Note: Descriptions are shown in the official language in which they were submitted.
CA 02378882 2002-02-O1
Apparatus for Forming a Strip of Dough
The invention relates to an apparatus for forming a strip of dough, comprising
a
framework and two sets of superimposed rollers disposed adjacent to each other
and driven
for rotation around their horizontal axes, the rollers of each set being
bearingly supported on
a roller carrier movable relative to the framework, wherein the dough passes
from above to
below through the gap remaining between the two roller sets, which gap narrows
to below,
all rollers of one set being driven in the same direction, however, the lower
rollers of the set
being driven faster than the upper rollers of the same set, and wherein the
roller carriers of
the two sets can be moved one against the other or apart from each other by
eccentric drive
means.
As it is known, difficulties occur when a mixed charge of dough, the volume of
which
can be of different size, however, in the most cases being equal to the
capacity of the
kneader, which volume in the most cases is supplied by a hopper, must be
formed in the
shape of a continuous strip of dough, which has a predetermined width and an
also
predetermined thickness that is at least substantially constant. These
difficulties result from
that mixed dough is sensitive with respect to its structure that means its
physical and
chemical properties, to the stresses occurring when it is formed to a
continuous strip. In
particular, this holds for doughs subjected to a long fermentation time that
is desired with
respect to increase the quality of the product without additional effort
(additions).
An apparatus of the initially described kind has become known (EP 744 126 A1
), in
which each set of rollers is bearingly supported for rotation on a pivoted
lever constituting the
roller carrier. The upper end of this pivoted lever is stationarily linked to
the framework and
can be pivoted around this linkage point by an eccentric drive means. The
pivotal
movements of the two roller carriers work always in opposite direction so that
the gap
through which the formed strip of dough discharges from the apparatus to
below, is
CA 02378882 2002-02-O1
-2-
alternately increased or decreased. Thereby, indeed a continuous strip of
dough of
substantially constant thickness can be obtained, but this known apparatus is
not completely
free of undesired dough stresses so that the dough structure is adversely
affected, in
particular for sensitive kinds of dough or for Boughs subjected to a long
fermentation time.
The invention has at its object to improve an apparatus of the initially
described kind
so that the dough is brought into its desired strip shape very carefully. The
invention solves
this task in that an eccentric is bearingly supported on each roller carrier
and is driven for
rotation opposite to the direction of movement of the dough, and that each
roller carrier is
bearingly supported on a further eccentric or a connecting rod at a point that
is located
higher or lower than this eccentric, wherein this further eccentric or this
connecting rod is
bearingly supported for rotation or pivotal movement on the framework. As
distinguished
from the pivotal movement of the two roller carriers occurring in the above
described known
construction, within the inventive apparatus there occurs a movement of each
roller carriers
that comprises not only a horizontal component but also a significant vertical
component,
this horizontal or vertical component occurs not only at the lowermost rollers
of the roller
carrier but also at the uppermost rollers. So to speak, there occurs a wave
motion of the two
roller carriers so that the dough disposed between the two roller sets is not
only subjected to
a thrust action performed by the rotational motion of the rollers, but also to
a pumping effect,
the size and kind of which depends from the size of the eccentricity of the
eccentrics used or
from the length of the connecting rods used and from how and where they are
pivotally
connected to the respective roller carrier. Simplifying, it can be said that
the dough is
stepwisely and gently rolled into the desired shape.
As distinguished from the above described known construction, according to the
invention the eccentrics act directly on the respective roller carrier,
whereas within the known
construction, the pivotable roller carrier is always connected via a
connecting rod to an
eccentric pin of the drive means.
CA 02378882 2002-02-O1
-3-
According to a further embodiment of the invention, the rollers of the two
roller sets
have diameters that are equal to each other, what results in low costs of
manufacture and
makes it easier to adjust as desired the different speeds of revolution and
the thereby
created thrust and pumping actions acting on the dough.
