Note: Descriptions are shown in the official language in which they were submitted.
This invention relates to the making of a
hollow baked product which comprises a body formed by
a wound baked strip conslsting preferably of a wafer
strip and coated on at least part of its inside surface
and optionally containing a filling material in at least
part of its cavity.
Various baked wafer products made by machine are
known, inter alia, in the food-processing inductry. The~e
baked wafer products are placed on the market in a filled
or unfilled state and are generally known as luxury foods.
Such products of the wafer-baking industry are, e.g.,
wafer cones, wafer cups, wafer plates, flat wafer discs,
low hollow wafers, hollow stlcks, wafer rolls, icecream
cones, filled wafers, icecream wafers, small fllled
wafer sticks, wafer slices and the like. These baked
wafer products made by baking a wafer dough are crisp
and brittle and break easily. They are baked to be as
dry as possible and have a very low moisture content.
The variou~ baked wafer products can be made
in various ways. Some wafer products are baked in their
final shape. This applies, e.g., to wafer cones, wafer
cups, wafer discs, low hollow wafers and the llke.
In the manufacture of other baked wafer products,
a wafer sheet or an endless wafer strlp i~ baked first and
is given its final shape when it is still soft after the
baking operation. In that final shape the baked wafer
product is permitted to cool and toassume a crisp and
brittle consistency. Examples of such baked wafer products
are sugar-containing icecream cones, hollow sticks,
sugar-containing wafer rolls and the like.
. ~
8~7
Other kinds of baked wafer products are made
in that a plurality of wafer sheets are baked, cooled,
coated with cream, and stacked to form a wafer block.
That cream-filled wafer block is subsequently cut into small
handy pieces of uniform size, which are then packaged in
units consisting of one or more pieces, possibly in vacuum
packages, and are placed on the market in that form.
Various baked wafer products may be provided with
coatings consisting, e.g., of sugar or chocolate, or may
contain various filling materlals, such as icecream,
various other creams, chocolates or the like.
The wafer products descrlbed hereinbefore differ
from waffles, which are usually baked by housewlves in
waffle irons and constitute a soft baked product, which
is similar to rolls or pancakes. These waffles made by
housewives do not resemble at all the above-mentioned
baked wafer products of the wafer lndustry as regards
conslstency and use.
It is known from Austrian Patent Speclficatlon
262,187 to make a tubular wafer body in that a baked wafer
strip which is delivered by a continuously operating
wafer-baking machine and is still in a warm, soft state
is continuously wound on a winding mandrel in overlapping
helical convolutions ~o as to form an endless tubular hody,
which is rotating as a result of the winding operation. The
wlnding mandrel may be stationary or may be rotatably
mounted and adapted to be driven and has a longitudinal
bore, which opens at the free end of the windlng mandrel
and tapers there to form a spray nozzle. Fat or chocolate
is sprayed through that nozzle onto the inside surface of
the tubular body. When the tubular body and the coating
-- 2 --
~1'78~ 7
material sprayed on it have hardened, the tubular body is
sawn through with a circular saw. Only coatlng materials
which are sprayable or which have been rendered sprayable
by heating can be used in that known process. An entraining
fluid, such as air, is required for a fine division of the
sprayed coating material. If the fat or chocolate to be
applied is liquefied by heating so that it is rendersd
sprayable, the danger of an overheating of the fat or
chocolate will impose a restriction on the liquefaction
so that it will also be necessary to admix air as an
entraining fluid. In that connection it has been found
that a disadvantage resides in that the quantity which
can be applied by spraying i5 restricted by the fact
that the entraining air escaping from the wound wafer
body during the cutting operatlon will inevitably destroy
the wafer body. It is not possible to liquefy coating
materials by dissolving them in a solvent or by mixing
them with other liquids so that the coating material
can be sprayed because the coating material will not
adhere to the inside surface of the tubular body unless
the solvent or the liquid vehicle either evaporates or
is absorbed by the wafer body. The cavity inside of the
wafer body is much too small and the time available until
the tubular body is severed is much too short to permit of
an evaporation of the solvent or of the liquid vehlcle. In
no case must the solvent or the liquid vehicle be absorbed
by the wafer body because the latter would be destroyed in
that case. Another disadvantage of the spraying of fat or
chocolate onto the inside surface of the tubular body
resides in that the cavity of the endless tubular wafer
-- 3 --
117~8~7
body will then be filled with a fog consistlng of the
spray and that fog will soil the circular saw used to
sever the body. As a result, the circular saw will become
inoperative in the course of time and must be cleaned
frequently so that the manufacture of the wafer body
will be interrupted. Besides, the fog which has been
formed will escape from the interior of the wafer body
into the environment during the cutting operations and
wlll then soil the entire environment. Another dlsadvantage
involved in the spraying of the coating material resides in
that only a single coating material can be applied. If the
tubular wafer bodies made by that known process are to be
filled, the tubular body must first be sawn into discrete
pieces because the filler can be introduced only into the
discrete tubular wafer bodies without a risk of a mixing
of the filler with the fat or chocolate which has been
sprayed. The subsequent filling of discrete tubular wafer
bodies involves a high handling expenditure because each
piece which has been sawn off must be suitably received
and then fed to a separate filllng apparatus.
From Austrian Patent Specificatlon 304,245 it
is known to make a filled~hollow baked product, which has
a tubular wafer body, ln a process in which a baked wafer
strip which is still soft after the baklng operation i8
continuously wound on a winding mandrel in overlapping
helical convolutions to form an endless tubular body,
which is completely filled with a creamlike material
supplied through a longitudinal bore in the winding mandrel
and is sheared into pieces of desired length before the
filler and the creamlike material have hardened. The
-- 4 --
t7
tubular body is sealed on its sides ln that steam ls
supplied to the several convolutions of the wafer band
before said convolutions overlap so that said convolutions
will adhere to each other, possibly under pressure. The
wafer strip used for that purpose contains 30 to 60 %
sucrose, glucose or malt products, which under the action
of heat ln the presence of moisture are quickly dissolved
to become tacky. As that known hollow baked product has no
coating on the inside surface of the tubular wafer body,
the filling material must consist of a substance which
will not ~often the wafer strip because this would adversely
affect the strength and quality of the wafer body.
