Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF THE INVENTION
APPARATUS AND METHOD FOR THREE-DIMENSIONAL SHAPING OF
EXTRUDABLE PROFILES
FIELD OF THE INVENTION
The apparatus and method relate to variably shaping extrudable
profiles in a continuous manner into bodies that have both convex and concave
shapes, inline with an extrusion process. The principles of the bending
apparatus
and method also apply to thin-wall metal profiles.
BACKGROUND OF THE INVENTION
Extruded profiles such as but not limited to thermoplastics are
commonly used in every sector of human life. Extruded profiles are usually
supplied in linear form. Currently bending of extruded profiles such as
plastic
pipes or arched plastic window frames is primarily done in post-extrusion
environments where a pre-determined length of linear-shaped profile is re-
heated
and gradually bent into a desired shape. Such methods of bending and shaping
of profiles are labor intensive and therefore costly, and limit profiles
utility.
Production costs further increase if some level of complexity is introduced in
the
geometry of the profile.
Spiral welding machines for wrapping a hot strip of metal or plastic
material around a constant-diameter coiler to form a pipe or a tank are also
known technologies. However, wrapping a hollow profile of complex cross-
sectional geometry around a deformable mold that enables the production of
both convex and concave shapes while maintaining both inner and outer cross-
sectional dimensions substantially constant during bending is a challenge.
Moreover, varying outer longitudinal dimensions of the profile
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including relative angles in relation to former profile wraps such for making
twisted bodies is a challenge that becomes compounded when all above
activities are to be accomplished in an economic manner in a commercial or an
industrial setting.
Accordingly, it is desirable to develop a cost-effective apparatus
and method for bending and shaping extruded profiles inline with an extrusion
process. It is also desirable that the method accommodates hollow profiles of
all
cross-sectional dimensions made of malleable materials that can solidify
outside
the extruder under the effect of cold, heat, or chemical treatment. Materials
may
range from thermoplastics to extrudable organic minerals or other compounds.
To address some of these requirements, a number of apparatus
and methods have been disclosed such as in US Pat.4,275,525, US Pat.
5,424,025, US Pat. 6,190,595 and US Pat. 6,952,942. Furthermore, few post-
extrusion processes have also been proposed, but none for continuously shaping
complex profiles involving the winding of hollow profiles into complex three-
dimensional shapes inline with an extrusion process. Finally, my U.S. Patent
Application 20090102090 and my Canadian Patent Application CA 2512411
addressed partially some of the above challenges.
PRIOR ART
US Pat. 4,275,525, US Pat. 5,424,025 and US Pat. 6,952,942 have
disclosed limited solutions in terms of shaping profiles of complex geometry
into
three-dimensional bodies of also complex geometry. US Pat. 6,190,595
proposed an extrusion arrangement for a die guided in an extrusion chamber.
This prior art 6,190,595' refers primarily to a die and not to a stand-alone
bending
apparatus that accommodates the bonding of adjacent coils into three-
dimensional bodies.
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Post-extrusion solutions disclosed in prior art related primarily to
tubes, pipes and other profiles of simple geometry which when bent in a post-
extrusion environment suffer from the disadvantage of being labor-intensive
and
limited in their ability to bend and shape hollow thermoplastic profiles of
complex
geometries, and this in a cost-effective and continuous manner.
Both my US Patent Application 20090102090 and my Canadian
Patent Application CA 2512411 disclosed an apparatus and method for shaping
thermoplastic profiles. In these prior art, the disclosed shapers were based
on
one or multiple series of sequential plates tethered by an elongate element of
short length. The disclosed plates slide over a rotating size-variable mold.
While both prior art 20090102090' and 2512411' addressed the
challenge of bending thermoplastic profiles they suffered from the limitation
of
disclosing a rotating mold that deformed only radially but not both radially,
angularly and asymmetrically. Additionally, prior art 20090102090' and
2512411'
disclosed a tethered system attached to a short-length series of external
calibrated plates for maintaining constant the outside cross-sectional
dimensions
of incoming profiles. These suffered from the limitation that they require
from an
operator to push the freshly made, not-yet-hardened profile through a series
of
calibrated plates.
Furthermore, mold disclosed in prior art 20090102090' and
2512411' suffered from the disadvantage of not being able to impart to a same
profile both a convex and a concave outer contour.
