Improvements in Apparatus for Baking Biscuits, Wafers, and other Articles or Materials.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Improvements in Apparatus for Baking Biscuits, Wafers, and other
Articles or Materials.
I, CHARLES MARIE JOSEPH BRAULT DE BOURNONVILLE, Manager of the
Société des Fabricants de Biscuits réunis of Valence near Bordeaux in the Republic
of France, 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 relates to apparatus in which biscuits or other articles or
materials are baked by being carried through an oven upon endless carriers or
chains and consists in an improved arrangement of the carriers or chains and chain
driving gear or mechanism with the object of increasing the efficiency and
usefulness of the apparatus as hereinafter described.
And in order that my said invention may be fully understood I shall now proceed
more particularly to describe the same and for that purpose shall refer to the
several figures on the annexed sheet of drawings the same letters of reference
indicating corresponding parts in all the figures.
Figure 1 of the accompanying drawing represents in front elevation an oven for
baking biscuits provided with endless chains for carrying the biscuits through the
oven in the usual manner.
Figure 2 represents the oven in side elevation and Figure 3 represents the oven
in horizontal section taken on a plane between the roof and the floor above the
endless chains.
Figure 4 illustrates in horizontal section an oven provided with improved
mechanism or apparatus arranged according to this invention for carrying the
materials through the oven.
Figures 5 and 6 illustrate likewise in horizontal section an oven provided with
two modified arrangements of the driving gear as hereinafter described.
Figure 7 illustrates in horizontal section an oven provided with improved
arrangements for transferring the moulds or plates from one pair of chains to
another as hereinafter explained.
Figure 8 illustrates in side elevation and in horizontal section a detail of this
transferring mechanism drawn to a larger scale.
The apparatus with endless chains as heretofore employed in connection with
ovens for baking fancy biscuits is usually constructed as represented in
Figures 1, 2 and 3. The endless chains in this apparatus are worked by a com-
bination of cones and pulleys A, B of different diameters enabling the speed to be
changed as required being driven by a belt from the engine or motor.
These cone pulleys drive a toothed wheel R which transmits motion to a
shaft V on which are fixed four chain pulleys or sprocket wheels R' driving two
pairs of endless chains C working over a corresponding set of pulleys or spocket
wheels R" at the other end of the oven carried by a shaft V. The two pairs of
endless chains are arranged to travel in one direction indicated by the arrows a in
Figure 3 namely from the end E where the raw articles are introduced into the
oven to the end D where the baked articles are removed.
Under these conditions the biscuits to be baked are placed on the pairs of
endless chains at the end E and the baked biscuits are taken out at the end D at
which the driving gear is situated.
This arrangement answers well enough for baking ordinary fancy biscuits the
pans or plates carried by the chains for the reception of the biscuits being emptied
at the delivery end of the oven are placed in the dough cutting machine where

page_text: they are charged with a fresh supply of biscuits and are then returned to the
feeding end of the oven.
On the other hand, when, in place of baking ordinary fancy biscuits, it is desired
to bake wafers (gaufrette) in an oven provided with these endless chains, a most
serious difficulty is encountered. In order to bake wafers under good conditions the
pasty liquid or batter from which the wafer is made must be poured onto an iron
plate whilst the latter is relatively highly heated. This condition has heretofore
been complied with by employing a number of iron plates or moulds (eight for
example) placed in a small circular oven and arranged to revolve vertically or
horizontally. By means of a crank the man making the wafers brings each plate
in succession opposite to the door of the oven when the wafer on the plate is
sufficiently baked the wafer is then removed and a fresh supply of batter being
placed upon the plate it is returned to the oven and the next plate is dealt with in
the same manner.
Other ovens for baking wafers have been constructed in which the iron plates or
moulds are rivetted on an endless chain which travels from one end of the oven to
the other being passed round pulleys or sprocket wheels situated at opposite
extremities of the oven. When a wafer plate or mould reaches the end of the
oven at which the baker is stationed he removes the baked wafer, places a fresh
supply of batter in the mould and closes the latter which being rivetted to the
chain is immediately carried round the sprocket wheel and travels in an inverted
position to the farther end of the oven.
This arrangement is extremely defective. In the first place the wafer moulds
being very weighty tend to drag down the chains when underneath the latter and
require an arrangement of supports which is very inconvenient in practice.
