Ar IMPROVED HEAT REGULATOR
Year: 1872

page_text: LETTERS PATENT to James Lockhart, of Glasgow, in the County
of Lanark, North Britain, Engineer,, for the Invention of "Ar
IMPROVED HEAT REGULATOR."
Sealed the 4th March 1873, and dated the 7th September 1872.
PROVISIONAL SPECIFICATION left by the said James Lockhart at.
the Office of the Commissioners of Patents, with his Petition, on
the 7th September 1872.
I, JAMES LOCKHART, of Glasgow, in the County of Lanark, North
Britain, Engineer, do hereby declare the nature of the said Invention
for "AN IMPROVED HEAT REGULATOR," to be as follows, that is to say :-
-
This Invention relates to a simple and sensitive instrument to be used
for regulating heat under various circumstances. It may be very con-
veniently applied where it is wished to keep up a supply of water heated
by gas to a certain temperature, as for baths, hot, water heating pipes,
and the like; and it may also be modified to act on the damper of a
furnace flue.
The instrument as applied to hot water heated by means of gas
comprises a passage through which the gas has to pass on its way to the
burners, and a small metallic vessel, closed by a diaphragm of vulcanised

page_text: rubber, or thin metal, or other suitable flexible material. The diaphragm
has resting on or connected to it a rod connected to a small valve which
is adapted to control the passage for the gas, but arranged so as never
to completely close. the passage. In the vessel a liquid boiling at a
suitable temperature is put, a mixture of methylated spirit and water
being used when the instrument is applied for regulating hot water;
and the water heated by means of the gas having access to the outside
of the vessel causes the liquid inside to boil whenever the desired tem-
perature is attained. The boiling of the enclosed liquid causes the
diaphragm to be raised and the valve in the gas passage to reduce the
supply of gas, the valve, however, opening again whenever the tempera-
ture of the heated water becomes too low.
The motion of the diaphragm and valve is by preference controlled in
both directions by means of springs.
The vessel enclosing the liquid is by preference itself encased by an
outer shell having openings formed round it, and being connected with
the cold water supply pipe, so that on any hot water being drawn off,
the cold water entering to supply its place acts on the closed vessel at
the outset, and by condensing the enclosed liquid causes the valve to be.
full opened.
The instrument may be made of various sizes, and when applied to a
furnace damper, the diaphragm is connected to the rods or levers by
which the damper is moved. Where the furnace is that of a boiler the
water or steam may be made to act on the closed vessel.
SPECIFICATION in pursuance of the conditions of the Letters Patent, 2
filed by the said James Lockhart in the Great Seal Patent Office
on the 6th March 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES.
LOCKHART, of Glasgow, in the County of Lanark, North Britain,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of September, in the
year of our Lord One thousand eight hundred and seventy-two, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,,

page_text: give and grant unto me, the said James Lockhart, Her special licence that
I, the said James Lockhart, my executors, administrators, and assigns, or
such others as I, the said James Lockhart, my executors, administrators,
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 "AN IMPROVED HEAT REGULATOR," upon the
condition (amongst others) that I, the said James Lockhart, my execu-
tors 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.
NOW KNOW YE, that I, the said James Lockhart, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement in writing, reference being had to the accom-
panying Drawings, that is to say:-
My said Invention relates to a simple and sensitive instrument to be
used for regulating heat under various circumstances. It may be very
conveniently applied where it is wished to keep up a supply of water
heated by gas to a certain temperature, as for baths, hot water heating
pipes, and the like, and it may also be modified to act on the damper of
a furnace flue or on a ventilating valve.
And in order that my said Invention and the manner of performing
the same may be properly understood I hereunto append a Sheet of
explanatory Drawings, to be herein-after referred to, and representing
modifications of my improved instrument as adapted for regulating the
supply of gas to apparatus for heating water. In these Drawings
the same reference numerals are used to mark the same or like parts
wherever they are repeated.
Figure 1 is a vertical section, and Figure 2 is an elevation of one
modification of the instrument, which comprises a passage 1, 2, 3,
through which the gas has to pass on its way to the burners, and a
small metallic vessel 4 closed by a diaphragm 5 of vulcanised rubber or

