Note: Descriptions are shown in the official language in which they were submitted.
CA 02355548 2002-06-14
METHODS AND APPARATUS FOR JOINING PIECES OF
THERMOPLASTIC MATERIAL TO FORM: CELLULAR BLOCKS
FIELD OF THE INVENT'ION
The present invention pertains to converting sheets or strip-like pieces of
material into cellular blocks and, more particularly, to welding cut pieces of
thermoplastic material together to form an expandable cellular block, which
can be
expanded to form a honeycomb structure, or the like.
BACKGROUND OF THE INVENTION
It is known to form honeycomb structures, and the like, by thermally fusing
(i.e., welding) cut pieces of thermoplastic material together to form an
expandable
cellular block, and then heating and pulling on the block to expand it and
thereby
convert it into a honeycomb structure. Although methods and apparatus are
known
for constructing honeycomb structures in this maimer, it is desirable to
improve the
speed at which such honeycomb structures can be formed, and the quality of
those
honeycomb structures. For example, some prior methods and apparatus for
forming honeycomb structures can be characterized as being too slow, or
inefficiently requiring that the honeycomb structures be formed in batches, as
opposed to via a continuous process. As another example of problems that can
occur in the manufacture of a honeycomb structure, in some cases the welds
between the pieces of thermoplastic material are not strong enough to
withstand the
pulling that is required to convert the expandable block into a honeycomb
structure. The breakage of the welds negatively impacts the integrity of the
final
honeycomb structure.
In view of the foregoing, there is a need for improved methods and
apparatus for forming expandable blocks and/or honeycomb structures.
CA 02355548 2002-06-14
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, methods and
apparatus are provided for solving the above and other problems by quickly and
efficiently forming three-dimensional structures, nainely cellular blocks and
more
specifically honeycomb structures, or the like. The cellular blocks are formed
by
thermally fusing (i.e., welding) together sheets or strip-like pieces of
material,
which are most preferably roll goods, especially thermoplastic nonwovens. In
accordance with one aspect of the present invention, a formed cellular block
is
expandable, and the welds are sufficiently strong to remain intact while the
expandable block is expanded to form a honeycomb structure, or the like.
In accordance with one aspect of the present invention, a carrying
mechanism supplies multiple cut pieces of theinzoplastic material that are
joined to
form the cellular block. The cas-rying mechanism includes at least one
station, and
the station repeatedly travels between supplying and forming mechanisms. The
supplying mechanism sequentially supplies the cut pieces to the station of the
carrying mechanism, the forming mechanism sequentially receives the cut pieces
from the station of the carrying mechanism, and the forming mechanism
sequentially welds those received cut pieces together to form the cellular
block.
The station includes multiple ports at which a partial vacuum is supplied to
at least
partially facilitate the carrying of the cut pieces by the station.
In accordance with one aspect of the present invention, first and second
pieces of the thermoplastic material, which may or may not be cut pieces, are
arranged in opposing face-to-face relation, and the fir=st and second pieces
are
welded together by contemporaneously (i.e., at the same time) forming multiple
spaced apart and elongate welds between the first and second pieces. The
welding
includes rolling a welding mechanism across at least one of the first and
second
pieces in a longitudinal direction so that each of the welds extends in the
longitudinal direction. Preferably, the welds are spaced apart from one
another in a
lateral direction that is at least generally perpendicular to the longitudinal
direction.
Advantageously, the welding mechanism is a rolling inechanism that
participates
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in defining nips for forming the welds by providing multiple rolling contact
regions, and each nip is relatively small due to the rolling aspect of the
rolling
mechanism, so that considerable pressure can be applied at the nip to form a
strong
weld. The rolling mechanism is preferably in the foim of multi;ile welding
rollers
that are spaced apart from one another in the lateral direction.
In accordance with one aspect of the present invention, at least one cut
piece to be added to the cellular block is supplied to the cellular block by
engaging
a plurality of spaced apart protrusions to the cut piece, and moving the
protrusions
along a path so that the protrusions carry the cut piece along the path.
Preferably
this feature is incorporated into the station of the carrying mechanism, so
that the
station includes multiple protrusions for repeatedly engaging and carrying cut
pieces to the forming mechanism. For the station, slots are defi:ied between
adjacent protrusions of the station and the welding rollers are respectively
received
in the slots.
In accordance with one aspect of the present invention, a cut piece to be
welded to the cellular block is arranged in opposing face-to-face relation
with a cut
piece most recently previously welded to the cellular block, then these cut
pieces
are welded together by contemporaneously forming naultiple spaced apart and
elongate first welds therebetween. In preparation for this welding, the
welding
rollers and a plurality of heating elements are contemporaneously moved along
opposite sides of, and in close proximity to, the cut piece to be welded to
the
cellular block, while the cut piece to be welded is being held by the station
of the
carrying mechanism in the opposing face-to-face relation with the cut piece
most
recently previously welded to the cellular block. The heating elements are
spaced
apart from one another in the lateral direction and respectively aligned with
the
welding rollers.
The welding more specifically includes using the heating elements to
contemporaneously heat laterally spaced apart strips of each of the cut piece
to be
welded to the cellular block and the cut piece most recently previously welded
to
the cellular block, while withdrawing the heating elements from between these
cut
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CA 02355548 2002-06-14
pieces. The heated and laterally spaced apart strips of the cut piece to be
welded to
the cellular block are aligned with the heated and laterally spaced apart
strips of the
cut piece most recently previously welded to the cellular block by virtue of
their
being respectively heated by the same heating elements, and these strips are
respectively nipped together to form elongate and laterally spaced apart welds
between these cut pieces. This nipping is preferably between the welding
rollers
and other welding structure. After the welds between these cut pieces are
completely formed, the heating elements and welding rollers have been
withdrawn
from the cellular block, and thereafter the heating elesments, welding rollers
and
carrying machanisim are together moved laterally, and then used with respect
to
the next cut piece being added to the cellular block. This coordinated lateral
translating of the welding rollers, heating elements and carrying machanism
continues in a reciprocatory fashion, with welds being formed while the
welding
rollers, heating elements and carrying machanism are in their first lateral
position,
then while they are in their second lateral position, then while they are in
their first
lateral position, and so on, to form the laterally offset welds of the celluar
block.
In accordance with the immediately preceding aspect more specifically, the
nipping alternately includes nipping cut pieces between the welding rollers
(which
can be characterized as a set of welding mechanisms) and a first set of
welding
mechanisms, then translating the welding rollers laterally and nipping cut
pieces
between the welding rollers and a second set of welding tnechanisms, then
translating the welding rollers laterally and nipping cut pieces between the
welding
rollers and the first set of welding mechanisms, and so on. In accordance with
this
aspect, the first and second welding mechanisms each preferably include
multiple
rod-like members that are laterally spaced apart. Generally described, the
welding
rollers alternately "roll along" the first and second sets of welding
mechanisms, and
each time the welding rollers are rolled they are welding a new cut piece to
the
cellular block. As a result, and for example, welding a first cut piece to the
cellular
block includes nipping between the welding rollers and the first set of
welding
mechanisms to contemporaneously form multiple spaced apart and elongate first
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welds between the first cut piece and a prior cut piece that was inost
recently
previously welded to the cellular block, and the welding of a second cut piece
to
the cellular block occurs after the welding of the first cut piece to the
cellular block
and includes nipping between the welding rollers and the second set of welding
mechanisms to contemporaneously form multiple spaced apart and elongate second
welds between the first cut piece and the second cut piece, so that the second
welds
are laterally offset from the first welds. This adding of additional cut
pieces by
forming laterally offset welds continues repeatedly by alternately using the
first
and second sets of welding mechanisms, which are respectively moved to
upstream
of the upstream end of the cellular block after each use.
