Improvements in Liquid Compounds for Thermostats.
Year: 1892

page_text: Date of Application, 16th Feb., 1892-Accepted, 2nd Apr., 1892
COMPLETE SPECIFICATION
[Communicated from abroad by THE CONSOLIDATED CAR-HEATING COMPANY,
of Wheeling, West Virginia, United States of America.]
Improvements in Liquid Compounds for Thermostats.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent
Agents, 45 Southampton Buildings in the County of Middlesex, 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 new and useful improvements in liquids for thermostats,
and the invention consists in the peculiar compound employed and in the relation
between the amount of compound and the capacity of the thermic cell in which it
is placed.
In the previous state of the art, thermic cells or expansible vessels have been
used containing liquids which would vaporize at or near the temperature desired to
be maintained for the purpose of obtaining pressure to actuate a valve or valves in
the ordinary use of such devices.
In controlling the temperature in dwelling houses or cars in which the aforesaid
liquids, are used, the cells have ordinarily been filled, and the temperature
maintained at approximately 70 deg., liquids being employed which will vaporize
at or near that temperature. During the summer months the temperature in the
apartment or car is frequently heated to 80, 90 or even 100 degrees, and the con-
tinuous expansion of the liquid filling the cell is frequently sufficient to burst or
permanently distort the form of the cell or its diaphragm, thereby destroying its
effectiveness.
I propose to use a compound made up of two or more liquids, having their boiling
point at progressively higher degrees commencing below and ranging to at or near
the temperature desired to be maintained and in placing in the cell such a quantity
of liquid that it will all pass into vapor before it reaches an abnormal temperature,
say 80 degrees. The continued expansion of the vapor or gas from 80 degrees to
say 90 or 100 is not sufficient to distort or damage the thermic cell. In car heating
to which I have given especial attention it is ordinarily desired to maintain a
temperature of 73 deg., and if I desire to open or close a valve by the action of
my thermostat at that temperature, I preferably employ a compound containing one
liquid which will vaporize at or about 68 deg. As soon as the temperature reaches
this point, all or nearly all of that liquid will pass into vapor filling the cell. Its
pressure will overcome any friction in the parts and slightly move the valve. In
connection with this I use another liquid which will vaporize at 70 deg., the
expansion of the gases from which will have full effect in actuating the valve.
Should it not move quickly enough or far enough a third liquid in the compound is
employed which will vaporize at 72 deg., and the expansion of the gases arising
therefrom will give sufficient power to close the valve tight and hold it closed until
the temperature lowers.
The relation between the amount of liquid in the thermic cell and the capacity
of that cell should be such that all of the liquids of the compound will pass into
vapor under say 80 deg., temperature. If the temperature in the room from any
unusual cause in winter or in the summer months rises above that point, the vapor
which is dry, will have so little additional expansion as to give but a few pounds
more pressure at 100 F., than at 80 deg.

page_text: Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me by
my foreign correspondent I declare that what I claim is :-
1. A compound liquid for thermostats composed of liquids, having their boiling
points at progressively higher degrees below or near the temperature at which they
are desired to act, substantially as described.
2. The combination with a thermic cell, of a liquid therein, adapted to vaporize
below or near the temperature at which it is desired to act and in such proportion
to the capacity of said cell as to allow of its entire vaporization at a normal
temperature, substantially as described.
Dated this 11th day of February 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.