As the known hollow baked product is filled
immediately after the wafer strip has been wo~nd and
the filling material is supplied through the wlnding
mandrel, it is not possible at all to coat the wound
tubular body on its inside surface before it is filled,
e.g., to provide a sealing layer between the filling
material and the wafer body.
Austrian Patent Specification 327,129 discloses
apparatus for making a hollow baked product which is adapted
to receive a soft filling material in a process in which a
baked strip is provlded on one side with a coating of a
material, such as chocolate, which acts as a sealant for
the fllling material, and the baked strip is then conti-
nuously wound on a windlng mandrel with overlapping helical
convolutions to form an endless tubular body which is coated
on its inside surface. The sealing coating is applied to
the baked strip by spraying, squirting or pouring and the
filling material is supplied through the central longi-
tudinal bore of the winding mandrel into the hollow baked
11'78~ 7
product thus obtained. In the operation of that apparatus,
the materials whlch can be applied to the baked strip are
substantially restricted to materials which can be sprayed,
squirted or poured at room temperature or at a temperature
to which they may be heated. Whereas in the operation of
that apparatus the alr which is admixed to permit the
spraying or squirtlng of the coating material can escape
and materials which can be liquefied by heating need be
heated only to a temperature at which they can be poured,
the materials which have been applied must be 80 elastic
that they continue to adhere to the baked strip and can
be deformed with the latter as it is wound. Besides, said
materials must retain an adequate bond strength during the
winding of the baked strip so that they will adhere to the
inside surface of the resulting ubular body. Moreover, the
material which has been applied must retain its sealing
capacity when the coating is upset during the winding
operation. Where coating substances are used which can
be liquefied by heating, this requirement will be met
by the contact of the coatlng material wlth the surface
of the baked strip, provided that the latter is at a
sufficiently high temperature. Materials which cannot
be sprayed or squirted or poured or which do not melt
as they contact the baked ~trip cannot be u~ed to form
a coating in this manner.
It i8 an object of the invention to eliminate the
above-mentioned dlsadvantages and deficiencies.
In a process of making a hollow baked product
which comprises a body formed by a wound baked strip
consisting preferably of a wafer strip and coated on
8~ >7
at least part of its inside surface and optionally con-
taining a filling material in at least part of its cavlty,
wherein a baked strip, particularly a baked wafer strip
which is still soft after the baking operation, is con-
tinuously wound in overlapping convolutions on a winding
mandrel having a forwara end to form a rotating endless
tubular body which advances toward and beyond sald forward
end of the mandrel and is coated on its inside surface with
an edible coating material and is subsequently severed into
discrete pieces of finite length and the coating material i8
supplled through the mandrel toward the forward end thereof
and is applied to the inside surface of the endless tubular
body ad~acent to said forward end of the mandrel, that
object is accomplished in that one or more coating materlals
in a pasty or liquid or spreadable state are applied to the
inside surface of the endless tubular body through one or
more openings which are formed in the mandrel in its forward
; end face or succeed the forward end of the mandrel when seen
in the direction in which the tubular body is conveyed along
the mandrel and/or are caused to emerge through one or more
openings provided in the periphery of the mandrel and/or at
the transition from the forward end face of the mandrel to
lts periphery, the coating material or material~ are
optionally spread on at lea~t part of said inside surface
to wh$ch they have been applied, and a particulate solid
mater$al and/or a filllng material is supplied through
~ the mandrel or an extension of the mandrel and introduced
into the endless tubular body after the coating material
or materials have been applied.
In the proceæs according to the invention, at
least one coating is formed on the inside surface of the
- 7 -
38~7
endless tubular body in that coating material supplied
through the winding mandrel is applied in the form of
at least one coherent stream to the inside surface of
the endless tubular body adjacent to the forward end
of the winding mandrel. The phrase "at least one coherent
stream" includes a continuous coherent stream, a plurality
of parallel continuous coherent streams and a plurality of
consecutive coherent streams of finite length.
In the process according to the inventlon, any
undesired adverse effect in the cavity of the tubular body
or on the severlng device will be avoided because the
coating materials are not atomized so that no fog is
formed in the cavity of the tubular body. The process
according to the invention may be used to apply liquid
substances and/or substances which cannot be liquefled
even by heating. If the process according to the invention
is used ~ coat the baked strip with materials having a
melting point above the temperature of the baked strip
during the winding operation, it will be sufficient to
heat these materials to such a temperature that they
will be just tacky as they are applied. Within the scope
of the invention the application of the coating materials
can be assisted in that the coating material which haQ been
applied to the inslde surface of the tubular body i8 spread
on said surface. The spreading of the material which has
been applied will result in an intimate contact of the
coating material with the baked strip. The consistency
of the material to be spread is selected so that the
forces required to spread the material on the inside
surface of the wound body will not adversely affect
the latter.
-- 8 --
~1788~7
In the process according to the invention,
a particulate solid material can be applied to the coated
inside surface of the tubular body. That particulate solid
material is supplied through the mandrel and applied to the
coating, e.g., when the latter is still tacky. As a result,
the roughness of the inside surface of the coated tubular
body is increased so that any filling material which may
subsequently be introduced will be more firmly held in the
hollow baked product. The particulate solid material whlch
is applied to the coatlng may preferably be granular and
may consist in that case of crystalllne sugar, croquant,
comminuted nuts or sugar-containing grits, or may consist
of a powder, such as powdered sugar or the like.
