A New or Improved Temperature Indicator, applicable to Domestic and Bakers' Ovens, Steam-pressure Boilers, and the like.
Year: 1892

page_text: Date of Application, 22nd Mar., 1892
Complete Specification Left, 22nd Dec., 1392-Accepted, 18th Mar., 1893
PROVISIONAL SPECIFICATION.
A New or Improved Temperature Indicator, applicable to Domestic
and Bakers' Ovens, Steam-pressure Boilers, and the like.
1 CHARLES HEIRONS. of 28 St. Margarets Grove St. Margarets Twickenham
in the County of Middlesex Smith and Machinist do hereby declare the nature
of this invention to be as follows:-
This invention which relates to a new or improved temperature indicator, has
for its object to indicate on the exterior, the interior temperature of domestic and
bakers ovens, steam-pressure boilers, and the like, in such manner, that should
the temperature in the said ovens or boilers, be allowed to rise higher than the
boiling point of mercury, there may be no danger of the bursting of the tube of
the thermometer, and is based upon the principle of causing a current of air to
automatically enter, and pass through a heated metallic tube or chamber, and upon
its exit in a heated condition at the higher orifice of the said tube or chamber, to
impinge upon the reservoir or bulb of a thermometer, the said thermometer being
affixed on the exterior of the said oven or boiler, and the metallic tube or chamber
being affixed in the interior of the same, but having its ends projected through the
wall of the said oven or boiler to the outer atmosphere.
The instrument wherein the foregoing principle is applied, under this invention,
as a temperature indicator, consists in piercing two holes at unequal heights
through the wall of the oven or boiler or other heat container to which it may be
applied, a metallic tube or chamber is affixed in the interior of the said oven or
boiler, having its ends projected through the said holes to the outer atmosphere,
the orifices of the said tube or chamber being left open; a thermometer having a
suitable range and corrected scale, is affixed in a suitable position outside the said
oven or boiler, and the higher end of the said metallic tube or chamber, is elongated
and bent around, as may be required to bring the orifice of the same in close
proximity to the bulb or reservoir of the said thermometer, so that a current of
air in passing upward through the said metallic tube or chamber, will upon its exit
at the higher orifice of the same, impinge upon the bulb or reservoir of the said
thermometer, thus causing the mercurial column of the thermometer to rise and
fall in conformity to the changes of temperature in the interior of the oven, boiler,
or other heat container to which this invention may be applied.
The aforesaid current of air which is automatically set up as the oven or boiler
becomes heated, is taken from, and returned to, the atmosphere of the room, or
other structure in which the oven or boiler is located, and is continually passing
from the lower to the higher end of the said tube or chamber (in which it becomes
heated) during the whole time the temperature of the oven, or boiler remains in
excess of the temperature of the surrounding atmosphere.
Dated this 21st day of March 1892.
CHARLES HEIRONS.
COMPLETE SPECIFICATION.
A New or Improved Temperature Indicator, applicable to Domestic
and Bakers' Ovens, Steam-pressure Boilers, and the like.
I CHARLES HETRONS of 28 St. Margarets Grove St. Margarets Twickenham
in the County of Middlesex Smith and Machinist 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 :-
My invention which relates to a new or improved temperature indicator, has for
its object to indicate on the exterior, the interior temperature of domestic and
го

page_text: bakers ovens, steam pressure boilers and the like, in such a manner that should
the temperature within the said ovens, boilers and other like heated chambers, to
which my invention may be applied, be allowed to rise to a very much higher
temperature than the boiling point of mercury, there will be no danger of bursting
the tube of the thermometer. It is based upon the principle of causing a current
of air to automatically enter and pass through a heated metallic chamber and upon
its exit in a heated condition at the upper orifice of the said chamber, to impinge
upon the bulb or reservoir of a thermometer, the said thermometer being affixed on
the exterior of the said oven or boiler and the metallic chamber being affixed in the
interior of the same, but having its ends protruded through the wall of the said
oven or boiler to the outer atmosphere, the utility of the apparatus as a
temperature indicator is limited to temperature above two hundred degrees of
Fahrenheit's thermometer.
In order that my invention may be more fully understood and readily carried
into effect will now proceed to describe the drawings hereunto annexed.
Figure 1, is a front elevation of a new or improved temperature indicator and is
constructed according to my present invention.
Figure 2, is a vertical section of the same.
Figure 3, is a front elevation of my invention showing the thermometer
suspended horizontally and having the free end of the nipple e, brought into close
proximity thereto but not inserted into the bulb casing f, of the thermometer.
