IMPROVEMENTS IN BAKING OVENS
Year: 1854

page_text: LETTERS PATENT to James Smith, of Liverpool, in the County of Lancaster,
Biscuit Baker, for the Invention of "IMPROVEMENTS IN BAKING OVENS."
PROVISIONAL SPECIFICATION left by the said James Smith at the
Office of the Commissioners, of Patents, with his Petition, on the 9th
March 1854.
I, JAMES SMITH, of Liverpool, in the County of Lancaster, Biscuit Baker, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN BAKING
OVENS" to be as follows:-
This Invention is chiefly applicable to that class of ovens known to biscuit
bakers as the "railway oven," that is to say, an oven having an endless metal
band or platform the width of the oven travelling through it, and upon which
are placed the articles to be baked, and which is accomplished during their
passage through the oven. (These endless bands or platforms are formed by
jointing together a series of iron plates. The band is extended by and
works upon two drums, mounted upon suitable bearings, at the front. and
back of the oven, and is supported by small wheels or friction rollers
placed on the sides of the band, and which run upon rails fixed within
the oven.)

page_text: These ovens are now heated by covered or enclosed-flues, extending above
and below the oven (or opening) through which the endless band travels. Now,
the object of the improvements proposed by the said Invention are, first, to
economise the heat, and have it more under the control of the baker; and
secondly, to reduce the manual labour, in removing the biscuit from the oven
to a convenient repository and room above.
To economise the heat, it is proposed to use no other covering for about two-
thirds of the length of the top of the lower flue but what is afforded by the
endless metal band or platform, which travels over it to introduce a current of
hot air between the folds of the endless band; and by forming the lower side
of the upper flue of a series of "luvres or plates, jointed so that. they can be
opened from the exterior of the structure at pleasure, to allow the heat from
the upper flue to act more directly upon the articles within the oven. In
baking fancy biscuits it is sometimes deemed desirable to place them on a
surface which has a temperature below that of the oven; to accomplish this,
it is proposed to cool down the revolving bottom at the point where it receives
the articles to be baked,' by means of a collar covered with a porus substance,
the lower edge of which revolves in water, and the upper in contact with the
endless band, or any other like convenient, method.
To reduce the manual labour in removing the biscuits to an upper story
it is proposed to receive them as they fall from the horizontal metal band
forming the bottom of the oven in a
attached to a vertical endless bandes of small troughs or pockets.
1.
within a chamber heated in
conjunction with the oven by which they are carried upwards; and on the
first downward motion of the pockets their contents fall into a "shoot,"
and slide into a basket placed to receive them. By this arrangement the
biscuit is further baked or dried during its passage to the upper story, where
they are discharged.
2.
The horizontal endless band forming the travelling bottom of the oven, and
the vertical endless band by which the biscuits are carried to the upper story,
are set in motion by steam or other motive power, applied through the drums
or cylinders upon which they are mounted.
3
It is proposed in most instances to use coke to heat ovens constructed
according to this Invention. That this Invention may be more readily under-
stood, hereunto is annexed a vertical sectional elevation of an oven constructed
according to this Invention; like letters refer to similar parts."
امة
A, "brickwork, forming exterior and ground work of the structure. B, fire-
placed, formed with a split draught, dividing the hot air into three parts, one

page_text: portion of which passes into and through C; the lower flue;- another portion is
carried by a suitable passage.from the back of the fire-place, between the
endless band F and the other portion through D, the upper flue, as indicated
by the arrows; E, luvres or jointed covers forming the lower or bottom
side of the upper flue, which are worked from the exterior of the oven. F,
the broad endless metal band; forming the bottom of the oven, and upon
which the articles to be baked are placed. f, square drums working on axles,
and to which the motive power for actuating the endless bottom is applied..
G, a wheel or cylinder, the lower part working in water, and the upper, in
contact with the. lower portion. of the endless band; forming the 'travelling
bottom of the oven, for the purpose of cooling it down previous to the
biscuit being placed upon it: H, vertical endless band, 'to which is attached
J; troughs or pockets, into which the biscuit falls (from F; the horizontal
endless band, forming the bottom of the oven), and is carried upwards and
discharged at the upper story into K, a basket, place on the upper floor
to receive the biscuits. L, drums upon which the vertical endless band traves,
and through which the working nower is applied
11178

page_text: performed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said James Smith, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the accompanying Drawings, that is to
say-
My Invention for Improvements in Baking Ovens have reference mainly
to the class of ovens known to biscuit bakers as "railway ovens," that is,
an oven having an endless metal band or platform the width of the oven
travelling through it, and upon which are placed the articles to be baked,
which is accomplished during their passage through the oven. (These
endless bands or platforms are formed by joining together a series of iron
plates edge to edge. The band is extended by and works upon two drums,
which are mounted upon suitable bearings at the front and back of the
oven, and is supported by small wheels or friction rollers placed on the
sides of the band, and which run upon rails fixed within the oven.) These
ovens are now heated by covered or enclosed flues above and below the
oven (or opening), through which the endless band travels.
The present
system of heating these ovens by enclosed flues is objectionable, on account
of the great consumption of fuel required to heat them, and at the same
time the want of a sufficient control to enable the baker to regulate the
action of the heat within the oven. Now, the object of my Invention is, first,
to economise the heat,, and have it more under the control of the baker; and
secondly, to reduce the manual labour in removing the biscuit from the oven
to a convenient repository or room above.
To economise the heat in the first place I do not enclose the lower flues
on the upper side (as now practised), except the portion immediately above
and for a short distance below the fire-place (or places where more than one
fire is used), as I have found by experience that the endless metal band or
platform which travels over it answers all the purpose, the heat acting directly
upon it, the intervention of brickwork or other substance being dispensed
with.
Secondly, I introduce between the folds of the endless band a current or
currents of hot air from the fire-place.
Thirdly, I construct the lower side of the upper flue or flues (which are
above the travelling bottom) of a sereis of "louvres" or plates jointed in such

