Improvements in Arrangements for Maintaining Equable or Nearly Equable Temperatures within Enclosed Spaces.
Year: 1891

page_text: Date of Application, 4th Aug., 1891
Complete Specification Left, 4th May, 1892-Accepted, 18th June, 1892
PROVISIONAL SPECIFICATION.
Improvements in Arrangements for Maintaining Equable or Nearly
Equable Temperatures within Enclosed Spaces.
I CHARLES EDWARD HEARSON of No. 5 Templar Street Camberwell in the
County of Surrey Engineer do hereby declare the nature of this invention to be as
follows:-
My invention consists of the improvements hereinafter described in arrangements
for maintaining equable or nearly equable temperatures within enclosed spaces such
as the chambers of incubators and other chambers and vessels in which equable or
nearly equable temperatures are required to be maintained.
According to my said invention 1 surround the chamber or vessel or other
enclosed space in which an equable or nearly equable temperature is required to be
maintained with a water jacket provided with an overflow pipe or outlet which
water jacket is when necessary charged with water heated or cooled to the tem-
perature required within the said chamber or vessel or other enclosed space. And
for the purpose of correcting any variation of temperature of the water in the
water jacket due to absorption of heat by or radiation of heat from the said water I
connect the water space of the water jacket with a refrigerating apparatus and with
a heating apparatus and provide for the automatic supply of water to the water
jacket either through the refrigerating apparatus or through the heating apparatus
as and when required for the said purpose by means of mechanism actuated by a
thermostat so situated within the water jacket as to be surrounded by the water
therein when it is charged with water.
In most cases I surround the water jacket and the refrigerating apparatus
and the heating apparatus with felt or cork or other imperfect conductor
of heat.
Where the temperature required in the chamber or vessel or other enclosed space
is higher than that of the external atmosphere I in some cases dispense with the
refrigerating apparatus and where the said temperature is lower than that of the
external atmosphere I in some cases dispense with the heating apparatus.
The thermostat which I prefer consists of a hermetically sealed expansible and
collapsible case or capsule containing a liquid which boils at the temperature
which is required to be maintained within the chamber or vessel or other enclosure.
The said case or capsule may be formed as described in the Specification of Letters
Patent granted to me and bearing date 24 November 1881 No. 5141.
Where it is desirable to limit the extent of expansion of the said case or capsule
which is produced by the boiling of the liquid contained therein I arrange within
it a frame or plate of metal of suitable form and size and having sufficient
rigidity to prevent change of figure of the said case or capsule beyond the required
degree.
Dated the 4th day of August 1891.
W. T. WHITEMAN,
Agent for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Arrangements for Maintaining Equable or Nearly
Equable Temperatures within Enclosed Spaces.
I CHARLES EDWARD HEARSON of No. 5 Templar Street Camberwell in the
County of Surrey Engineer do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement:-
My invention consists of the improvements hereinafter described in arrangements
for maintaining equable or nearly equable temperatures within enclosed spaces such
as the chambers of incubators and other chambers and vessels in which equable or
nearly equable temperatures are required to be maintained.
And
According to my said invention I surround the chamber or vessel or other
enclosed space in which an equable or nearly equable temperature is required to be
maintained with a water jacket provided with an overflow pipe or outlet which
water jacket is when necessary charged with water heated or cooled to the tem-
perature required within the said chamber or vessel or other enclosed space.
for the purpose of correcting any variation of temperature of the water in the
water jacket due to absorption of heat by or radiation of heat from the said water
I connect the water space of the water jacket with a refrigerating apparatus and
with a heating apparatus and provide for the automatic supply of water to the
water jacket either through the refrigerating apparatus or through the heating
apparatus as and when required for the said purpose by means of mechanism
actuated by a thermostat so situated within the water jacket as to be surrounded
by the water therein when it is charged with water.
In most cases I surround the water jacket and the refrigerating apparatus and
the heating apparatus with felt or cork or other imperfect conductor of heat.
The thermostat which I prefer consists of a hermetically sealed expansible and
collapsible case or capsule containing a liquid which boils at the temperature
which is required to be maintained within the chamber or vessel or other enclosure.
The said case or capsule may be formed as described in the Specification of Letters
Patent granted to me and bearing date 24 November 1881 No. 5141.
I will further describe my invention with reference to the accompanying
drawings
Figures 1, 2 and 3 of which are respectively a front elevation a side eleva-
tion and a plan view of apparatus constructed according to my invention for use in
the cultivation of micro-organisms.
Figure 4 is a vertical section of the same apparatus taken on the line 1.
Figure 3 and Figures 5 and 6 are horizontal sections of the same taken respec-
tively on the lines 2 and 3 Figure 4.
