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Description  |
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BACKGROUND OF THE INVENTION
The present invention relates to the field of kneading machines for food
products and particularly (but not exclusively) to machines for preparing
flour-based mixtures, of the type comprising:
a kneading bowl, defining a channel having a loading area for the product
to be kneaded and an unloading area for the kneaded product,
a plurality of kneading tools arranged within said channel and rotatable
around axes which are preferably substantially vertical, and
means for advancing the product through said channel from said loading area
to said unloading area.
Kneading machines of the above indicated type are disclosed for example in
European patent EP-B-0 469 500 of the same Applicant, in the corresponding
U.S. Pat. No. 5,312,183 and in European patent application EP-A-0 554 513
also of the same Applicant.
According to the most conventional art, the kneading machines for food
products include a container in the form of a rotary bowl in which the
ingredients of the mixture are placed and which then brings the various
portions of the mixture up to the kneading tool during kneading. Machines
of this type have kneading tools of various configurations. A particularly
advantageous version is a so-called "helical" machine, that is, a machine
with a helical kneading tool constituted by a bar with a circular
cross-section arranged helicoidally around a theoretic ideal cylinder.
These machines produce very good results from the point of view of the
quality of the mixture, they perform the kneading cycle fairly quickly,
and they can be used to work on different mixtures, their operating
characteristics being adapted from time to time to the type of mixture
being kneaded.
Machines with rotary bowls have the disadvantage, however, that their
operating cycles are discontinuous. In other words, each kneading cycle
includes the loading of the bowl with the ingredients of the mixture and
finishes with the discharge of the mixture produced from the bowl. Only
after the discharge stage is completed can the bowl be refilled with the
ingredients necessary to make a fresh mixture. Moreover, for large-scale
commercial production, kneading bowls of ever-increasing size tend to be
used in order to produce the largest possible batch of mixture in each
kneading cycle. At the end of the kneading cycle, the mixture is
discharged from the bowl and sent to the user machines, for example, a
chopping machine or a moulding machine. In the case of a
mixture-containing yeast, the first portion of mixture discharged from the
bowl will reach the user machine considerably in advance of the last
portion of the mixture, and this results in a different rising time and,
eventually, to non-uniform characteristics of the final product.
Naturally, this disadvantage could be avoided by the use of kneading
machines which can work continuously. In fact, another conventional
technique uses a continuous-flow kneading machine which comprises,
essentially, a tubular element containing an Archimedean screw shaft or
the like which advances the product along the tubular element and at the
same time forms the mixture. However, these known kneading machines of the
continuous-flow type cannot produce a mixture of a quality comparable to
that which can be produced by a machine with a rotary bowl, particularly a
helical machine.
In European patent EP-B-0 469 500, the Applicant has proposed a kneading
machine of the type indicated at the beginning of the present description
which is able to work continuously and does not have the drawbacks typical
of the conventional continuous kneading machines which have been mentioned
above. According to this proposal, a kneading machine for food products
comprises a container constituted by a straight channel-shaped element
along which the mixture being formed is advanced and which has an input
end for admitting the product to be kneaded and an output end for
discharging the mixture produced. Along the channel-shaped element there
are distributed many kneading tools rotatable around vertical axes and
preferably of helical shape. The input end of the channel-shaped element
is fed alternatively by two mixing units with a sequence of batches of
mixed product, so as to form a continuous elongated mass of product which
advances along the channel-shaped element meeting thereby in sequence the
various kneading tools which provide the kneading thereof. Each of the
pre-mixing units arranged upstream of the channel-shaped element is
provided for preparing batches of pre-mixed product with precisely weighed
quantities of predetermined ingredients. By pre-mixed product, it is meant
herein a mixture of the various ingredients having a mass of uniform
composition in which however the kneading stage proper, in Which formation
of gluten takes place, has not yet commenced, this stage being performed
in the channel-shaped element. Due to the above mentioned arrangement, the
elongated mass of dough coming out of the machine which has been
previously proposed by the Applicant has a uniform composition and the
adjustment of the machine for production of a dough according to a
different recipe is rapid and without difficulty. Therefore, the
continuous kneading machine previously proposed by the Applicant does not
have the drawbacks typical of the conventional continuous machines.