In accordance with one aspect of the present invention, the cellular block is
formed in and flows in a generally horizontal direction, so as to
advantageously
mini:mize vertical constraints. In accordance with this aspect, the pieces
being
welded extend generally upright, the welds are formed so that they are
elongate and
extend generally upright while being formed, the carrying mechanism
reciprocates
generally horizontally between the supplying mechanism and the forming
mechanism, and the cellular block is pulled generally horizontally to expand
it and
convert it into a honeycomb, or the like.
In accordance with one aspect of the present invention, inultiple cut pieces
of thermoplastic material are joined one after the other by positioning a cut
piece
being added to the cellular block parallel with each of the cut pieces of the
cellular
block; heating, to the welding temperature of the cut pieces, first strips
which are
opposite one another on surfaces of the cut piece being added to the cellular
block
and a cut piece most recently previously added to the cellular block; pressing
together the surfaces of the cut piece being added to the cellular block and
the cut
piece most recently previously added to the cellular block, so that the first
strips of
the cut piece being added to the cellular block and the first strips of the
cut piece
most recently previously added to the cellular block respectively meet and
thereby
the cut piece being added to the cellular block and the cut piece most
recently
previously added to the cellular block are welded or thermally fused together
and
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the cut piece being added to the cellular block becomes the cut piece most
recently
previously added to the cellular block; a cut piece being added to the
cellular block
is brought in a parallel position to the cut piece inost recently previously
added to
the cellular block, whereby flat surfaces of the cut piece being added to the
cellular
block and the cut piece most recently previously added to the cellular block
oppose
each other; heating, to the welding temperature of the cut pieces, second
strips
which are opposite one another on the surfaces of the cut piece being added to
the
cellular block and the cut piece most recently previously added to the
cellular
block, wherein the second strips are spaced apai-t fro:m the first strips by
approximately double the width of the first and second strips; and pressing
together
the surfaces of the cut piece being added to the cellular block and the cut
piece
most recently previously added to the cellular block, so that the second
strips of the
cut piece being added to the cellular block and the second strips of the cut
piece
most recently previously added to the cellular block receptively meet and
thereby
the cut piece being added to the cellular block and the cut piece most
recently
previously added to the cellular block are welded or thermally fused together
and
the cut piece being added to the cellular block becomes the cut piece most
recently
previously added to the cellular block.
In accordance with one aspect of the present invention, an apparatus for
joining multiple cut pieces of thermoplastic material to form a cellular block
includes an open-ended magazine that receives the cellular block, and a
carrying
mechanism positioned in front of the magazine and including a plurality of
stations
that are distributed about the circumference of the carrying mechanism. In
accordance with this aspect, each station includes a carrying mechanism for
carrying a cut piece, a heating mechanism oriented towards the carrying
mechanism and capable of being driven back and forth between a position in
front
of the carrying mechanism and a position which is pulled back jrom the
carrying
mechanism, and a pressure mechanism that operates in conjunction with the
carrying mechanism and the heating mechanism for adding the cut piece to the
cellular block.
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According with another aspect of the present invention, an apparatus for
joining tnultiple pieces of thermoplastic material to form a cellular block,
comprising:
at least one welding mechanism for welding the pieces to the cellular block;
and
a supplying mechanism for successively supplying to the welding mechanism
the pieces to be welded to the cellular block, by arranging each piece to be
welded to
the cellular block in opposing face-to-face relation with the piece most
recently
previously welded to the cellular block,
wherein the welding mechanism welds the piece to be added to the cellular
block and the piece most recently previously welded to the cellular block by
contemporaneously forming nlultiple spaced apart and elongate welds between
the
piece to be added to the cellular block to the piece most recently previously
welded to
the cellular block, each of the welds extends in a longitudinal direction, the
welds are
spaced apart from one another= in a lateral d:irection, and the welding
mechanism
13 includes a rolling mechanism that engages and rolls in the longitudinal
direction
across at least one of the piece to be added to the cellular block and the
piece most
recently previously welded to the cellular block to provide a plurality of
rolling
contact regions that form the welds.
According with a further aspect of the present invention, an apparatus for
21) joining multiple cut pieces of thermoplastic material to form a cellular
block,
comprising:
a supplying mechanism including at least one station mounted for repeatedly
traveling along a path to a position proximate a plurality of welding
mechanisms for
welding the cut pieces together to form the cellular block, wherein the
station includes
25 a plurality of protrusions for repeatedly engaging and carrying cut pieces
along the
path to proximate the welding mechanisms, and the welding mechanisms are
mounted
for respectively moving in slots defined between adjacent protrusions of the
plurality
of protrusions while the station is proximate the plurality of welding
mechanisms.
According with another aspect of the present invention an apparatus for
30 joining multiple cut pieces of thermoplastic material to form a cellular
block,
6a
CA 02355548 2003-02-07
comprising:
a supplying mechanism for supplyirig the cut pieces;
a forming mechanism where the cut pieces are sequentially received and
welded together to form the cellular block; and
a carrying mechanism mounted for translating between the supplying
mechanism and the forming mechanism, and including at least one station that
is
operative for receiving at least one of the cut pieces from the supplying
mechanism,
carrying the cut piece from the supplying mechanisni to the forming mechanism
while
the carrying mechanism translates, and supplying the cut piece directly to the
forming
mechanism.
According with a further aspect of the present invention, a method of joining
multiple cut pieces of thermoplastic material to form a cellular block,
comprising:
a) positioning a cut piece being added to the cellular block in opposing
face-to-face relation with a cut piece most recently previously added to the
cellular
block;
b) heating, to the welding temperature of the cut pieces, first strips which
are opposite one another on surfaces of the cut piece being added to the
cellular block
and the cut piece most recently previously added to the cellular block;
c) pressing together the surfaces of the cut piece being added to the
cellular block and the cut piece most recently previously added to the
cellular block,
so that the first strips of the cut piece being added to the cellular block
and the first
strips of the cut piece most recently previously added to the cellular block
respectively
meet an(i thereby the cut piece being added to the cellular block and the cut
piece most
recently previously added to the cellular block are thermally fused together,
and the
cut piece being added to the cellular block becomes the cut piece most
recently
previously added to the cellular block;
d) positioning a cut piece being added to the cellular block in opposing
face-to-f'ace relation with the cut piece most recently previously added to
the cellular
block;
e) heating, to the welding temperature of the cut pieces, second strips
which are opposite one another on the surfaces of the cut piece being added to
the
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cellular block and the cut piece most recently previously added to the
cellular block,
wherein the second strips are laterally spaced apart from the first strips;
fJ pressing together the surfaces of the cut piece being added to the
cellular block and the cut piece most recently previously added to the
cellular block,
so that the second strips of the cut piece being added to the cellular block
and the
second strips of the cut piece most recently previously added to the cellular
block
respectively meet and thereby the cut piece being added to the cellular block
and the
cut piece most recently previously added to the cellular block are thermally
fused
together, and the cut piece being added to the cellular block becomes the cut
piece
most recently previously added to the cellular block; and
g) (a) through (f) are continuou.sly repeatecl with many further cut pieces.
According with another aspect of the present invention, a method of joining
multiple pieces of thermoplastic material to forrn a cellular block,
comprising:
arranging first and second pieces of the thermoplastic material in opposing
face-to-face relation; and
then welding the first and second pieces together by engaging a rolling
mechanism against, and at the same time rolling the rolling mechanism across,
at least
one of the first and second pieces to provide a plurality of spaced apart
rolling contact
regions that at least partially form a plurality of spaced apart nips that
travel in a
longitudinal direction to form multiple spaced apart and elongate first welds
between
the first and second pieces, so that the first welds extend in the
longitudinal direction.
