermined maximum or falls below a
predetermined minimum, the occurrence of such excessive rise or fall may be
immediately notified at stations or places no matter how far distant from the
situation of the recording or transmitting device.
The invention will be readily understood by reference to the accompanying
drawing in which
Figure 1 is an elevation of a thermometer combined with the signalling or
transmitting apparatus, and
Figure 2 is a diagram showing the electrical connections.
The fact that it has been impossible hitherto to provide suitable means for
automatically signalling or recording that the temperature has fallen below a
predetermined minimum or risen above a desired maximum, in rooms in which the
temperature is required to be kept between certain limits, and that it has therefore
been indispensable to employ special attendants for the purpose, has long been
complained of as a very serious drawback, inasmuch as the accuracy of the records
of temperature taken by those persons, and the reliability of the check which it
was their duty to exercise, were entirely dependent on the care and attention which
they devoted to their work.
Whilst there have been known for some considerable time thermometers and
similar apparatus for notifying at a distance the occurrence of predetermine.l
maximum temperatures and for setting in operation an alarum or signalling device
whenever such maximum was exceeded, similar arrangements for recording the
occurrence of predetermined minimum temperatures or temperatures below such
minimum and for notifying the same at distant places in the same way, have not
heretofore been devised; much less have any suitable means been devised for
signalling that deviations or fluctuations of temperature have occurred both below
and above predetermined limits.
both
Now it is the object of this invention to remove the inconvenience arising from
that state of things, by providing a single apparatus capable of performing the
double function of announcing at distant points the occurrence of
predetermined maximum and minimum temperatures, and at the same time adapted
to set alarums or calls in motion whenever the temperature descends below the
given minimum, or rises above the desired maximum; the nature of the sound
or "call" at once indicating which particular change the temperature has
undergone.
Into the wall of the glass tube a of a thermometer, on either or both sides, and
at convenient distances apart (say every 1° or 5°), there are fused or otherwise
suitably secured small platinum rods or pins i, protruding only a short distance
outwardly, but extending beyond the inner surface of the tube in the interior of

page_text: the same.
Next to the glass tube, there is arranged a non-conducting bar or rod d
whereon are placed the contacts e, for the passage of the currents operating the
bell C working on the open circuit system, and f, for the passage of a constant or
continuous current operating in conjunction with the bell D working on the closed
circuit system; the arrangement being such that the springs or resilient pins of
the said contacts sweep past the platinum pins welded into the glass, in close
proximity to the same. Into the glass bulb 6, are similarly fused platinum rods or
pins g, h. These are connected with the binding posts of the conductors m and n,
and serve the purpose of poles for the passage of the currents used with both the
open and closed circuit bells. The mercury in the thermometer serves as an
intermediate conductor. c is the thermometer scale.
In Figure 2 the preferable arrangement or connection of the conducting wires is
illustrated. But it is to be understood that the connections.may vary to suit the
particular requirements of each case.
Inasmuch as it is necessary that the mercury should in all cases rise above the
predetermined minimum temperature, it follows that a constant or continuous
current operating in conjunction with the closed-circuit bell must be employed in
connection with the minimum contact, while for the maximum contact generally,
the bell working on the open-circuit system must be used. Hence it follows that
for the operation of the improved apparatus two currents are necessary, and, this
being so, the mode of arrangement to be adopted will be readily realised.
A (Figure 2) designates the thermometer, and the conductor k from its maximum
contact e is connected to the bell C, adapted to be rung whenever the maximum
temperature is exceeded. From the bell C, the conductor G leads to the
battery R, from the other side of which the conductor n extends back to
the contact located in the mercury bulb. Since, as before stated, for the
operation of the minimum contact f, a constant current is required, by reason of
the fact that the mercury column surmounting it continually acts as a conductor,
the constant current wire l is in the first place led up to the battery B operating the
closed circuit, thence, as a conductor J, extended to the minimum bell D; and
then, as a conductor m, brought back to the other pole g of the mercury-containing
bulb.
When the mercury column sinks below the minimum contact, this results in an
interruption of the closed circuit, and causes the relay armature in the bell D to
leave its position of rest and put the conductor H into connection with the bell
circuit. Now the current passes through the pole g and through the medium of the
mercury in the bulb communicates with the pole h passing on, through the
conductor n to the battery R, through the conductor G, then through
the conductor H branching off from G, and lastly into the bell D. The current
from the battery R, therefore begins to operate the bell D, so that the fact that
the temperature has fallen below the predetermined minimum, is also immediately
notified.
It will be understood that the whole arrangement may be modified so as to adapt
it to existing circumstances. Thus the apparatus may be fitted up for one bell
only; the contacts e and f may be adapted to be displaced or adjusted on the glass
tube itself instead of on the rod d; the conductors may lead up to various points
other than those indicated; and instead of mercury, other suitable .fluids which it
is customary to employ for thermometers may be used. Again, there may be
interposed at any convenient part of the system of conducting wires any suitable
automatic recording or registering device adapted to keep a record of the times at
which such maximum and minimum temperatures occur.
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 that which I
claim is :-
An automatic apparatus for transmitting to a distance signals of excessive
deviations
» predatormined maximum or

page_text: below a predetermined minimum, the main feature of which apparatus is that, by
means of small platinum rods or pins sealed into the glass tube of a thermometer
at predetermined distances apart (which rods or pins protrude on one side beyond
the inner surface of the tube, and on the other side, beyond the outer surface
thereof) and by means of contacts adjustably arranged upon an insulating bar or
rod, or upon the glass tube itself, two kinds of electric currents are conducted
to corresponding alarum or call bells and batteries, viz. :—a "transmitting
" continuous
electrical current for the maximum position, and
current for the minimum position; so that both an excess of temperature, beyond
the maximum, and a fall of temperature below the minimum (whenever they may
occur, and whatever their extent) are notified at stations or places no matter how
far removed from the situation of the thermometer.
Dated the 16th dor of July 1895
a
66
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or
constant
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D. YOUNG & Co.,
11 & 12 Southampton Buildings, London, W.C.,
Agents for the Applicant.