Improvements in and connected with Bakers' Ovens.
Year: 1894

page_text: Date of Application, 18th Jan., 1894
Complete Specification Left, 18th Oct., 1894-Accepted, 29th Dec., 1894
PROVISIONAL SPECIFICATION.
Improvements in and connected with Bakers' Ovens.
1, FREDERICK SMITH of 23 York Street, York Road, Lambeth, in the County
of Surrey, Builder, do hereby declare the nature of this invention to be as
follows:-
propose
The objects of this invention are to promote cleanliness in bakeries, to preserve
the health of the operatives by reducing the temperature in bakeries particularly
at the oven mouth and to save time, labour and fuel. For this purpose
to construct the oven furnace in such position in regard to the oven that the said
furnace shall be separated by a wall or else by a chamber with iron doors and
frame from the bakery proper and I also provide means for automatically supplying
the furnace with heated air in place of leaving the upper door partly open as set
forth in the Specification of my Patent No. 2278 of 1891 ; my present invention is
applicable to the invention described in that Specification.
I also build the furnace vertically deeper so that a greater body of fuel may be
kept on the bars thus saving frequent stoking and admitting of the use of coke
after the oven has been first heated up by coals.
Instead of giving the furnace bars a rocking motion for the purpose of removing
the clinkers and ashes I adapt some or all of them to be partially withdrawn
towards the front by preference by a lever or bar. I may with this view also
make the front and back bearing bars with recesses or notches to enable the
correspondingly shaped end parts of the bars to be placed within the same and so
producing the least amount of friction and with the necessary windage. The
underside of both ends of the bars are so made as to allow of their being pulled
forward and the back bearing bar is placed more towards the front so as to support
the back ends of the furnace bars when they are pulled forward. These bara may
have each a cross notch on the underside 3 or 4 inches from the front end in order
to lock themselves temporarily in the forward position on the bearing bar and so
prevent their running backwards during the process of removal of clinkers. This
arrangement enables the delivery of ashes and refuse at the far end of ash pit thus
keeping same out of the bakery proper.
Instead of the inside furnace door being made in two heights as by my aforesaid
Patent I employ one door only (which may be perforated to assist combustion of
fuel) with slot in bottom of same for. insertion of a poker. This door would not
cover the whole of the aperture of frame, a space being left for charging the
furnace over top of same. Over and in front of this door I provide a box door
which closes on the ashpit frame in such a manner as to allow the heated air from
the ashpit to pass between it and the inner door and so obtain automatic action by
hot air supply to the top of the furnace independently of the stoker. Over these
doors I may in some cases hang another door to conduct the sulphurous steam
which is evolved from the oven, while bread is baking, into a flue provided for that
purpose. In order to obtain the necessary space for constructing the furnace in
the stokehold I advance the furnace more towards the farther end or head of oven.
Or where the oven is built up against a side wall I may construct the furnace
through the said wall and into the oven and so keep the fuel and dust entirely out
of the bakery proper. I propose to ventilate and light the stokehold by any simple
well known plan or by arranging position of brickwork above same.
In places
where the furnace is built through the side wall access to same must be obtained

page_text: Dy widening that portion of the building or by a passage or enclosure leading
to same.
In order to facilitate the admission of air to the furnace over the inside door
I stand the ashpit frame immediately under the box or second furnace door before
named.
Under the ashpit I could, if required, construct a cellaret for fuel as
heretofore.
I may also as by my aforesaid 1891 Patent construct air flues under the bed of
the oven, the air passing through which is conveyed to the ashpit but instead of
entering at the back I let it enter as near as possible to the front near the ashpit
frame and provide enclosing or sliding door to shut off this air supply.
Instead of this air passing into the ashpit at a continuous level with the bed of
oven I propose to form a dip or siphon close to the ashpit to prevent as much as
possible the steam from the oven descending into the air passage under the bed of
oven in case the sliding door in the ashpit is inadvertently left open.
I also construct the register or flue damper with a double check in order to
more perfectly retain the steam in the oven and I in some cases influence its action
by utilizing the damper over the oven's mouth for that purpose.