In the process according to ~he invention, a
filling material may be introduced through the mandrPl
into the interior of the tubular body before the latter
is severed into length sections if a sealing layer which
is required between the baked strip and the filling material
has previously been applied to the inside surface of the
tubular body. In that case, each piece which is severed from
the endless tubular body will constitute a complete hollow
baked product, which is coated on its inside surface and
contains a filling material ana can then be packaged.
Because the coating i8 formed on the wound tubular
body, the convolutions of the wound baked strip consisting
of a wafer strip may be adhered to each other, e.g., in that
steam is ~upplied to the subsequently overlapping regions of
the convolution~ of the strip so that the coating material
applied to the inside surface need not comply with such high
requirements as are to be met, e.g., when a layer applied to
11788'~'~
the baked strip ls wound with the latter. In the process
according to the invention, the quantity of the coatlng
material which is applied may be restricted to the ~u~ntity
which is absolutely required for the desired sealing.
In one embodiment of the process, one or more
coating materials are discharged through openings formed
in the forward end face of the mandrel or succeeding the
forward end of the mandrel in the direction in which the
tubular body is conveyed and are permitted to desciend from
said opening or openings substantially only by gravity. That
embodiment of the process will be of special advantage with
coating materials which are llquid or can easily be
li~uefied because a splashing or spraying of the coating
materials will be avoided.
In another embodiment of the process, one or
more coating materials are caused to emerge through one
or more openings provided at the periphery of the mandrel
under such a pressure that the tubular body is temporarlly
expanded in the radial direction by not more than the
approximate thickness of the coating to be formed. In
that case it will be possible to apply a coating material
which is merely spreadable or pasty and for this reason
mus~ be conveyed under a relatively high pressure and the
thickness of the coating to be applied can simply be
controlled by a change of the pressure under whiah the
coating material is conveyed and of the pressure under
which it is discharged.
The invention provides also apparatus for
carrylng out the process. That apparatus comprises a
winding device, which is associated with at least part
of the mandrel, means for continuously feeding the baked
-- 10 --
l~t7~8'1~
strip to the winding device, coating material supply means
for supplying a coating material, comprising at least one
supply passage, which extends through the mandrel toward
its forward end and has at least one outlet opening, and
means for severing the tubular body into individual pieces.
That apparatus is characterized in that the outlet opening
or openings formed in the mandrel or in extensions thereof
are provided in the forward end face of the mandrel or of
said extensions or in the periphery of the mandrel or in a
transitional portion between the forward end face and the
periphery of the mandrel and have a cross-section which is
sufflciently large to prevent a spraying of the coating
material supplied by said coating material supply means,
any device for introducing a filling material comprises
also at least one passage which extends through the mandrel
and/or through extensions thereof and is separate from the
supply passage or passages for the coating material or
materials and has one or more outlet openings which in
the direction of conveyance of the tubular body succeed
the outlet opening or openings for the coating material
or materials, the passage for the filling material op-
tionally contains a conveying device, and at least one
device for spreadlng at least part of the coatlng material
or material~ applied to the inside ~urface of the tubular
body i8 optlonally provlded.
With that design, the outlet openings can be
arranged close to that portion of the tubular body to
which the coating material is to be applied.
In the apparatus according to the invention,
the means for introducing the filling material may be
so designed that the filling material is introduced
- 11 -
li7~38~7
into the interior of the tubular body with an optimum
orientation for the filling operation.
Another advantage of the apparatus according
to the invention resides in the provision of means for
conveying the filling material in the passage for the
filling material. In that case even a filling material
which can be conveyed only with ~reat difficulty can be
introduced into the interior of the tubular body. Within
the scope of the invention, the means for conveying the
filling material may have separate drive means, which are
independent from the means for driving the winding device
or for driving the mandrel. In that case the means for
conveying the filling material can be operated to convey
the filling material under optimum conditions at a volu-
metric rate or speed which is independent of the speed at
which the ba~ed strip is wound and of the rate at which a
coating material is applied.
Also within the scope of the invention, the outlet
opening or openings may consist of one or more annular
channels, slots or holes and may be formed in the mandrel
in a coating section, which succeeds the winding section
of the mandrel in the direction of conveyance of the tubular
body. That feature permits a very compact design of the
entire apparatus.
Within the scope of the invention the coating
section of the mandrel may consist of a separate coating
head. This will permit a simple alteration of the mandrel,
e.g., from the application of only one coating material to
the application of a plurality of coating materials in that
one coating head is replaced by another. The mandrel is
- 12 -
3847
formed in its winding section with all passages which are
required for one coating head and the other.
Within the scope of the invention, at least one
tube extends through the mandrel in its longitudinal
direction and may be used to feed the filling material
through the mandrel and is not rotated in unison with
a rotatable mandrel. That tube may be fitted in a bore
which is formed in the mandrel and may be in snug contact
with the tube, or a clearance left between the outside
surface of the tube and the inside surface of the bore
in the mandrel may be used as a passage for feeding a
coating material or filling material.
Within the scope of the invention, the mandrel
may consist of a sleeve and the tube fitted into the mandrel
may preferably consist of a material of low thermal
conductivity and may be in substantially snug contact
with the inside surface of the sleeve and on the outside
of that portion which contacts the inside surface of the
sleeve may have one or more flats or one or more grooves,
which together with the sleeve define one or more supply
passages for one or more coating materials, which supply
passage or passages communicate with the outlet opening
or openings formed in the sleeve for the discharge of the
coating material or materlals whereas the bore of the tube
constitutes a passage for a fllling material. In that
embodiment of the invention, the interior of the tubular
body formed by winding the baked strip may be supplied
with a filling material which when introduced into the
tubular body must be at a predetermlned temperature above
or below the temperature required for the winding of the
baked strip. In that case the filling material may be
- 13 -
introduced into the tubular body at a temperature which
ls optimum for said introduction and said temperature
will not be affected by the temperature of the baked
strip, which during the winding and coating operations
may be at optimum temperature for these operations.
