Improvements Connected with Gas Ovens for Baking Pastry and Cakes.
Year: 1888

page_text: PROVISIONAL SPECIFICATION.
Improvements Connected with Gas Ovens for Baking Pastry and
Cakes.
I, DAVID WILSON, of The Wilson Engineering Company Limited, 227 High
Holborn, Middlesex, Stove and Range Manufacturer, do hereby declare the nature of
this invention to be as follows :-
This invention relates to certain construction or arrangement of apparatus
constituting a gas heating oven for the baking of pastry, cakes and the like.
The apparatus consists of a rectangular or other shaped frame, within which, is a
lower chamber termed the "Try Oven," above which is a baffle plate heated by means
of Bunsen or atmospheric burners. This baffle plate has a partition for directing the
fumes and heat froin some of the burners in combination with inflowing air from a
bottom aperture, so that the two commingle with the heat of the other burners on the
opposite side of the partition. The great heat thus generated passes up a channelled
passage formed by gills cast on or projecting from the wall of the baking oven, the
floor of which is composed of fire brick or fire clay with which the inner side walls
and also the roof, if desired, may be lined, necessary side ribs being arranged for
carrying division plates for allowing the pastry or cakes to be baked in layers.
The gas expansion and heat distributing channels, of which there are a great number,
are formed by the projecting gills and on the outside of the oven proper, are covered
by a plate to keep the gas expansion passages distinct from each and this plate which
protects the oven on three sides is covered by asbestos, slag wool, or other non-
conducter of heat, the whole being covered by the frame or casing first mentioned.
The heated air or gases after leaving, what might be termed, the mixing or combus-
tion chamber, pass upwards in the expansion and distributing channels and impinge
against the wall of the oven and also against the gills, they then continue over the top
of the oven and down on the other side from whence the fumes pass into an uptake or
outlet.

page_text: The escape of the excess of steam from the oven proper is regulated by a damper in
a top tube.
The front of the oven is provided with doors, which can be opened independently of
each other and in no case is the heat of the oven interfered with when either of the
doors is opened.
The gills on the outside of the oven proper are preferably of tapered form with the
thickest part of the taper next. the oven and said gills may be plain, fluted, or undu-
lating as desired, the object of employing them being that they partake of the heat and
transmit it to the oven and maintain an uniform temperature therein.
Dated this 2nd day of May 1000
H. GARDNER,
166, Fleet Street, London,
Agent for the said David Wilson.

page_text: Improvements Connected with Gas Ovens for Baking Pastry and
Cakes.
I DAVID WILSON of The Wilson Engineering Company Limited, 227 High
Holborn, Middlesex, Stove and Range Manufacturer do hereby declare the nature of
my said 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 relates to a novel construction or arrangement of apparatus con-
stituting a Gas heating oven for the baking of Pastry, Cakes and the like.
The apparatus is preferably rectangular in shape of cast or sheet metal provided
with an inner jacket or liner between which and the outer casing suitable non con-
ductor of heat material is placed so that uniformity of heat is maintained within the
oven proper.
The oven is composed of cast metal box of three sides provided with outside gills or
it may be of two sides only and a plain backing. This box or oven proper may be in
one or two castings, the gills being on the outside of it and with ledges or fillets on the
inner side walls upon which fillets, trays can be slid and be shifted from one to the
other for baking purposes.
If the oven proper is in two parts it is constructed like the example shown at
Figure 1 of the annexed drawings and having a gas supply pipe A fitted between so
that the bottom oven which is closed by the doors B can be utilized for keeping pastry
warm while the upper half which is closed by the doors C is utilized for actual
baking.
The gas supply A may be atmospheric or a chamber may be formed for the reception
of air to be heated previous to its combination with the gas.
The gas supply pipe A may be rigid or jointed and as the gas flame impinges upon
the bottom plate of the oven proper it passes in the direction of the arrows up between
the gills on one side wall and over the top and then down the other side wall to an
outflow D the heat in its travel having been absorbed by the inner box or oven
proper.
At Figure 2 I show an apparatus with only one door and I purpose placing the
gas supply pipe at the lower part of the apparatus as seen by the sectional views
Figures 3 and 4 said gas pipe A being jointed to the front branch also jointed near
the tap end E but the joint at E may form the tap so that when the branch and
pipe A are swung outwards from the chamber in which it is placed the gas passing
through the joint E would only give sufficient for a pilot light but as the pipe A is
pushed more and more into the chamber the gas passage is more and more opened
according to the distance that the pipe A is pushed in.
Air is admitted from the underside of the apparatus into the channel F, see Figure 3,
if no atmospheric burner be used and it is heated in its passage by heat from the baffle
plate G so as to be in a better state for combustion in the chamber H which forms a

page_text: gas chamber previous to the heated air passing up the channels I, I, between the gills
in the side walls, as seen by Figure 5, so that the heat is not only imparted
to the box or oven proper J but to the gills the thickest part of which are next the
box J.
The top of the oven J is also provided with gills and channels I so that the heat is
utilized at the top of the oven as well as down the side as seen at Figure 3 before
escaping by the outlet tube D which tube may be provided with a damper to regulate
the outflow. It is preferable however to make the pipe D of a size proportionate to
the inflow of air and its expansion by heat to obviate bad smells or gas effluvia passing
into the room in which the oven is placed.
The bottom of the oven has a fire brick or fire tile floor K against which the gas
jets impinge whether the jets be open flame of ordinary gas or Bunsen or atmo-
spheric jets.
The narrow edge of the gills bear against a liner plate L to compel the heat to be
.broken up and pass round the oven in channels and a space between the liner plate L
and the outer casing M is filled with any non conductor of heat material to prevent
radiation.
I prefer the apparatus shown at Figures 2. 3. 4 and 5 with one door C only because
I have found in practice that for slow baking if the pastry or cakes to be baked are
first placed upon the upper ribs or fillets N they become sufficiently heated so that by
shifting them gradually on their trays from N to P from P to Q from Q to R the
degree of heat being gradually increased that perfect baking is the result the pastry
when placed on the ribs R being beautifully browned without burning. The ribs N
serve also for keeping pastry warm so that fresh pastry can be first placed upon the
ribs P and then brought gradually to the actual heat or hottest part as at R for baking
purposes. These ribs N, P, Q, R, may be extended so that they form vertical racks
and the trays placed in them can be determined by the kind of pastry to be cooked.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. The construction of gas ovens for baking pastry or cakes in which the inner box
or oven proper has internal ribs for carrying pastry trays and external gills for breaking
up and dividing the heat into channels as described with reference to the annexed
drawings.
2. The construction of gas baking ovens in which the arrangement for air supply
and expansion in combination with a gas chamber for the full development of heat and
the utilization of said heat from channels I formed between gills of the oven proper and
passing up one side over the top and down the other side as described with reference
to the annexed drawings.
3. The construction of gas cooking apparatus in which gills on the outer surface of
the oven proper are employed the backing L between which and the outer casing M
a packing of non conductor of heat material is arranged as and for the purpose
described.
4. In a gas cooking oven such as shown on the annexed drawings the swinging gas
supply when in combination with the baffle G and gas expansion chamber Has
described.