According to a particular favourable embodiment of the invention, each roller
carrier
is formed by two walls, laterally confining the gap. The ends of the rollers
can be bearingly
supported in these walls, for example by means of bearing necks, and the drive
members for
the rotational motion of the rollers can also be supported by the roller
carriers. Within such a
construction, the walls constituting the roller carriers may form the lateral
delimitation for the
dough that flows through the gap between the roller sets, and, therefore, can
act as lateral
shields for the width of the dough strip to be produced, if this was not
already made earlier,
for example by a corresponding exit cross section of a supply hopper or the
like.
According to a further embodiment of the invention, the eccentric or the
eccentrics or
the connecting rod can be adjustable. This adjustment may comprise a change of
the
eccentricity of the eccentric andlor a change of its bearing location andlor a
change of the
length and/or of the linkage points of the connecting rod. In such a manner,
the motion of the
roller carrier and thus its roller action onto the dough can be varied, so
that one can
accommodate to different qualities of the dough, what is of importance in
particular for
processing dough of different viscosity.
It is particular suitable to dispose above the gap delimited by the driven
roller sets,
adjacent to the respective upper rollers, two further sets of freely rotatable
superimposed
rollers side by side, wherein preferably the gap delimited by these two roller
sets is at least
as width as the mean width of the gap delimited by the driven roller sets. The
space
disposed between these further roller sets constitutes a compensating space
for a dough
mass that is disposed between the driven roller sets carried by the roller
carriers and is
pressed to above, when these roller sets are moved and thereby projects beyond
the
CA 02378882 2002-02-O1
-4-
uppermost rollers of the two driven roller sets. This upwardly pressed amount
of dough is
taken up by the said compensating space and is again delivered to below as
soon as the
driven roller sets move away from each other. Within this, it is suitable to
dispose the rollers
of each one of the further roller sets superimposed in vertical direction and
to make them of
always the same size, however, to keep the diameter of the rollers of these
further roller sets
less than that of the driven rollers.
As it is well known, it is frequently desired to introduce one or more
flowable
substances onto or into the dough. Such substances may be for example baking
oil,
separating oil, olive oil, however, also egg white, honey, sugar solution or
oxygen or
fermentation gases to influence the properties of the dough, further
moistening agents, in
particular water as a preparation for a subsequent sprinkling or dusting step,
for example
with poppy seed, sesame or the like, or sodalye for the production of salted
baked products,
gloss substance for the production of brioche, substances (in particular oils)
to improve the
taste and the like. The invention enables one to impinge the dough with the
flowable
material, when the dough passes the gap disposed between the driven roller
sets. For this,
according to the invention, at least one roller is provided with at least one
conduit for
supplying a flowable medium to the dough, which conduit extends in
longitudinal direction of
the roller, the roller jacket surrounding this conduit being constituted by a
sintered body that
is permeable for this medium. The medium that is to be supplied onto the dough
can flow or
diffuse through this sintered body, and, if desired, the applied medium may be
worked into
the dough by the stresses exerted onto the dough by the roller sets. Within
that, it is of
advantage that thereby the medium can be substantially more regular applied
onto the
dough, as this was possible by the usual dropping or spraying of the medium.
Further,
losses are substantially reduced because the medium can be applied onto the
dough by the
rollers in a completely exact manner, so that, nothing or nearly nothing that
leaves the rollers,
misses the dough. Thereby, the amount of the medium that is applied onto the
dough can be
-5-
exactly dosed and soiling of neighbouring machine elements can be avoided.
Further, this
applying is more flexible with respect to different kinds of,
the medium to be applied, and is more exact with respect to the location where
it is
applied.
It is recommendable for rollers constructed in the above sense to use sintered
bodies of a material that is compatible with foods and is dough repelling,
preferably
polyamide. The average molecular weight for this has to be suitably chosen,
for example
about 800 to 1200, preferably about 1000, whereby the sinter volume amounts to
60 to
90 % (corresponding to a hollow space content of 40 to 10 %). In particular
suitable within
the spirit of the invention are sintered bodies of sintered granules of
synthetic plastic
material having an average grain size of 0.1 to 1.0 mm.