If the baked strip is wound at a temperature
which is much higher than the temperature of the filling
material, the outlet opening of the heat-insulating tube
is suitably spaced a sufficiently large distance from the
outlet openings provided on the periphery of the mandrel
for the discharge of the coating material so that the baked
strip which has been wound to form a tubular body can cool
down before the cold filling material contacts the coating
on the inside surface of the tubular body formed by winding
a baked strip.
Also within the scope of the invention, at least
one length section of the mandrel may consist of two
concentric tubes which define between them a supply
passage for a coating material in an arrangement in
which the inner tube extends beyond the forward end
of the outer tube and is provided at its forward end
with a flange, which together with the forward end face
of the outer tube defines an annular channel which con-
stitutes an outlet opening for the coating material. In
that case the supply passage may have a large cross-section
so that the coating material can be conveyed through the
mandrel at a high rate and a tubular body which is inter-
nally coated can be produced at a high rate. If the inner
tube has a sufficiently small wall thickness, filling
material at a high rate, corresponding to the high pro-
- 14 -
~17~3847
duction rate of the tubular body, can be fed through the
interior of the inner tube.
Within the scope of the invention the outer and
inner tubes may be rotatable relative to each other so that
the filling material can be introduced into the hollow baked
product through the inner tube which is stationary whlle the
outer tube is rotating. Alternatively, the inner tube may be
rotated at a higher speed than the outer tube so that that
portion of the coating head which succeeds the outlet
opening or openings for the coating material will spread
the coating material.
Also within the scope of the invention, recesses
and elevations may be formed on the surface of the passage
for the filling material so that the surface of the passage
acts to convey the filling material, particularly if the
latter consists of a particulate solid material. If the
surface of the passage is formed by the inside surface
of the inner tube and the latter is rotatable relative
to the outer tub~, the veloclty at which the filling
material is conveyed may be controlled independently
of the winding speed of the mandrel.
; Also within the scope of the invention, the
passage for the filling material may contain a conveyor
screw, which is preferably adapted to be driven indepen-
- dently of the mandrel. With that design the rate or
velocity or pressure at which the filling material is
conveyed can be selected in dependence on the nature
of the filling material. Because the conveyor screw
is driven independently of the mandrel, these parameters
can be selected in dependence on the production rate of
- 15 -
1178~ 7
the tubular body. In case of a change of the filling
material, it will be sufficient to exchange the conveyor
screw so that optimum filling conditions will be obtained
even when an entirely different filling material is
employed.
The invention will subsequently be explained
with reference to a hollow baked product which is made
in a process in whlch the tubular body is made from a
baked strip consisting of a wafer ~trip which is still
soft after the baking operation as it is wound around the
mandrel. It will be understood that the invention is not
restricted to the use of a baked strip made from wafer
dough. The dough may consist of a wafer dough having a
low sugar content or of a wafer dough which has a high
sugar content so that the baked strip will be plastic
when it is still soft from baking and will harden as
it is cooled, or of other baked doughs which can be
made in the form of continuous strips.
Illustrative embodiments of the apparatus
according to the invention are shown on the accompanying
drawings, in which
Figure 1 is a diagrammatic side elevation showing
a first embodiment of apparatus according to the invention
and
Figure 2 is a sectional view taken on line II-II
in Flgure t.
Figures 3 to 5 are longitudinal sectional views
showing additional embodiments of apparatus according to
the invention.
Figures 6a, 6b, 7, 8a, 8b, 9a, 9b and 10 show
various embodiments of a mandrel which may be used within
- 16 -
117~7
the scope of the invention to apply only one coating material
to the inside surface of the tukular body, or of the coating
section of such mandrel,
Figures lla and llb show another embodiment of a
mandrel which may be used within the scope of the invention to
apply up to three different coating materials,
Figures 12a and 12b show another embodiment of a
mandrel which may be used within the scope of the invention for
applying only one coating material,
Figure 13 shows another embodiment of a mandrel which
may be used within the scope of the invention to apply one coat-
ing material or two different coating materials,
Figure 14 shows another embodiment of a mandrel,
Figures 15a and 15b show another embodiment of a
mandrel,
Figures 16a, 16b, 17a, 17b, 18a, 18b, 19, 20, 21a, 21b,
21c, 22, 23a, 23b, 23c show various embodiments of a mandrel
which may be used within the scope of the invention to coat the
tubular body on its inside surface and to introduce a filling
material or a particulate solid material into the interior of
the tubular body,
Figure 24 shows the applying section of a mandrel,
which applying section consists of a plurality of concentric
tubes and serves to apply two coating materials and to introduce
a filling material or a particulate solid material into the
interior of the tubular body,
Figure 25 shows an embodiment of a mandrel provided
with two applying heads for applying two coating materials,
Figures 26a, 26b, 27a, 27b show two more embodiments
o a mandrel which may be used within the scope of the invention
and has a heat-insulating core, and
Figure~ 2~ to 31 are iongitudinal sectional views
- 17 -
. --
1:1788~'7
showing four different embodiments of a hollow baked product
made in accordance with the invention.