SUMMARY OF THE INVENTION
The apparatus and method provide a cost-effective approach of
continuously bending and shaping extruded profiles into shaped strands of
variable sizes and shapes inline with an extrusion process.
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The apparatus and method also provide a process for fabricating
elongate and curved three-dimensional bodies using means that are simple in
terms of manufacturing, handling, and quick set-up time, so that elongate
curved
bodies' costs of manufacturing can be largely reduced.
Furthermore, the apparatus and method provide a continuous
method of fabrication of partially curved hollow profiles, such as elbows or
fully
closed profiles such as window-like frames, made inline with an extrusion
process.
The apparatus and method also provide a simple process for
producing elongate bulky bodies having concave, convex and twisted portions by
winding a profile around a rotating deformable mold which virtual contour is
able
to vary both radially and angularly.
The apparatus and method provide shapers that maintain the
profile cross-sectional dimensions constant but allow only for longitudinal
dimensions to vary.
The apparatus and method also provide a simple process for
creating three-dimensional bodies by interlocking and bonding abutting edges
of
shaped profile coils, side-by-side.
Profile materials to be shaped by the bending apparatus include
extrudable materials such as thermoplastic polymers, organic minerals and
exceptionally thin-wall metal profiles.
The bending apparatus is provided with a central rotating hub that
cooperates with multiple linear guides that are radially-oriented vis-a-vis
the hub
center and angularly movable in relation to each other or relative to a
reference
point. Each linear guide supports a positionable shaper. Positioning of
shapers
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along linear guides and angular movement of linear guides around the hub are
provided by drive means such controlled by a computer. The apparatus is also
provided with a hardening means and a profile carrier.
The radially and angularly positionable shapers around the rotating
hub define collectively a rotating deformable mold. The number of linear
guides
in a deformable mold is determined by the number of curves present in the
product to be created by the apparatus.
While being drawn by the rotating deformable mold, a not-yet-
hardened profile is submitted to a gradual hardening process, such as cooling,
heating or a chemical treatment depending on the nature of the extruded
profile.
In operation, a profile portion passes from a partially-shaped and partially-
hardened stage to a fully-shaped and fully-hardened stage.
The process of drawing, shaping, hardening and releasing a profile
portion, is repeated portion-after-portion in a continuous manner. As shaped
and
hardened profile portions are formed, they are slightly shifted sideways, like
helicals, so that they can leave the mold and stack side-by-side over a
profile
carrier.
After a 5D model of a desired product is created using a CAD
program, a slicing software is used to slice the 5D model into layers
distanced
from each other by a-product-width. The slicing software provides a dataset of
the product inner and outer dimensions, layer by layer. A second software
subdivides said dimensions into curves of various radiuses and straight lines.
These curves and lines are then translated into drive signals to position the
shapers in corresponding locations around the hub.
In the preferred embodiment of the invention, shapers are made of
roller-like forms or triangular-like forms placed around the hub. These are
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machine cut or molded to dimensions to best replicate the product curves while
maintaining constant the profile outer cross-sectional dimensions during
bending.
In another embodiment of the invention, shapers are made of roller-
like or triangular-like supports that in turn support an endless flexible
conveyor-
like series of calibrated plates provided with cavities corresponding to some
of
the cross-sectional dimensions of the profile. Collectively, the rotating hub,
guides, shapers, extendable elements and series of plates form a rotating
deformable mold.
Depending on the size and final shape of the object or body to be
created, the axis of the deformable mold may be oriented vertically,
horizontally
or obliquely at a desired angle.
The invention has been described with reference to several
preferred embodiments. Obviously, modifications and alterations will occur to
others upon reading and understanding the preceding detailed description. It
is
intended that the invention be construed as including all such modifications
and
alterations insofar as they come within the scope of the appended claims or
the
equivalents thereof.
BRIEF DESCRIPTION OF DRAWINGS
The apparatus may take form in various components and
arrangements of components; and the method may apply various steps and
arrangements of steps. The drawings are only for purposes of illustrating
preferred embodiments of the method and apparatus and are not to be construed
as limiting the same. The below detailed description of the preferred
embodiments is in conjunction with appended drawings, wherein like reference
numerals refer to like elements in figures, and wherein-
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FIG. 1 is a perspective view of the preferred embodiment of an
inline bending apparatus showing a deformable mold created by moveable rollers
mounted on radial linear guides cooperating with to a central rotating hub.
