New or Improved Apparatus for Approximately Indicating the Temperature of the Ovens of Cooking Ranges and Kitchen Ovens.
Year: 1888

page_text: Date of Application, 13th Nov., 1888
Complete Specification Left, 2nd Aug., 1889-Accepted, 14th Sept., 1889
PROVISIONAL SPECIFICATION.
New or Improved Apparatus for Approximately Indicating the
Temperature of the Ovens of Cooking Ranges and Kitchen
Ovens.
We GEORGE GORDON BRODIE of Catherine Street Aston. near Birmingham in the
County of Warwick Ironfounder and JAMES DAMREL PRIOR of No. 143 Isledon Road
Finsbury Park London in the County of Middlesex Manager do hereby declare the
nature of this Invention to be as follows:-
It is often important or desirable in the use of the ovens of cooking ranges and
kitchen ovens to be able readily to ascertain approximately the temperature of the
oven as the various uses to which the oven is put require considerable differences of
temperature.
Our invention consists of the new or improved apparatus hereinafter described to
be fixed to the doors of the said ovens or placed on the bottom or shelves of the
said ovens for the purpose of indicating the temperature of the said ovens.
In constructing according to our invention an apparatus for approximately
indicating the temperature of the oven of a cooking range we proceed as follows. To
the inner face of the door and preferably near the edge most distant from the fire we
fix a flat vertical case extending from the top to the bottom of the door. In this
case is a series of vertical metallic tubes preferably made of brass and corrugated
longitudinally. Ordinarily we employ three of the said tubes. The lower end of one
of these tubes which we will call the first tube rests in the end of a screw working in
a fixed bracket. By means of the said screw the position of the tube vertically can be
accurately adjusted. The top of this the first tube bears against the undersides of the
short arm of a nearly horizontal lever the long arm of which bears ou the top of the
second tube. The bottom of the second tube bears on the upper side of the short
arm of a lever on the long arm of which the bottom of the third tube rests. The
third tube is somewhat shorter than the other two and near its top has a horizontal
pin which engages in a slot in an arm turning on a centre and carrying a quadrant
plate. This plate is situated immediately behind an opening in the oven door and can
be inspected through the said opening.
The part of the quadrant plate seen through the said opening in the oven door is
graduated according to Fahrenheit's or other thermometric scale and may also have
the words 'cold " "
warm "hot" " very hot" at the parts respectively corre
sponding approximately with the temperatures on Fahrenheit's scale of 60° 150° 350°
450°. Or the said plate may have any other series or signs or words for indicating
the temperature of the oven.
The action of the apparatus is as follows: When the kitchen range is not in use
the brass tubes are cold and the quadrant plate presents at the opening in the oven
door the appropriate sign and word say for example "60°" and "cold." When the
fire in the kitchen range is lighted and the oven becomes hot the brass tubes
described expanding more than the iron which carries them they operate the levers
described and turning through a greater or less angle cause those signs and words on
the quadrant plate which approximately indicates the temperature to be presented at
the opening in the oven door.
When for any reason it is undesirable to attach the apparatus to the door of the
oven the tubes and quadrant plate may be carried by an independent frame and the
apparatus placed on any convenient part of the bottom of the oven or on a shelf in

page_text: the oven.
In this modification the figures and words are made on the periphery of
the quadrant instead of on its face and the temperature is indicated by that part of the
periphery which is brought near a fixed edge or pointer.
Dated this 13th day of November 1888
W. T. WHITEMAN,
Agent for the Applicants.
COMPLETE SPECIFICATION.
New or Improved Apparatus for Approximately Indicating the
Temperature of the Ovens of Cooking Ranges and Kitchen
Ovens.
We GEORGE GORDON BRODIE of Catherine Street Aston near Birmingham in the
County of Warwick Ironfounder and JAMES DAMREL PRIOR of No. 143 Isledon Road,
Finsbury Park, London in the County of Middlesex, Manager do hereby declare the
nature of our invention and in what manner the same is to be performed to
be particularly described and ascertained in and by the following statement :-
It is often important or desirable in the use of the ovens of cooking ranges and
kitchen ovens to be able readily to ascertain approximately the temperature of the
oven as the various uses to which the oven is put require considerable differences of
temperature.