Respecting the frame comprising oven's mouth I omit the usual cheeks or sides
leading from the oven door to the interior of the oven and substitute a slightly
increased thickness of iron in the oven frame which is set back to the slopings of
the interior of the oven in order to prevent the bread from being fouled or sooted
on its being withdrawn from the oven by the unavoidable occasional contact with
the cheeks. It also facilitates very materially the working of the oven. As this
proposed arrangement increases the space between the operator and the oven door,
propose to use the jointed lever handle as by my aforesaid Patent but to increase
the length of the lever to make it more convenient and also cooler. While thus
reducing the space or thickness at this part of the oven frame between the inside
and the outside of the oven I close in the space or chamber so formed with an iron
door glazed with mica or glass. The gas burner to light the interior through the
mica could be placed conveniently at one side with say a semi-circular shade in the
back part of which could be placed a reflector and which would be an effectual
shade to the operator's eyes whilst looking into the oven. The mica door may be
suspended at the top on a spindle which can be advanced from the front line
enabling the mica door when out of use to rest against the upper part of frame
comprising oven's mouth, whilst at the same time could be easily removed for the
purpose of cleaning or renewal of the mica. It could also be provided with a
quadrant to operate an iron door inside the oven which irou door would be used
during firing of oven. The gas could also be easily lighted and the reflector
cleaned.
When a naked burner only is employed for lighting the interior of oven, I
propose to adopt the same plan as by my aforesaid Patent but with this addition
that as the gas is advanced to pass into the oven it shall also automatically raise
and lower another burner attached to the same pipe, when required by the operator
to examine the goods he may have drawn to the mouth of the oven for inspection.
This light may also be shaded from the eyes. In order to allow the use of this
plan for gas either with or without mica I propose to make the mouth plate which
is the flat surface leading to entrance of oven a greater length than usual and in
order to facilitate the working of the oven with the peel, I propose to increase the
width of plate not altogether gradually as at present but by breaks or set-offs and
so afford more room for adapting the gas arrangement before mentioned for lighting
interior of oven.
Instead of continuing the front of the oven upwards in a vertical line I set back
the chimney bar and brickwork above it say 41", 9", or 14″, as circumstances
permit, which would enable that portion of the heat and gases passing out of the
oven's mouth that escape going up the flue provided to pass away that extra
distance of 4", 9" or 14" from the face of operator using the oven or by setting

page_text: back the brickwork I may form an air flue say of 41" to draw away the heated air
in which case the present line of brickwork would be preserved. This would also
afford more daylight on the mouth plate when goods are drawn out for
examination.
The top of the piers so formed by this set back may receive floral or other
decorations. The other parts of brickwork of front of oven above the level of the
chimney bar I also propose where desirable or necessary to set back. I propose to
employ glass or other smooth surface material fixed at such an angle as would
prevent beetles or cockroaches from gaining an entrance to the air flue leading to
the space under the oven bed.
In order to still further quicken the admission of the peel while inserting dough
into the oven I propose to have a portion of the mouth plate sunk or have a rail
outside same to permit interchange of peels. In the mouth plate on the right hand
side in order to promote cleanliness I provide a recess forming a receptacle for the
flour dust or sweepings.
On one side and outside the oven frame I provide a recess or space in which to
place a thermometer in order to enable the baker to judge the temperature of the
oven. In order to avoid the necessity for placing the saucepan containing potatoes
for cooking in the oven (as usual in the manufacture of bread) I may form a
separate chamber or receptacle by the side of the furnace or other convenient
position enclosed with a door and frame with pipe to carry off the steam. I may
also employ a vertical or hanging iron shield sliding on a top rail to cover the
mouth of furnace inside the oven.
Dated this 18th day of January 1894.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.
COMPLETE SPECIFICATION.
Improvements in and connected with Bakers' Ovens.
I, FREDERICK SMITH of 23 York Street, York Road Lambeth in the County
of Surrey Builder 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 :-
The objects of this invention are-
1. To promote cleanliness in bakeries by shutting off as much as convenient the
furnaces from the bakery proper by improving the construction of the furnace
generally and by an improved method of unclinkering the firebars.
2. To preserve the health and increase the comfort of the operatives by reducing
the temperature in bakeries particularly at the oven mouth this being effected
chiefly by setting back the chimney bar.
3. By an improved construction of the frame on which the oven door is mounted
to give greater facility for working the oven and for withdrawing the baked loaves
without soiling them, and
4. By an improved arrangement of the damper to retain the steam better in the
oven.
My invention also covers minor improvements which tend to the more convenient
working of the furnace and oven. This invention is especially applicable to the
invention described in the Specification of my Patent 2278 of 1891.
Figure 1 of the accompanying drawings is a plan section of two adjoining ovens
having their furnaces in a chamber which can be shut off from the bakery
proper.
Figure 2 is a plan section of an oven having its furnace outside the bakery and
Figure 3 is a vertical longitudinal section through an oven furnace.

page_text: Figure 4 is plan view of the furnace bars and Figure 5 side view of one set of
the furnace bars, while Figure 3 shews the other set of furnace bars in side
elevation.