Another most serious disadvantage of the system is that when any accident occurs
such as are very liable to take place in handling the thin fragile wafers when for
instance the wafer adheres to the mould plate the plate being rivetted to the chain
which partakes of a continuous motion the baker is compelled to work under great
difficulty owing to the plate being carried away by the continual motion of the
chain so that he has not sufficient time to remove the adhering wafer properly and
being necessarily hurried in his movements the mould is not properly cleared out
thus rendering the next wafer hastily poured in more liable to stick, in short the
work is badly done the materials are wasted and loss results.
This arrangement consequently gives very unsatisfactory results the arrangement
previously described gives a better product but costs a considerable amount in
labour. Wafer baking conducted in a large oven with endless chains as herein-
before described with reference to Figures 1, 2 and 3 is consequently preferable
on all accounts, less labour is required the baking is more uniform and the wafer
irons or moulds not being permanently attached to the chains any mould can in
case of accident be simply placed on one side to be attended to leisurely another
mould being put in its place so that the work goes on regularly and without
interruption.
Another important advantage attending the employment of large ovens consists
in the facility which is afforded for baking ordinary or fancy biscuits and wafers in
one and the same oven in place of being compelled to provide separate ovens for
baking these two different products.
It has been herein before explained that in order to bake wafers properly the
batter must be poured onto the mould plate when the latter is highly heated. Now
this is impossible when as is the case with ovens worked with endless chains as
heretofore arranged, it is necessary to carry the moulds outside the oven from one
end of the latter to the other being a distance of say about 45 feet in order to
replace them in the oven at the feeding end after filling, the moulds being
evidently cooled to a considerable extent whilst being conveyed from the delivery
end to the charging or feed end of the oven. Moreover the work of carrying the
hot and heavy moulds from one end of the oven to the other presents serious
difficulties in practice. By means of the present invention the disadvantages

page_text: attending the apparatus as heretofore constructed are entirely obviated as next
hereinafter explained.
With this object the disadvantage resulting from the necessity for carrying the
wafer plates or moulds from the delivery to the charging end of the oven outside
the latter as heretofore practised is obviated by so arranging the endless chains
that one part of them delivers the baked wafers at one end of the oven and the
other part delivers them at the other end feeding and delivering being consequently
performed at both ends of the oven simultaneously.
Figure 4 of the accompanying drawing illustrates one example of an arrangement
enabling this result to be obtained. In place of providing one driving apparatus
with cones and pulleys at one end of the oven two such apparatus or driving gear
are provided being arranged one at each end of the oven as represented at Cand C¹
and the two sprocket wheel shafts A and A' carrying sprocket wheels R R¹ are
each divided into two lengths driving the endless chains in opposite directions.
The cone pulleys at each end of the oren drive the corresponding chains in
opposite directions so that one pair of chains marked M moves towards the end D
in the direction indicated by the arrow a for example whilst the other pair
marked L travels in the opposite direction or towards the end E as indicated by
the arrow b.
The wafer plates or moulds introduced at the end E are carried by the pair of
chains M through the oven to the opposite end D where they are removed and are
immediately returned to the oven being now placed upon the pair of chains L by
which they are carried back to the end E where they are again transferred to the
chains M. By these means the moulds or wafer plates are caused to circulate in
the oven without intermission and all the disadvantages attending the operation of
carrying the moulds round the oven from one end to the other are entirely
obviated.
When the plates or moulds have been sufficiently heated by circulating in the
oven as hereinbefore described the moulds as they are removed from the chains at
the end E for example are filled with the wafer paste or batter before they are
placed on the chains M by which they are afterwards carried through the oven to
the end D where the baked wafers are removed from the moulds. The moulds
being then recharged with batter are placed upon the chains L and carried back to
the end E where the baked wafers are removed and a fresh charge of batter being
introduced the moulds are again placed upon the chains M these operations being
repeated as often as required.
When it is desired to use the same oven for baking ordinary fancy biscuits
for example it is simply necessary to couple together the adjacent ends of the
sprocket wheel shafts A and A' and to work the apparatus by means of one only
of the two driving gears thereby causing both pairs of chains to travel simul-
taneously in the same direction.
The two pairs of chains may be caused to move in opposite directions without
dividing the sprocket wheel shafts A and A' into two lengths and without employing
two driving gears.