Our invention consists of the new or improved apparatus hereinafter described to
be fixed to the doors of the said ovens or placed on the bottom or shelves of the said
ovens for the purpose of indicating the temperature of the said ovens.
In constructing according to our invention an apparatus for approximately
indicating the temperature of the oven of a cooking range we proceed as follows. To
the inner face of the door we fix a fat vertical case or plate of metal or porcelaiu
extending from the top to nearly the bottom of the door. In this case is a series of
vertical metallic tubes preferably made of brass and corrugated longitudinally.
Ordinarily we employ three of the said tubes. The lower end of one of these tubes
which we will call the first tube rests in the end of a screw working in a fixed bracket.
By means of the said screw the position of the said tube vertically can be accurately
adjusted. The top of this the first tube bears against the underside of the short armi
of a nearly horizontal lever the long arm of which bears on the top of the second
tube. The bottom of the second tube bears on the upper side of the short arm of a
lever on the long arm of which the bottom of the third tube rests. The third tube
is somewhat shorter than the other two and near its top has a horizontal pin which
engages in a slot in an arm turning on a centre and carrying a quadrant plate.
This plate is situated immediately behind an opening in the oven door and can be
inspected through the said opening. The part of the quadrant plate seen through the
said opening in the oven door is graduated according to Fahrenheit's or other
thermometric scale and may also have the words "cold," warm, 'hot," "very hot"
at the parts respectively corresponding approximately with the temperatures on
Fahrenheit's scale of 60°; 150°; 350°, 450°. Or the said plate may have any other
series or signs or words for indicating the temperature of the oven.
35 86
When for any reason it is undesirable to attach the apparatus to the door of the
óven the tubes and quadrant plate may be carried by an independent frame and the
apparatus placed on any convenient part of the bottom of the oven or on a shelf in
the oven.
In this modification the figures and words are made on the periphery of
the quadrant instead of on its face and the temperature is indicated by that part
of the periphery which is brought near a fixed edge or pointer.
Figure 1 represents an inside elevation; Figure 2 an outside elevation and
Figure 3 a vertical section of a heat indicating apparatus constructed according to
our invention to be applied to the oven door of a cooking range or kitchen oven;

page_text: Figure 4 represents a cross section of the regulating apparatus of the same drawn to
a larger scale.
The same letters of reference indicate the same parts in the several Figures of the
Drawing.
a is the flat plate or case of metal or porcelain fixed to the inside of the oven door /
and c, d and are the three parallel brass tubes corrugated longitudinally by the
expansion of which tubes and the mechanism hereinafter described the temperature of
the oven is approximately indicated. The three tubes c, d, e are hereinafter called
the first, second and third tubes.
The said tubes are capable of sliding in the fixed brackets on the plate a. The
lower end of the first tube c rests on the end of the screw working in a screw box
made in the fixed bracket i for adjusting the position of the said tube with respect to
the lever k.
The top of the first tubo bears against the underside of the short arm of the
horizontal lever & the end of the long arm of which bears on the top of the second
tube d. The bottom of the second tube d bears on the upper side of the short arm
of the horizontal lever on the end of the long arm of which the bottom of the
tbird tube e rests the end of the said tube e being forked or slotted to engage on the
said lever. The third tubo e carries the horizontal pin m which engages in a slot n
in the arin p turning on the centre q. The pin or centre 7 on which the arm p turns
passes from the back of the plate a to the front of the oven door b and carries at the
front of the oven door b, the arm to the end of which the quadrant plate s is
attached which plate may be graduated and marked in the manner shown in Figure 2
or otherwise graduated and marked. On the front of the oven door is a cover or
covering plate t for covering the greater part of the graduated quadrant s. In the
said covering plate t is an opening u opposite which the graduations on the quadrant
are in succession brought as the heat in the oven increases. Through the said
opening the quadrant graduated plates can be inspected. For the purpose of
adjusting the pin m on the third tube e in the slot n in the arm p more or less
distant from the centre 9 on which the said arm and the quadrant graduated plate s
turn so as accurately to adjust the range of motion of the said graduated plate, wo
use the regulating apparatus shown in Figure 1 and drawn to a larger scale in
Figure 4. This regulating apparatus consists of the collar w through which the
tube e passes and the adjusting screws, working in screwed lugs on the plate u
the said adjusting screws taking into depressions in the sides of the said collar w. By
driving home more or less one of the screws and withdrawing the other screw,
the collar w and with it the tube e can be moved laterally in one or other direction
and its pin m adjusted nearer to or further from the centre 9 of the arm p and
graduated quadrant s.