FIG. 2 is a close-up perspective front view of FIG. 1 illustrated from
another angle showing a profile being shaped around its periphery.
FIG. 3 is a front view of a deformable mold of the bending
apparatus of FIG. 1 showing in dotted lines trajectories of a single convex
shaper, of a concave shaper and of a hardened profile portion.
FIG. 4 is a front view of a deformable mold of the bending
apparatus provided with an endless shaper supported by triangular supports.
FIG. 5 is a front view of another deformable mold of the bending
apparatus showing multiple roller-like supports holding an endless conveyor-
like
shaper.
FIG. 6 is a perspective side-view of the preferred embodiment of
FIG. 1 with linear actuators for moving angularly shapers around the central
hub.
FIG. 7 is a perspective view of a linear guide a shaper moveable by
a linear belt drive and an angular drive means.
FIG. 8 is a perspective view of a three-dimensional twisted body
produced by the bending apparatus of the invention.
FIG. 9 is a side view of a prior art bending apparatus for fabricating
variable-size coils made of profiles.
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FIG. 10 is a perspective close-up view of multiple components of an
endless shaper of the deformable mold of FIG. 5.
FIG. 11 is a close-up perspective view of a triangular-like shaper
mountable on the bending apparatus of FIG. 1
FIG. 12 is a front view of a prior art bending apparatus provided
with a short series of calibrated plates sliding over a rotating mold.
FIG. 13 is a perspective view of a profile portion being shaped by
an endless rubber shaper that is supported by a roller-like shaper support
mounted to a deformable mold.
FIG. 14 is a perspective view of a series of embossed plates.
DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings wherein the showings are for purposes of
illustrating the preferred embodiments of the apparatus and method only and
not
for purposes of limiting the same, the figures show a bending apparatus having
five linear guides which should not be read as a limitation in numbers of
guides,
but as an example.
Protecting walls of a hollow profile from collapsing during a
continuous bending and shaping process is a challenge of the plastic industry.
In
addition to this challenge, comes the need to manufacture on a continuous
basis
bended and shaped products inline with an extrusion process, so that the
latent
heat of the extrusion process can be used more efficiently. Still another
challenge
is to bend and shape profiles of complex cross-sectional dimensions and do so
in
a cost-effective and timely manner.
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Going beyond the needs of the plastic industry, the present
application discloses principles that cover not only the bending and shaping
of
thermoplastics and polymers but also other extrudable materials such as
composites and organic compounds such as clay, mineral pastes, resins and
concrete-based materials. Roll formed thin-wall metal and alloy profiles may
also
be shaped by the apparatus and method of the present invention.
The amount of time and methods used to solidify an extrudate may
vary. While thermoplastic materials need relatively short cooling time to
solidify,
some clay-based compounds require longer time for drying and curing, while
other materials require heating, UV light, rapid Induction-hardening
techniques
and yet others such as certain cements have rapid setting time. In all cases,
to
apply the teachings of the present invention a rapid method of solidification
is
required. In the current application, the term conditioning is used to refer
to
cooling, heating, drying or chemical treatment of materials.
Exceptionally, hollow, thin-walled extruded or roll-formed metal
profiles that otherwise collapse when bended continuously without filler means
may also be shaped by the bending apparatus 10 of the present invention;
metals are known to retain their shapes after they are formed, therefore no
further treatment may be needed.
The key shape generating principle underlying the operation of the
bending apparatus 10 is best illustrated in FIGS. 2 and 3. A freshly extruded,
not-yet-hardened profile portion 100 is first longitudinally drawn around
multiple
shapers 200 rotating around a central hub 50; as profile portion 100 is being
re-
shaped into a fully shaped profile portion 104, it is also hardened resulting
into a
fully hardened profile portion 104 that can be carried away without affecting
its
newly acquired shape. The last shaper 200 that accompanied and shaped that
hardened profile portion 104 is retracted to release it from that last shaper
200 so
that it can, from one hand, be carried away by profile carrier 500, and from
the
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other hand, be relocated into a new or an old position around hub 50, ready to
shape the next incoming profile portion 100. This process is repeated portion-
after-portion, creating coils of shaped profile portions 104 that when bonded
side-
by-side form together a three-dimensional body as complex as one shown in
FIG. 8.