Furthermore, the use of kneading tools of the helical type enables all the
advantages typical of the conventional helical kneading machines, with
respect to rapidity and quality of the kneading action, to be retained.
Also with reference to the continuous kneading machine previously proposed
by the Applicant, in order to control precisely the advancement of the
elongated mass of mixture along the channel element, there are provided
means to create a cyclic relative movement between the channel element and
the group of kneading tools. This cyclic movement includes a first step of
horizontal movement (of the channel element with respect to the kneading
tools) against the flow of the product, a second descending step, a third
step of horizontal movement in the direction of flow of the product and a
fourth climbing step. This relative movement may be provided as a movement
of the channel element with respect to the kneading tools, or as a
movement of the structure carrying all the kneading tools with respect to
the channel element. At any rate, the need of providing said relative
movement gives raise to a relatively complicated and costly structure,
which can be a source of vibrations and problems in operation because of
the relatively high weight of the various moving unbalanced masses.
It is also to be noted that the Applicant, in the endeavour to further
improve the above described kneading machine, has proposed in its European
patent application EP-A-0 554 513 an improved version of this machine
which is provided inside of the channel element with a number of counter
member walls, rigidly connected to the structure carrying the kneading
tools, and each arranged immediately after a respective kneading tool
(with reference to the direction of flow of the product), so as to avoid
that while a portion of the elongated mass is worked by the kneading tool
which has intercepted it, a portion of the dough is thrown by centrifugal
force away from the tool, thus escaping to the kneading action.
This improved machine has improved the ability of controlling the kneading
process, but has not eliminated the need of using the above described
complicated structure in order to provide the relative movement between
the channel element and the kneading tools. Also this machine keeps the
drawback that during the step of the above described cyclic movement in
which the bottom of the channel element is more spaced apart from the
kneading tools, the kneading action is interrupted.
SU-A-1.414.659 discloses a machine of the type indicated at the beginning
of the present description, belonging to a different field (building
mixtures). This machine would be completely unuseful for preparing food
admixtures, due to a number of reasons. Firstly, in this known machine the
circumferential inner wall of the endless channel rotates relative to the
bottom wall of the channel, thus originating the danger of a leakage of
product through the gap between said walls. Moreover, which is more
important, the channel obstructing walls, in this known machine, are
spaced apart fromthe respective mixing tools and have a planar
configuration, which would prevent, in case of processing a food
admixture, a product of high quality to be obtained.
SUMMARY OF THE INVENTION
The object of the present invention is that of providing a continuous
kneading machine for food products which keeps all the advantages of the
continuous kneading machines previously proposed by the Applicant, while
eliminating the drawbacks of the Prior Art.
More generally, the invention aims to provide a continuously working
kneading machine, which has no dead time for loading and unloading the
product, nor during the kneading action, which has a structure relatively
simple, low cost and free from vibrations and unbalancements, which
assures high characteristics from the point of view of rapidity and
quality of the kneading and enables the intensity and speed of the
kneading to be controlled as desired.
In view of achieving this object, the invention provides a kneading machine
for food products, particularly for flour-based doughs, comprising:
a kneading bowl, defining a channel having a loading area for the product
to be kneaded and an unloading area for the kneaded product,
a plurality of kneading tools arranged in said channel and rotatable around
substantially vertical axes, and
means for advancing the product in said channel from said loading area to
said unloading area, wherein:
said bowl is a circular bowl and said channel is an endless channel defined
within said bowl, having a bottom wall, an outer circumferential wall and
an inner circumferential wall,
said kneading tools are distributed along the endless channel and are
rotatably supported around their respective axes by a support structure,
said support structure on its turn is rotatably mounted relative to the
bowl around the central axis of the bowl, so that the kneading tools,
beside rotating around their axes, are all simultaneously moved with
respect to said endless channel,
said support structure also carries channel obstructing walls each
projecting within said channel behind a respective kneading tool and
movable with respect to the channel together with the kneading tools, to
define a kneading chamber substantially isolated from the remainder of the
channel in association with each kneading tool, such chamber being filled
with a batch of product to be kneaded when it passes by the loading area
and being emptied from the product kneaded by the respective kneading tool
when it passes by the unloading area, after that it has been moved
throughout the whole endless channel,
characterized in that:
each kneading tool has a theoretical enveloping cylinder which is
substantially tangent to said outer circumferential wall and said inner
circumferential wall and has its lower end adjacent to the bottom wall of
the bowl,
said obstructing walls of the channel are each made by a substantially
curved wall located at the rear of the respective kneading tool (with
reference to the direction of movement of the kneading tool along the
endless channel) and surrounding at least partially coaxially the rear
portion of the theoretical enveloping cylinder of this kneading tool, so
as to cooperate with the kneading tool in the kneading action.