Figure 4, is a vertical section of a part of my invention showing the manner of
constructing the heating chamber a, in the wall or plate of a boiler, or an oven
door, or other heated chamber.
Figure 5, is a side elevation of a part of my invention showing the manner of
constructing the heating chamber a, and the connecting tubes c c, in one piece of
tube by bending the same to the required form.
In constructing an instrument according to my invention a metallic tube or
chamber a, (which for facility of reference I will call the heating chamber) is
provided preferably of platinum iron or copper of the requisite size and strength
and having male or female screw-threads A, as may be required at or near the ends
thereof, to which are screwed two other metallic tubes c c, of any required length
and diameter, having screw threads on each and all of their ends; these tubes
being connected to the aforesaid heating chamber a, at right angles to the same
form when in their proper position three sides of a parallelogram. Upon the
free end of one of the aforesaid tubes r, (which for facility of reference I will
call the lower connecting tube) is screwed a back-nut b, or its equivalent, and upon
the free end of the other aforesaid tube (which for facility of reference I will call
the upper connecting tube) c, is screwed a right angle elbow d, or its equivalent,
and into the free end of the said elbow d, or its equivalent is screwed another
metallic tube e, of any requisite length and diameter, (which for facility of reference
I will call the nipple) the whole forming when screwed together one continuous,
circuitous tube.
The same may be performed by bending one continuous tube, to form three
sides of a parallelogram and affixing by screw threads, a right angle elbow d,
carrying a nipple e, in one end thereof, and by the same means a back-nut, or its
equivalent on to the other end thereof (as shown at Fig. 5).
The same end may also be arrived at by forming a metallic chamber in the wall
of the oven, boiler or other heated chamber, to which my invention may be applied,
and piercing two holes ss, at unequal heights\ through the outer side thereof, to
the interior of the chamber a, and affixing an elbow d, carrying a nipple e, in the
higher one of the said holes s, the lower hole s, being bored of the required size to
control the herein to be described air current (as shown at Fig. 4).
A thermometer tube of glass J, containing by preference mercury X, is provided
having a suitable range and an expansion or safety chamber y, at the higher end
thereof; this is affixed on the reverse side of a scale plate h, preferably of brass,
having an elongated slot i, through which the position of the mercury in the

page_text: aforesaid glass tube J, may be readily observed. A scale N, indicating the several
degrees of temperature, may be marked upon the aforesaid glass tube J, but I
prefer to mark it upon the obverse side of the aforesaid scale plate h. For the
more effectual protection of the aforesaid glass tube J, from fracture, I enclose the
same on three sides, for a distance of three fourths or there-about from its higher
end downward, in a metallic casing g, (which for facility of reference I will call
the tube casing) the said tube casing being lined by preference with asbestos y.
Over the lower or bulb end of the aforesaid glass tube J, I affix a casing f, (which
for facility of reference I will call the bulb casing) having an opening m, (this
opening will call the outlet of the bulb casing) at its higher end, and having a
hole pierced in either side or in the lower end thereof 1, as may be required, to
admit of the free end of the aforesaid nipple e, being inserted therein, or brought
into close proximity thereto as may be required, (this hole I will call the inlet of
bulb casing). The aforesaid tube casing g, and bulb casing, is secured to the
reverse side of the aforesaid scale plate by rivets, screws or solder in a manner
common to such operations.
I will now proceed to describe the manner in which the instruments herein
described are applied and secured in their respective positions when in use as a
temperature indicator, two holes of a given diameter and distance apart are at
unequal heights pierced through the wall of the oven, boiler or other heated
chamber to which my invention may be applied, the herein before described
heating chamber a and the aforesaid upper and lower connecting tubes cc, being
connected one to the other and the aforesaid back-nut b, and the right angle
elbow d, or their equivalents being removed, the aforesaid heating chamber a, may
be placed in position by inserting the free ends of the connecting tubes cc, into
the inner ends of the aforesaid holes and passing them through the same to the
outer side of the aforesaid wall, a washer t, if required may be placed around the
protruding ends of the connecting tubes cc. and the aforesaid backuut, or its
equivalent has then to be screwed on to the lower tube end c, and tightened, and
the right angle elbow d, or its equivalent carrying the aforesaid nipple e, has to
be screwed on to the upper tube end c, and tightened, and at the same operation
the free end of the aforesaid nipple e, should be brought into its required position.