FIG. 1 shows the general layout of the preferred embodiment of the
bending apparatus 10 comprising a central hub 50 that is entrained by an axle
450 which is rotated by a drive means 400. The hub 50 cooperating with
multiple
linear guides 210, each guide supporting a shaper such as a shaper 200 that
slides along linear guide 210 when moved by a drive means 800. Linear guides
210 are radially-oriented in relation to hub axle 450 and are angularly
movable by
drive means 900 relative to each other or relative to a reference point.
Collectively, rotating hub 50, shapers 200, linear guides 210 and
their drive means 800 and 900 define a deformable mold 110. In addition, the
bending apparatus is provided with a hardening means 700 and a profile carrier
500 that rotates with hub 50 and is configured to receive and transfer shaped
and
hardened profile portion 104, portion-after-portion to an exterior
cantilevered
profile carrier (not shown). Drive means 800 and 900 may include a stepper
motor, a servomotor, linear motor or a linear actuator.
An extruded profile 100 exiting from an extruder die 3000 may be
drawn by said rotating deformable mold 110 from above the rotating hub 50 as
shown in FIGS. 4 and 5 or from below hub 50 as shown in FIGS. 2, 3 and 6 or on
the side of hub 50 (not shown).
Optionally, deformable mold 110 may be rotated around a
horizontally-oriented hub axle 450 as shown in FIGS. 1, 2, 3, 4 and 5, around
an
obliquely-oriented axle 450 (not shown) or a vertically-oriented hub axle 450
(not
shown). The orientation of hub axle 450 depends on the size, shape and the
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material of the product or of the three-dimensional bodies to be produced. For
example producing very large batches of coil-shaped profile strands 104 or
long
three-dimensional bodies 120 (Fig. 8), it is preferable to shape the product
around a horizontally-oriented hub axle 450 wherein the long product can be
gradually loaded sideways on an outside cantilevered carrier (not shown). For
very wide bodies of short length, it is preferable to use a deformable mold
110
that rotates in a horizontal plane or an oblique plane with a corresponding
vertical
or oblique hub axle 450.
The number of linear guides 210 cooperating with hub 50 may be
as high as required, but no less than two. This minimum number is required so
that at least one of the two shapers 200 can retract while the other holds a
portion of profile 100 being shaped. However, there is no limitation on the
maximum number of linear guides 210 cooperating with hub 50. As long as all
linear guides 210 are radially-oriented towards hub axle 450 and as long as
the
product to be shaped is large enough to accommodate many linear guides 210
around hub 50, no higher limitation exists besides costs, space and
practicality.
In fact, the higher the number of linear guides, the more convex- and concave-
shaped curves may be imparted to an incoming profile 100.
For smaller products, the need to fit multiple convex shapers 200
around hub 50, all inside the product contour limits the number of linear
guides
210 that may be mounted in a bending apparatus 10.
The bending apparatus 10 is also provided with multiple sensor
means as shown in FIG. 1. First, sensor means 500 are mounted to detect when
a portion of deformable mold 110 must retract so that a shaped and hardened
profile portion 104 may be released from deformable mold 110 and then return
to
a desired position; second, sensor means 550 are provided to read distance to
the contour of a shaped profile 104 and to generate a contour pattern dataset
that may be compared to a dataset of a desired CAD model in order to prompt
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linear drivers 800 and angular drivers 900 to reposition shapers in a more
suitable position to minimize differences between the two datasets. Distance
sensor 550 cooperates with an encoder (not shown) on axle 450 to signal
angular position of hub 50 in relation to distance sensor 550. A third pair of
sensors 580 such as optical sensors is also provided for moving hub 50 to
reduce angular deviations of profile 100 in relation to deformable mold 110
which
has a variable outer contour. For a deformable mold 110 rotating around a
horizontal hub axle 450, hub 50 moves up and down, whereas for a vertical axle
450, hub 50 moves sideways. The hardening means 700 is provided with its own
temperature sensors (not shown).
It should be noted that at every rotation of hub 50, a controller 980
such as a PLC, a CPU or a computer resets the position of each shaper 200
after
it was retracted by drive means 800 to release a hardened profile portion 104,
thus redefining whether a shaper 200 shall reposition itself in a same
position as
in the former cycle and therefore replicate a former mold shape or shall move
into a new position, defining a new mold shape. By repeating this process,
rotation after rotation, or in other words, layer after layer, and by bonding
adjoining layers together a three-dimensional body such as body 120 shown in
FIG. 8 will emerge.
