A THERMOSTAT, OR APPA- RATUS FOR THE REGULATION OF TEMPERATURE AND OF VENTILATION
Year: 1853

page_text: LETTERS PATENT to William Sykes Ward, of Leeds, in the County
of York, Esquire, for the Invention of "A THERMOSTAT, OR APPA-
RATUS FOR THE REGULATION OF TEMPERATURE AND OF VENTILATION."
PROVISIONAL SPECIFICATION left by the said William Sykes
Ward at the Office of the Commissioners of Patents, with his
Petition, on the 6th January 1853.
I, WILLIAM SYKES WARD, of Leeds, in the County of York, Esquire,
do hereby declare the nature of the said Invention for "A THERMOSTAT,
OR APPARATUS FOR THE REGULATION OF TEMPERATURE AND OF VENTILATION,"
to be as follows:-
My Invention consists in using metallic vessels in which the vapour
of a volatile liquid is used to give motive power for opening or shutting
ventilators or dampers, or regulating the flow of hot or cold water, or
similar applications for regulation of temperatures. I am aware that
the vapour of æther has been used for such purposes when confined in
tubes by mercury; but in such apparatus the amount of power to be
obtained is much limited by the weight and consequent expense of
mercury required. I therefore make use of vessels of thin metal, of

page_text: which the ends or sides, being discs of metal, are so thin and flexible as
to be changeably either convex or concave, and in which the vapour of
sulphuric ether (or of suitable volatile liquid), along with a portion of
such liquid, is inclosed. The discs or ends of such a vessel acting as
diaphragms, separating the vapour from the external atmosphere, will,
at temperatures under the boiling point of the fluid employed, be
pressed inwards by the atmosphere, but with a pressure varying accord-
ing to the temperature. I therefore attach a counterpoise, or a spring
of sufficient weight or tension, partially to counteract the pressure of the
atmosphere; or, in another form of apparatus, inclose the vessel in another.
vessel from which the air is partially exhausted, so that the differential
pressure of the ethereal vapour above or below the degree at which the
pressure is counterbalanced gives motive power. And as the extent of
motion from each of such moveable surfaces is very slight, I prefer
generally to combine several of such vessels together, so as to have
several moveable ends or discs; and as there is a peculiar action when
a weight is employed to extend such discs, I find it advisable to use a
combination of two pulleys placed eccentrically on the same axis, so that
a descending weight may operate in a rapidly increasing ratio. Motion
being thus produced, it is obvious that if the thermostat be geared to the
ventilators of hothouses or of buildings, and to pipes supplying hot or
cold water, or to dampers of furnaces, and to numerous similar purposes,
by a sufficient size and number of flexible surfaces, any reasonably
required power and extent of motion may be obtained.
SPECIFICATION in pursuance of the conditions of the Letters Patent, a
filed by the said William Sykes Ward in the Great Seal Patent
Office on the 6th July 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, . I,
WILLIAM SYKES WARD, of Leeds, in. the County of. York, Esquire,..
send greeting..
WHEREAS Her Most Excellent Majesty Queen Victoria, by Her,
Letters Patent, bearing date the Sixth day of January, in the year of
our Lord One thousand eight hundred and fifty-three, in the sixteenth

page_text: year of Her reign, did, for Herself, IIer heirs and successors, give and
graut unto me, the said William Sykes Ward, Her special licence that
I, the said William Sykes Ward, ny executors, administrators, and
assigns, or such others as I, the said William Sykes Ward, my executor's,
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, arid
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "A THERMOSTAT,
OR APPARATUS FOR THE REGULATION OF TEMPERATURE AND OF VENTILATION,"
upon the condition (amongst others) that I, the said William Sykes
Ward, by an instrument in writing under my hand and seal, should pár-
ticularly 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 William Sykes Ward, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof (that is to say):
My Invention consists in using metallic vessels in which the vapour
of a volatile liquid is used to give motive power for opening or shutting
ventilators or dampers, or regulating the flow of hot or cold water, or
similar applications for regulation of temperatures. I am aware that
the vapour of ether has been used for such purposes when confined in
tubes by mercury; but in such apparatus the amount of power to be
obtained is much limited by the weight and consequence expence of
mercury required. I therefore make use of vessels of thin metal,
of which the ends or sides, being discs of metal, are so thin and flexible
as to be changeably either convex or concave, and in which the vapour
of sulphuric ether (or of suitable volatile liquid, along with a portion of
such liquid, is enclosed. The discs or ends of such a vessel acting as
diaphragms, separating the vapour from the external atmosphere, will,
at temperatures under the boiling point of the fluid employed, be pressed
inwards- by the atmosphere, but with a pressure varying according to