For the purpose of securing the herein before described thermometer one or more
hooks p, or their equivalent are affixed as may be required upon the outer side of
the wall of the oven, boiler or other heated chamber to which my invention may
be applied, and holes o, corresponding to the position of the said hooks p, or their
equivalent are pierced through the aforesaid scale plate h, of the thermometer, by
means of which the said thermometer is suspended in such position that the free end
of the aforesaid nipple e, is inserted into the inlet. 1, of the aforesaid bulb casing f
or brought into close proximity thereto as may be required, as shown at W Fig. 3.
The action of the instruments herein before described is as follows:-
The heating chamber a, being within the oven, boiler or other heated chamber,
and being subjected to heat, the air contained in the said heating chamber a
expands, and becomes less dense than that of the outer atmosphere, a current of
air more or less heated is at once set up, and is automatically continued during the
time the said heating chamber a, is subjected to a higher temperature than that of
the outer atmosphere, by a portion of the more dense air at the orifice. of the
aforesaid lower connecting tube c, rushing therein and driving out the heated air
therein contained, it in its turn also becomes heated and driven out through the
aforesaid upper connecting tube c, elbow d, and nipple e, into the bulb casing,
of the thermometer, wherein it impinges upon the bulb of the thermometer K,
communicating a part only of its heat thereto, and thence passing out at the
atoresaid outlet of the bulb casing m, to the outer atmosphere, thus causing the
mercurial column =, or its equivalent of the aforesaid thermometer to rise and fall
in conformity to the various changes of temperature to which the aforesaid heating
chamber a, may be subjected, and so to indicate on the exterior of ovens, boilers
and the like heated chambers ratio temperatures of the interior of the same.

page_text: As the temperatures indicated by my invention are ratio temperatures it becomes
necessary when readings of temperatures according to standard scales are required
to employ a corrected thermometer. This can be effected by placing a ther-
mometer carrying the required scale inside a heated chamber to which my present
invention is applied, the said chamber being provided with a pane of glass in the
wall thereof thereby giving facility for observation, the temperature as indicated
by the inside thermometer, may then be marked as indicated by the top of
the mercurial column of the outside thermometer, on a prepared scale plate and
from this scale other thermometers may be constructed which will give the required
reading sufficiently accurate for practical operations in connection with ovens,
boilers and other like heated chambers, but I prefer to space out a scale the equal
to the range of the thermometer, and to divide the same into ten equal parts, and
to mark each division with its respective numerals, from nought N, to one
hundred N, consecutively, and to again divide each intervening space into five
parts each and every part indicating two degrees of temperature according to the
scale of my invention.
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 what
I claim is
1. fi a new or improved temperature indicator, applicable to domestic and
bakers ovens, steam pressure boilers and the like, the combination of the inlet tube
and the heating chamber with the outlet tube to permit the air to pass auto-
matically through the heating chamber out and on to the bulb of the glass containing
the mercury, and the thermometer with the scale plate affixed over, or on either
side of the outlet of the nipple in an horizontal position, or at any angle diverging
from the horizontal toward a vertical position as may be required, the whole to be
fixed in and to a wall of oven, oven door, or oven door frame, boiler or the like,
substantially as herein described with reference to the annexed drawings.
2. In a new or improved temperature indicator, applicable to domestic and
bakers ovens, steam pressure boilers and the like, the combination of the tubes,
elbow, nipple, back nut, hooks, thermometer or other analogous fittings, fixed in
and to a wall of oven, oven door, door frame, boiler or the like, substantially as
herein described with reference to the annexed drawings.
3. For indicating the interior temperatures of domestic and bakers ovens, steam
pressure boilers and the like upon the exterior of the same, the combination of
the fittings and a thermometer, substantially as herein described with reference to
the annexed drawings.
4. For constructing a passage having ingress to and egress from the interior of
boilers, ovens and the like heated chambers, the said passage having facility of
direction at the exit of the same, the application of a circuitous tube or chamber
substantially as herein described with reference to the annexed drawings.
5. For the purpose of causing a thermometer affixed upon the exterior of ovens,
boilers and the like heated chambers, to indicate the interior temperatures of the
same without risk of bursting the tube of the thermometer by the over heating
of the said ovens, boilers and the like heated chambers the application of heat
contained in an air current to the bulb or chamber of the said thermometer the
said air current having been passed into and through the said ovens, boilers and
the like heated chambers without having contact with the air contained therein,
substantially as herein described with reference to the annexed drawings.
6. The apparatus wherein are embodied the features or properties claimed by
the preceding claiming clauses substantially as herein-before described with
reference to the annexed drawings.
L Damn 1900
CHARLES HEIRONS,
Applicant.