In another embodiment of the invention, bending apparatus 10 is
provided with a distance laser 550 (see FIG. 1) that works in cooperation with
an
encoder (not shown) to collect data on the contour of a product produced in
real-
time by the bending apparatus 10. This data is compared to the desired shape
of
the CAD model originally used as a base to generate signals for positioning
shapers 200 around deformable mold 110. The difference of data obtained
between the two measurements determines the amount of electrical input
required to move shapers 200 in the right position. The bending apparatus 10
is
also provided with a laser protractor 570 to visually verify or calibrate
manually
the position of linear guides 210.
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The sequential operation of shaping, hardening and releasing a
shaped profile portion creates continuous spirally-formed products. The range
of
products produced in this manner may range from profiled elbows, closed frames
to three-dimensionally shaped bodies when newly shaped profile portions are
bonded side-by-side to former profile coils.
In the preferred embodiment, roller-like shapers are given numeral
200. For sake of simplicity, numeral 200 is also used to represent other forms
of
shapers 200 being attached to deformable mold 110 unless specified otherwise.
The ability for shapers 200 in a deformable mold 110 to retract at
the right time enables a shaped profile portion 104 to be released without
affecting the shaping process. FIG. 3 illustrates trajectories of both a
conventional convex shaper 200 such as a roller-like shaper 200 versus a
hardened profile portion 104. As shown, while a convex shaper 200 follows a
partially-circular and a partially-truncated trajectory forming collectively
trajectory
12, a shaped profile portion 104 follows a fully circular trajectory 14. The
truncated portion of trajectory 12 corresponds to a virtual retracted zone
created
between two sensors 300 that are positioned around hub 50. In other words, any
drive means 800 of any linear guide 210 that enters that virtual retracted
zone by
crossing sensors 300 will be prompted to retract its shaper 200 and move
closer
to hub axle 450 and then that shaper 200 is moved to reposition itself in a
position defined by controller 980 so as to be ready for the next shaping
operation.
Referring again to FIG. 3, the trajectory of a concave shaper 320 is
configured to be different than trajectory of a convex shaper 200. For a
concave
shaper 320, two optional trajectories 16 and 18 may be provided. In the
preferred trajectory 16, concave roller 320 is driven to move in and out
linearly
along a radially-oriented linear guide 310 vis-a-vis hub axle 450. In this
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arrangement, linear guide 310 is provided with an angularly fixed position in
relation to the bending apparatus frame 600.
Optionally, concave roller 320 may also follow an oval-shape
trajectory 18. In both cases, linear guide 310 is provided with a linear drive
means 800 to move it radially vis-a-vis hub axle 450 and optionally an angular
drive means 900 to move it angularly vis-a-vis hub axle 450.
As shown in FIG. 2, while linear guide 310 of a concave shaper and
linear guides 210 of convex shapers are located in different planes, their
respective shapers 320 and 200 move in a same plane. This implies that the arm
that holds concave shaper 320 must avoid interference between movements of
shapers 200 and 320 and between linear guides 210 and 310, therefore an
arrangement such as such an external U-shape arm 350 is provided.
All embodiments of the bending apparatus 10 are provided with a
profile carrier 500 such as shown in FIG. 1. Profile carrier 500 is provided
with
multiple radially-oriented carrier arms 510, each attached directly to a
linear
guide 210 via a carrier bottom support 520. While a carrier bottom support 520
is
attached at a position lower than the retracted position of its associated
shaper
200, its carrier arm 510 is located to receive a freshly hardened profile
portion
104 at its highest point before being released.
In all embodiments of the invention, a carrier arm 510 is positioned
next to a convex shaper 200 so that as soon as a shaped profile portion 104 is
formed and released from a shaper 200 it may be freely shifted sideways to
slide
over carrier arm 510 and be carried away by it. As hub 50 continues to rotate,
profile 100 continues to be drawn around deformable mold 110 and the process
continues to deliver over carrier arms 510, portion-after-portion, continuous
strands of coil-shaped profile.
