Note: Descriptions are shown in the official language in which they were submitted.
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ASSEMBLY AND PROCESS FOR CREATING AN EXTRUDED
MARINE DOCK BUMPER
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This Application is a Continuation-in-Part of Application Serial No.
14/817,278,
filed August 4, 2015, which is in turn a Continuation-in-part of Application
13/726,771 filed on
December 26, 2012. Application 13/726,771 claims the benefit of U.S.
Provisional Application
61/586,464 filed on January 13, 2012, the contents of which are incorporated
herein in their
entirety.
FIELD OF THE INVENTION
[0002] The present invention discloses both an assembly and process for
sequential two
stage extrusion of an elongated marine dock from a plasticized material, such
as including but
not limited to cxtruding a first generally "L" shaped bracket from a first
more rigid
thermoplastic, such as including but not limited to HDPE (high density
polyethylene), following
which a cross head die arrangement is utilized in order to extrude a secondary
arcuate (typically
parabolic shaped) and flexible material, such as a TPE or other flexible
elastomer, in extending
fashion from a lower side of the "L" bracket. The secondary/flexible elastomer
is extruded in an
open flexed position relative to the first extruded bracket, and further such
that, following
completion and mounting to an edge of a dock structure, can be flexed into a
closed engagement
with an upper perpendicularly extending side of the bracket in order to
establish an impact force
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absorbing and deflecting construction, such as in response to contact from a
marine craft or the
like.
BACKGROUND OF THE RELEVANT ART
[0003] The
prior art is documented examples of dock or marine craft mounted bumpers,
these utilizing some version of force absorption and/or illumination. Notable
among these is the
light altering bumper device of Taylor 2015/0152616, this including an
illuminating dock
bumper for attachment to a dock and exhibiting an elongate, body with a main
attachment
bracket portion and a secondary parabolic arch shaped portion.
[0004] US
8,567,333, to Berman, teaches a protective boat rub rail system for a vessel
and
including a rigid track extrusion attached to the vessel, as well as a
flexible fender extrusion and
a shock absorbing inner core. The inner core is disposed in the fender
extrusion and the core is
substantially softer than the fender extrusion. The fender extrusion is
configured to matingly
engage the track extrusion. The fender extrusion has an upper barb engaging an
upper receiving
cavity of the track extrusion and a lower barb engaging a lower receiving
cavity of the track
extrusion. The track extrusion has an upper tang engaging an upper recess of
the fender
extrusion and a lower tang engaging a lower recess of the fender extrusion.
The track extrusion
also includes an upper lip configured to engage a top portion of the perimeter
of the vessel and a
lower lip configured to engage a lower portion of the perimeter of the vessel.
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SUMMARY OF THE INVENTION
[0005] The present invention discloses a two stage extrusion process for
creating an
elongated marine dock from a plasticized material, such as including but not
limited to a first
generally "L" shaped bracket from a first more rigid thermoplastic, such as
which can include
but is not limited to a HDPE (high density polyethylene), following which a
cross head die
arrangement is utilized in order to extrude a secondary arcuate and flexible
material, such as a
TPE or other flexible elastomer, in extending fashion from a lower side of the
"L" bracket. The
"L" shaped bracket is initially shaped and cooled in the first stage extrusion
process, following
which it enters the cross head die at which the secondary/flexible and
parabolic shaped elastomer
portion is extruded in an open flexed position relative to the lower adjoining
side of the first
stage extruded bracket.
[0006] Upon completion, the secondary elastomer portion can be flexed into
a closed
engagement with a pre-extruded feature associated with an upper
perpendicularly extending side
of the bracket. A forward facing surface of the lower bracket side can further
be extruded with
additional features in order allow post-securement of such items a LED
lighting or the like.
[0007] Other steps include linearly drawing and any of spray, immersion or
other types of
cooling of the dual stage dock bumper, as well as sectioning and stacking the
bumper sections.