In the embodiment shown in Figures 1 and 2 a baked
strip 1 consisting, e.g., of a wafer strip which is still
soft from baking is supplied to a driven mandrel 2 at an
oblique angle to its axis of rotation and is urged against
the winding section 4 of the mandrel 2 by a feeding and
pressure-applying roll 3, which is also driven. The feeding
and pressure-applying roll 3 is axially parallel ~o the
rotating mandrel 2 and is provided on it~ periphery with
screw threads, which tend to advance the wafer band that
is supplied at an oblique angle to the axis of the man-
drel 2. The mandrel 2 is succeeded by a severing device 5
for severing the baked strip 1 when the same has been wound
on the mandrel to form a tubular body. The severing device
may consist of a shearing machine or of a travelling
circular saw or the like. The winding apparatus consisting
of the feeding and pressure-applying roll 3 and the
mandrel 2 is supplied with the baked strip 1, e.g.,
from a continuously operating wafer-baking machine,
and winds the strip around the mandrel to form a tubular
body, which i~ advanced along the mandrel and rotates as
it ls advanced. The overlapping edges of the baked wafer
~trip will stlck together if the ~ubsequently overlapping
portlons of the baked wafer strip that has not yet been
wound are supplied with steam from a steam discharge
nozzle 6, which extends substantlally tangentially to
the mandrel 2 (Figure 2). Steam may also be supplied
to the baked strip 1 in that water is continually fed
at a low rate to a hot metal plate or the like which
is disposed under the path of the baked strip. The winding
- 18 -
li788~7
section 4 of the mandrel 2 is succeeded toward the free endof the mandrel by a coating sectlon 9, whlch i8 formed ln
its periphery with an annular groove 10 near the free end of
the mandrel. The annular groove is defined toward the free
end of the mandrel by a sizing shoulder 38, which is smaller
in diameter than the mandrel by an amount which is approxi-
mately twice the thickness of the coating to be applied. The
coating materlal 56 is supplied to the annular groove 10
through radial passages 35 from a supply passage 36 that
extends centrally in the mandrel 2. The coating material 56
completely fills the annular passage which is defined by the
annular groove 10 and the tubular body 39 and the coating
material contacts the inside surface of the tubular body 39
throughout the periphery of the mandrel. Moving relative to
the mandrel 2, the tubular body takes from the mandrel the
coating material, which sticks to the inside surface of the
tubular body. The sizing shoulder 38 will scrape surplus
coating material from the inside surface of the tubular
body 39 so that the thickness of the coating applied to
the inside surface of the tubular body 39 will be determined
by the annular clearance between the tubular body 39 and the
sizing shoulder 38. If the sizing shoulder 38 is cylindri-
cal, the coatlng of the tubular body 39 will have a
cyllndrlcal inslde surface.
The coating on the inside surface will be
formed wlth radlally lnwardly protrudlng rlbs lf the
sizing shoulder 38 has axlal grooves conforming to the
desired cross-section of the ribs, or with grooves, lf
the sizing shoulder 38 i~ formed with corresponding
radially protruding ribs.
_ 19 _
~1'i'~38~7
In the embodiments shown in Figures 3 to 5,
the winding section ~ of the mandrel 2 is succeeded by a
coating section, which at the periphery of the mandrel is
a].so formed with an annular groove 10. Supply passages 11
extend longitudinally through the mandrel and serve to
supply the annular groove with a coating material that
is to be applied to the inside surface of the tubular
body. The supply passages 11 for the coating material
extend through the winding sectlon 4 of the mandrel 2
near the periphery thereof and open laterally into the
annular groove 10. The supply passages extend from a
manifold 12, which is disposed behind the roll 3 and
is fed with the coating material through a conduit 13
from a supply bin or a pump (not shown). The mandrel 2
has a central bore 7, which extends throughout the length
of the mandrel 2 and serves to supply a filling material 8
into the interior of the tubular body.
A passage 15 extends from a supply bin 14 for
filling material to that end of the bore 7 which is
disposed at the rear end of the mandrel 2. A blast nozzle 16
which is coaxial to the mandrel 2 opens into the passage 15
(Figure 3). A particulate solid filling material which is
dellvered from the supply bin 14 through the passage 15 i9
blown by the blast nozæle 16 through the bore 7 into the
interior of the tubular body to fill the same in part~ If
the particulate solid material, such as comminuted nuts,
crystalline sugar, croquant, sugar-containing grlts or the
llke should be deposited only in a small quantity on the
coated inside surface of the tubular body, the bore 7
suitably flares toward the free end of the mandrel 2
(Figure 20).
- 20 -
1:1'7~
In another embodlment (Figure 4), a conveyor
screw 17 is mounted in the bore which extends through
the mandrel 2 and is supplied from the supply bin 14
with the filling material that is to be conveyed. The
conveyor screw 17 terminates at the forward end of the
mandrel 2 and is driven by the screw shaft at the rear
end of the mandrel 2. That concept may be adopted in
conjunction with a driven or stationary mandrel because
the filling rate will be determined by the variable speed
of the conveyor screw, independently of the rotation of
the mandrel. Alternatively, the conveyor screw may be
non-rotatably connected to a rotating mandrel so that
the speed of the latter will also determine therate
at which the filling materlal is supplied.
As is apparent from the embodiment shown in
Figure 5, a rotating mandrel 2 may be used directly to
convey the filling material through the central bore 7
of the mandrel 2. For this purpose, individual helical
ribs 18 are provided on the surface which defines the
bore 7. These rlbs 18 may constitute a single, continuous
rib.
Figures 6 to 11 show various embodiments of
mandrels 2 having applying sections 9 for applying only
one coating material to the lnside surface of the tubular
body.
The embodiment shown ln Flgure 6 dlffers from
the mandrel shown in Figures 3 to 5 only in that there
is no central bore for the filling material. The design
of the coating section 9 of the mandrel 2 is common to these
four embodiments. Between the annular groove 10 and the
- 21 -
38'~
forward end face of the mandrel 2, the latter has a portion
that is equal in diameter to the body of the mandrel 2. If
such a coating section 9 is used, the coating material will
be delivered into the annular groove 10 under such a
pressure that the tubular body is temporarily locally
inflated adjacent to the annular groove.