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Carrier 500 may also be provided with a slightly different mounting
arrangement (not shown). In such an arrangement, all carrier arm supports 520
are supported directly by hub axle 450 and perform the same function as in the
preferred embodiment shown in FIG. 1. However, this arrangement works well
when linear guides 210 do not move angularly in relation to each other and
require that arm supports 520 be readjusted angularly. This limits the
creation of
three-dimensional bodies that have twisted portions such as body 120 shown in
FIG. 8.
In another embodiment of the bending apparatus 10 as shown in
FIGS. 4 and 5 an endless flexible shaper 1000 is provided. FIG. 10 shows more
closely how the endless shaper 1000 is provided with two types of plates, some
external plates 1010 and some internal plates 1500 and filler means 1600.
Endless shaper 1000 is comprised of a series of sequential adjacent calibrated
plates 1010 configured as an endless conveyor-like flexible mold 1000, with
adjacent plates 1010 collectively forming an endless flexible conduit 1000;
calibrated plates 1010 are flexibly attached on said plates' same edges with
each
plate 1010 calibrated so that each plate has a cavity with similar cross-
sectional
outer dimensions as said profile 100 but configured so that fully shaped
profile
portion 104 may be released from deformable mold 1000 once a profile portion
104 is fully shaped. However, contrary to conveyors that move longitudinally,
endless shaper 1000 is stationary in relation to roller-like supports 250 or
in
relation to triangular-like supports 270 shown respectively in FIGS. 4 and 5.
As shown in FIG. 14, preferably all calibrated plates are embossed
whether they are internal plates (not shown) similar to plates 1500 or similar
to
external plates 1010 to reduce friction and improve flow of profile 100,
namely
when internal plates (not shown) slide inside the profile hollow space.
As shown again in FIGS. 4 and 5, endless shaper 1000 while
supporting and shaping longitudinally profile 100 in the confine of its cavity
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imparts to profile 100 a generally convex shape and optionally a concave
shape.
However, the radiuses of the curves imparted by roller-like supports 250 and
triangular-like supports 270 are slightly bigger than their own, this being
caused
by the added height of the base of calibrated plates 1010 of endless shaper
1000.
To enable a not-yet-hardened extruded hollow profile 100 to
withstand external bending forces without having its walls to collapse or its
cross-
sectional dimensions to substantially vary, the bending apparatus 10 is
further
provided with a profile filler means 1500 or 1600. Filler means 1500 is
comprised
of a tethered series of sequential plates 1500 or a tethered long continuous
flexible filler 1600 having similar cross-sectional dimensions as that of said
profile
internal dimensions. The number of tethered filler means 1500 or 1600
required for shaping a hollow profile 100 depends on the number of cores that
a
hollow profile 100 has. All tethered filler means 1500 or 1600 one end being
attached to die 3000.
As taught earlier, filler means 1500 and 1600 play an essential role
in the shaping of hollow and semi-hollow profiles 100. FIG. 10 shows how an
internal shaper 1500 and/or 1600 may fill the empty space inside a hollow or a
semi-hollow profile 100 during shaping. Internal shaper 1500 or 1600 is
selected
from the group of tethered fillers having one end attached to a profile
extruder die
face 3000 and other end attached to floating mandrels 1500 flexibly held
together
at a fixed distance from said extruder die 3000. Such floating mandrels or
plates
1500 or 1600 are configured to maintain constant internal cross-sectional
dimensions of profile 100 during shaping but allow only longitudinal
variations to
take place.
Shapers 200 and 320 are configured to be removably attachable to
sliders positionable on respective linear guides 210 and 310 of deformable
mold
110. Shapers 200 and 320 are optionally lathed, machine cut, molded or
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stamped so as to replicate the desired deformable mold shape around which a
final product will be shaped.
Generally, shapers 200 and 320 are divided into two groups of
shapers: external shapers 200 that come externally in contact with a profile
contour and internal shapers 1500 or 1600.
External shapers 200 also referred as convex shapers 200 are
again sub-divided into two sub-groups of shapers. In the preferred embodiment
of the invention shown in FIGS. 1, 2 and 3 the bending apparatus 10 is
provided
with roller-like convex shapers 200 and triangular-like convex shapers 260
(FIG.
11) that come in direct contact with profile 100 and shape it longitudinally
by
pressing on profile 100 outwardly away from hub axle 450.