Each of guide shape retention, cold-water spray or immersion hardening, and
cutting steps are
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provided for creating a plurality of individual sections which are on site
assembleable, such as in
end-to-end fashion along a perpendicularly angled dock edge.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Reference will now be made to the attached drawings, when read in
combination
with the following detailed description, wherein like reference numerals refer
to like parts
throughout the several views, and in which:
[0009] Fig. 1 is plan schematic of the overall assembly and process
according to the present
invention;
[0010] Fig. 2 is a perspective illustration of the first stage extruder for
forming the "L"
shaped bracket;
[0011] Fig. 3 is an illustration of a vacuum chamber through which the
bracket passes after
exiting the first extruder, an arrangement of upper and lower rollers
communicating with the
bracket at an outlet of the vacuum chamber for imparting a cross sectional
profile, such in order
to compensate for heat induced deformation of the bracket during the
subsequent crosshead die
operation for extrusion forming the parabolic shaped softer second stage
elastomeric material in
engagement with bracket;
[0012] Fig. 4 is an illustration of an interior of the vacuum chamber of
Fig. 3 and which
depicts a plurality of progressing sizing dies for maintaining the first stage
extruded bracket in its
proper shape during cooling thereof;
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[0013] Fig. 5 is a succeeding secondary cooling tank operation for further
cooling the first
stage bracket utilizing a water spray;
[0014] Fig. 6 is a first overhead perspective illustration of a cross head
die operation
following the second cooling tank, the cross head die including a pair of
spaced and elongated
mandrels between which traverses the first stage bracket to facilitate the
second stage extrusion
forming of the elastomeric and parabolic shaped portion;
[0015] Fig. 7 is a rotated perspective of Fig. 6 and illustrating a
plurality of cooling lines
communicating to the cross head die and interior passageways formed into each
of the elongated
lobe forming mandrels for temperature control during the forming and attaching
of the second
stage parabolic shaped elastomeric portion;
[0016] Fig. 8 is a back side perspective of the cross head die and stand
and illustrating the
arrangement of the inlet feed of coextruded and flowable material to the
reverse side extending
mandrel, as well as the plurality of coolant lines extending from the
thermocouple controlled
sub-assemblies for controlling the temperature profiles of the mandrel;
[0017] Fig. 9 is a side-by-side perspective of the coolant supply units
also depicted in Fig. 8
and associated with the coolant lines and thermos-electric coupling devices
extending to the
parabolic shaped portion forming mandrel;
[0018] Fig. 10 is an end perspective of the parabolic shaped forming
mandrel extending
from the die head into the (spray or immersion) cooling and final shaping
tank;
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[0019] Fig. 11 is an elongated perspective view of the second stage die
forming mandrel for
extruding the elastomeric parabolic shaped portion onto the first stage "L"
bracket;
[0020] Fig. 12 is a further illustration of the cooling and shaping tank of
Fig 10 in
combination with the second stage forming mandrel of Fig. 11;
[0021] Fig. 13 is a downward looking perspective view of the cooling and
shaping tank of
Fig. 12 and further illustrating the pairs of spaced apart guiding spindles
for assisting in
transitioning the two stage extruded marine bumper from the parabolic shaped
portion forming
mandrel;
[0022] Fig. 14 is a puller assembly for assisting in drawing of the dual
stage extruded
marine bumper and which precedes a press for sectioning the finished pipe into
predetermined
lengths; and
[0023] Figs. 15 and 16 illustrate a pair of end plan views of a non-
limiting example of a
marine dock bumper produced according to the extrusion process of the present
invention, with
Fig. 15 depicting an initially extruded configuration with the second stage
parabolic shaped
elastomeric portion in an open arrayed configuration relative to the first
stage conjoined bracket,
Fig. 16 depicting the installation of an LED element to an extruded feature of
the lower side of
the first bracket, a latch end of the second stage elastomeric portion being
pivoted into
engagement with a further extruded feature associated with the top
interconnected side of the
bracket.
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] With reference to the following illustrations, the present invention
discloses a
sequential two stage extrusion assembly and process for creating such as a
polymeric type
marine bumper, see as generally shown at 10 in cross section in each of Figs.
15-16. The present
invention is again directed to the extrusion process for creating the bumper,
as opposed to the
physical article itself, the physical shaping and features of which can be
modified as a variable of
the extrusion die forming mandrels (as will be further described) for shaping
the first and second
stage extrusions collectively defined by the bumper 10.
[0025] As previously described, and in one non-limited application, the
bumper can be (but
is not limited to) being extruded from two different materials including a
first HDPE (high
density polyethylene) material employed for producing an "L" shaped mounting
bracket (such as
for securing to the angled edge of a dock). A second, more flexible or
elastomeric themloplastic
(TPE or like) material exhibits a parabolic or other arcuate shaped second
portion, with the first
stage extrusion potentially including both colored/painted and translucent
portions and the
second extrusion portion including any combination of clear and/or translucent
portions.