In the following description the parts of the drawings are referred to by the
letters and figures marked thereon, the same letters and figures of reference being
used to indicate the same parts in all the figures of the drawings hereinbefore
referred to.
a is a chamber formed of sheet metal and provided with a glazed door a¹ (see
Figure 6) and containing a perforated plate or shelf a³ for supporting vessels in
which the organisms to be cultivated are placed as usual. bis the water jacket
which surrounds the said chamber a. 6' is the overflow pipe of the water jacket
and 6 is a pipe communicating with the water space of the water jacket and pro-
vided with a screw cap 6 through which pipe 62 the water in the water jacket may be
allowed to run off when necessary. c is a wooden case which encloses the jacketted
chamber a and certain other parts of the apparatus hereinafter referred to the
said chamber a being supported a little above the bottom of the case e on blocks
of wood cc. The said case is provided with a door 2 which admits of access to
the glazed door a¹ of the chamber a. The refrigerating apparatus consists of a

page_text: vessel d for containing ice which vessel is supported within the case c above the
chamber a on bars of wood c³ ³ and communicates with the water jacket b by
means of a pipe d'. The mouth of the said vessel d lies below an aperture in the top
of the case c which aperture is closed by a removable cover c. d² is a perforated
diaphragm within the said vessel d on which diaphragm the ice rests.
The heating
apparatus consists of a casing e secured outside the case c and containing a gas
burner and a receptacle for water consisting of a metal-tube g closed at the lower
end and communicating by means of a pipe g' with the water jacket 6 of the
chamber a and connected by brazing to another metal tube h which receives heat
from the gas flame. The upper part of the casing e in which the tubes o and h are
supported is closed on all sides and the part of its interior which is not occupied
by the said tubes is packed with slag wool. d³ is a pipe by which water is
conveyed to the refrigerating apparatus and 9 is a pipe by which water is
conveyed to the heating apparatus the upper ends of which pipes are secured in a
cup which is mounted on a shelf or bracket within the upper part of the case c
and projects through an aperture in the top thereof. The interior of the said cup i
communicates with the water jacket 6 by means of a pipe which passes into a
tube j communicating with the said water jacket and projecting into an opening in the
top of the case c. The mechanism by which water is supplied as and when required
to the refrigerating apparatus and to the heating apparatus consists of a lever k
mounted on pivots carried by lugs 11 formed on a base plate m screwed on the top of
the case c which lever carries a set screw k¹ and an adjustable weight k³ and a forked
rod the fork of which rod is engaged with a tube n secured horizontally to a
spindle n¹ mounted vertically on the base plate m the upper end of the said spindle
being supported by an arm o formed on a standard o' screwed to the said plate m.
By this arrangement the end of the tube n which projects over the cup i is caused
to move to the left when the lever k is raised and to the right when the said lever
is
is depressed. p p are stops which limit the range of motion of the said tube.
is the thermostat which actuates the said mechanism. The said thermostat is of
the kind described in the Specification of Letters Patent granted to me and bearing
date 24 November 1881 No. 5141 that is to say it consists of a flat hermetically
sealed case or capsule containing a liquid which boils at or a few degrees below the
temperature required within the chamber a. The said capsule is supported in the
water jacket by a frame suspended in the tube which frame consists of a plate r
connected by wires to a tube secured at its upper end in a hole formed in the
plate m below the screw carried by the lever k. In the said tube 2 is a rod t
which rests on the capsule q and projects above the plate m on the projecting end of
which rod the said screw k¹ bears. By means of the said rod t expansion and
collapsion of the capsule 9 produced by variations of temperature of the water
in the water jacket bare caused to actuate the lever k. u is a thermometer the
bulb of which is within the chamber a. The spaces between the parts of the
apparatus within the case c and between the said parts and the sides and top and
bottom of the said case are packed with sawdust or other suitable imperfect
conductor of heat as indicated at in Figures 4 and 6. In order that the parts of
the apparatus illustrated in Figure 5 may be clearly seen the said packing is not
shown in the said figure.