Further features and advantages of the invention can be seen from the
description
of embodiments schematically shown in the drawings. Fig. 1 shows an embodiment
in a
vertical section. Fig. 2 shows the driven roller sets, bearingly supported in
roller carriers,
of the embodiment according to Fig. 1, in an enlarged scale. Fig. 3 is a
section taken
along the line III - III of Fig. 2. Fig. 4 shows a variant to Fig. 2 and Fig.
5 is a section taken
along the line V - V of Fig. 4. Figs. 6 to 9 show in sections similar to Figs.
2 and 4 further
embodiments. Figs. 10 and 11 show two variants for the adjustment of the gap
existing
between the two roller sets. Fig. 12 shows in a vertical section the supply of
a flowable
medium to the rollers and Fig. 13 is a section taken along the line XIII -
XIII of Fig. 12.
Within the embodiment according to Figs. 1 to 3, the dough to be processed
which
may have been subjected to a long fermentation time, for example a kettle
fermentation, is
filled into a filling hopper 1 from above, the capacity of which corresponds
suitably to the
nominal capacity of the kneader by which the dough was previously processed.
The
hopper 1 is put onto the machine framework 2 and has below an outflow opening
3, the
width of which, measured perpendicularly to the drawing plan, already
determines the
width of the dough strip or dough band to be produced. From the outflow
opening 3 the t
dough 4 gets between two endless bands 5, 6 guided over rollers 7, 8, the
rollers 7 of
which are so driven that the two bands 5, 6 circulate stepwisely or
continuously in
direction of the arrows 9. The two bands 5, 6 have a longitudinal extension
that is so
obliquely disposed that the smaller rollers 8 are disposed below and
neighbouring the
CA 02378882 2002-02-O1
AMENDED SHEET
CA 02378882 2002-02-O1
-6-
vertical axis 10 of the hopper 1. Guide members, which are not shown, may
guide the
bands 5, 6 so that the two lower most rollers 8 change their position
periodically so that
the gap 11 between the two rollers 8 changes its width and/or its position
relative to the
axis 10 periodically. From the gap 11, the dough 4 comes between two cylinders
12 or
rollers which rotate in opposite direction in the sense of the arrows 13 and
may, but must
not, be driven in this direction. The gap 14 between the two cylinders 12
determines in the
first instance the thickness of the strand or band of dough and may have an
adjustable
size, if desired. The so produced dough band reaches a conveyor belt 15 which
conveys
the dough 4 to a further hopper 16 fixed in the framework 2 of the
apparatus. Thereby, the dough band guided to the hopper 16 looses its
substantial uniform
thickness again, which, however, will be restored in a manner which will be
described later
on. The outflow opening 17 of the hopper 16 can, but must not, have a width
corresponding
to that of the outflow opening 3, and can define the width of the dough band
to be produced.
From the hopper 16, the dough gets between two roller sets 18, 19, each of
which
comprising four rollers 20 superimposed above each other in vertical direction
and
respectively of equal size. These rollers are freely rotatable, their
peripheries are closely
neighbouring each other or are in contact with each other. The rollers 20 are
stationarily
bearingly supported within the framework 2, suitably in sidewalls adjacent the
outflow
opening 17.
Adjacent to the roller sets 18, 19 further roller sets 21, 22 are disposed,
each of
which in the embodiment shown comprises four superimposed rollers 23. The
rollers 23 of
each one of the roller sets 21, 22 have ends in the form of shaft stubs 69 and
are bearingly
supported therewith on roller carriers 24 by means of rolling bearings 25
(Fig. 3), the roller
AMENDED
SHEET
CA 02378882 2002-02-O1
carriers 24, when measured perpendicularly to the axial direction of the
rollers 23, have a
substantial greater width than the diameter of the rollers 23, which diameter
suitably is the
same for all rollers 23. In such a manner, each roller carrier 24 consists of
two walls 54
bearingly supporting the rollers, which walls constitute the sidewalls for
limiting the side of
the dough, mostly only a narrow gap 26 (Fig. 2) remaining between each two
roller carriers
24, which gap enables the relative motion of the two roller carriers 24 in
direction towards
each other or away from each other. The bearing locations of the rollers 23 in
the roller
carriers 24 are so chosen that the distance between each two opposing rollers
23 narrows
towards below, therefore in flow direction of the dough, and this is in all
positions of the roller
carriers 24, so that, therefore, the gap 50 relevant for the flow of the dough
between the
roller sets 18, 29 narrows towards below. From the roller group formed by the
two roller sets
21, 22, the dough 4 flows out in form of a continuous dough band of constant
width and
substantially constant thickness and gets onto a conveyor belt 27 guided over
a roller 29
driven by a motor (not shown) so that it circulates in direction of the arrow
28. At the deliver
position 30, this conveyor belt 27 may deliver the dough band to a further
processing step,
for example forming, portioning and the like, or these further processing
steps of the dough 4
can be made partially or completely already on the section of the conveyor
belt 27 being
positioned laterally with respect to the roller group 31.