According with a further aspect of the present invention, a method for joining
multiple cut pieces of thermoplastic material to form a cellular block,
comprising:
supplying at least one cut piece to be added to the cellular block by engaging
a
plurality of spaced apart protrusions to the cut piece to be added to the
cellular block
and moving the protrusions along a path so that the protrusions carry the cut
piece to
be added. to the cellular block along the path to a position proximate the
cellular
block; and
then welding the cut piece to be added to the cellular block to a cut piece
most
recently previously welded to the cellular block, including moving a plurality
of
welding mechanisms respectively within respective slots defined between
adjacent
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protrusions of the plurality of protrusions, and engaging the welding
mechanisms
against the cut piece to be added to the cellular block.
According with another aspect of the present invention, a method of joining
multiple cut pieces of thermoplastic material to form a cellular block,
comprising:
arranging a cut piece to be welded to the cellular block in opposing face-to-
face relation with a cut piece most recently previously welded to the cellular
block;
then welding the cut piece to be welded to the cellular block and the cut
piece
most recently previously welded to the cellular block together by
contemporaneously
forming multiple spaced apart and elongate first welds therebetween, wherein
the
welding includes:
contemporaneously moving a plurality of welding mechanisms and a
plurality of heating elements along opposite sides of the cut piece to be
welded to the
cellular block during the opposing face-to-face relation,
heating at least one of the cut piece to be welded to the cellular block
and cut piece most recently previously welded to the cellular block with the
heating
elements,
then nipping the cut piece to be welded to the cellular block and the cut
piece most recently previously welded to the cellular block between the
plurality of
welding mechanisms and structure to weld the together the cut piece to be
welded to
the cellular block and the cut piece most recently previously welded to the
cellular
block to thereby form a plurality of cells in the cellular block; and
continuously repeating the arranging and welding.
According with a further aspect of the present invention, a method of joining
multiple cut pieces of thermoplastic material to form a cellular block,
comprising:
moving a carrying mechanism having a first station and a second station so
that the carrying mechanism carries at least a first cut piece to proximate
the cellular
block;
welding the first cut piece to the cellular block, including forming a first
plurality of longitudinally extending welds that are laterally spaced apart
from one
another;
releasing the first cut piece from the carrying mechanism;
6d
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moving the carrying mechanism so that the carrying mechanism carries at least
a second cut piece to proximate the cellular block;
welding the second cut piece to the cellular block;
moving the carrying mechanism laterally prior to welding the second cut piece
to the cellular block, so that the step of welding the second cut piece
includes forming
a second plurality of longitudinally extending welds that are laterally spaced
apart
from one another, and the first and second plurality of longitudinally
extending welds
are laterally spaced apart from one another;
releasing the second cut piece from the carrying mechanism.
6e
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BRIEF DESCRIPTION OF THE DRAWINCS
Having thus described the invention in general terms, reference will now be
made to the accompanying drawings, which are not necessarily drawn to scale,
and
wherein:
Figure 1 is a schematic side view of a machine for forming expandable
cellular blocks and honeycomb structures, or the like, in accordance with a
first
embodiment of the present invention;
Figure 2 is an isolated elevational view of a heating mechanism of the
machine of Figure 1;
Figure 3 is a plan view schematically illustrating an expandable cellular
block / honeycomb structure that can be formed by the machine of Figure 1, and
at
least portions of the illustrated cellular block / honeycomb structure are
representative of that which can be formed by a machine of a second embodiment
of the present invention;
Figure 4 is a schematic pictorial view of a machine for forming expandable
cellular blocks and honeycomb structures, or the like, in accordance with the
second embodiment of the present invention;
Figures 5a-12a are schematic top plan views illustrating portions of a
forming mechanism and carrying mechanism of the machine of Figure 4, and an
expandable cellular block and honeycomb structure being formed, at successive
stages of operation;
Figures 5b-12b are schematic and enlarged top plan views of portions of
Figures 5a-12a, respectively;
Figures Sc-12c are schematic side sectional views illustrating portions of
the forming mechanism and carrying mechanism, and the expandable cellular
block and honeycomb structure being formed, respectively and substantially at
the
successive stages of operation of Figures 5a-12a;
Figure 13 schematically illustrates a control system of the machine of
Figure 4; and
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Figure 14 is a schematic plan view of portions of a machine for forming
expandable cellular blocks and honeycomb structures, or the like, in
accordance
with a third embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention now will be described more fully hereinafter, in some
cases with reference to the accompanying drawings, in which pi-eferred
embodiments of the invention are shown. This invention may, l-iowever, be
embodied in many different forms and should not be construed as limited to the
embodiments set forth herein; rather, these embodiments are provided so that
this
disclosure will be thorough and coinplete, and will fully convey the scope of
the
invention to those skilled in the art. Like numbers refer to like elements
throughout.
In accordance with one aspect of the present invention, methods and
apparatus are provided for creating a low-density cellular block out of
thermally
bonded (i.e., welded), fibrous, thermoplastic roll and/or sheet material, and
the
cellular block is expandable. After being expanded and thereby transformed
into a
honeycomb structure, or the like, the expanded block can easily be
incorporated
into a constructed object. The cellular block can advantageously be
manufactured
without the use of chemical adhesives or glue, and without pre-folding or
precorrugation of the roll material. In accordance with this and other aspects
of the
present invention, the cellular block can be manufactured at a high rate of
production, and the welds joining the pieces that form. the block are
sufficently
strong to inhibit inadvertent separation of the pieces while the expandable
block is
expanded. -
In accordance with a first embodiment of the present invention, which will
be described generally, followed by a description of a specific example with
reference to Figures 1-3, the expandable cellular block is formed by:
8
CA 02355548 2002-06-14
a) positioning a cut piece being added to the cellular block parallel
with each of the cut pieces of the cellular block;
b) heating, to the welding temperature of the cut pieces, first strips
which are opposite one another on surfaces of the cut piece being added to the
cellular block and a cut piece most recently previously added to the cellular
block;
c) pressing together the surfaces of the cut piece being added to the
cellular block and the cut piece most recently previously added to the
cellular
block, so that the first strips of the cut piece being added to the cellular
block and
the first strips of the cut piece most recently previously added to the
cellular block
respectively meet and thereby the cut piece being added to the cellular block
and
the cut piece most recently previously added to the cellular block are welded
or
thermally fused together, and the cut piece being added to the cellular block
becomes the cut piece most reeently previously added to the cellular block;
d) a cut piece being added to the cellular block is brought in a parallel
position to the cut piece most recently previously added to the cellular
block,
whereby flat surfaces of the cut piece being added to the cellula.r block and
the cut
piece most recently previously added to the cellular block oppose each other;
e) heating, to the welding temperature of the cut pieces, second strips
which are opposite one another on the surfaces of the cut piece being added to
the
cellular block and the cut piece most recently previously added to the
cellular
block, wherein the second strips are offset from the first strips by
approximately
double the width of the first and second strips;
f) pressing together the surfaces of the cut piece betng added to the
cellular block and the cut piece most recently previously added to the
cellular
block, so that the second strips of the cut piece being added to the cellular
block
and the second strips of the cut piece most recently previously added to the
cellular
block meet and thereby the cut piece being added to the cellular block and the
cut
piece most recently previously added to the cellular block are welded or
thermally
fused together, and the cut piece being added to the cellular block becomes
the cut
piece most recently previously added to the cellular block; and
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CA 02355548 2002-06-14
g) (a) through (f) above are continuously repeated with many further
cut pieces.
Through the foregoing joining method, an expandable cellular block is
created without the use of adhesives or pre-folding (e.g., preconugating) of
the roll
material. This joining method is suitable for reaching high procuction speeds.
Cutting the cut pieces from rolls of the material precedes the joining
procedure.