page_text: thin metal or other suitable flexible material. The diaphragm 5 has
resting on it a rod 6 connected to a conical valve 7 working in a
correspondingly conical part 2 of the gas passage, and thus adapted to
control the flow of the gas; the valve 7 is however made with a small
groove 8 so that the gas is never completely shut off by it, sufficient
being able to pass by the groove 8 when the valve 7 is otherwise
quite close to maintain a minute light at the burner. In the vessel 4 a.
liquid boiling at a suitable temperature is put, a mixture of methylated
spirit and water being used when the instrument is applied for regulating
hot water; and the water heated by means of the gas being allowed
access to the outside of the vessel 4 causes the liquid inside to boil
whenever the desired temperature is attained. The boiling of the
enclosed liquid causes the diaphragm 5 to be raised, and the valve 7 in the
gas passage 2 to reduce the supply of gas, the valve 7, however, opening
again whenever the temperature of the heated water becomes too low.
The motion of the diaphragm 5 and valve 7 is by preference con-
trolled by springs 9, 10, applied one, 9, beneath the diaphragm, and the
other, 10, so as to act in the opposite direction against the other end of
the valve rod 11; a screw 12, with an external button, is applied for
adjusting the upper spring 10, and works through the end of a cap 13
which can be screwed off the body of the instrument to give access for
adjusting the valve 7 relatively to the diaphragm; the valve rod 11 is
screwed into an enlargement or piston 14 formed on the upper end of
the diaphragm rod 6, and this piston which also serves to guide the rods
and valve is prevented from turning by ribs 15 attached to the inside of
the body, to fit which it is formed with grooves at the sides.
The vessel 4 enclosing the liquid is by preference itself encased by an
outer shell 16, having openings 17 formed round it, and is connected
with the cold water supply pipe at 18, so that on any hot water being
drawn off the cold water entering to supply its place acts on the closed
vessel 4 at the outset, and by condensing the enclosed liquid causes the
valve 7 to be full opened. A stop cock 19 is provided to completely
'shut-off the gas when required.
The instrument may be made of various sizes and when applied to a
furnace damper the diaphragm (5) is to be connected to the rods or
levers by which the damper is moved. Where the furnace is that of a
boiler the water or steam may be made to act on the closed vessel (4).

page_text: When using the instrument to regulate heat through the agency of a
ventilating valve, the closed vessel (4) must be filled with ether or other
volatile liquid or mixture of liquids boiling at a sufficiently low tem-
perature, and the vessel must be exposed in the passage or space the
beat of which is to be regulated, whilst the diaphragm 5 must be
connected to the ventilating valve. An accurately fitted piston may in
some cases be substituted for the diaphragm (5).
Figure 3 is a vertical section of a simplified modification which is
applicable in some cases where it may be convenient to use mercury
as the liquid from the expansion of which the regulating action is to
be obtained. In this case the gas is admitted into the upper end of a
tube 20, having a bulb 21 at its lower end and passes onwards to the
burners by a lateral branch 22. Such a quantity of mercury is put into
the bulb 21 and tube 20 as that when the fluid in which the bulb 21. is
immersed reaches the desired temperature the consequent expansion of
the mercury will make it rise and all but close the opening into the
branch pipe 22.
Having thus particularly described my said Invention, and the manner
of performing the same, I have to state that I do not restrict myself to
the precise details herein described or delineated; but that what I believe
to be novel and original, and claim as the Invention secured to me by
the herein-before in part recited Letters Patent is, the constructing of
heat regulators to act by the expansion of an enclosed liquid, and sub-
stantially in the improved manner herein-before described.
In witness whereof, I, the said James Lockhart, have hereunto set
my hand and seal, this Fifth day of March, in the year of our
Lord One thousand eight hundred and seventy-three.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
JAMES LOCKHART. (L.S.)