The rollers 23 of each roller set 21, 22 are driven in the same direction, the
direction
of circulation is indicated by arrows 32 (Fig. 1, 2). These directions of
circulation are
oppositely directed for the two roller sets 21, 22, so that the dough between
the two roller
sets 21, 22 is conveyed downwardly by the rollers 23. Each roller set 21, 22
is driven by a
motor 33 each (Fig. 3), which drives chain wheels 35 via a chain 34, which
chain wheels are
connected for common rotation with the shaft stubs 69 of the rollers 23. Since
the two roller
carriers .24 move relative to each other, suitably an own drive means is
provided for the
rollers of each one of the roller carriers 24 (Fig. 6 to 9). However, by
suitably choosing the
CA 02378882 2002-02-O1
_$_
transmission ratio between chain 34 and chain wheels 35, the construction is
such that the
lower rollers 23 rotate with a higher rotational speed than the upper rollers
23.
A further motion is superimposed to the described circulating movement of the
rollers
13, which further movement is transferred to the rollers 23 via the roller
carriers 24. For this,
each roller carrier 24 is driven by means of an eccentric means 36. Each
eccentric means 36
has an eccentric disk 37 bearingly supported within the framework 2 by means
of bearings
38 and carrying an eccentric pin 39 lenghtened to a rod extending in axial
direction of the
rollers 23, which rod connects the two roller carriers 24 disposed on both
sides of the rollers
23. This rod-shaped eccentric pin 39 is bearingly supported within the roller
carriers 24 by
means of bearings 40. This construction is shown in Figs. 2 and 3. However,
the
arrangement can also be an inverted one, i.e. that the eccentric disks 37 are
bearingly
supported within the roller carriers 24 and the eccentric pins 39 within the
framework 2.
Within the embodiment shown, the one eccentric disk 37 carries a concentric
chain wheel 41
driven by a motor 43 via a chain 42. The chain 42 runs over a further chain
wheel 44 that
drives a further eccentric means 45, the eccentric disk 46 and the eccentric
pin 47 of which
are bearingly supported within the framework 2 or within the roller carrier
24, respectively, in
an analogous manner as this has been described for the eccentric means 36.
This supporting by eccentric means 36, 45 is the same for the roller carriers
24 of
both roller sets 18, 19, however, symmetrical with respect to the axis 48 of
the gap 26.