[0026] As shown in example of the article in Figs. 15-16, the first (harder
material) bracket
includes a lower side 12 and an upper interconnected side 14. As further
shown, the lower side
can include a contoured lower rounded end profile 16, the lower side further
including a pair of
spaced apart and tab-like features 18/20 on an outwardly facing surface
thereof. The upper
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interconnected side 14, typically at an "L" shaped angle relative to the lower
side 12, concludes
in a latch or angled rear edge 22.
100271 The second (softer material) elastomeric and parabolic/arcuate
extending portion 24
is second stage extrusion molded to the previously extruded and formed
bracket, at an
intermediate location 26 along the lower side 12 thereof. As will be better
understood with
reference to the succeeding description of the dual stage extrusion process of
the present
invention, the second stage parabolic shaped portion 24 is extruded in an open
position relative
to the first stage bracket (see again Fig. 15).
100281 The elastomeric portion 24 can include any irregular cross sectional
features, such
exhibiting a bulbous intermediate location 25, with a terminating length of
the elastomeric
portion, proximate an extending end 28 thereof, exhibiting a cavity or recess
configured
underside with opposing underside ledges 30 and 32, this for permitting the
arcuate portion 24 to
be flexed downwardly (arrow 33), and so that the extending rear edge 22 (along
with a further
adjoining edge 36 established between the upper 14 and lower 12 interconnected
sides of the first
stage extruded bracket), allows for closing the second stage parabolic portion
24 in the manner
depicted in Fig. 16. Also depicted is a clear lens or the like, at 38 which
can be associated with
the integration of lighting elements such as LED's or the like, mounted into a
three dimensional
extending track associated with the tab features 18/20 in the extruded first
stage bracket.
[0029] Without limitation, the bracket is mounted to an angled and
typically horizontally
extending support surface generally represented at 1 in Fig. 16 and which can
include a sea wall,
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dock or the like. Although not shown, the configuration of the marine bumper
extrusion can
further be such that other features not limited to electrical processors for
controlling the lighting
assemblies can be integrated into the construction of the extruded article.
[0030] Having provided an adequate description of one non-limiting example
of a marine
bumper article produced by the present extrusion process, and referring to
Fig. 1, an overall
schematic of the overall assembly and process is shown according to one non-
limiting
embodiment of the present inventions, these being further described in detail
with additional
reference to succeeding Figs. 2-14, as well as additional post extruding and
sectioning/routing
stations set forth in Figs. 12 and 13 respectively. A feed hopper assembly 40
contains a volume
of extrudate material (including but not limited to an HDPE material which can
be in pellet or
granulate form) and which is fed in a flowable form to in-fee hopper
associated with the first or
main extruder 42 via a feed line 44.
[0031] An extrusion die (also termed as any of a forming head or first
mandrel) is shown at
46 associated with the first extruder 42 (see also Fig. 2) and which is heated
and temperature
controlled as known in the art in order to extrude the interconnected sides
12/14 (as described in
Figs. 15-16) of the first "L" shaped bracket in a first extrusion operation,
the initial stage
extrusion of the tabbed locations 18/20 on the first side 12 for establishing
the track for receiving
the lighting track also being shown. As again shown in Fig. 2, a known
arrangement of heating
elements, thermo-electric coupling devices and other controls are provided in
order to extrude
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the first "L" bracket through a disk shaped template configured within the
forming head 46, such
exhibiting a desired wall thickness and dimensions.
[0032] A vacuum chamber 48, which is depicted as having a generally three
dimensional
and rectangular shape, is provided in communication with an outlet of the
first extruder 42 and
for receiving the first rigid extruded "L" bracket. As further shown in Fig.
4, the vacuum
chamber 48 includes a hinged lid 50 which, upon opening, reveals a plurality
of disk shaped
forming dies 52, 54, 56 arranged in linearly spaced fashion between inlet 58
and outlet 60 ends
of the chamber 48.
[0033] The vacuum chamber 48 operates create a desired negative pressure
within its
interior (see extending fixture 62 and air evacuation passageway 64 in Fig. 4)
this in order to
maintain the "L" bracket component 12/14 in its proper shape while it cools.