However, it is possible to produce directly froni pre-cut pieces, if they are
delivered as such. The product of the procedure, which is the expandable
cellular
block, can be delivered as is to end-users, for further work (i.e.,
expansion), as this
provides for an optimum use of freight space. Of course, it is also possible
to
expand the expandable cellular block directly behind the production device, as
part
of the overall process. Through the invented procedure, the expandable
cellular
block is created via cyclical addition of cut pieces, whereby the cross
section of the
expandable cellular block is detennined by the choice of the width of the cut
pieces. The width of the cut pieces (which can correspond to the roll width of
the
original thermoplastic roll material) can be freely chosen by the operator,
and the
height of the produced expandable cellular block corresponds to the width of
the
cut pieces.
In accordance with the first embodiment of the present invention, the cut
piece that is to be added to the expandable cellular block and the expandable
cellular block, which is facing the cut piece that is to be added, are moved
towards
one another in the above-described steps (c) and (f). As a result, an extended
compression time is available for welding strips together, which has positive
effects on the weld quality.
In accordance with the first embodiment of the present invention, in steps
(c) and (f) during and/or after the their initial contact, the cut piece that
is being
added to the cellular block and the cellular block are together moved parallel
to the
production direction a distance equal to the thiclcness of one cut piece. That
is,
simultaneously with the addition of the new cut piece, the produced expandable
CA 02355548 2002-06-14
cellular block is moved in the production direction by the thickness of the
new cut
piece.
Preferably, the newly produced expandable cellular block is held or wedged
under some pressure exerted perpendicular to the production direction. This
wedging or pressure is applied across the upstream area of the expandable
cellular
block, where the cellular block is produced. This pressure is adjustable and
thus
enables the adjustment of the pressure used for and during compression and
welding of each new cut piece, namely the pressure with which each new cut
piece
is joined with the expandable cellular block.
In order to create newly expanded honeycomb material, the expandable
cellular block, which was created via the above-discussed steps (a) through
(g), is
heated to a temperature which enables plastic defomiation, and then the block
is
expanded perpendicularly to its constituent cut pieces, i.e. in the production
direction.
Surprisingly, it has been shown that the expandable cellular block can be
expanded under heating conditions shortly after its creation, without the risk
of
separation or even stressing of the newly formed welds. In this case, the heat
required for the plastic deformation, which is used for expansio:l purposes,
is lower
than the heat required for welding purposes. For example, in the case of roll
material made of polypropylene fibers, heating between 75 to 85 C is
sufficient for
expansion, whereas the welding temperature lies above 120 C, up to 165 C.
Heating of the produced cellular block may occur via infrared light. The
advantage of infrared light heating is that the heat readily penetrates the
section of
the expandable block where a partial expansion has already taken place. The
radiant heat (or another form of heating) is directed into the spaces (i.e.,
cells)
opened up as a result of the partial expansion, in order that a fairly even
heating of
the entire cellular block cross section will result.
Preferably the cut pieces to be added to the expandable cellular block are
transported along a circular path, cyclically, into the welding position in
front of
11
CA 02355548 2002-06-14
the expandable cellular block. This way, many. cut pieces can be transported,
one
after the other, on a rotor, which thus enables high rates of production.
In accordance with the first embodiment of the present invention, a
machine joins a multiplicity of cut pieces of a thermoplastic roll material to
form
the expandable cellular block. The machine includes a rotor and an open-ended
magazine that accepts the newly formed cellular block. The rotor is positioned
in
front of the open-ended magazine and includes several stations that are
distributed
evenly about the circumference of the rotor. Each such station contains:
a) a mechanism for carrying the cut pieces, which can reach beyond
the width of the cut pieces;
b) a heating mechanism, which is oriented towards the carrying
mechanism, and which can be driven back and forth between a position in front
of
the carrying mechanism and a position that is pulled back from the carrying
mechanism; and
c) a pressure mechanism, which is oriented towards the carrying
mechanism. Preferably, the pressure mechanism is arranged in the rotor turning
direction, behind the carrying mechanism.
The rotor is located between the open-ended magazine and a transfer
station, which can also be characterized as a supplying mechanism. At the
stationary transfer station, the rotor takes on each newly cut piece of strip
material
("cut piece") and transports it towards the magazine, which already contains
the
cellular block, which has been produced thus far. The welding, or heat fusion,
between the newly cut piece and the previously produced cellular block occurs
in
front of the magazine. The stations of the rotor, which are distributed about
the
circumference of the rotor, have several functions. The stations take on and
transport each newly cut piece to the welding position in front of the
magazine.
The stations heat the opposing surfaces of the cut piece most recently
previously
added to the cellular block and the newly cut, transported and weld-positioned
cut
piece that is being added to the cellular block, and effect the pressure,
through
12
CA 02355548 2002-06-14
which the weld between these two cut pieces occurs, by squeezing one onto the
other, while they remain adequately heated.
According to the first embodiment of the present invention, the rotor is
equipped with an even number of stations and the heating mechanisms are
axially
offset from one station to the next, with the subject axis being the axis of
rotation
of the rotor. This way, each of the cut pieces, which are constitaents of the
produced cellular block, are provided with offset welded strips, as required
to
provide a honeycomb structure. At the conclusion of this process, the produced
expandable cellular block can then be expanded to provide the honeycomb
material, with each honeycomb cell having six equidistant sides. The even
number
of stations on the rotor can be freely chosen as the size of the rotor will
permit; e.g.
six or eight stations are a practical number. The offset of the heating
mechanisms
of neighboring stations equals twice the width of the welding st:-ips formed
on the
cut pieces in the production of honeycomb material. The presstire mechanisms
can
extend across the entire width of the carrying mechanism. However, it is only
across the width of the welding strips that the pi-essure mechanisms can exert
their
pressure. The pressure mechanisms as well as the heating mechanisms are offset
from station to station.
According to the first embodiment of the present invention, the
pneumatically driven carrying mechanisms of the rotor s stations are provided
with
drilled holes, which can be connected to a negative pressure source. At the
transfer
station, each cut pieces is transferred onto the carrying mechanism by suction
and
thus held in place. In the welding position, in fi-ont of the magazine,, once
heating
of each cut piece, via the heating mechanisms, has occurred, the negative
pressure
is disengaged, so that each cut piece is available for immediate welding.
Then, the
pressure mechanism presses the correctly prepared cut piece onlo the cut piece
most recently previously added to the cellular block, which has thus grown by
the
newly attached cut piece.
In accordance with the first embodiment of the present invention, the
heating mechanisms consist of a number of chatnber-like heating elements,
which
13
CA 02355548 2002-06-14
are offset from station to station by twice the width of the welding strips.
The
heating mechanisms on the rotor can be substituted with other heating elements
of
another width and an appropriately (and differently) sized distance between
the
chamber-like heating elements. In this way, one may adjust the honeycomb cell
size.
Preferably, the pressure mechanisms are roller-shaped. The rollers of the
pressure mechanisms can be equipped with an adjustable spring loading
mechanism so that the pressure exerted along the welding strips, in concert
with
the wedging of the produced cellular block in the magazine, can be adjusted as
required.
In order to convert the expandable cellular block material into expanded
honeycomb material, the magazine is equipped with a heater and at least one
pair
of expansion rollers. The heater can consist of a single sided or a double
sided set
of infrared lamps. The heat is directed towards the welding strips, after the
partial
expansion, and towards the consequently created channels (i.e., cells). The
expansion rollers can be brush rollers, or rollers that have been provided
with an
elastic material, such that the cellular block, whicli is intended to be
expanded,
suffers no damage during the expansion process.