The direction of revolution of the motor 43 or, respectively, the direction of
the run of
the chain 42 are so chosen that the eccentric pins 39 or 47 revolve in a
circular movement in
direction of the arrows 49, and therefore, opposite to the direction of
movement of the dough
in the gap 50 between the two roller sets 21, 22. Within this, the two
eccentric pins 39, 47
are angularly offset with respect to each other. As Fig. 2 shows, the lower
eccentric pin 39
has already reached almost its highest position, whereas the upper eccentric
pin 47 has only
started its upward movement. Thus, when the eccentric means 36, 45 rotate,
there results
CA 02378882 2002-02-O1
_g_
for the two roller sets 21, 22 a movement that is superimposed to their
revolving motion,
which superimposed movement comprises a horizontal component as well as a
vertical
component. Therefore, there results a motion of the two roller sets 21, 22
that is directed
towards each other or, respectively, opposite to each other and is directed
upwardly or,
respectively, downwardly, wherein, however, the lower rollers 20 of the two
roller sets 21, 22
mostly approach or, respectively, remove from each other at another time than
the upper
rollers 20 of these roller sets. The so produced wobbling motion of the two
roller sets 21, 22
results in a pressure or kneading action on the dough, however, the dough is
treated gently,
so that the dough is gently brought into the desired dough band shape. Within
this, there
results a certain breaking effect onto the dough flowing between the rollers
20, caused by
the correspondingly selected revolving direction of the eccentric means 36,
45. However, the
conveyance action of the rotational motion of the rollers 20 around their axes
is directed
opposite to this breaking effect, whereby the lower rollers 20 of each roller
set 21, 22 rotate
with a higher speed than the upper rollers of the same roller set. This
different rotational
speed of the single rollers 20 can easily be achieved by selecting the size or
teeth number of
the chain wheels 35 co-operating with the chain 34. By the co-operation of all
of these
movements, the dough is not only pumped or pressed through the gap 50 existing
between
the roller sets 21, 22 and tapering downwardly, but is also stepwisely and
gently rolled into
the desired shape.
The embodiment according to Figs. 4 and 5 differs from that according to Figs.
1 to 3
in that instead of the upper eccentric means 45 connecting rods 51 are
provided. Each
connecting rod 51 is pivotally connected at its one end by means of a swivel
bearing to the
framework 2, and at its other end to the corresponding roller carrier 24, also
swivellably.
Suitably, the latter pivot location 53 is so chosen, that it coincides with
the axis of the
uppermost roller 20. Within this embodiment, the connecting rods 51 are
directed
CA 02378882 2002-02-O1
-10-
downwardly from the swivel bearings 52 and towards the gap 50. Within this,
the operation is
substantially the same as within the embodiment according to Figs. 1 to 3.
In the Figs. 6 to 9 different embodiments for those members are shown by which
the
said wobbling motion of the two roller carriers 24 is created. Within this,
the embodiment
according to Fig. 6 is, in general, equal to that according to Fig. 4, i.e.,
the eccentric drive
means is disposed below and the connecting rods are disposed above, wherein
the
connecting rods 51 are directed inwardly and downwardly from their pivot
locations 52 at the
framework 2.
Therefrom, the embodiment according to Fig. 7 differs in that the connecting
rods 51
are directed upwardly from their pivot locations 52 at the framework 2.
Within the embodiment according to Fig. 8, the eccentric bearing is located
above
and the connecting rod pivot below. The connecting rods are directed from
their pivot
locations at the framework downwardly and inwardly. The pivot location 53,
therefore, is no
more located near the uppermost roller 20 of the respective roller set 21 or
22, but near the
lowermost roller 20.
Therefrom the embodiment according to Fig. 9 differs in that the connecting
rods 51
are directed upwardly from their swivel bearings 52 at the framework 2.
The Figs. 6 to 9 show further schematically the already described drive means
for the
revolving motion of the rollers 20 and for driving the respectively used
eccentric means 36 or
45.
In addition thereto, in the Figs. 1, 2 and 6 to 9 means are shown by which the
average width of the gap 50 can be varied that remains between the two roller
sets 18, 19
and is relevant for the through-flow of the dough. These means comprise
adjustment means
acting onto the two roller carriers 24. For this, within the described
embodiments each roller
carrier 24 in its lower section is provided with a toothed rack 55 meshing
with a toothed
wheel 56 that is bearingly supported on the framework 2. Thereby, an
adjustment of the two
CA 02378882 2002-02-O1
-11-
roller carriers 24 in direction of the double arrows 57 is possible. The
adjusted position can
be secured by fixing means, not shown.
Fig. 10 shows the described adjustment possibility in the extreme position in
which
the two lower sections of the two roller carriers 24 are brought into maximum
approach to
each other, so that the gap 50 between the two roller sets 18, 19 has reached
its narrowest
adjustment below. As Fig. 10 shows, the adjustment possibility for the width
of the gap 50
described until now has its effect chiefly onto its lower section. If it is
desired to adjust also
the upper section of the gap 50, a similar adjustment possibility can be
provided also for the
upper sections of the two roller carriers 24, as this is shown in Fig. 11.