It is to be noted that the invention is directed both to the preferred case
in which the bowl is fixed and the kneading tools with said obstructing
walls are moved along the endless channel of the bowl, and the opposite
case, in which the kneading tools and the obstructing walls are fixed and
the bowl is rotated.
Preferably, said inner circumferential wall of said endless channel is
rigidly connected to said bottom wall and said outer circumferential wall
and forms therewith the body of said bowl. Also, in the preferred
embodiment the kneading tools are of the helical type.
Due to the above indicated features, the machine according to the invention
is able to keep all the advantages characteristic of the continuous
kneading machines previously proposed by the Applicant. It is indeed able
to work continuously. The loading area of the bowl is fed with a
continuous elongated mass of mixed product which fills in sequence the
various kneading chambers of the bowl as they come at this loading area.
This continuous elongated mass of mixed product is preferably provided by
the mixing unit forming the subject of Italian patent application No.
TO93A000095 filed on 16 Feb. 1993 by the same Applicant.
At the same time, the machine according to the invention does not have the
drawbacks of the continuous kneading machine previously proposed by the
Applicant, since it has no unbalanced moving masses. The structure of the
machine is greatly simplified and less costly and is not subject to
vibrations. Furthermore, during the operation of the machine, there are no
dead times during which the dough escapes to the kneading action of the
kneading tools. All the advantages typical of the helical kneading
machines are also retained by adopting kneading tools having this
configuration. Finally, the machine according to the invention may be
easily controlled in order to modify the intensity and speed of kneading.
It is indeed sufficient to adjust the speed rotation of the kneading tools
around their respective axes and/or the speed of rotation of the whole
structure carrying the kneading tools around the center of the bowl (which
determines a different speed of movement of the kneading tools in the
channel). Preferably, to this end, for each kneading tool there is
provided a respective driving motor.
The above mentioned obstructing walls of the channel define kneading
chambers which are isolated from each other and are occupied each by a
respective kneading tool. This enables a high kneading intensity to be
obtained, since there is no risk that portions of the dough may escape to
the action of the respective kneading tool.
In a preferred embodiment, each kneading tool has a direction of rotation
around its axis such that it pushes the product towards the bottom wall of
the bowl.
Due to these features, the machine is able to obtain a dough of high
quality in a short time, since the product contained in each kneading
chamber is worked by the respective kneading tool against the side wall of
the bowl, and also against the central column of the bowl, and also
against the bottom wall of the bowl, and finally, which is most important,
also against the obstructing wall of the channel arranged immediately
behind the kneading tool.
In the case of a preferred embodiment, the spacing between the various
kneading tools along the channel element is such that each kneading tool
has its respective channel obstructing wall arranged immediately behind
it, but is also spaced from the channel obstructing wall which is
associated with the kneading tool which precedes it in the movement along
the channel. Therefore, each kneading chamber defined between two
subsequent channel obstructing walls has a free space in front of the
respective kneading tool. During operation, the dough rises as a reaction
within the helix of the kneading tool until it reaches the top of the
latter, whereupon it falls again on the bottom of the wall in said free
space where the dough is caught again by the kneading tool, as a result of
the movement of the latter along the channel. As already indicated, in
fact, the bowl (and hence the bottom of the channel) is fixed, whereas the
channel obstructing walls, which define the various kneading chambers, are
moved along the channel together with the kneading tools. The above
mentioned action in which the dough falls down and is caught again is
beneficial for the quality of the dough since the latter is cyclically
turned upside-down so as to ensure a greater final homogeneity.
According to a further preferred feature, the side wall and the central
column of the bowl, as well as the channel obstructing walls are hollow
and there are provided means for circulating a cooling liquid therewithin.
Thus, the heat increase due to the kneading action may be limited or
nullified, so that the final temperature of the dough is reduced.