An example of the first embodiment of the present invention is illustrated in
Figures 1-3. Figure 1 shows a table 1 for guiding the newly produced cellular
block 2. At the front end of the table 1, there is an open-ended magazine 3
through
which the expandable cellular block 2 extends. The open-endect magazine 3
includes a securing mechanism that subjects the expandable cellular block to
an
adjustable pressure that is perpendicular to the production direction. The
table 1
with the open-ended magazine 3 can be moved or positioned back and forth via a
mechanism in the directions indicated by the arrows 4. An infrared radiator 5
is
positioned in the production direction, behind the open-ended magazine 3 and
above the cellular block 2. The infrared radiator 5 heats the expandable
cellular
block 2 to its plastic deformation temperature. In the production direction
behind
the table 1 there is a pair of expansion-rollers 15, which grab the cellular
block 2
14
CA 02355548 2002-06-14
from the magazine 3 and thus cause the expansion to take place. turning the
expandable cellular block into honeycomb material. As illustraced in Figure 1,
the
expansion-rollers 15 are equipped with brushes. The distance between the upper
roller and the lower roller 15 is adjustable, in concert with the height of
the cellular
block 2 and the desired pressure. In the production direction, behind the
expansion-rollers 15, there is a conveyor belt 16, which accepts and
transports the
expanded cellular block / honeycomb.
Between the open-ended magazine 3 and a supply magazine 7, from which
the cut pieces are supplied, there is a rotor 6 that extends along the entire
length of
the cut pieces. The rotor 6 is held in bearings to permit circular motion and
is
connected to a cyclical drive mechanism. The rotor 6 is equipped with six
stations
spaced equally along its circumference, each of which transports one cut
piece,
provides the cut piece with welding strips and presses the cut piece onto the
previously formed expandable cellular block 2, in front of the magazine 3.
Every
station essentially encompasses three units, specifically a radial,y
adjustable and
bar-shaped carrying mechanism 8, a tangentially adjustable heating mechanism
9,
situated in front of the carrying mechanism 8, and a roller-shaped pressure
mechanism 10. These three units essentially extend across the entire width
(perpendicular to the plane of the drawing sheet containing Figttre 1) of the
rotor 6.
Motion of the carrying mechanism 8 and the comb-shaped heating mechanism 9
are guided and driven pneumatically and centrally. The pressure mechanism 10
generally consists of a spring loaded roller, which, ir- concert with the
turning
motion of the rotor 6, presses the cut piece, which has been provided with
welding
strips, from the top, downwards towards the expandable cellular block 2, and
thereby completes the welding process through which the newly cut and
positioned
piece is attached to the expandable cellular block 2.
Regarding operation of a representative station of the rotor 6 more
specifically, in front of the supply magazine 7, the carrying mechanism 8 is
activated, while the heating mechanism 9 is pulled back, whereby a cut piece
is
taken on by the carrying mechanism 8, from the supply magaziiie 7. More
CA 02355548 2002-06-14
specifically, the carrying mechanism 8 is provided with drilled holes or ports
8a
that are opened to a negative pressure source so that a vacuum causes the cut
piece
to be retrieved and carried by the carrying mechanism.
During the turning motion of the rotor 6, in the direction of the arrow 11,
the heating mechanism 9 is driven forward so that the cut piece being carried
by
the carrying mechanism 8 is positioned between the carrying mechanism 8 and
the
comb-shaped heating mechanism 9. During this process, the carrying mechanism 8
remains in a position that is radially inward and away from the lieating
mechanism
9. As soon as this station has completed three "cycles" and has assumed a
position
in front of the open-ended magazine 3, the carrying mechanism 8 carrying the
cut
piece and the open-ended magazine 3 carrying the expandable cellular block 2
are
moved so that the cut piece carried by the carrying mechanism 8 and the
expandable cellular block 2 can both be contacted by the comb-sliaped heating
mechanism 9. Now the comb-shaped heating mechanism 9 is pulled back between
the cut piece on the carrying mechanism 8 and the expandable cellular block 2,
so
that welding strips are formed through contact between the heating mechanism 9
and the opposing surfaces of the cut piece carried by the carrying mechanism 8
and
the expandable cellular block 2. Finally, the carrying mechanism 8 with the
cut
piece and the open-ended magazine 3 with the expandable cellular block 2 are
moved more closely toward one another, until the welding strips just formed on
the
cut piece and the expandable cellular block 2 come in contact with one
another.
Following this last step, the carrying mechanism 8 and the open-ended magazine
3
once again move apart, and the rotor 6 cycles forward. During this process,
the
roller of the pressure mechanism 10 of this station rolls over the cut piece
that was
just added to the expandable cellular block 2, so that pressure is applied and
the
expandable cellular block 2 is pushed forward a distance equivalent to the
thickness of the cut piece. These operations are repeated each time a station
of the
rotor 6 is moved into position in front of the expandable cellular block 2.
Figure 2 is a frontal view of a representative heating mechanism 9 whose
chamber-like heating elements 12 are heated electrically to the i-equired
16
CA 02355548 2002-06-14
temperature in order to effect the welding bonds between the cut pieces of the
thermoplastic material to form the expandable cellular block 2.
Figure 3 illustrates the cellular block 2 during a three part transition from
the non-expanded cellular block material in area a, through the partially
expanded
status in area b, to a substantially expanded status in area c. The heating
via the
infrared radiator 5 occurs at least partially in area b, so that the i-adiant
heat can
reach the inside of the cellular block 2.
Figure 4 illustrates a machine 20, and Figures 5-12 illustrate successive
operations of the machine 20 and a honeycomb structure / expandable cellular
block at different stages of being formed, in accordance with a second
embodiment
of the present invention. The honeycomb structure / expandable cellular block
formed by the machine 20 can be generally characterized as a cellular block 24
(Figures 5-12, and also see Figure 3, because it illustrates a cellular block
whose
downstream portions are at least substantially similar to the cellular block
24).
Referring to Figure 4, the machine 20 has a supplying mechanism 26 that
includes
a carrying mechanism 28 in the form of a laterally extending, rotating mandrel
or
drum, which is more generally a rotor. That is, the carrying mechanism 28 of
the
second embodiment of the present invention is in the form of a rotor. However,
in
accordance with a third embodiment of the present invention, the carrying
mechanism preferably does not rotate, and is therefore not characterized as a
rotor,
as is discussed in greater detail below. The supplying mechanism 26 also
includes
supplying submechanisms for feeding strips 30 from first and second rolls 32
and
34 respectively to stations of the carrying mechanism 28, as wil t be
discussed in
greater detail below. The rolls 32 and 34 may contain the same or different
types
of material, to provide a cellular block that includes o:r is constructed of
different
types of material.
Referring to Figures 4-12, the carrying mechanism 28 stipplies pieces cut
from the strips 30, including cut pieces 36a-e (see Figures 5-12, with an
emphasis
on Figures 5b-12b, for example), to a forming mechanism 22 (Figure 4) of the
machine 20. The strips 30 can be many different materials, but are most
preferably
17
CA 02355548 2002-06-14
strips of thermoplastic polymeric material that is in the form of a film,
sheet or
nonwoven fabric. Preferably the strips 30 have a narrow width, such as in the
range of four to five inches; however, other and larger widths can also be
used.
The cellular block 24 is formed in the forming mechanism 22 from the cut
pieces, including cut pieces 36a-e, that are sequentially supplied from the
carrying
mechanism 28. The cellular block 24 progresses downstream fi-om the forming
mechanism 22 into an expansion mechanism 38 (Figure 4) of the machine 20. In
the expansion mechanism 38, the cellular block 24 is expanded (e.g., pulled in
the
downstream direction) during the application of heat to form a completed
honeycomb structure, or the like. In accordance with one example, the
expansion
mechanism 38 includes heating and pulling components like those of the first
embodiment, described above, that operate to expand the expandable cellular
block
to form a completed honeycomb structure, like that shown in area c of Figure
3.
Referring in greater detail to supplying operations carried out by the
supplying mechanism 26 of the machine 20, they will be described with respect
to
representative pieces 36d (see Figures 4, 7a and 7c, for example) and 36e
(Figures
12a and 12b) that originate from the first and second rolls 32 and 34,
respectively.