page_text: the temperature. I therefore attach a counterpoise, or a spring of
sufficient weight or tension, partially to counteract the pressure of the
atmosphere; or, in another form of apparatus, inclose the vessel in
another vessel from which the air is partially exhausted, so that the
differential pressure of the ethereal vapour above or below the degree
at which the pressure is counterbalanced gives motive power. And as
the extent of motion from each of such moveable surfaces is very slight,
I prefer generally to combine several of such vessels together, so as to
have several moveable ends or discs; and as there is a peculiar action
when a weight is employed to extend such discs, I find it advisable to
use a combination of two pulleys, placed eccentically on the same axis,
so that a descending weight may operate in a rapidly increasing ratio.
Motion being thus produced, it is obvious that if the thermostat be
geared to the ventilators of hothouses or of buildings, and to pipes sup-
plying hot or cold water, or to dampers of furnaces, and to numerous
similar purposes, by a sufficient size and number of flexible surfaces, any
reasonably required power and extent of motion may be obtained.
And in order that my said Invention may be more fully understood
and readily carried into effect, I will proceed to describe the means
pursued by me. And I would at the outset state that the form of the
apparatus may be varied, so long as the peculiar mode of action herein
described be retained.
the temperature. I therefore attach a counterpoise, or a spring of
sufficient weight or tension, partially to counteract the pressure of the
atmosphere; or, in another form of apparatus, inclose the vessel in
another vessel from which the air is partially exhausted, so that the
differential pressure of the ethereal vapour above or below the degree
at which the pressure is counterbalanced gives motive power. And as
the extent of motion from each of such moveable surfaces is very slight,
I prefer generally to combine several of such vessels together, so as to
have several moveable ends or discs; and as there is a peculiar action
when a weight is employed to extend such discs, I find it advisable to
use a combination of two pulleys, placed eccentically on the same axis,
so that a descending weight may operate in a rapidly increasing ratio.
Motion being thus produced, it is obvious that if the thermostat be
geared to the ventilators of hothouses or of buildings, and to pipes sup-
plying hot or cold water, or to dampers of furnaces, and to numerous
similar purposes, by a sufficient size and number of flexible surfaces, any
reasonably required power and extent of motion may be obtained.
And in order that my said Invention may be more fully understood
and readily carried into effect, I will proceed to describe the means
pursued by me. And I would at the outset state that the form of the
apparatus may be varied, so long as the peculiar mode of action herein
described be retained.
DESCRIPTION OF THE DRAWING.
Figure 1, represents a section, and Figure 2, a front view of an
apparatus construced according to my Invention; and Figure 3, shows a
section of another arrangement, which somewhat differs from that shewn
at Figures 1, and 2. In Figures 1, 1, and 2, the same letters indicate the
like parts. A, A, A, A, A, A, represent a series of thin vessels, by pre-
ference of copper tiuned, in the form of very short cylinders, having the
ends slightly raised or dished. These vessels are independant of cach
other, being connected by socket joints and vins, and are suspended

page_text: therein, so as to expel the atmospheric air, the aperture is sealed with
solder. Such sealing is easily effected, if two apertures be made in any
part of the apparatus, one about of an inch in diameter, and the
other about one hundredth of an inch, and the larger one first sol-
dered, the soldering being effected just when the æther has ceased to
boil. In such apparatus the boxes A, are about eight inches diameter,
and six in number, so that twelve flexible surfaces are combined. The
thickness of the copper is such that one square foot thereof weighs
about one pound. The weight W, may be varied from about 5 to 50 lbs.,
according to the temperature which the apparatus is intended to regulate.
The proportions of the excentric pulleys used by me are such, that when
the weight is raised the tension upon the series of vessels is a little
increased by leverage; but when the weight has descended, so as to
turn the pulley about half round, on account of the varying leverage,
the tension on the series of vessels becomes about five times that
amount; but this will require adjustment by trial with each apparatus.
In good adjustment the weight should have equal tension on the vessels
throughout the half turn of the pulleys, as in the fusce of a watch; and
the excentrics are made with slots, so that they may be adjusted on the
axis. I have represented supports E, and E', and rods F, F, for com-
municating motion to ventilators, which will be easily understood on
inspection. To the support E, is connected the uppermost of the
vessels A; and E', supports the axis on which the pulleys turn. In
Figure 3, I have represented an arrangement in which, by partially re-
lieving the flexible surfaces from the pressure of the atmosphere, the
necessity of using weights is avoided. A, A, A, A, represent vessels
combined together, and having flexible ends, and connected with another
vessel B, of rigid material, so that the vapour generated in B, passes
freely to each of them. The external surfaces of B, are exposed to the
atmosphere or fluid of which the temperature is to be regulated. C, is
a rigid vessel inclosing the vessels A, A, A, A, and from which the
atmosphere has been partly exhausted by an exhausting syringe. The
extent of exhaustion regulating the temperature at which the apparatus
acts, the greater the exhaustion the lower the temperature at which
motion to act on a ventilator will take place. D, D, D, are a series of

page_text: grods and levers connected. with the vessels A, A, A, A, so as to commu-
nicate their motion to the exterior of the vessel C; through air-tight
: fittings, or other apertures rendered air-tight:in, any convenient manner,
- which I have represented as rendered air-tight by a small portion..of
cvulcanized india-rubber tube a. I would here state that I do not confineŭ
myself, to the use of the particular fluid and its vapor above: mentioneil,
but have found sulphuric æther the most suitable. for. teniperatures
ranging from 40 to 90 degrees of Fahrenheit's, thermonieter; alcohol
, with its vapour for temperatures from about 90 to 180 degrees; water
..with its vapour from temperatures from about 180 to 212 degrees.
Other fluids may, however, be used.
When the thermostat is fixed in such structures as.hothouses; :I
(prefer that it should be shaded from the:direct.rays of the sun...
What I claim is, the combination of metallic. vessels having a flexible
*surface, and filled with a volatile liquid and its vapour,, and apparatus,
herein described, for the purpose of obtaining, motive power from the
varying tensions of the vapour, and communicating such power to regu-
"late ventilators, dampers, or valves.
In witness whereof I, the said William Sykes Ward, have hereunto
hand and seal, this Fifth day of July, in the year of our
Lord One thousand eight hundred and fifty-three.
set my
Witness,
WILLIAM SYKES WARD. (L.S.).
WILLIAM STEAD, of Leeds,
Clerk to the above named
William Sykes Ward.