Chambers, such as Ovens.
Year: 1886

page_text: Chambers, such as Ovens.
I, WILLIAM LEGGOTT, of Park Road, Bradford, in the County of York, Brass
Finisher do hereby declare the nature of this invention for IMPROVEMENTS IN
APPARATUS FOR INDICATING THE HEAT IN ENCLOSED CHAMBERS SUCH AS OVENS
to be as follows:-
=
·
This invention has for its object the arrangement of an apparatus to be fixed to
the side or door of an oven or other hot chamber by which the temperature of the
interior is indicated on a dial fixed on the outside of the same.
I accomplish the above object by securing to the side or door in the interior of
the hot chamber or oven, a inetal casing in which are placed two narrow strips of
metal such as brass and steel or other suitable metal of unequal expansion. These
strips are curved and fixed at one end so that the same are in close contact with
each other, the other end of the two bars being free.
By the curved bars expanding and contracting according to the temperature,
they operate the arm of a toothed quadrant lever, the teeth of which gear with a
pinion secured on a short shaft, at the opposite end of which, on the exterior, ia
secured a pointer which indicates on a dial the temperature of the interior of the
hot chamber or oven.
Dated thin 10th day of Tan 1000
JOHN WAUGH,
Agent.
Improvements in Apparatus for Indicating the Heat in Enclosed
Chambers, such as Ovens.
I, WILLIAM LEGGOTT, of Park Road, Bradford, in the County of York, Brass
5 Finisher 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 :—
This invention has for its object the arrangement of an apparatus to be fixed to
the side or door of an oven or other hot chamber. by which the temperature of the

page_text: interior is indicated on a dial fixed on the outside of the same; and consists in
securing to the interior of the hot chamber, a casing containing two curved narrow
strips of metal of unequal expansion, one end of which are fixed and the other free,
but connected to the arm of a toothed quadrant, which is geared with a pinion
· secured on a shaft capable of rotation, and to the other end of which is fixed a
pointer for indicating on a dial the temperature of the interior.
In order that my invention may be better understood, I will explain the same
more in detail by making reference to the accompanying drawings, in which Fig. 1
represents a side elevation of my apparatus detached from a hot chamber, Fig. 2
shews the interior with the casing removed, Fig. 3 a front view of the dial, and
Fig. 4 a side view with the casing removed.
The plate A is secured to the side or door in the interior of a hot chamber or
oven, and is covered by the metal casing B, provision being left for the heat to
enter freely into the interior of the said casing. In the lug A¹ is cut a groove in
which are secured two curved narrow strips of metal C of unequal expansion, the
inner one being of brass and the outer strip of steel, the other ends of the curved
strips C being free for expansion are connected by a staple, and a slot cut through
them to allow of the working of the arm D of the toothed quadrant E. The before-
mentioned staple passes through the slot in the arm D, and the teeth of the
quadrant E gear with a small pinion secured on a small spindle that extends
through the tube F to the dial, where the pointer G is fixed thereto.
The connecting tube F may be of any convenient length to suit the thickness of
the side or door of the heated chamber, and when heat is applied to the latter, the
curved metal strips C are affected, expanding from their original position as the
temperature increases, so that the toothed quadrant E is actuated; thereby
operating the toothed pinion gearing therewith and the pointer G, in accordance
with the varying temperature of the chamber; the strips and pointer returning to
their original position on the cooling of the chamber.
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
A heat indicator in which the pointer is operated by two curved narrow strips
of metal combined with a quadrant and pinion, substantially in the manner shewn
and described.