Located on an
exterior of the chamber 48, in intercepting proximity to its outlet 60, are
upper 66 and lower 68
and 70 spaced apart rollers, these further being rotatably supported upon a
vertical shelf or
bracket 72. The "L" bracket component 12/14, upon exiting the vacuum chamber
48, is
intercepted between the lower rollers 68/70 (such as shown in fixed rotational
support with the
shelf 72) and the upper roller 66 which is both rotatably and pivotally
supported a limited
distance to a further bracket 74, in turn having an end pivot location 76 and
an opposite (free
end) abutment location 78, see further upper adjustable end stop 80 extending
downwardly from
the uppermost end of the shelf 72.
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100341 The purpose of the upper 76 and lower 78/80 spaced rollers is to
flatten or reshape
the first "L" shaped bracket component at first 82 and second 84/86 cross
sectional locations as it
passes through the rollers (see directional arrow 88) and so that the
component acquires a
modified cross sectional profile 12'/14'. The purpose of employing the rollers
and of imparting
the offset/flattened shaping to the profile has been found through trial and
experimentation to
compensate for the existence of any deformation experienced by the "L" bracket
profile as it
passes through the subsequent second extrusion stage crosshead die in
proximity to the elongated
mandrel for forming the second stage extruded arcuate/parabolic portion 24.
For purposes of the
present description, the use of the rollers 82 and 84/86 is optional (see
again Fig. 4 which does
not include a roller arrangement supported at an exterior outlet of the vacuum
chamber 48) and it
is further understood that other mechanisms are envisioned according to one of
ordinary skill in
the art for purposes of introducing an offset to the elongated profile 12'114'
while it is still in a
heated and formable shape.
[0035] Following exiting of the vacuum chamber 48 and passing through the
shape offset
upper roller 66 and lower rollers 68/70, (see again directional arrow 88 in
Fig. 3), the now
deformed "L" bracket 12'/14' is fed through a cooling tank 90 (Fig. 5) for
further cooling the
first stage extruded "L" bracket utilizing a water spray. To this end, a
plurality of nozzles 92 are
arranged in inward opposing fashion along each of the opposite length
extending sides of the
cooling tank, with water (or other coolant fluid) being communicated through
lines (see at 94)
which supply the plurality of spray nozzles.
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[0036] As further shown in Fig. 5, the cooling station 90 (optional)
includes inlet 96 and
outlet 98 ends through which the angled bracket 12/14 passes. Additional
partitions 100 and 102
are defined at interior locations of the cooling station 90 and include
additional aligning
passageways (at 104 and 106, respectively) through which bracket 12'/14'
passes during cooling
and solidifying.
[0037] Referring again to Fig. 1, in combination with Figs. 6-9, a second
stage or co-
extruder station 108 is located downstream of the main extruder 42 and, in the
illustrated
embodiment, beyond the optional cooling tank 90. The second stage extruder 108
includes a
cross head die 110 supported in elevated fashion upon a stand 112 (again Fig.
1) and so as to be
arranged in horizontal alignment with the "L" bracket. A second extruded
material is fed from
the second stage extruder 108 (such again including a melted and flowable TPE
or other suitable
plastic exhibiting the necessary properties of flexibility and resiliency)
from a pipe or conduit
(see at 114) in Fig. 8 to the cross head die 110 and so that the extrudate
material flows through
an internal template (not shown) defined within the cross die head.
[0038] The second extruder also includes an elongated mandrel, generally at
116 in the
elongated perspective of Fig. 11 (such as which can be constructed of any
aluminum or other
suitable metal or like material) which extends from an outlet of the cross
head die 110 and between
which communicates the first stage extruded "L' bracket. As best shown in Fig.
11, mandrel 116
includes a plurality of laterally spaced apart and arcuatc profile forming
portions, beginning at 118,
120, 122, et seq. at an inception end proximate the cross head die 110, these
being more closely
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spaced together at the inception end and gradually expanding to more spaced
apart intervals,
further at 124, 126, 128, et seq., and such further corresponding to the
gradual solidification of the
second arcuate portion 24.
[0039] The individual profile defining forming portions 118, 120, 122, . .
. 124, 126, 128 are
spatially arranged via a pair of elongated stems 130 and 132. The stems can
also each include an
exteriorly threaded profile, see further at 130' and 132' in Fig. 11, these
receiving pairs of threaded
nuts 134, 136, 138, et. seq. which are located on both sides of each forming
portion 118, 120, 122,
et seq., the forming portions likewise being aperture for receiving the stems
130/132 in extending
fashion there through, with rotational to linear adjustability via the
opposite surface adhering pairs
of nuts in order to spatially inter-adjust the spatial positioning of the
individual forming portions as
desired based upon the parameters of the second stage extrusion process.