The piece 36d is supplied from the first roll 32 to a first station 40 (see
Figures 4,
5a, 7a, l0c and 11c, for example) of the carrying mechanism 28 by a carriage
system 41 (Figure 4) of the supplying mechanism 26,. The carriage system 41 is
positioned in front of and travels laterally along (i.e., between the opposite
ends of)
the carrying mechanism 28. As best understood with reference to Figures 4 and
7a,
the carriage system 41 grips the free end of the strip 30 originating from the
first
roll 32, and draws the strip, for example the piece 36d of the strip, across
the first
station 40. A partial vacuum supplied at the first station 40 via vacuum ports
42
(see Figure 1 lc, for example) fonned in the canying mechanisni 28 holds the
cut
piece 36d to the first station. The vacuum (i.e., the flow toward a vacuum
pump or
other source of negative pressure) is illustrated by small arrows that extend
toward
the rotational axis of the carrying mechanism 28 in Figures 5c-12c, and by
small
arrows that extend toward and then along the rotational axis of the carrying
18
CA 02355548 2002-06-14
mechanism in Figures 5a-12a. A cutter mounted proximate the end of the
carrying
mechanism 28 closest to a control panel 43 (Figure 4) cuts the piece 36d from
the
strip 30 of the first ro1132 once the carriage system 41 has drawn the piece
36d
across substantially the entire length of the first station 40.
Thereafter, the carrying mechanism 28 is rotated 180 about its elongate
axis (see Figure lOc) so that the first station 40, and the cut piece 36d it
is carrying,
both face the forming mechanism 22 and the cellular block 24 being formed
within
the forming mechanism. The cut piece 36d is then operated upon by the forming
mechanism 22 so that it is incorporated into the cellular block 24, as will be
discussed in greater detail below.
Similarly, and while the cut piece 36d is being operated upon by the
forming mechanism 22, the piece 36e (Figures 12a and 12b) originating from the
second rol134 is supplied to a second station 44 (see Figures l Oc and 12a,
for
example) of the carrying mechanism 28 by the carriage system 41 (Figure 4)
that
travels in front of and along the carrying mechanism 28. The carriage system
41
grips the free end of the strip 30 originating from the second rol 134, and
draws the
strip, for example the piece 36e of the strip, across the second station 44. A
partial
vacuum supplied at the second station 44 via vacuuni ports 46 (see Figure l
Oc, for
example) formed in the carrying mechanism 28 holds the cut piece 36e to the
second station. A cutter mounted proximate the end of the carrying mechanism
28
farthest from the control pane143 (Figure 4) cuts the piece 36e from the strip
30 of
the second ro1134 once the carriage system 41 has drawn the piece 36e across
substantially the entire length of the second station 44.
Advantageously, the cut pieces, such as the cut pieces 36a-e, which are
supplied to the carrying mechanism 28 and respectively held by the first and
second stations 40 and 44 of the carrying mechanism, are at least originally
substantially planar while being held by the carrying mechanism. This avoids
problems associated with handling precorrugated strips, since precorrugated
strips
are preferably not used by the machine 20.
19
CA 02355548 2002-06-14
In addition to rotating about its axis, the carrying mechanism 28
reciprocates in the upstream / downstream directior.L (with the
upstream/downstream direction being defined by the "flow" of the cellular
block
24 being formed) as part of the process of supplying the cut pieces to the
forming
mechanism 22. The reciprocation of the carrying mechanism 28 is at least
partially
illustrated by directional arrows closely associated with the carrying
mechanism in
some of the figures. The carrying mechanism 28 rotates while it is not
reciprocating, it reciprocates while it is not rotating (i.e., it translates),
and the
opposite stations 40 and 44 of the carrying mechanism extend generally
upright,
and most specifically and preferably vertically, while the carrying mechanism
28 is
not rotating. However, both motions could also be achieved contemporaneously.
Although the illustrated version of the second embodiment includes only two
stations 40 and 44, additional stations can be incorporated into the carrying
mechanism 28.
As illustrated in Figures 12a-c, the cut piece 36d is welded to the cellular
block 24 while the piece 36e is being supplied to the second station 44 of the
carrying mechanism 28, with both of these operations occurring while the
carrying
mechanism 28 is in its most downstream position. 'Chis supplying process
continues repeatedly, so that cut pieces, including cut pieces 36a-d, are
supplied to
the forming mechanism 22 in sequence. Each cut piiece 36a-d preferably extends
substantially upright, and most preferably vertically, while it is ultimately
supplied
to the forming mechanism 22, witllin the forming mechanism, and within the
expansion mechanism 38. Whereas this vertical orientation is preferred since
it
allows the cellular block 24 to be formed and "flow" horizontally such that
the
floor supporting the machine 20 does not impede formation of a cellular block
of
infinite length, the entire machine 20 could be rearranged. For example, the
machine could be oriented so that the cut pieces 36a-d extend substantially
horizontally while they are ultimately supplied to the forming mechanism 22,
within the forming mechanism, and within the expansion mechanism 38.
CA 02355548 2002-06-14
The forming mechanism 22 of the machine 20 includes a laterally
extending set of welding rollers 50 (Figure 5-12) and a laterally extending
set of
rod-like heating elements 48 (Figures 5-12) that are all mounted at a position
below the cellular block 24. The set of welding rollers 50 can be collectively
and
generally referred to as a welding mechanism or rolling mechanism. Although
multiple of the welding rollers 50 and heating elements 48 are shown in
Figures
5a-12a and 5b-12b, in many cases only a representative few are identified by
their
reference numeral in an effort to clarify the drawings. However, the set of
welding
rollers 50 extends parallel to the axis of rotation of the carrying mechanism
28, and
the welding rollers remain aligned with one another and parallel to one
another;
therefore, they can be easily identified in the drawings, even without being
identified by their reference numeral. Likewise, the set of heatiiig elements
48
extends parallel to the axis of rotation of the cariying mechanisin 28, and
the
heating elements remain aligned with one another and parallel to one another;
therefore, they can be easily identified in the drawings, even without being
identified by their reference numeral.
The set of welding rollers 50 and the set of heating elements 48 are
respectively aligned with one another. The heating elements 48 and welding
rollers 50 are mounted for reciprocating both up / down and in the upstream /
downstream direction, as at least partially illustrated by the directional
arrows
closely associated therewith in some of the figures. Also, the welding rollers
50
are each mounted for pivoting, as evident from comparing some of the figures
(see
Figures 7c and 12c, for example), and as at least partially illustrated by the
directional arrows closely associated therewith in Figure 8b. Alternatively,
this
pivoting is not required, and the welding rollers 50 translate into engagement
with
the respective cut piece. In addition, each of the welding rollers 50 is
mounted for
rotating about an axis that is parallel to the axis of rotation of the
carrying
mechanism 28, as indicated by arrows closely associated with the welding
rollers
50 in Figures 7c and 12c.
21
CA 02355548 2002-06-14
Referring in greater detail to forming operations of the forming mechanism
22 of the machine 20, they will be described with respect to representative
cut
pieces 36a-d that are serially provided from the carrying mechanism 28 to the
forming mechanism in the manner described above, with the cut pieces 36a-d
being supplied in alphabetical order. Referring to Figures 5, while the cut
piece
36c is being positioned adjacent the cellular block 24, which already includes
cut
pieces 36a and 36b, the heating elements 48 and welding rollers 50 all
contemporaneously move upward, so that the welding rollers are on the upstream
side of (and in opposing face-to-face relation with) the cut piece 36c and the
heating elements are on the downstream side of (and in opposing face-to-face
relation with) the cut piece 36c. More specifically, the cut piece 36c is
positioned
adjacent the cellular block 24 by the carrying mechanism 28 in the manner
described above, and then the heating elements 48 aiid welding rollers 50
contemporaneously move upward on the opposite sides of the cat piece 36c while
the cut piece 36c is still being held by the carrying mechanism 28. As best
understood with reference to Figure 6c, the piece 36c, carrying mechanism 28,
heating elements 48 and welding rollers 50 then generally together move toward
the cellular block 24, so that the heating elements are sandwiched between the
cut
piece 36c being added to the cellular block and the cut piece 36b most
recently
previously added to the cellular block.