Figure 6 is a vertical longitudinal section of the register.
Figure 7 is a front view of the oven and Figure 8 a vertical longitudinal section
of same.
As shown in Figure 1 the oven furnace is constructed in such a position in regard
to the oven proper as to be away from the bakery proper the furnace being removed
towards the further end of the oven. A chamber A is thus formed in front which
is provided with iron doors A¹ and A'. In Figure 2 the furnace mouth is shewn
outside the bakery proper being separated therefrom by a wall A*. Thus dirt and
dust are kept out of the bakery proper. The furnace shown in Figures 1, 2 and 3
is of the general form of my aforesaid Patent.
Instead of giving the furnace bars B B' a rocking motion for the purpose of
removing the clinkers and ashes I adapt some of them, that is to say those marked B,
to be partially withdrawn towards the front while those marked B₁ are kept in the
position shown. With this view I make the front ends of the bars B to rest in
notches in the front upstanding flange C* of the furnace frame forming the bearing
bar and the back ends of these bars B have grooves B* underneath which mesh with
lugs Dx formed on the top of the back bearing bar D; the latter is placed some
distance towards the front so as to support the back ends of the furnace bars B when
they by means of a hook inserted in the hole B° of each are pulled forward some
distance, without leaving their bearing on the bearing bar D. The furnace bars B¹
are not made thus to slide, but rest on the horizontal flange C¹ of the furnace frame.
The clinkers and ashes will thus drop into the ashpit away from the front and be
kept out of the bakery proper.
Instead of the inside firedoor being made in two parts an upper and a lower as in
my aforesaid Patent I may in some cases and as here shown employ one door E only
(which may have holes to assist the combustion of the fuel by air entering said
holes). This door is provided with slot Ex in the bottom part for inserting a poker
preferably of the construction described with reference to Figures 8 and 9 of my
aforesaid previous Patent Specification. This door does not cover the whole
aperture of the frame a space being left as shewn for charging the furnace over
the top of same. Over and in front of this door I provide a box door F which
closes on the ashpit frame F' immediately under it in such a manner as to allow the
heated air from the ashpit G to pass between the door F and the inner door E and
so obtain automatic action by hot air supply to the top of the furnace independently
of the stoker. Over the doors E and FI may in some cases hang another door to
conduct the sulphurous steam which is evolved from the oven while bread is baking
into a flue provided for that purpose.
Under the ashpit I may if required and as shown construct a cellaret H for fuel as
heretofore. I may also as by my aforesaid Patent construct air flues under the oven
bed the air passing through which flues is passed to the ashpit. The air passes in
by the flue Figure 2 but instead of letting it enter the ashpit at the back I let it
enter the ashpit by a flue J as near as possible to the front near the ashpit frame Fl
and I provide enclosing or sliding door or damper K Figure 2 to shut off this air
supply. Instead of this air passing into the ashpit at a continuous level with the
bed of the oven I prefer to form a dip or syphon close to the ashpit to prevent as
much as possible the steam from the oven from descending into the air passage
under the bed of oven in case the sliding damper K in the ashpit should be
inadvertently left open.
I also provide the ordinary register or flue damper L Figures 1 and 6 with means
for more perfectly retaining the steam in the oven, the power of the draught on the
register being lessened. For this purpose 1 fix to the front edge of the damper L
and at right angles thereto a vertical iron door M which encloses a chamber M
constructed of iron or brickwork and forming part of and covering the exit of the
flue L' from the oven. The damper L and the door M forming one piece are

page_text: operated simultaneously by one nanure
in any convenient place.
Ine damper may ve ne as sewn or
Referring to Figures 1 and 2 it will be seen that I omit the usual cheeks or sides
leading from the oven door N to the sloping interior parts or shoulders P P¹ of the
oven and substitute a slightly increased thickness of iron in the oven frame O which
latter is set back to the said shoulders P P' in order to prevent the bread from
being fouled or sooted on being withdrawn from the oven by the unavoidable
occasional contact with the said cheeks. It also very materially facilitates the
working of the oven. As this arrangement increases the space between the operator
and the oven door N the jointed bow lever handle described with reference to
Figure 3 and 5 in my aforesaid Patent Specification may be used but of increased
length to make it convenient and also cooler. While thus reducing the space or
thickness at this part of the oven frame O between the inside and the outside of the
oven I close in the space or chamber so formed with an iron door Q glazed with
mica or glass.