The action of the apparatus is as follows: When the kitchen range is not in use
the brass tubes c, d, e are cold and the quadrant plates presents at the opening u in
the oven door b the appropriate sign and word say for example "60° F." and "cold"
as represented. When the fire in the kitchen range or the gas in the gas stove is
lighted and the oven becomes hot the brass tubes c de expanding more than the iron or
other plate or case which carries them they operate the levers kl which turning
through a greater or less angle cause those signs and words on the quadrant plate
which approximately indicate the temperature to be presented at the opening in the
oven door, that is, either the word "warm" and sign 153° F. or the word "hot" and
sign 350° F. or the words "very hot" and the sign 450° F.
Figure 5 represents in side elevation and Figure 6 in end elevation a modified
apparatus adapted for use on the shelf of the oven or bottom of the oven; Figure 7
represents the regulator for the same drawn to a larger scale.
In this modification two brass corrugated tubes 1, 2 are used which are carried
by the independent frame 3 placed on the shelf or on the bottom of the oven. The
tube 1 is adjusted by the screw 4 and the inner end of the said tube bears against the
short arm of the lever 5 jointed at 6 to the upper tube 2; 7 is the quadrant plate
carried by the arm 8 jointed at 9 to the frame 3 the inner end of the said tube 2

page_text: bearing against the arm 8 to raise and lower the quadrant 7. The quadrant 7 works
through a slot at 10 in the frame 3 and the figures and words berein before mentioned
or other figures and words are made on the periphery of the quadrant, the
temperature heing indicated by that part of the periphery of the quadrant which is
brought near the fixed edge or pointer at 10 Figure 5. In the use of this apparatus
the door of the oven must be opened in order to inspect the indicating quadrant 7.
The action of this modified apparatus is the same as that first described. In Figures 5
and 6 the quadrant 7 is represented partly raised through the slot 10 in the frame 3
by the expansion of the tubes 1 and 2 and the action of the lever 5.
To cause the end of the tube 2 to act upon the arm 8 at a greater or less distance
from its centre and thereby to regulate the range of motion of the quadrant 7 we
use the collar 11 through which the tube 2 passes and the regulating screw 12.
By turning the said screw in one or other direction the collar It can be raised or
lowered and with it that end of the tube 2 which bears against the arm 8.
In place of tubes in the apparatuses represented rods of brass may be employed.
Although we have found three tubes or rods answer well in practice we do not
limit ourselves to that number, neither do we limit ourselves to any particular position
of the tubes or rods.
Having now particularly described and ascertained the nature of our inven-
tion and the manner in which the same is to be performed, we declare that what
we claim as our invention :—
First The construction and combination of the parts of apparatus herein before
described and illustrated in Figures 1, 2, 3 and 4 of the accompanying Drawing to
be applied to the oven doors of cooking rangos and kitchen ovens for approximately
indicating the temperature of the said ovens.
Secondly-The modified apparatus for the same purpose to be placed on the shelves
or bottoms of the ovens of cooking ranges and kitchen ovens hereinbefore described
and illustrated in Figures 5, 6 and 7 of the accompanying Drawing.
Dated the First day of August 1889.
GEORGE GORDON BRODIE.
JAMES DAMREL PRIOR.