It is also to be noted that kneading machines are also known in the art
having orbiting kneading tools which have a fixed circular bowl and
kneading tools which, beside rotating around their axes, are also caused
to orbit around the bowl axis. However, this machines cannot operate
continuously. They are non-continuously operating machines absolutely
similar to the most conventional machines. In other words, in order to
carry out a kneading cycle, it is firstly necessary to fill the bowl, when
the machine is inactive, with the ingredients of the dough. When the dough
is completed, it is then necessary to stop the machine and to empty the
bowl in order to carry out a new kneading cycle. Furthermore, there is no
channel defined within the bowl and all the space inside the bowl can be
occupied by the product. Each kneading tool processes in sequence the
various portions of the dough as it intercepts them. Therefore, it is
clearly apparent that these machines do not have the features, nor the
advantages of the machine according to the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the invention will become apparent from
the description which follows with reference to the annexed drawings,
given purely by way of non limiting example, in which:
FIG. 1 is an elevational view of a kneading machine according to the
invention,
FIG. 2 is a cross-sectional view of the machine of FIG. 1,
FIG. 3 is a plan view, partially in cross section, of the machine according
to the invention, where there is indicated the cross-section line II--II
corresponding to the cross-section of FIG. 2,
FIG. 4 is a diagrammatic plan view of the machine which shows its principle
of operation,
FIGS. 5, 6 are cross-sectional views of some details of FIG. 2, and
FIG. 7 is a cross-sectional view at an enlarged scale of a detail of FIG. 2
.
DETAILED DESCRIPTION OF THE INVENTION
With reference to the drawings, numeral 1 generally designates a kneading
machine for food products, particularly for flour-based doughs, comprising
a fixed supporting structure 2 which rests on the ground by adjustable
feet 3. On the support structure 2 there is rigidly connected a circular
bowl 4 having a hollow side wall generally designated by 5, a bottom wall
generally designated by 6 and a central cylindrical column designated by 7
(FIG. 2). More in detail, side wall 5, bottom wall 6 and the wall of
central column 7 of bowl 4 all have an inner space defined by two parallel
walls 5a, 5b through which a cooling fluid flows, such as water or water
and glycol. The cooling fluid coming from a refrigerating unit (not shown)
enters into the inner space through a hole 8 (FIG. 2), fills completely
the space and comes out through a tube 9 which is to be connected to the
refrigerating unit. This unit provides to recirculate the cooling fluid,
so as to keep the walls of bowl 4 very cool, removing heat from the dough
which is within the bowl during operation of the machine. For particular
applications where it is desired to reduce the temperature of the dough to
very low values, there is provided the introduction of cryogenic gas
(CO.sub.2) directly into the dough through a conduit 10 (FIG. 1) passing
through the bottom 6 of bowl 4.
With reference to FIG. 2, side wall 5 and bottom wall 6 of the bowl,
together with the wall of central column 7, define an endless channel 11
within which there are distributed many kneading tools 12. The surface of
the channel has a substantially U-shaped cross-section, with the bottom
branch having reduced ends connected to the two vertical branches. Each
kneading tool is of the helical type, i.e. it is constituted by a bar
having a helical configuration, with a vertical axis 12a parallel to the
central axis 4a of the bowl. In the illustrated example, each kneading
tool 12 has a right-hand helix and is to be rotated in a counterclockwise
direction, with reference to a plan view, as indicated by arrows X in FIG.
4. Due to this feature, during operation of the machine, each kneading
tool 12 tends to compress the mixture against the bottom of the bowl. The
theoretical enveloping cylinder of each kneading tool 12 is substantially
tangent both to the side wall 5 of the bowl and to the wall of the central
column 7. Furthermore, the lower end of each kneading tool 12 is arranged
immediately adjacent to the bottom surface of the endless channel 11 and
has the same profile (FIG. 2). Due to these features, during operation of
the machine, the mixture is compressed both against the bottom wall, and
against the side walls of the endless channel 11, to the advantage of
rapidity and quality of the kneading action. The various kneading tools 12
are rotatably mounted around their respective axes 12a within vertical
cylindrical bodies 13 which are rigidly connected to a circular table 14
rotating around axis 4a. The direction of rotation of the rotary table 14
is that indicated by arrow Y in FIG. 4, i.e. it is opposite to the
direction of rotation of the kneading tools 12 around their respective
axes. However, it is clearly apparent that, contrary to the illustrated
example, the kneading tools might be provided with a left-hand helix and
they might rotate in a clockwise direction (with reference to FIG. 4).