The method of using the apparatus hereinbefore described and its action are as
follows:-
The end of the tube n farthest from the cup i is connected by a flexible pipe to
a convenient supply of cold water capable of regulation by means of an ordinary
tap and the tube of the gas burner projecting from the casing of the heating
apparatus is in like manner connected to a supply of gas the doors c³ and a¹ are
opened the water jacket b is charged with water of slightly lower temperature than
that desired within the chamber a by pouring the water into the vessel d until it
begins to run out from the pipe b' the water so poured in passing into the water
jacket by way of the pipe d' and ice is placed in the vessel d. Gas is then
admitted to the burner and ignited the tap regulating the supply of water is opened

page_text: sufficiently to allow the water to pass in drops from the free end of the tube n the
screw kis turned until the drops of water passing from the said tube n fall into the
pipe and the doors a¹ and c² are closed. The water thus entering the said pipe g
passes thence into the tube g of the heating apparatus and causes a portion of the
heated water in the said tube to flow into the water jacket b the temperature of
the water therein being thereby gradually raised until it has reached the boiling
point of the liquid in the capsule g when the said capsule expands and raises the
rod t and lever k the motion of which lever throws the tube n to the left until it
bears against the stop p. The water dropping from the said tube n then passes
into the pipe d³ by which it is conveyed into the ice vessel d whence it passes by
the pipe into the water jacket the temperature of the water in which is thereby
lowered until the capsule q collapses to a sufficient extent to cause the mechanism
on the top of the case c to move the tube n over the pipe g² when the temperature of
the water in the water jacket is again raised as herein before described. When
the said water is of such a temperature that the capsule is expanded only to a
comparatively slight extent the tube n stands midway between the stops p p¹ and
the water drops therefrom into the cup i whence it passes by the pipes i and j into
the water jacket without passing through either the heating apparatus or the
refrigerating apparatus the effect being to slowly lower or raise to a slight extent
the temperature of the water in the water jacket according as the temperature
of the dropping water is lower or higher than that required in the chamber a. When
the doors a¹, c² are kept closed for a considerable time the tube n is automatically
maintained in such a position that the water dropping therefrom passes partly into
the cup'i and partly into one or other of the tubes g² d³ according as the temperature
which causes expansion of the capsule under the pressure to which it is subjected is
higher or lower than that of the surrounding atmosphere.
In the drawings the weight 2 carried by the lever k is shown nearly close to the
fulcrum of the said lever and this is the position which the weight should occupy
when the apparatus is being started. If after the apparatus has been in action
about two hours while the doors a¹ c2 have remained closed it be found that the
temperature within the chamber a is below the degree required the said weight is
slidden along the lever k towards its free end at intervals of about half an hour a
distance of about one inch at a time until the desired temperature is indicated by
the thermometer u. The effect of thus altering the position of the said weight is
to increase the pressure on the capsule 7 and consequently to raise the boiling
point of the liquid within it and thereby to cause the thermostat to act at a higher
temperature.
Although I prefer a thermostat of the kind hereinbefore referred to and described
an electrical or other thermostat such as a compound bar may be used in substitution
therefor.
Instead of placing the thermostat in the water jacket as herein before described
and illustrated in the accompanying drawings it may be placed in the chamber a.
If preferred the pipe may be carried outside the case of the apparatus so that
the water entering it may be directed into any convenient receptacle instead of
passing into the water jacket.
Where desirable a lamp or other means for heating the water in the tube g may
be substituted for the gas burner f.
Where the temperature required in the chamber or vessel or other enclosed space
is higher than that of the external atmosphere I in some cases dispense with the
refrigerating apparatus and where the said temperature is lower than that of the
external atmosphere I in some cases dispense with the heating apparatus.
Where it is desirable to limit the expansibility of the case
or capsule of
the thermostat herein before referred to arrange within it a frame or plate of
metal of suitable form and size and having sufficient rigidity to prevent change
of figure of the said case or capsule beyond the required degree.
Figure 7 of the accompanying drawings is a face view of a capsule containing a
suitable metal frame. Figure 8 is a section of the same taken on the line 4

page_text: Figure 7 and Figure 9 is a separate view of the said frame. The said Figures 7, 8
and 9 are drawn to a larger scale than the other Figures of the drawings herein-
before referred to.
Referring to the said Figures 7, 8 and 9 w is the said metal frame a¹ x are the
outer portions of the capsule which are formed preferably of thin sheet copper or
brass. yy are pieces of blotting paper or other suitable absorbent material and z
is a boss of metal affixed to the part ¹ which boss is provided for the bearing of
the rod t hereinbefore referred to. In constructing the capsule the edges of the
part are turned over on the paper y¹ and the edges of the part 2 are turned over
on the frame w the paper y2 being between the said part 2 and the said frame.
The two parts of the shell are then soldered together at their edges and the
liquid with which the capsule is to be charged is passed into it through a hole in
the outer shell and is absorbed by the paper y' y' the said hole being afterwards
hermetically sealed with solder.
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 I
claim :-
First Arrangements for the purpose of maintaining an equable or nearly
equable temperature within a jacketted chamber substantially as hereinbefore
described that is to say automatically acting arrangements for the said purpose
whereby variation from a predetermined degree of temperature in the jacket or in
the chamber causes the passage to the jacket of fluid at a higher or lower tem-
perature according as required to correct the said variation.
Secondly-The general combination and arrangement of parts constituting the
apparatus hereinbefore described and illustrated in Figures 1 to 6 inclusive of the
accompanying drawings.
Thirdly: The application to the case or capsule of a thermostat of the kind
described in my aforesaid Specification of means substantially as hereinbefore
described for limiting the expansibility of the said case or capsule.
Fourthly―The means herein before described with reference to Figures 7, 8
and 9 of the accompanying drawings for limiting the expansibility of the case or
capsule of a thermostat of the kind described in my aforesaid Specification.
Dated the 4th day of May 1892.
W. T. WHITEMAN,
Agent for the Applicant.