IMPROVEMENTS IN BAKERS' OVENS
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by George Coles and Henry Coles at
the Office of the Commissioners of Patents on the 14th May 1880.
A communication from abroad by Thomas Hunter, of Toronto, Ontario,
Canada.
GEORGE COLES, of Clapton, in the County of Middlesex, and HENRY COLES, of
Brixton, in the County of Surrey. "IMPROVEMENTS IN BAKERS' OVENS."
A communication from abroad by Thomas Hunter, of Toronto, Ontario, Canada.
This Invention relates to improvements in the arrangement and construction of
the furnace or fire place and flues of bakers' ovens, whereby economy of fuel and
labour in working is effected, regular heat obtained, and smoke prevented by using
hard steam coal, smokeless fuel, or coke.
For this purpose it is advantageous to construct the fire place or furnace A of
circular form at one side of the oven door, the ring or grate frame being placed
about 9 inches below the sole of the oven. The ring or grate frame is formed with.
an arm so that it can be caused to rotate a few inches in either direction to shake
out the dust and ashes when required.
The arrangement of the furnace or fire place and flues will be better understood
by reference to the Drawing hereto annexed, Figure 1 of which shows part of a
vertical section, and Figure 2 part of a plan of oven and its fire place and flues
arranged in accordance with this Invention. A is the fire chamber advantageously
of fire brick, and A¹ the shoot or opening through which the fuel is supplied; B is
the cinder box and ash pit, and C, the flues furnished with dampers to regulate the
heat of the oven O.
The ash pit is built the width of door, and in building the circle below the ring
or grate frame A³, the ring A³ is placed on bars in a circle, about one inch wider all
around than the inner circle of ring A, then built to this line by gradually splaying
off the portion extending over the sides of ash pit until the complete circle is
formed. In setting ash pit and fire doors the top is placed about six inches below
sole of oven O, and the door frames are fastened by hooks secured to eyes
built into brickwork behind frame. The cinder bars rest at front end on ledge
inside of door frame, and at other end on a bar built into brickwork.
The fire brick around fire place may be either moulded to shape or put
in alternate radiator, and wedge bricks all laid in fire clay. In setting ring or
grate frame the pivot rests are exactly in the centre on each side, so that the grate

page_text: when dumpted will fall exactly to the front. The grate is set with the shaker arm
to the front.
In forming splay on inner side of front of oven the splay line just touches the
outside of the fire brick around fire place, and touches the corner of square projection
on side wall.
In building fire brick walls above fire place they are gradually worked from the
coved wall, corresponding to the edge of fire place, to a straight wall at crown,
leaving a 4 inch break on each side of coal shoot and striking straight to corners on
inside of oven. The lower end of shoot A¹ is about on a level with top of
fire-pot bricks, the shoot rising about 9 inches to sliding door having counterpoise
weights.
The oven door is placed a short distance from the contro line of oven, away from
grate.
The crown of oven is arched independently of the splay at grate side of oven,
and the portion over grate continues in with a barrel vault springing from side
only.
The iron tie rods below oven solo are placed with the top of rods about two
inches below sole brick.
The rods on top just clear the crown bricks.
A flue from back of oven commences in centre of back above the sole to turn
down and to the side in order to avoid arch of prover.
The main flue from corner of oven starts at level of sole and passes up, as most
convenient, to chimney. The flue over recess at oven door may be splayed at
bottom to accommodate lifting damper on top of frame.
The flue from under grate starts with the top just under ring, and from
the centre of circular ash pit side, being carried up in pier and connnected with
other flues..
Hard steam coal, smokeless fuel, or coke is employed, by which smoke is
avoided.
In starting fire open dampers to flue C, and when the fire is properly kindled
shut one of the dampers.
When the oven is ready for the bread shut both dampers, and throw a small
shovel of coal on to fire to damp it during baking process.
If at any time it is found that there is not sufficient heat to properly color the
bread, open one damper for a few moments.
When the batch is drawn open both dampers again, preparatory for another
batch.
When the grate is to be shaken shut two of the dampers, one being open. Also
open the oven door a few inches.