[0040] Each of the individual forming portions, see again as exemplary
shown at 118,
includes an arcuate forming surface thrther defined by each of a plurality of
individual and
interconnecting surface portions collectively defining the extruded profile of
the elastomeric
portion 24. These include a first surface portion 140 (defining the base
connecting portion of the
arcuate/parabolic elastomeric portion 24), a portion 142 (defining the
protuberant bump 25), a
further portion 144 (defining an intermediate adjoining range of the portion
24), an embossed or
raised portion 146 (defining the recessed underside cavity corresponding with
inner ledge edges
30/32 in Fig. 15) and, finally, a last portion 148 defining latch end 28 of
the arcuate portion.
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[0041] Although not clearly shown, the second extrudate material delivered
through the pipe
114 and such as which can again without limitation include any previously
melted or flowable
material which results in the arcuate second extruded portion 24 having the
necessary flexibility
and durability. This material is communicated to an interior of the die head
110, which is in turn
configured to communicate the material via an inner profile or template such
that it flows over and
around each of the succeeding profile defining portions 118, 120, 122, et
seq., over the course of
which the second arcuate/parabolic portion 24 is formed in a manner in which
its base end is
integrated into the intermediate location of the lower bracket side (again at
26 in Fig. 15) and its
extending end is originally extruded in free/open extending fashion as shown
by the article
configuration in Fig. 15 and the length looking perspective of Fig. 10.
[0042] The second extruder further includes independent temperature
controls for each of the
profile defining portions 118, 120, 122, et seq., associated with the
elongated mandrel 116, these
assisting in shaping the attachment interface between the arcuate/parabolic
portion 24 and the first
stage "L bracket 12/14. The independent temperature controls for the elongated
mandrel 116
further include pluralities of fluid lines, one non-limiting arrangement of
which is shown in Fig.
7 at 150, 152, 154, 156, 158 and 160, and for communicating a coolant to each
of the profile
defining portions of the mandrel 116, such as which can further be dictated by
separate thermo-
electric coupling devices in communication with the mandrel.
[0043] Figure 8 is a back side perspective of the cross head die 110 and
stand 112 and
illustrating the arrangement of the inlet feed of coextruded and flowable
material to the second
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stage arcuate portion defining mandrel 116, as well as the plurality of
coolant lines 150-160
extending from a pair of fluid generating sub-assemblies (see as represented
at 162 and 164
which may include internal pumps or the like for assisting in generating fluid
flow through the
mandrels) and for controlling the temperature profiles of the mandrels. The
coolant lines extend
to locations along the axial installed length of the mandrel 116, see at 150',
152', 154', et seq. in
Fig. 12, this in order to control the temperature of the mandrel 116 at each
forming location
during the second stage extrusion process for engaging the arcuate/parabolic
portion 24 to the
main first stage extruded "L" bracket, sides 12/14.
[0044] Also shown in Fig. 8 at 114 is a separate unit which may include any
type of
Thermalatore or thermo-electric coupling controls, these interfacing with the
pump controlled
upper 162 and lower 164 coolant subassemblies and associated valve structure
in communicating
with the fluid lines 150-160 in order to direct fluid through the interior of
the elongated second
stage forming mandrel 116.
[0045] In this manner, the surface temperatures of the mandrel 116 is
independently
controlled so as to assist in shaping and smoothing the inner wall of the
attachable
arcuate/parabolic shaped portion 24 of material as it is joined to lower side
12 of the previously
formed "L" bracket, at location 26. At this point, the hcat associated
previous cross sectional
offset or correction effectuated by the intercepting upper 66 and lower spaced
apart 68 and 70
rollers into the cross sectional profile of the pipe is further deformed by
the heat of the elongated
mandrel 116 in the second stage extrusion process, such resulting in the
creation of a two stage
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extruded marine bumper in which the inner single walled component reverts back
to a more
precise perpendicularly angled relationship established between the sides
12/14.