Then the welding rollers 50 and heating elements 48 are
contemporaneously moved downward, with the upper tips of the heating elements
slightly leading the welding rollers along the downward path of travel.
Additionally, the welding rollers 50 are moved further downstream, such as by
pivoting, as best understood with reference to Figure 7c, to engage and force
laterally spaced apart heated strips of the cut piece 36c against laterally
spaced
apart and heated strips of the cellular block 24, namely laterally spaced
apart and
heated strips of the cut piece 36b most recently previously added to the
cellular
block. The heated strips of the cut pieces 36c and 36b are heated by the
heating
22
CA 02355548 2002-06-14
elements 48 that are sandwiched between and being withdrawn from between these
cut pieces.
The heated strips of the cut pieces 36c and 36b are respectively pinched
together (i.e., nipped) between the welding rollers 50 and a laterally
extending set
of rod-like, first welding anvils 52 (see Figures 5a-12a and 5b-12b, for
example).
The welding rollers 50 and heating elements 48 are moved downward while the
welding rollers continue to nip the cut pieces 36c and 36b together, so that
the cut
piece 36c is added to the cellular block 24. Although multiple of the first
welding
anvils 52 are shown in Figures 5a-12a and 5b-12b, in many cases only a
representative few are identified by their reference numeral in an effort to
clarify
the drawings. However, the set of first welding anvils 52 extends parallel to
the
axis of rotation of the carrying mechanism 28, and the first welding anvils
remain
aligned with one another and parallel to one another; therefore, they can be
easily
identified in the drawings, even without being identified by their reference
numeral.
The set of first welding anvils 52 can be collectively anci generally referred
to as a welding mechanism. In this regard, the cut piece 36c is added to the
cellular
block 24 via thermal fusing (e.g., welding) that occurs at upright and
elongate
points of engagement between the cut pieces 36c and 36b as a result of the
elevated
temperature of the heating elements 48 and the forces applied by the welding
rollers 50 as they roll downward across the upstream surface of the cut piece
36c
and cooperate with the first welding anvils 52 to nip the cut pieces 36b and
36c.
Referring to Figures 8, the welding rollers 50 and heating elements 48
continue to
move downward so that they become completely rerrioved from the cellular block
24, at which time the welding rollers move upstream, preferably by pivoting.
Thereafter, the carrying mechanism 28 moves upstream, as shown in Figures 9a
and 9b, so that it can be rotated without hitting the cellular block 24 or
components
of the machine 20, as shown in Figures l0a and l Oc.
As best understood with reference to Figures 10, thereafter and while the
carrying mechanism 28 rotates 180 , the first set of welding anvils 52
reciprocates
23
CA 02355548 2002-06-14
both upwardly / downwardly and in the upstream / downstream direction to
become positioned proximate the upstream side of the cellular block 24. Also,
the
heating elements 48 and welding rollers 50 translate in the lateral direction
each
time, and while, the carrying mechanism rotates 180 . As soon as the first set
of
welding anvils 52, heating elements 48 and welding rollers 50 have
repositioned
and the carrying mechanism 28 has rotated 180 , which are completed at about
the
same time, the carrying mechanism moves downstream to supply the cut piece 36d
to the forming mechanism 22 in the manner described above, and as best
understood with reference to Figures 11-12. Then, the welding rollers 50 and
the
heating elements 48 contemporaneously move upward on opposite sides of the cut
piece 36d in the manner that was described above wi:th reference to the cut
piece
36c. Thereafter, the welding rollers 50, heating elements 48 and carrying
mechanism 28 function with respect to the cut piece 36d similarly to the
manner in
which they functioned with respect to the cut piece 36c, except for being
laterally
offset, and except that the welding rollers 50 cooperate with a laterally
extending
set of rod-like second welding anvils 54 (see Figures 5a-12a and 5b-12b, for
example). As a result, the cut piece 36d is thennally fused (i.e., welded) to
and
becomes part of the cellular block 24, as is illustrated in Figures 12.
The welding rollers 50 cooperate with the set of second welding anvils 54
generally in the same manner that they operate with respect to the first set
of
welding anvils 52, to form the welds by nipping. Accordingly, the set of
second
welding anvils 54 can be collectively and generally referred to as a welding
mechanism. Although multiple of the second welding anvils 54 are shown in
Figures 5a-12a and 5b-12b, in many cases only a representative few are
identified
by their reference numeral in an effort to clarify the drawings. However, the
set of
second welding anvils 54 extends parallel to the axis of rotation of the
carrying
mechanism 28, and the second welding anvils remain aligned with one another
and
parallel to one another; therefore, they can be easily identified in the
drawings,
even without being identified by their reference numeral.
24
CA 02355548 2006-03-27
Thereafter, the carrying mechanism 28 rotates 180 , and the second set of
welding anvils 54 reciprocates both upwardly/downwardly and in the
upstream/downstream direction to become positioned proximate the upstream side
of
the cellular block 24. Also, the heating elements 48 and welding rollers 50
translate
in the lateral direction while the carrying mechanism rotates 180 . As soon as
the
second set of welding anvils 54, heating elements 48 and welding rollers 50
have
repositioned and the carrying mechanism 28 has rotated 180 , which are
completed at
about the same time, the carrying mechanism moves downstream to supply the cut
piece 36e (Figures 12a and 12c) to the forming mechanism 22 in the manner
described above. Then, the forming mechanism 22 operates with respect to the
cut
piece 36e in generally the same manner that it previously operated with
respect to the
cut piece 36c, to weld the cut piece 36e to the cut piece 36d. More
specifically, the
welding rollers 50 respectively cooperate with the heated first welding anvils
52 so
that the cut piece 36e is fused to and becomes part of the cellular block 24.
As best understood with reference to Figures 5b-12b, the two sets of welding
anvils 52 and 54 are arranged in a laterally alternating fashion, and the two
sets are
aligned, except when one of them is repositioning. As mentioned above, the
heating
elements 48 and welding rollers 50 translate laterally each time the carrying
mechanism 28 rotates. As a result, the welding rollers 50 and heating elements
48
shift so as to be associated with a different one of the sets of welding
anvils 52 and 54
with each 180 rotation of the carrying mechanism 28. That is, the welding
rollers 50
and heating elements 48 reciprocate and the above-described concerted
operations of
the machine 20 continue repeatedly so that the cellular block 24 continues to
be
serially formed.
Generally describing the operations of the forming mechanism 22 of the
machine 20, each new cut piece (for example see cut pieces 36a-e) is joined to
the cut
piece immediately previously joined to the cellular block 24 by
contemporaneously
forming multiple spaced apart welds between the new and prior cut pieces. The
welds
are formed by contemporaneously heating opposed strips of the new and prior
cut
pieces with the heating elements 48, and
CA 02355548 2002-06-14
respectively nipping those heated strips of the new and prior cut pieces
between
opposed welding mechanisms, namely the welding rollers 50 and the respective
set
of welding anvils 52 or 54. The 1leating elements 413 provide the heat that is
utilized to form the welds, and the welding rollers 50 move to provide rolling
contact regions that cause the nipping, which provides the pressure that is
utilized
in combination with the heat to foi-m the welds. More specifically, the
welding
rollers 50 roll in close proximity to and relative to the respective welding
anvils 52
and 54, while the respective welding anvils 52 or 54 remain substantially
stationary, to cause the nipping, and the nips closely lag behind and follow
the
upper tips of the heating elements 48 as they are moved downward between the
respective cut pieces being welded together. Stated differently, heat is
supplied
from heating elements 48 that are positioned between the respective cut pieces
being welded together, and immediately thereafter the resulting heated strips
are
nipped between the welding rollers 50 and respective welding aavils 52 or 54,
which supplies the pressure that, with the heat, forms the welds. This
advantageously minimizes the risk that cut pieces ot]'ner than those being
currently
nipped will be welded. This process is repeated sequentially foi- each new cut
piece that is added to the cellular block 24, so that the nipping by the
welding
rollers 50 alternates between the welding anvils 52 and 54.