With reference to FIGS. 2 and 7, table 14 to which cylinders 13 supporting
the kneading tools are anchored, is fixed by bolts 15 arranged along its
outer periphery to a ring 16 whose outer surface has teeth 17 (FIG. 7).
The ring 16 is freely rotatably supported around axis 4a on an inner ring
18, by interposition of a crown of balls 19. The inner ring 18 is fixed by
bolts 20 to brackets 21 (see also FIG. 3) which project in a cantilever
fashion from columns 22 (FIGS. 1, 2) forming part of the fixed supporting
structure 2 of the machine 1.
As already indicated, each kneading tool 12 is rotatably mounted within the
respective cylinder 13. To this end, each tool has a shaft 23 which is
rotatably supported by radial and axial bearings (not shown) within
cylinder 13. The upper end of each shaft 23 is connected by a reducing
unit 24 to a respective electric motor 25 (FIG. 2). All electric motors 25
which drive the kneading tools 12 are on their turn supported by the
rotary table 14 through a central column 26. The electric supply to
electric motors 25 is carried out by a brush collector 27 (of a type known
per se) which has at its upper end the stationary inlet of the supply
cables 28. The above described unit for driving rotation of the kneading
tools 12 is protected by a dome-shaped cover 29 which is supported through
arms 30 by the fixed supporting structure of the machine (FIG. 3).
In a preferred embodiment, motors 25 for driving helical kneading tools 12
are made slave to an inverter so that it is possible to vary the speed of
the kneading tools according to a predetermined program for obtaining
doughs with different characteristics and to vary the intensity of the
kneading action.
The rotation of the rotary table 14 is driven by an electric motor 31 which
is connected through a reducing unit 32 to a toothed wheel 33 meshing with
toothed crown 17 of ring 16. Also motor 31 is made slave to an inverter
for varying the speed of rotary table 14. The possibility of varying this
speed enables the time in which the dough remains within the bowl to be
increased or decreased, as it will become apparent in the following, thus
affecting the degree of kneading of the processed product.
Side wall 5 of bowl 4 has an aperture 34 (FIGS. 1, 6) through which a
continuous flow of premixed product may be introduced within the endless
channel 11. By the expression "premixed product" a product is meant hereby
which is obtained by carrying out a first mixing of the ingredients of the
mixture. Preferably this operation is carried out by the device forming
the subject of Italian patent application TO93A000095 filed on 16 Feb.
1993 by the same Applicant.
With reference to FIGS. 2-4, to each kneading tool 12 there is associated a
wall 35 rigidly connected to the rotary table 14, so that it is fixed with
respect to the corresponding kneading tool 12, but movable therewith
around the central axis 4a. Each wall 35 is fixed through the respective
cylinder 13 to the rotary table 14 and extends downwardly from the lower
end of this cylinder so as to obstruct the channel 11. In the preferred
embodiment which is shown in the drawings, each wall 35 is located at the
rear of the respective kneading tool 12, with reference to the direction
of movement of the kneading tools 12 in the endless channel 11.
Furthermore, each wall 35 has a curved surface facing the respective
kneading tool, which is immediately adjacent and coaxial with the rear
portion of the enveloping theoretical cylinder of the kneading tool. Also
in the embodiment which has been shown in the drawings, between each wall
35 and the subsequent kneading tool 12 (again with reference to the
direction of movement of the tools 12 in channel 11) there is left a free
space K, indicated in FIGS. 3, 4. As it clearly appears from these
figures, said walls 35 extend throughout the whole radial dimension of
channel 11, so that they define within this channel a plurality of
kneading chambers 36 isolated from each other, each associated with a
kneading tool 12. Since walls 35 are moved together with the kneading
tools 12 along the endless channel 11, also said kneading chambers 36
defined by walls 35 are rotated around the central axis 4a of the bowl.
Therefore, in the operation of the machine, when the elongated mass of
premixed product is fed inside the bowl through aperture 34, this
elongated body fills the kneading chambers 36 in sequence, as they come in
front of aperture 34. The portion of premixed product which comes into
each kneading chamber is processed by the respective helical kneading tool
12, while it is compelled to move along the endless channel 11 because all
the kneading tools 12 and the obstructing walls 35 are simultaneously
rotated around central axis 4a. In each kneading chamber 36, the product
is worked by the kneading tool 12 against the bottom 6 of bowl 4, against
the respective obstructing wall 35, against the central column 7 and
against the side wall 5 of the bowl.