page_text: a way that they can be readily opened or closed from the exterior of the
structure by removing these louvres (or jointed plates, which form the
bottom of the upper flue or flues,) from a horizontal position; the heat from
the upper flue is allowed to act directly upon the biscuit or other articles
within the oven. If preferred, the "louvres" can be dispensed with in ovens
where coke, antracite coal, or other fuel, which emits but little smoke, is used,
by introducing currents of hot air above the travelling bottom in the same
way as it is done between the folds of the endless band formning the bottom of
the oven.
In baking fancy biscuits, it is sometimes deemed desirable to place them on
a surface which has a temperature below that of the oven; to accomplish this,
it is proposed to cool down the revolving bottom at the point where it receives
the articles to be baked, by means of a roller covered with a porus substance,
the lower edge of which revolves in water, and the upper in contact with the
endless band, or by directing a current of cold air upon it, or any other like
convenient method.
To reduce the manual labour: in removing the biscuits to an upper story, it
is proposed to receive them as they fall from the horizontal endless metal band
forming the bottom of the oven in a series of small troughs or pockets attached
to a vertical endless band, working within a chamber heated in conjunction
with the oven, by which they are carried upwards, and on the first downward
motion of the pockets their contents fall into a "shoot," and slide into a
basket placed to receive them. By this arrangement, the biscuit is further
baked or dried during its passage to the upper story, where they are
discharged.
The horizontal endless band forming the travelling bottom of the oven, and
the vertical endless band by which the biscuits are carried to the upper story,
are set in motion by steam or other motive power, applied through the drums
or cylinders upon which they are mounted. It is proposed in most instances
to use coke to heat ovens constructed according to this Invention. That
this Invention may be more readily understood, hereunto I have annexed
a vertical sectional elevation and an horizontal sectional plan of a large
oven (having two fire-places) constructed according to my Invention. Like
letters used on the Drawings denote similar parts.
Figure 1 is a vertical sectional elevation; Figure 2 is an horizontal section
taken from points a to b. A, brickwork, forming the exterior and ground-
work of the structure. B, fire-places, formed with split draughts, dividing the
hot air and gasses, so that one portion acts against the lower side of the end-

page_text: less band, forming the bottom of the oven, and passes upwards into the heated
chamber at the end thereof, and in which works the vertical endless band
upon which 'the elevators are placed. Another portion of the heat is carried
through or between the folds of the horizontal endless band, and into the
heated chamber of the vertical endless band, the heat being allowed to
escape at the top of the chamber; the other portion of the heat from the
fire-places is carried over the upper surface of the horizontal band; and as
this portion of the hot air becomes charged with steam, arising from the
biscuits or other articles in the oven, I have provided an independent outlet
for this portion of the draught. C, flues, with split draughts, to carry the
heat above and between the folds of the travelling bottom. D, opening of
passage to admit the heat between the folds of the travelling bottom.. E, out-
let or passage, through which the heat that has been admitted between
the folds of the travelling bottom, and which in this case is carried into the
heated chamber of the vertical endless band; but if preferred, it can be
carried directly into a flue. F are "louvres" or jointed cover, forming the
lower side of the upper flue, which are worked from the exterior of the oven.
G, the broad endless metal band forming the bottom of the oven, and upon
which the articles to be baked are placed. g, square drums working on axles,
and to which the motive power for actuating the endless bottom is applied.
H is an opening or passage formed in the brickwork, for the introduction
of a current of cold air, to cool down the revolving bottom at the point it
receives the articles to be baked; but this will not be found requisite, except
in the baking of fancy biscuits. I, a vertical endless band, to which is
attached K, troughs or pockets, into which the biscuits fall (from G, the
horizontal endless band forming the bottom of the oven), and are carried
upwards: and discharged at the upper.. story. L shows the position of a
basket placed on the upper floor to receive the biscuits. M, drums upon
which the vertical endless band travels," and through which the working
power is applied. .N, dampers used to regulate the draught.
Having now described my Invention, and the manner in which it may be
performed, what I claim is,-..
First, the combinations of the various parts, as herein-before described, to
form an improved baking oven.
Secondly, the direct application of heat to ovens having travelling bottoms,
substantially, and, in. the manner herein-before described.
Thirdly, the heating of the chamber or passage containing the vertical endless
band, as herein-before described..

page_text: Fourthly, the cooling down the horizontal endless band forming the bottom
of the oven at the point where it receives the articles to be baked, as herein-
before described.
In witness whereof, I, the said James Smith, have hereunto set my
hand and seal, the Second day of September, in the year of our Lord
One thousand eight hundred and fifty-four.
Witness,
W* WALKER.
JAMES (L.S.) SMITH.