In the embodiment shown in Figure 7, the coating
section 9 of the mandrel 2 is conically tapered at 33. At
the transition from the callndrical portion of the mandrel
to its conically tapered portion 33, the mandrel 2 is formed
at its periphery with four outlet openings 34, which are
equally spaced around the periphery of the mandrel and
communicate through radial passages 35 with an axial
passage 36 for supplying the coating material. The outlet
openings 34 consist of slots, each of which extends along
the mandrel partly in its cylindrical portion and partly
in its conically tapered portion. Owing to that design the
coating material supplied through passages 3~, 36 emerges
fxom the outlet openings 34 in part at the periphery of the
mandrel and in part toward its forward end face. The
selection of the taper and of the distance over which
the outlet openings extend into the conicall~ tapered
portion 33 will depend on the de~ired thicknes~ of the
coating.
In this embodiment, a helical strip of coating
material is applied from each outlet opening to the inslde
surface of the tubular body. The lead of the helical strips
will depend on the ratio of the rotational movement to the
axial movement of the tubular body relative to the statio-
nary or rota$ing mandrel 2. In the embodiment shown in
- 22 -
1:1'7~8~
Figure 7, four separate helical strips will be formed
on the inside surface of the mandrel if the tubular
body is axially moved at a high velocity an~ is only
slowly rotated relative to the mandrel or four helical
strips having overlapping edges will be formed. This
will depend on the lead of the helical strips and on
the length of the outlet openings 34 measured at right
angles to the helix.
If the mandrel rotates in synchronism with
the tubular body, parallel longitudinal strips of the
coating material will be formed on the inside surface
of the tubular body.
The outletcpenings for delivering the coating
material may alternatively consist of slots 40, which
extend at an oblique angle to the axis of the mandrel
and open at the periphery of the mandrel and may also
open at its forward end face.
In the embodiment shown in Figures 8a, 8b the
slot 40 is so arranged that its end 41 lie on the periphery
of the mandrel on a straight line which intersects the axis
of the mandrel at an oblique angle. In the embodiment shown
in Figures 9a, 9b the ends 41 of the slot 40 lie on a
straight line which intersects the axis of the mandrel
at right angles.
Each slot communlcates at its bottom with a
central supply passage 36 formed in the mandrel 2. With
that design, the coating material can be applied at a high
rate.
In the embodiment shown in Figure 10, the coating
section 9 is provided at the forward end face of the mandrel
- 23 -
t~
with outlet openings 19, which communicate through pas-
sages 11 with one or more feeders for supplying one or
more coating materials. Each of these feeders comprises
a feed conduit 13 and a manifold 12. The coating material
emerges through these outlet openings from the ~rward end
face of the mandrel and in dependence on the consistency of
the coating material may be squirted from said outlet
openings as a thick jet onto the inside surface of the
tubular bod~ or may be applled under pressure as an
extrusion to the inside surface of the tubular body.
As the coating material emerges from the outlet openings
in a substantially llquid state, it will spread on the
inside surface of the tubular body as soon as it has
been applied thereto and will thus form a coherent coating
or a plurality of helical strips, which merge only in part
or are entirely separate from each other. This will depend
on the velocity at which the tubular body is advanced along
the mandrel.
From a stationary mandrel, the coating material
will fall by gravity on that portion of the inside surface
of the tubular body which is substantially vertically below
the respective outlet opening.
When it is desired, for instance, to apply a
plurality of different coating materials to the inside
surface of the tubular bodies in superimposed or juxtaposed
layers, another embodiment of the lnvention may be adopted
in which the mandrel 2 has a plurality of axial passages
which open in the forward end face of the mandrel. To
ensure a separation of the several coating materials,
the passages extend through respective extensions, which
- 24 -
~'78E~'7
protrude from the forward end face of the mandrel, and
the openlngs of the several passages are spaced different
distances from the forward end face of the mandrel. Said
extensions which protrude from the end face of the mandrel
may suitably consist of tubes, which are fitted in bores
formed in the coating section of the mandrel. Alternatively,
said extensions may consist of tubes which extend through a
sleevelike mandrel and protrude different distances from the
forward end face of the mandrel (Figure 12).
In another embodlment the outlet openings 19 are
provided in the forward end face of the mandrel 2 in a
circular annular region 20 which is close to the periphery
of the mandrel and is ad~oined toward the axis of the
mandrel by an extension 21, which protrudes from the
forward end face of the mandrel 2 and has a radially
outer boundary surface 22, which axially adjoins the
outlet openings 19. The boundary surface 22 ensures
that the coating material emerging from the outlet ope-
nings 19 in the forward end face will be confined closely
to the inside surface of the tubular body, which is sliding
a(1ong the periphery of the mandrel 2, so that the coating
ma~erial applied to the inside surface of the tubular body
will form a coating of uniform thickness (Figures 11a, 11b).
If the mandrel 2 is stationary or rotates at low
speed, the cylindrical boundary surface 22, which may be
formed with recesses axially adjoining the outlet ope-
; nings 19, if re~uired, will prevent a premature sagging
of the coating material which has emerged from an outlet
opening 19.
If the mandrel 2 is rotating, the boundary
- 25 -
i t'7~
surface of the extension at the forward end of the mandrel
will promote the spreading of the coating material emerging
from the several outlet openings 19 so that a continuous
coating of uniform thickness will be formed. In that
embodiment the coating material may emerge from the
forward end face of the mandrel at a low velocity relati~e
to the tubular body. For instance, the mandrel and the
tubular body wound on the mandrel may rotate about the
axis of the mandrel substantially at the same angular
velocity. In that case, the tubular body will perform
only a longitudinal movement relative to the mandrel
and lt will no longer be necessary to impart a rotation
to the coating material as it reaches the inside surface
of the tubular body. The outlet openings 19, which are
angularly spaced apart in the circular annular region 20,
and the boundary surface 22 of the extension 21 will then
ensure that the coating has a uniform thickness throughout
the periphery of the inside surface of the tubular body.
The extension 21 may be integral with the
mandrel 2 or may consist of a sealing plug, which is
fitted in a bore of the mandrel 2 (Figure 11a).