Within this, the
adjustment region can be so wide that the edges of the walls 24 constituting
the roller
carriers 24 contact each other in pairs, as this is shown in Fig. 11.
An analogous adjustment possibility, of course, can be applied also for the
swivel
bearings 52 of the connecting rods 51.
It is suitable to dispose the described adjustment means, in particular the
toothed
racks 55 and the toothed wheels 56, in the region of the eccentric means 36 or
45 or in the
region of the swivel locations 52 of the connecting rods 51. If desired or
necessary, however,
the described adjustment means for the width of the gap 50 can act also on
other locations
of the roller carriers 24.
Within the embodiment according to Figs. 12 and 13, a flowable medium can be
conducted into several or all of the rollers 20 of the roller sets 18, 19,
which medium reaches
the dough through the rollers 20. For this, each roller 20 has at least one
conduit 59
extending in the longitudinal direction of the roller, suitably in the region
of the roller axis 58.
into which conduit the flowabte medium, for example baking oil, egg white,
aroma compound
solutions, but also oxygen or fermentation gases for influencing the dough
properties, is
introduced in direction of the arrow 60 from a line 61 via a rotating coupling
62. Suitably, the
conduit 59 is formed by a hollow shaft 63 of steel, the end of which remote
from the rotating
CA 02378882 2002-02-O1
-12-
coupling 62 is closed. The wall of the hollow shaft 63 comprises a plurality
of radially
extending openings 64 through which the flowable medium can flow to the jacket
65 of the
roller 20. Suitably, this jacket 65 on its inner side is provided with an
annular distribution
space 66 into which the medium flows in direction of the arrows 67 and from
which it enters
the jacket 65. In order to enable the flow through the jacket 65, it consists
of a sinter body
permeable for the medium, suitably of dough-rejecting material, for example
polyamide
having an average molecular weight of about 1000, whereby the sinter volume
amounts to
60 to 90% (corresponding to a hollow space content of 10 to 40%). Such a
porous sinter
body may consist of grains of synthetic plastic material having an average
grain size of 0.1
to 1.0 mm, for example 0.2 to 0.35 mm. The medium passed into such a sinter
body
penetrates this sinter body or diffuses it and, therefore, reaches the
peripheral surface 68 of
the jacket 65 and therewith the dough 4 being in contact with this peripheral
surface.
Such an apply of the medium onto the dough 4 is advantageous as well with
respect
to the local apply as with respect to the uniformity of the apply and with
respect to avoiding
soiling of neighbouring machine elements.
As Fig. 12 shows, a plurality of rollers 20 can be connected in common to the
line 61,
into which the medium to be applied onto the dough 4 is introduced under
pressure by a
pump, not shown. An alternative embodiment consists in to connect individual
rollers 20 to
different lines 61, so that different media can be applied in different doses.
As Fig. 1 and 12 show, above the roller group 31 formed by the roller sets 21,
22
there is provided the device formed by the roller sets 18, 19. This device has
the purpose to
take up dough quantities, if any, rising upwardly from the roller group 31
during the pumping
motion of the roller sets 21, 22, and to conduct these dough quantities back
again into the
roller group 31. For this, the rollers 20 of the roller sets 18, 19 are freely
rotatable, suitably
the peripheral surfaces of these rollers 20 contact each other so that a
sidewise escape of
the dough is avoided. A similar contact of the peripheral surfaces 68 of the
rollers 20 is also
CA 02378882 2002-02-O1
-13-
present within the embodiment according to Fig. 12, however, this is not
compulsory, as Fig.
1 shows, wherein the peripheral surfaces of the several rollers 23 are spaced
apart from
each other for a small distance.
As Fig. 1 shows, the rollers 20 of the roller sets 18, 19 are disposed
adjacent to the
uppermost rollers 23 of the roller group 31. The gap confined by the roller
sets 18, 19 is at
least as wide as the mean width of the gap 50 of the roller group 31. The
rollers 20
superimposed in vertical direction have the same size, however, their
diameters are always
smaller than the diameters of the rollers 23 of the roller group 31.