More specifically and for example, the nipping alternately includes nipping
cut pieces between the welding rollers 50 and the first welding anvils 52,
then
translating the welding rollers laterally and nipping cut pieces between the
welding
rollers and the second welding anvils 54, then translating the welding rollers
laterally and nipping cut pieces between the welding rollers and the first
welding
anvils 52, and so on. The heating elements 48 are moved in a concerted manner
to
apply the heat that is necessary for the welding, with the heat being applied
immediately prior to the nipping and substantially solely between the cut
pieces
being welded and to the strips that are in the process of being nipped.
Referring to
Figure 7b for example, welding the cut piece 36c to the cellular block 24
includes
contemporaneously forming multiple laterally spaced apart and elongate first
welds
26
CA 02355548 2002-06-14
between the cut piece 36c and the cut piece 36b that was most recently
previously
welded to the cellular block. Thereafter, and referring to Figure 12b for
example,
welding the cut piece 36d to the cellular block 24 includes forming multiple
spaced
apart and elongate second welds between the cut piece 36c and the cut piece
36d,
so that the second welds are laterally offset from the first welds. This
adding of
additional cut pieces by forming offset welds continues repeatecily.
Referring to Figures 6a and 11 a, for example, each of the stations 40 and 44
of the carrying mechanism 28 respectively includes or is defined by a set of
protrusions 56 and 58, and slots are defined between adjacent ones of the
protrusions. The welding rollers 50 are respectively received by the slots of
the
station of the carrying mechanism 28 that is oriented toward the cellular
block 24,
while the welding rollers and heating elements 48 move upwarc; along opposite
sides of a new cut piece that is about to be welded to the cellular block. The
series
of slots / protrusions that define one station of the carrying mecllanism 28
are
laterally offset from the series of slots / protrusions that define the
opposite station
of the carrying mechanism, to accommodate for the lateral reciprocation of the
welding rollers 50, which is described above. More specifically, the carrying
mechanism 28 can be a rectangular shaft with slots formed into opposite sides
thereof, and each slot can be described as a gap defined between protrusions
of the
shaft, with the protrusions and gaps extending perpendicular to and radially
from
the rotational axis of the shaft. The vacuum-supplyirig ports 42 and 46 are
respectively open at the outwardly oriented faces of the protrusions 56 and
58.
Referring back to Figure 4 and the supplying mechanisni 26, for each of the
rolls 32 and 34, a cutter 59 can be positioned for cutting the stri;)s 30 as
they are
drawn from the roll, so that two layers of cellular block are
contemporaneously
manufactured by the machine 20. Additionally, each of the cutters 59 can
perform
scallop-like cuts (e.g., sinusoidally shaped cuts) in the respective strip 30,
so that
the broad surface of a resulting cellular block has a varied topography, which
enhances the resilient / cushioning functionality of the cellular block in a
direction
normal to the broadest surfaces of the cellular block.
27
CA 02355548 2002-06-14
Although the Figures 5a-12a and II lc illustrate that the vacuum is
supplied to the vacuum ports 42 and 46 continuously, in another embodiment of
the present invention the vacuum is supplied to a station of the carrying
mechanism
28 only so long as that station is intended to hold a cut piece of material
from
which the cellular block 24 is formed.
Referring to Figure 13, the above-described operations of the machine 20
are facilitated by a control system 60 that includes a controller 64, such as
a
computer, that is programmed to control the above-described operations. The
control system 60 also includes aii actuator system 62 that includes multiple
actuators whose actuations are controlled by the controller 64. The actuators
are
respectively connected to, and facilitate the movements of, the inoving parts
of the
machine 20. The actuators can acceptably be motors, pneumatic actuators or/and
other types of actuators suitable for facilitating the above-described
movements of
the components of the machine 20. The control panel 43 (also see Figure 4) is
part
of, or connected to, the controller 64 to allow an operator of the machine 20
to
specify and adjust operating parameters of the machine 20. Similarly, the
machine
of the first embodiment, which is illustrated in Figure 1, includes a control
system
that is generally like the control system 60, except that it is tailored to
the machine
of the first embodiment. Although the heating elements 48 and welding rollers
50
are illustrated as being mounted to separate beams in the drawings, they may
alternatively or ultimately be mounted to the same beam.
A machine for forming expandable celh.i lar blocks and honeycomb
structures, or the like, in accordance with the third embodiment of the
present
invention is substantially similar to the machine of the second embodiment of
the
present invention, except for variations noted and variations that will be
apparent to
those of ordinary skill in the art in view of this disclosure. Referring to
Figure 14,
the strips 30 are drawn from first and second rolls 32 and 34, which rotate
about
horizontal axes, and the strips are rotated 90 , due to the action and
arrangement of
feed roller systems 70. The strips 30 are respectively supplied from the feed
roller
systems 70 to accumulator systems 72. The carriage system 41 is mounted for
28
CA 02355548 2002-06-14
traveling laterally along and behind the carrying mechanism 28', between the
carrying mechanism and the forn-iing mechanism 22. The carriage system 41
respectively supplies the strips 30, which are respectively cut by cutters 74,
from
the accumulator systems 72 to the sole station 44 of the carrying mechanism
28'.
That is, and in accordance with the third embodiment of the present
invention, rather than the carrying mechanism 28' rotating 180 as in the
second
embodiment, the carrying mechanism translates / reciprocates laterally with
the
heating elements 48 and welding rollers 50, to achieve substantially the same
result
as that achieved by the machine of the second embodiment of the present
invention, while eliminating the rotating and the first station 40 (see
Figures 4, 5a,
7a, lOc and 11c, for example) and its associated vacuum ports. Otherwise,
according to the third embodiment the motions of the carrying mechanism 28'
and
the forming mechanism 22, and their interaction, are substantially as
described
above for the second embodiment of the present invention. Accordingly, Figures
5-12 can be made illustrative of the operations of the machine of the third
embodiment (i.e., they are illustrative of the operations of the machine of
the third
embodiment) by removing the station 40; never rotating the carrying mechanism
28 / rather than rotating the carrying mechanism 28 as illustrated in Figures
1 a-
l Ob, moving the carrying mechanism 28 laterally with the heatiiig elements 48
and
welding rollers 50 and always having the station 44 oriented toxvard the
forming
mechanism 22; and respectively applying the cut pieces of the strips 30 to the
station 44, via the carriage system 41, each time the carrying mechanism 28 is
at its
farthest position from the forming mechanism 22.
In accordance with the third embodiment of the present invention, multiple
rotating brush-like rollers (for example see the brush-like rollers 15
illustrated in
Figure 1) are positioned immediately downstream of the forming mechanism 22 to
engaging the formed cellular block and thereby assist in moving the formed
cellular block toward the downstream expansion mechanism (for example see the
expansion mechanism 38 of Figure 4).
29
CA 02355548 2002-06-14
Many modifications and other embodiments of the invention will come to
mind to one skilled in the art to which this invention pertains having the
benefit of
the teachings presented in the foregoing descriptions and the associated
drawings.
Therefore, it is to be understood that the invention is not to be limited to
the
specific embodiments disclosed and that modifications and other embodiments
are
intended to be included within the scope of the appended claims. Although
specific terms are employed herein, they are used in a generic and descriptive
sense
only and not for purposes of limitation.