The extension 21 may be integrally formed
with a sealing plug 23, which seals a bore 7 extending
through the mandrel 2. The supply passages 11 termlnate ln
outlet openings 19, whlch are formed in the forward end face
of the mandrel 2 and disposed radially outwardly of the
plug 23. Such a mandrel can be used for numerous purposes.
When the sealing plug 23 has ~een inserted, the
mandrel 2 can be used to coat the inside surface of the
tubular body with coa~lng material emerging from outlet
- 26 -
'~'
li78847
openings 19 formed in the forward end face of the mandrel
whereas no filling material ls introduced into the interior
o~ the tubular body. When the ~ealing plug 23 is replaced by
a plug which has a through bore, the same mandrel 2 can also
be used to introduce filling material into the interior of
the tubular body.
In another embodiment, shown in Figure 13, the
sealing plug 23 is replaced by a coating head 24 and the
supply passages 11 open into an annular channel 26, which
is defined by the forward end face of the mandrel 2 and a
shoulder 25 of the coating head. The shoulder 25 tapers
toward the forward end of the coating head 24 and is
formed with another annular groove 27, which communicates
through radial passages 28 with a blind hole 29, which
continues the bore 7 of the mandrel. In that case the
bore 7 of the mandrel 2 constitutes a passage for supplying
a second coating material, which flows through the annular
groove 27 and is applied to the coating formed by the first
coating material, which has been applied from the annular
channel 26 to the inqide surface of the tubular body.
The thickness of the coating formed by the first
coating material and the thickness of the coating formed by
the second coating material are respectlvely controlled by
the largest and smallest diameters of the shoulder 25 and
by the pressures applied to the coating materials in the
annular channels 26 and 27.
In another embodiment of the coating head, the
; shoulder 25 is adjoined by a step 30 and the supply
passages 31 communicating with the bore 7 of the mandrel 2
have outlet openings 19 in the forward end face of the
- 27 -
11~8~'7
step 30 (Figures 15a, 15b). From that coating head, one
coatlng material emerges through the annular channel 26
disposed at the periphery of the mandrel and the second
coating material emerges through the outlet openings 19
formed in the forward end face of the mandrel 2 or of
its coating section.
In the embodiment shown in Figures 16a, 16b,
the outlet openings 34 are arranged llke those of Figure 7
but communicate with respective supply passages 35, which
extend axially near the periphery of the mandrel. In this
embodiment, different coating materials can be supplied to
respective outlet openings or a single coating material can
be supplied through all supply passages. A bore or pas-
sage 37 extending through the mandrel can be used to
intr-duce a filling material or a particulate solid
material into the interior of the tubular body which
has been coated on its inside surface.
In the embodiment shown in Figures 17a, 17b,
the outlet opening consists of a slot 40, which is similar
to that shown in Figures 8a, 8b and has ends 41 which are
disposed on the periphery of the mandrel on a straight line
which inter~ects the axls of the mandrel at an oblique
angle. In the embodiment shown in Figures 2ta, 21b, 21c
the outlet opening conslsts of a slot 40, which i8 ~lmilar
to that shown in Figures 9a, 9b and has ends 41 which are
disposed on the periphery of the mandrel on a straight line
which intersects the axis of the mandrel at right angles. In
these two embodiments the mandrel has a centrally disposed
through passage 42 for a filling material or for a particu-
late solid material, the slot is separated at its bottom
- 28 -
117~38~7
from that passage by a wall (Figures 17b, 21b) and the
stspply passages 35 of the mandrel open in the side walls
of the slots 40 (Figures 17a, 17b, 21a).
In the embodiments shown in Figures 8a, 8b and
17a, 17b, the slots 40 open at the periphery of the mandrel
and the opening of the slots 40 extends around one-half of
the periphery of the mandrel.
In the embodiments shown in Figures 21a, 21b, 21c,
9a and 9b the slot 40 extends into a step 43, which is
directed toward the forward end of the mandrel 2. Part
of the opening of the slot is open toward the forward
end of the mandrel 2.
Rather than through a plurality of supply
passages 35, which are provided in the mandrel 2 near
its periphery and open in the side walls of the outlet
opening or openings, which may consist of one or more
annular channels or slots, a single passage defined by
coaxial cylindrical surfaces may be used to supply coating
material (Figures 14, 19 and 25).
That passage may be defined by an outer tube 44
and a cylindrical rod coaxially extendlng in said tube.
The tubular body slides on the outside of the outer
tube 44. The cylindrical rod protrudes from the forward
end of the outer tube and has a flange 46, whlch ls
disposed outside the outer tube and together wlth the
forward end face 47 of the outer tube 44 defines an
annular channel, which constitutes an outlet opening.
The flange 46 of the rod constitutes a sizing shoulder
for the application of the coating material.
The cylindrical rod may have a longitudinal
- 29 -
1178847
bore, which serves as a supply passage leading to a
coating head 48, which is mounted on the forward end
of the rod. In this embodiment, shown in Figure 14,
two coating materials can be applied in successlon.
One coating material is applied through the coating
head 48 and the second coating material emerges from
the annular channel defined by the forward end face 4
of the outer tube 44 and the coating head 48.
The embodiment shown in Figure 14 may also be
used to apply a single coating material by mean~ of the
coating head 48, which is rotated independently of the
mandrel 2 so that the coating materlal will be spread
and the irregularities which will occur when the coating
head is stationary will be avoided.
To permit a coating of the tubular body and an
introduction of a filling material or a particulate solid
material into said tubular body, the rod of the mandrel 2
is replaced in the embodiments shown in Figures 19, 22,
23a, 23b, 23c by an inner tube 45, which extends in the
outer tube 44. The inner tube 45 carries at its forward end
a flange 46, which together with the forward end face 47 of
the outer tube constitutes the coating section of the
mandrel. The bore of the inner tube 45 serves as a passage
for supplying the filling material or the particulate solid
material and may contain a conveyor screw 17 for conveying
the filling material or the particulate solid material
(Figure 22).