Tests conducted by the Applicant have shown that the helical kneading tool
12 has a tendency to hold the dough while exerting a refining action
against the above mentioned surfaces. The above described free space K,
although not being absolutely necessary, is however preferable since the
dough rises cyclically within the kneading tool 12 and escapes by
centrifugal force and by gravity from the upper end thereof, falling in
the free space K. Immediately after this fall, the dough portion, which is
motionless on the fixed bottom of channel 11, is caught again by the
helical tool, which is moved in the channel, and processed as described
above. There cyclical falls of the dough in the free space K are very
useful since the processed dough portion is cyclically turned upside-down,
thus ensuring a greater final homogeneity. The dough portion within each
kneading chamber 36 is processed while, as indicated already, it is
compelled to move along the endless channel 11 (in a clockwise direction
with reference to FIG. 4) starting from the loading area 34. Once
substantially the whole circumferential extension of channel 11 has been
covered, each kneading chamber 36 reaches the discharge aperture 37 formed
in the bottom 6 of the bowl. Aperture 37 is a circular aperture and
communicates channel 11 to a discharge conduit 38 (FIG. 5) for the kneaded
product, which in the preferred embodiment shown in the drawings has a
frusto-conical shape in the portion which is located through the inner
cavity of bowl 4. Aperture 37 may be obstructed by a cap 39 of synthetic
material carried by a lever 40 which is pivotally mounted around an axis
41 on the fixed supporting structure 2 of the bowl and which is movable by
a fluid cylinder 42 between a closing position and an opening position of
conduit 38. FIG. 5 shows cap 39 in the closing condition. When, starting
from this condition, lever 40 is rotated in a counter-clockwise direction
around axis 41, conduit 38 is opened and allows the kneaded product to be
discharged above a belt conveyor 43 which advances the dough towards the
user machines. In FIG. 5, arrows 44, 45 respectively designate the
direction of fall of the dough on the belt conveyor 43 and the direction
of movement of the upper run of this belt conveyor.
As the kneading chambers 36 pass over aperture 37, they discharge the
respective portion of kneaded product over the belt conveyor 43, where
these portions form again a continuous elongated mass of dough.
With reference to FIG. 3, bowl 4 has a removable section 50 to enable
maintenance operations inside the bowl to be carried out.
The bowl is closed at the top by a rotating cover 51 carried by the rotary
table 14 through tie-rods 52 (FIG. 2). The upper edge of the bowl is
provided with a safety shield 53 formed by a circular band fixed at its
bottom to the upper edge of bowl 4 and provided along its upper edge with
an insert of a low friction material, to enable the sliding engagement
with the rotating cover 51. On cover 51 there are also arranged nebulizer
nozzles 54 which receive a detergent liquid by a manifold 55 and may be
supplied according to a programmed automatic cycle in order to carry out
an automatic washing of the bowl at the end of a working period or when
the recipe of preparation of the dough is modified. Manifold 55 is also
used to supply cooling liquid coming through the central column 7 to the
inner cavity of the obstructing walls 35, through conduits 56.
As it is apparent from the foregoing description, the machine according to
the invention enables operation by supplying a continuous flow of product
to be kneaded to the machine itself and gives as its output a continuous
elongated mass of kneaded product. It is not necessary to stop the machine
for loading and unloading the product, and there are no stages in the
operation of the machines in which the product escapes to the engagement
by the kneading tools.
The machine according to the invention, therefore, keeps all the advantages
of the continuous kneading machine previously proposed by the Applicant,
while improving it from the point of view of simplicity of construction
and effectiveness of the kneading. The movable equipment of the machine is
well balanced and free from vibrations. Finally, all the advantages of the
helical-type kneading machines are retained as to the quality of the
kneaded product.
As indicated already, the invention covers also the case in which tools 12
and walls 35 remain in a fixed position and bowl 4 is rotated.
Naturally, while the principle of the invention remains the same, the
details of construction and the embodiments may widely vary with respect
to what has been described and illustrated purely by way of example,
without departing from the scope of the present invention.
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