As shown in FIG. 4, triangular-like shaper supports 270 attached to
linear guides 210 are connected to each other via spring means 850 or flexibly
attached via a rubber silicon band (not shown). Similarly calibrated plates
1010
forming collectively endless shaper 1000 are connected by spring means such as
interior springs 920 as shown in FIG. 10 or flexibly held together by a
silicon
rubber band stretched over its periphery (not shown).
In another embodiment of the invention, the bending apparatus 10
is provided with convex shapers that are configured as shaped supports for
convex shapers such as roller-like convex supports 250 as shown in FIG. 5, and
triangular-like convex supports 270 as shown in FIG. 4.
Alternatively, ss shown in FIG. 13, a roller-like convex shaper
supports 250 or a triangular-like convex shaper supports 270 is configured to
support an extruded endless shaper 1300 made of a rubber profile stretched
around the periphery of a deformable mold 110; said endless shaper 1300
having similar external cross-sectional dimensions as said profile 100 but
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configured for longitudinal shaping a profile portion 100 and for releasing a
shaped and hardened profile 104.
In all embodiments of the invention, shapers may also provide
concave shapes to profile 100 such as shown in FIGS. 1, 2, 3 and 4 which
illustrate a roller-like concave shaper 320 that moves along a radially-
oriented
concave linear guide 310 that is, preferably, angularly fixed vis-a-vis hub
axle
450. A concave shaper may also take a triangular-like or an oval-like shape
such
as triangular concave shaper 350 shown in FIG. 5 that presses on a partially-
shaped profile portion 102 towards hub axle 450 to impart its shape.
FIG. 10 shows in more detail how three types of shapers such as
endless shapers 1000, roller-like supports 250 and internal tethered shapers
1500 and 1600 cooperate together to keep profile 100 cross-sectional
dimensions constant while allowing only for longitudinal dimensions to vary.
FIG. 9 shows a prior art from my US Patent Application
20090102090 wherein the bending apparatus 10' has a rotating mold that
deforms only radially a profile 100' into a shaped profile 104'. In this prior
art,
deformable mold does deform both radially, angularly or asymmetrically as
taught in the present invention.
FIG. 12 shows another embodiment of my prior art from US Patent
Application 20090102090 wherein mold 200' supporting a short-length series of
external calibrated plates 1010' for maintaining constant the outside cross-
sectional dimensions of a incoming profile 100'. A profile 100' must slide
over
said plates 1010' and overcome resistance during shaping whereas in the
present invention plates 1010 accompany a profile 100 during shaping without
resisting flow.
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By repositioning a shaper 200, 250, 260 or 270 to a new
designated position slightly different than positioned in the previous cycle,
the
bending apparatus 10 is able to generate at every rotation of hub 50 coils of
shaped profile portion 104 that vary slightly in size. When these coils are
interlocked and bonded together, three-dimensional objects are created with a
surface or skin made of profile shaped portions 104.
This coiling process may be compared to a layering or laminating
process wherein adjacent strands are bonded next to each other to collectively
form a three-dimensional body. Inversely, slicing a hollow three-dimensional
object into layers one-profile-width apart provides the necessary data to
replicate
the shape of a product 120. Applying this principle to the present invention,
the
bending apparatus 10 is provided with a computer program that first takes a
desired CAD model of an object, slice it into an array of 2D contour plots,
analyzes each 2D contour plots to derive radius curves, distances to the
center
of these curves from a central point such the center of a hub, and angles
between said curves relative to said center point. Then a database of said
curves, said distances and said angles is communicated to drives 800 and 900
for positioning shapers 200 around hub 50, on layer at a time. Said center
point
may be preferably be, but not limited to, the center gravity of said profile
100 2D
contour.
FIG. 6 shows an arrangement of different drive means for operating
the bending apparatus 10 of the present invention. Hub 50 is driven by a hub
drive means 400 such as a constant torque motor 400. Radial positioning of
convex shapers 200, 250, 260 and 270 along a linear guide 210 or positioning
of
a concave shapers 320 and 350 along a linear guide 310 is provided by linear
drive means 800. Angular movement of linear guides 210 and 310 is provided by
angular drive means 900. As shown in FIGS. 1, 2, 3, 4 and 5 each angular drive
means 900 is associated to a pinion 970 that either locks into large gears 650
fastened to each linear guide 210 to rotate said linear guides 210 around hub
50
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or meshes together with said large gears 650 to rotate and move angularly
linear
guides 210 around hub 50.