Figure 5 of the accompanying drawings illustrates an arrangement enabling this
result to be obtained. At the end of the oven at which the driving gear is situated
the sprocket wheel shaft A is prolonged at the end farthest from the said driving
gear and the sprocket wheel shaft A' at the other end of the oven is likewise
prolonged at the corresponding end. On the projecting ends of these two prolonged
shafts are fixed bevel wheels S and S'. A shaft R is arranged outside the oven at
one side of the latter being provided at each extremity with bevel wheels V and V₁
gearing with the wheels S and S' fixed on the extremities of the sprocket wheel
shafts. The two sprocket wheels F on the shaft A and the two sprocket wheels F¹
upon the shaft A₁ are free to rotate upon their respective shafts but the two
sprocket wheels P on the shaft A and the two sprocket wheels P' upon the shaft A'
are fixed upon the shafts and act as driving wheels the loose wheels F and F' simply
acting as guides which support the endless chains,

page_text: The effect of this arrangement is that the cone pulleys or driving gear C cause
the shaft A to rotate in the direction of the arrow n so that the sprocket wheels P
being fixed on this shaft propel the chains M in the direction of the arrow o and
cause them to travel from the end E of the oven in towards the end D; the
sprocket wheels F' being loose upon the shaft A' and not acting as driving wheels
but simply supporting the chains at the end E of the oven. In like manner the
sprocket wheels F being loose upon the shaft A do not transmit motion to the
chains L but the shaft A rotating as herein before described drives the bevel
wheel S in the same direction as indicated by the arrow n¹ thereby transmitting
motion to the wheels V and V' upon the shaft R and causing them to rotate in a
direction indicated by the arrows't and t' and drive the wheel S' and shaft A.' in the
opposite direction to the shaft A (arrow u).
The sprocket wheels P¹ being fixed upon the shaft A¹ consequently propel the
chains L' in the direction indicated by the arrow so that the two pairs of chains L
and M are caused to travel through the oven in opposite directions.
Figure 6 illustrates another arrangement enabling the division of the shafts A
and A' to be dispensed with. In place of dividing each of these shafts into two
lengths the sprocket wheels F and F are free to rotate but the two sprocket
wheels P and P' are fixed upon their shafts as in the arrangement hereinbefore
described with reference to Figure 5. The shaft A is caused to rotate in the
direction of the arrow n by the cone pulleys C and the sprocket wheels P which
are fixed upon this shaft drive the pair of chains M in the same direction (arrow a)
these chains being supported at the other end of the oven by the loose sprocket
wheels F. The pair of chains L is caused to travel in the opposite direction to the
chains M by means of the cone pulleys C driving the shaft A¹ in the direction of
the arrow the sprocket wheels P₁ fixed upon this shaft propelling the pair of
chains L in the same direction (arrow) and the loose sprocket wheels F on the
shaft A supporting the said chains at the other end of the oven.
When the oven is required for baking ordinary biscuits that is to say when the
two pairs of chains require to be propelled in the same direction it is simply
necessary to fix the loose pulleys F or F' apon their respective shafts and drive the
chains by means of the one or the other of the cone pulleys C or C¹ so that the
two pairs of chains are propelled in the same direction.
The mechanical means by which the chains are propelled in opposite directions
is a matter of secondary importance; the arrangements hereinbefore described form
part of the present invention but any other mechanical arrangement whereby the
movement of the chains in opposite directions can be obtained may evidently be
employed without departing from the main principle of the invention. The same
remark applies to the principle of the accessory arrangements by the aid
of which the moulds are transferred from one pair of chains to the other at each
end of the furnace.
These means are susceptible of numerous modifications examples of which are
hereinafter described without limiting myself thereunto as it is evident that any
other suitable means may be employed without affecting the principles of the
invention.
The moulds may be transferred from one pair of chains to the other by hand one
or two men being employed for this purpose to take hold of the moulds by means
of handles specially constructed to protect the hands of the operatives from the
heat. The mould is then placed upon a suitable support and opened; the baked
wafer is then removed from the mould and a fresh supply of paste or batter is
introduced after which the mould is returned to the oven being placed upon the
other pair of chains which carry it back to the opposite end of the oven.
obvious method of performing the operation may sometimes be employed in practice
but cannot be regarded as a patentable invention. I will now proceed to describe
other arrangements in which manual labour is partly dispensed with and which form
part of the invention to be secured to me.