The gas burner to light the interior through the mica door or window R may
conveniently be placed at one side with say a semicircular shade in the back of
which may be placed a reflector; this shade effectually shades the eyes of the
operator when looking into the oven. The mica door might be suspended at the
top on a spindle which can be advanced from the front line, so that the said door
when out of use may rest against the upper part O' of oven mouth frame whilst at
the same time it can be easily removed for the purpose of cleaning or reglazing. It
might also be provided with a quadrant to operate an iron door suspended from the
top inside the oven which door would be used during the firing of the oven. The
gas could also be easily lighted and the reflector cleaned. When a naked burner
only is employed for lighting the interior of the oven I propose to adopt the same
plan as by my aforesaid Patent in which the gas pipe K swivels on the cock K and
is fitted with a stop K³ which comes against the latch of the oven door but with this
addition that as shewn in Fig. 9 of the accompanying drawing as the gas burner K
is advanced to pass into the oven the cock K shall also automatically raise the flame
of another burner K attached to the same pipe and enable the operator to examine
the goods which he may have drawn to the mouth of the oven for inspection. The.
flames of both burners are lowered as the pipe is drawn out the plate K* acting as.
a stop. This light K may also be shaded from the eyes. In order to allow the
use of this plan for gas either with or without the mica door I make the mouth
plate O¹, which is the flat plate leading to entrance of oven, of a sensibly greater
length than usual and in order to facilitate the working of the oven with the peel I
sensibly increase the width of the said plate, not altogether gradually as at present
but by breaks or set-offs as shown in Figures 1 and 2 and so afford more room
for adopting the gas arrangement before mentioned for lighting the interior of the
ovell.
Instead of continuing the front of the oven upwards in a vertical line 1 set back
the chimney bar S and the brickwork above it, say 41", 9" or 14" as circumstances
permit, which will enable that portion of the heat and gases which pass out of the
oven's mouth and escape up the flue T to pass away that extra distance of 41", 9" or
14" further away from the operator who is using the oven; or by setting back the
brickwork I may form an air flue in front of it to draw away the heated air, while
the present front line of brickwork will be preserved. This also affords more light
on the oven mouth plate O when goods are drawn out for examination.
The top of the piers so formed by this set back may receive floral or other
decorations as shewn in Figure 7. The other parts of the brickwork of the front
of oven above the level of the chimney bar S may also be set back if desirable or
necessary. I propose to employ glass or glazed tile or other smooth surface
material fixed at such an angle, as shewn for instance at I Figure 2 as will prevent
beetles or cockroaches from gaining an entrance to the air flue leading to the space
under the oven bed.
In order to still further quicken the admission of the peel, while inserting dough

page_text: into the oven I provide a rail W₁ outside to permit interchange of peels. In the
mouth plate at the right hand side I provide a recess W* forming a receptacle for
the flour dust or sweepings.
- On one side and outside the oven frame. I provide a recess or space in which to
place a thermometer X in order to enable the baker to judge the temperature of the
oven. In order to avoid the necessity for placing the saucepan containing the
potatoes for cooking in the oven (as usual in the manufacture of bread) I may form
a separate chamber or receptacle by the side of the furnace or other convenient
position, such chamber being closed by a door and frame with pipe to carry off the
the steam. I may also employ a vertical or hanging iron shield sliding on a top rail
to cover the mouth of furnace inside the oven.
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. In bakers' ovens the improved position or arrangement of the furnace viz. away
from or shut off from the bakery proper as described and shown and for the purpose
set forth.
2. The improved construction of bakers' oven furnace according to which it is
provided with a door F closing over the usual furnace door and forming a chamber
which is open to the ashpit so that the heated air from the latter may enter th
furnace through an aperture above the furnace door, and the operators be shielded
against the sulphurous air arising from the closed ashpit when the bread is baking
in the oven, with or without an outer door for closing up the chamber A. formed in
front of the furnace door.
3. The construction of furnace bars, some of them being adapted to be slided
forward, the back bearing bar being accordingly brought forward for the purpose
of discharging the clinkers and ashes at or towards the back of the furnace
substantially as set forth.
4. The improved arrangement of air flues under the oven bed whereby the
temperature of the air in the ashpit is raised and the steam from the oven is
prevented from entering the said flues also the arrangement whereby the inlet is
protected against the entry of beetles and the like.
5. The improved construction and arrangement of oven front according to which
the chimney bar and brickwork above it are sensibly set back from the front line of
brickwork substantially as and for the purposes stated.
6. The improved construction of sides or cheeks of oven mouth according to
which the surface with which the bread can come in contact with said sides is
reduced to a minimum substantially as set forth.
7. The improved construction of register over the oven mouth or in the shoulder
substantially as 'and for the purpose set forth.
Dated this 18th day of October 1894.