FIG. 6 shows a similar relative movement being achieved among
linear guides 210 using actuators 990 positioned on a turntable rotating with
hub
50. Angular drive means 900 may be selected from the group consisting of
stepper motors, servomotors, pneumatic drive, hydraulic drive, belt-driven
actuators, linear stepper drives, pneumatic actuators, linear actuators,
linear
motors and a combination thereof.
FIGS. 1 and 2 show a drive means 980 such as an elevator drive
means for moving hub 50 up and down to reduce angular deviations between a
freshly not-yet-hardened profile 100 exiting from an extrusion die 3000 and
the
periphery of a deformable mold 110; up-and-down movement of the elevator
drive means 980 is activated by control signals generated by an upper optical
sensor 992 and a lower optical sensor 994 both positionable on the bending
apparatus frame 600 in close position to extruder die 3000. For a deformable
mold 110 provided with a vertical hub axle 450, drive means 980 moves hub 50
sideways.
In operation, as shown in FIGS. 1 and 2, hub 50 is rotated by drive
means 400 which entrains a cylindrical support 52 that in turn supports
angular
drive means 900 and associated pinions 970.
As shown in FIG. 3, a not-yet-hardened profile 100 travels through
four cooperating shaping zones 22, 24, 26 and 28 before being carried away.
For sake of illustration, only a convex shaper 200 is represented in this
drawing.
Trajectory of shaper 200 represents the same trajectory as all other shapers
250,
260, 270 and 1000.
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In a first reception zone 22, the not-yet-hardened profile 100 drawn
tangentially around periphery of the rotating deformable mold 110 is compelled
to
accompany the first convex shaper 200 it encounters at that time, closest to
extruder die 3000. As this first shaper 200 continues to rotate around hub 50
and
draws more profile portion 100 over a second shaper 200, profile portion 100
starts to adopt the longitudinal shape of the two shapers and some of their
curves. While profile 100 is being partially shaped, it is also submitted to a
gradual hardening process.
As deformable mold 110 continues to rotate around hub 50, the
partially-shaped and partially-hardened profile portion 102 is drawn into a
second
shaping and hardening zone 24 wherein both the shaping process and the
hardening process are finalized. The newly and fully shaped profile portion
104 is
hardened to reach a non-changeable solid state. Depending on the profile
material, hardening is achieved by either cooling or chilling, by heating
including
but not limited to induction or laser, or by optical beams such as UV light or
by
chemical treatment such as exposure to chemical hardeners.
As the shaped and hardened profile portion 104 is further rotated
around hub 50, it enters a third zone referred to as virtual retraction zone
26
wherein shaper-after-shaper, each shaper 200 of deformable mold 110 is
prompted first to retract and disengage from a newly shaped and hardened
profile portion 104 and second to reposition again itself around hub 50.
Retraction and repositioning is activated by sensors 300 at any time a linear
guide enters the retraction zone 26, which in turn activate drive means 800 to
first move inwardly and then outwardly shaper 200 along linear guide 210
towards hub axle 450; each linear guide 210 is driven by their own drive means
800. This retrieval and repositioning is comparable to the movement of a cam
follower that moves inwardly and outwardly when entering a truncated section
of
the cam.
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Finally, as deformable mold 110 continues to rotate around hub 50,
the released shaped and hardened profile portion 104 enters a fourth
transition
zone 28 wherein the released profile portion 104 is shifted slightly sideways
so
as to exit deformable mold 110 by taking on a helical trajectory that lands a
hardened profile portion 104 over a profile carrier arm 510. Loading portion-
after-
portion of hardened profile portion 104 accumulates into finished products
that
are carried away.
The effect of a slight deviation introduced for allowing shaped
profile portions 104 to exit helically is virtually negligible when the ratio
of a
shaped profile length to its width is large enough as is often the case for
most
elongate profiles extruded because of the importance of this length-to-width
ratio.
This value of this deviation is in the order of one-profile-width to a profile
one-
loop length.
The method and apparatus has been described with reference to
several preferred embodiments. Modifications and alterations will occur to
others
upon reading and understanding the preceding detailed description. It is
intended
that the present application of the method and apparatus be construed as
including all such modifications and alterations insofar as they come within
the
scope of the appended claims or the equivalents thereof.