This
According to the arrangement illustrated in Figure 7 an apparatus marked B is

page_text: provided at one end of the oven for the purpose of transferring the wafer moulds
from one pair of chains to the other. This apparatus is composed of two strong
iron plates set on edge and bent in the form of a U. These plates are arranged
one within the other in such a manner that the space between them is equal to the
space between the endless chains of each pair. To the sides of these plates near
the upper edges are attached small iron discs or rollers 1 rotating freely upon studs
fixed to the plates as represented in Figure 8 being so arranged that the peripheries
of these rollers project beyond the upper edges of the plates which are suitably
connected together so as to form parallel curved lines and the apparatus thus con-
structed is fixed upon supports which place the rollers on a level with the two pairs
of endless chains and outside the oven.
When a mould arrives at the end of the oven and ceases to be propelled by the
chains the attendant takes hold of it by means of a removeable handle and draws
it onto the two curved plates of the apparatus B hereinbefore described the mould
moving readily over the discs or rollers attached to the said plates. The mould is
then opened and the baked wafer being removed the mould is suitably cleaned and
prepared and filled with fresh paste or batter then continuing its movement upon
the rollers it travels round the curve described by the plates B and onto the second
pair of chains by which it is carried to the other end of the oven where a similarly
constructed apparatus is provided enabling the mould to circulate in a continuous
manner.
The apparatus for transferring the moulds from one chain to another may
evidently be constructed in various ways for example the small discs or rollers
herein before described may be replaced by small cylinders rotating in the same
direction as the rollers but being of such length as to extend from one curved plate
to the other. A wide U shaped flat plate arranged horizontally may be substituted
for the two curved plates standing on edge the moulds being provided with rollers
or castors enabling them to travel either upon plates set on edge or upon the flat
plate the edges of the latter being bent up so as to act as guides. The moulds may
be transferred from one pair of chains to the other by means of small trucks
travelling upon rails attached to the floor and provided with switches and turn-
tables for enabling the trucks to pass one another. Again the moulds may be
provided with grooved rollers which engage with the endless chains and when the
mould arrives at the end of the oven run upon two rails bent to a semi-circle and
arranged in such a manner as to enable the mould to run from one pair of chains to
the other.
The improved oven arranged for producing in opposite directions the movement
of the endless chains and the arrangements herein before described for transferring
the articles from one pair of chains to the other may be employed for baking
pastes or batters other than that hereinbefore specified or for baking articles or
materials not used as food.
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 baking apparatus or ovens worked with endless chains or carriers the
improvement consisting in driving the carriers or pairs of endless chains in
opposite directions for the purpose of enabling the ovens to be employed for
baking wafers and other articles or materials at the same time enabling the
same ovens to be worked in the ordinary manner for baking biscuits when
required substantially as herein before described.
2. In baking apparatus or ovens worked with endless chains or carriers and for
the purpose of propelling the said chains or carriers either in opposite directions
or in the same direction according to the nature of the materials to be baked
the arrangement at both extremities of the oven of a
cone pulley or like
driving gear in combination with the divided shafts A and A¹ (Figure 4) or
with shafts A and A' made in one piece combined and one lateral shaft R

page_text: (Figure 5) all operating in the manner and for the purpose hereinbefore set forth
with reference to the accompanying drawings.
3. In baking apparatus or ovens worked with endless chains and for the purpose
of propelling the said chains either in opposite directions or in the same direction
according to the nature of the articles or materials to be baked the arrangement
at each extremity of the oven of a cone pulley or like driving gear in
combination with shafts A and A' made in one piece each of the said shafts
carrying one pair of loose wheels or pulleys and one pair of fixed wheels or
pulleys arranged inversely or at opposite extremities of the said shafts and
engaging with the chains or carriers which are to be propelled all operating in
the manner and for the purpose substantially as hereinbefore described with
reference to Figure 6 of the accompanying drawings.
4. In baking apparatus or ovens worked with endless chains or carriers in
combination with the movement of the said chains or carriers in opposite
directions as herein before described and claimed and the means for obtaining
the said movement an apparatus (B Fig. 7) for transferring the wafer moulds or
the like from one pair of chains to the other substantially as hereinbefore set
forth.
5. The combinations and arrangements of parts constituting the improvements in
apparatus for baking biscuits wafers and other articles or materials substantially as
hereinbefore described.
Dated this 8th day of July 1893
J. H. JOHNSON & Co.,
Agents.