In another embodiment, the inner tube 45 is
provided on its inside surface with a continuous helical
rib (Figures 23a, 23b, 23c).
- 30 -
1-178~
In the embodiment shown ln Figure 24 the coating
section 9 of the mandrel consists of a plurality of
concentric tubes, which define supply passages between
them. An inner tube 45 is provided at its forward end
with a coating head 48 and is inserted into the outer
tube 44. The coating head 48 consists of a cylindrical
flange, which protrudes from the inner tube 45 and is
formed between its two end faces with a peripheral groove
49, which communicates through radial passages with the
interior of the inner tube 45. Another concentric tube 50
is fitted in the coating head 48 and extends from the
forward end face of the coating head 48 and together
with the inner tube 45 defines the passage for supplying
the coating material which emerges from the coating head.
The interior of the tube 50 serves as a passage for
supplying the filling material or the particulate solid
material or is used as a passage for supplying the coating
material to another coating head 48' (Figure 25). The rear
end face of the first coating head 48 and the forward end
face 47 of the outer tube 44 define another annular channel,
through which a coating material emerges.
In the embodiments shown in Figures 27a, 27b, 26a,
26b the mandrel consists of a cylindrical sleeve 51, which
contalns a tubular insert 52, whlch is in snug contact with
the inside surface of the tube and is formed in its outside
peripheral surface with a flat 53, which together with the
inside surface of the sleeve 51 aefines a passage for
supplying a coating material. That supply passage terminates
just as the flat 53 near the forward end face of the
sleeve 51. The insert 52 is provided with a collar 54,
which is disposed closely beyond the forward end of the
- 31 -
11788~7
flat 53 and together with the forward end face of the
sleeve 51 defines an annular channel 55. The passage
defined by the flat 53 opens laterally into said annular
channel. That passage may alternatively be formed by one
or more longitudinal grooves formed in the outside peri-
pheral surface of the insert but the flat is preferably
to the longitudinal groove because the contact surface
between the coating material fed in the passage and the
heat-insulating materlal is smaller than the contact
surface between the coating material fed in the passage
and the mandrel sleeve 51.
As a result, more heat will be transferred
through the winding mandrel to the coating material
than is dissipated through the insulating material.
The insert 52 may consist of heat-insulating
material and may terminate at a large distance from the
annular channel 55. This will be the case, e.g., when a
tubular body formed by winding a wafer strip is to be
filled with icecream. In that case a coating material
such as chocolate which seals the wa~er strip agalnst
an absorption of moisture is applied through the annular
channel 55 to the inside surface of the tubular boay and
the internally coated wafer body is cooled so that the
icecream fed through the tubular insert 52 reaches a
wafer body whlch is cooler than during the winding operation
and which is completely sealed. In a length section which
corresponds to the desired length of the hollow baked
product the endless tubular wafer body is completely
filled with icecream and that length section is then
severed from the endless wafer body.
1~'78E~'~7
Figures 28 to 31 are longitudinal ~ectional
views showing some examples of hollow baked products
which have been made by the process according to the
invention.
Figure 28 shows a hollow stick 57, which has
been formed by winding a wafer strip and has a chocolate
coating 56a on its inside surface. Within the scope of
the invention that chocolate coating 56a may be continuously
applied throughout the periphery of the inside surface of
the hollow stick. Alternatively, a plurality of helical
chocolate strips may be applied, which merge to form a
coherent coating. The several chocolate strips may consist
of different chocolate compositions.
Alternatively, part of the helical strips may
consist of a fat icing or part of the inside surface of
the hollow stick may remain uncoated.
In another emboaiment of the process according to
the invention the coating material is applied to the inside
surface of the hollow stick 57 in the form of narrow ribs or
winding strips, which may be helical and may cross each
other.
Said strips of chocolate or deposited ribs may
be applied to extend parallel to the longitudinal axis of
the hollow sticks.
Figure 29 shows a hollow stick in which a
partlculate solid material 8, such as nuts, croquant
or the like has been applied on a coating 58 consisting
of one or more layers of chocolate or fat icing.
Before the solid particulate material 8 is
applied, jam may be applied in discrete strips to the
- 33 -
~7 ~ ~ ~t~
coating consisting of chocolate or fat icing.
Figure 30 shows an internally coated hollow
stick 57, which has been completely filled with a nougat
composition 59 or with icecream or with a cream.
Figure 31 shows a hollow stick ~7, which has been
coated on its inside surface with cocolate and with a
second coating material 60 consisting of nougat, whereafter
a particulate solid material 8 consisting of croquant has
been applied to the nougat layer.
Chocolate, fat icings, nougat or jam have been
mentioned hereinbefore as coating materials. It will be
understood that other materials of creamlike to pasty
consistency can be applied by the process according to
the invention. Such substances may include marzipan or
a caramel composition.
The mandrel may consist of surface-hardened
metal or of a metal sleeve and a plastic core or entirely
of plastic. The coating heads may consist of plastic
material.
It will be understood that the present invention
is not restricted to the illustrative embodiments described
hereinbefore. The several features of the various embodi-
ments of the mandrels used within the scope of the lnventlon
and of the coating sections of said mandrels may be combined
in any desired manner without departing from the scope of
the invention. For isntance, mandrels which are shown to
be integral may alternatively be composed of two or more
elements. Besides, the coating heads may be integral with
the mandrel or may consist of units wh~ch are screwed to
the mandrel.
- 34 -
~i71~847
Each of the mandrels described, which may be
used within the scope of the invention, or of the coating
sections or coating heads of such mandrels, may be used in
any of the er~odiments of the apparatus shown in Figures 1
to 5.
- 35 -
