Improvements in Means for Indicating the Temperature of Ovens for Baking, Cooking, and other similar Purposes.
Year: 1891

page_text: Date of Application, 17th July, 1891-Accepted, 5th Sept.,
1891
COMPLETE SPECIFICATION.
Improvements in Means for Indicating the Temperature of Ovens for
Baking, Cooking, and other similar Purposes.
I, THOMAS LEECH of 63 Millgate, Hollinwood near Manchester in the County
of Lancaster Inventor do hereby declare the nature of my said invention and in
what manner the same is to be performed to be particularly described & ascer-
tained in and by the following statement :-
'
My invention has for its object improvements in indicating the temperature of
ovens for baking, cooking, and other similar purposes, and is for the purpose of
making the cook or other attendant aware from the outside of the oven, when the
oven is in suitable condition for cooking any desired article of food. At present
this is most difficult to ascertain and has frequently to be ascertained under difficult
conditions and is often guessed and much waste is occasioned and irritation and
disappointment caused. My invention entirely meets these difficulties and is equally
applicable to present ovens as to the constructions of new ones though in the case of
new ones a neater appearance may be given to the finish.
In order that my invention may be clearly understood & more easily carried into
practical effect I have appended hereunto a double sized sheet of drawings showing
examples of its application both to new gas ovens and fire ovens as well as of its
application to existing ovens and by which any person acquainted with the trade
will be able to apply the invention to other varying conditions and circumstances
without difficulty.
Figure 1., an elevation of the exterior of an ordinary oven door shewing my
improved arrangement for indicating the heat of the interior attached thereto.
Figure 2., is an enlarged view of the indicator shewing the mode of indicating
the various heats which may be required.
Figure 3., is a vertical section through Figure 2.
Figure 4., is a vertical section through an ordinary oven door such as the one
shewn by Figure 1 shewing the mode of applying my improved arrangement
thereto.
Figure 5., is a similar section to Figure 4 but with the oven door jacketed.
Figure 6., is a part vertical section through a jacketed oven door specially con-
structed to receive the indicator.
Figure 7., is also a part vertical section through a single oven door specially
prepared to receive the indicator which is shewn in a modified form.
Figure 8., is a plan shewing the wire guard for protecting the projecting part of
the indicator.
In carrying my invention into effect and applying it to existing oven doors
whether heated by gas or fire I drill a small hole a through the thickness of the
door sufficiently large to receive the tail piece of the indicator glass d' which tail
piece contains mercury and is cranked to pass through the door the indicating glass
being mounted in a suitable metal frame D such as shewn in Figures 2 & 3 which
is secured to the outside of the door A by screws through suitable holes d³ and d
the screws being preferably inserted from the inside of the oven into snugs formed
on the inside of the frame D to receive them. The frame D is marked on the face
at one side of the mercury glass with the different degrees of heat and figures and
upon the other side the names of the various articles of food to be cooked placed in
the various positions so that the rise of the mercury to any one of those points
indicates that the oven is in a suitable condition for cooking the particular article
or articles at that point enumerated. To prevent any damage to the bulb d³ a
suitable wire guard E is provided which completely covers it & at the same time
does not present any resistance to the heat acting with its full effect upon the

page_text: bulb d. In the case of jacketed doors as shown by Figure 5 the tail piece & of
the glass is made sufficiently long to pass through the thickness of the door.
In doors in which provision is made to receive the indicator a recess a² is formed
in the outside casing of the door as shewn by Figure 6 which illustrates a jacketed
door. The indicating glass is inserted in the recess with the tail piece d passing
through the door and the bulb d³ projecting into the oven as before described the
indicator being inserted from the front & retained in position by two small plates a
& a which are screwed to the door by which means the indicator is made flush
with the outside of the door. In Figure 7 a modification is shewn to which
an indicator having a rounded bulb d' is inserted so as to be flush with the outside
of the door the wire bracket d³ being attached to the door to support the glass in
the position shewn.
It will readily be understood that my arrangement may be placed in any con-
venient part of the oven other than the door so as to indicate the required heat in
any position most desirable but generally I prefer to attach it to the door in a
manner similar to that herein explained and shewn.
The articles of food marked at the side of the indicator serve as an example only
and may be varied to any extent, the letters may be carried out on a white enamel
plate and may be arranged obliquely as shewn at din sectional plan by Figure 9;
and the glass may be carried up 300 or 400 degrees higher to prevent any possi-
bility of the glass bursting.
Having now particularly described & ascertained the nature of my said inven-
tion & in what manner the same is to be performed I declare that what I
claim is :-
The improvements in indicating the temperature of ovens for baking, cooking,
and similar purposes by which the suitable temperature of the inside is at once
indicated for various classes of cookery; substantially in the manner set forth and
such as shewn by Figures 1 to 9 of the accompanying drawings.
1001
GEORGE BARKER,
77, Colmore Row, Birmingham, Agent for Applicant.