[0046] Although not clearly shown, it is also understood that the linear
dimensions of the
mandrel 116 can be tapered or otherwise modified, such including an inward
taper of 6% in one
non-limiting variant between the crosswise dimensions taken from the cross
head die 110 to the
extending ends of the mandrel (this as further defined by the exterior surface
dimensions
established by each of the succeeding and linearly spaced forming portions
118, 120, 122, et
seq.,. . . 124, 126, and 128.. The dimensioning of the second stage forming
mandrel 116 is
intended to counter the natural phenomena effects of the extrudate material
for creating the
arcuate portion 24 as it is fowled, conjoined and hardened to the extcrior
location 26 of the "L"
bracket lower side 12, and so that the resultant two stage extruded marine
bumper exhibits
consistent length and width dimensional profiles.
[0047] The mandrel 116 extends from cross head die 110 and into an interior
of a cooling
station 166. The cooling station 166 further includes a plurality of linearly
spaced apart pairs of
supporting spindles, these depicted in Fig. 13 at 168/170, 172/174, 176/178 et
seq., between which
traverses the two stage extruded marine bumper. The mandrel 116 extends
between at least the
first two pairs of spaced apart spindles 168/170 and 172/174 during the
progressive second stage
extrusion of the arcuate/parabolic portion 24 onto the first stage "L"
bracket.
[0048] Without limitation, the pairs of spindles can each exhibit a
modified spool shape, with
each including upper and lower arcuate or otherwise shaped surfaces separated
at an intermediate
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height by any type of ledge or profile shape for seating and translating the
"L" bracket 12/14 and
the co-extruded arcuate/parabolic portion 24. As such, the shaping of the
spindles is such that the
extruded profile of the portion 24 formed by the mandrel 116 rides between the
upper and lower
arcuate opposing surfaces of the pairs of spindles, with the cross sectional
separation between the
individually spaced forming portion 118, 120, 122, et seq. of the mandrel 116
and the previously
extruded first stage "L" bracket 12/14 seating between the likewise opposing
intermediate ledge of
each spindle.
[0049] The construction of the spindles, such including a metallic or any
suitable supporting
material, is also such that the spindles are capable of being inter-
displaceable in at least one of first
x 180 and second y 182 axes (see again Fig. 13) in response to contact with
the co-extruded
bumper as it is displaced there between. X axis displacement can be
effectuated by rotatably
supporting the spindles upon vertical mounting posts, these extending upwardly
from a base
interior surface of the cooling station 166 (likewise exhibited as an
elongated three dimensional
rectangular shaped structure with a generally open interior and having an
inlet end 184 and an
outlet end 186).
[0050] As further shown, a plurality of coil springs (see at 188, 190, 192
et seq.) equal in
number to each respective pair of guiding spindles is provided and each
includes opposite curled
ends which engage the upper ends of each pair of vertical spindle support
posts (see as depicted by
pairs of posts at 194, 196, 198, et seq. in Fig. 13). The posts can be
configured so that they are
allowed an incremental degree of lateral give or displacement (along axis x
180) in response to
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incidental contact between the extruded pipe and the spindles, thereby
allowing the spindles to flex
laterally against the biasing effect of the coil springs. As further clearly
shown, y axis 182
displacement of the spindles is further easily accomplished by their vertical
channel seating
interiors (not shown but through which the posts extend) allowing the spindles
to slide up and
down along the respective pairs of vertical posts.
[0051] The cooling station 166 further includes pluralities of nozzles, see
at 200 and 202
and which are supported on opposite interior extending sides of the station
166 via fluid supply
lines 204 and 206 (these in turn connected to remote coolant supply
reservoirs) for supplying a
spray coolant to the two stage extruded pipe as it translates through the
station 166. As with the
initial stage cooling station 90, spray coolant is collected at an interior
drain basin within the
station and recycled or drained as desired. Following exiting from the cooling
station 166, the
completed two stage extruded bumper is drawn through a puller 208 (Fig. 14)
for sectioning at a
subsequent operation 210 (also depicted by blade 212) in Fig. 12) for
subdividing the finished
bumper coextrusion into predetermined lengths.
[0052] An associated process for creating a two stage extruded marine or
dock bumper is
also provided and includes the steps of extruding a first "L" cross sectional
shaped and elongated
component, and sizing the first component within a chamber incorporating a
series of linearly
spaced sizing dies in order to maintain a shape of the first component during
cooling thereof.
Additional steps include extruding an arcuate/parabolic shaped elastomeric
portion 24, such as
from a second softer material, to an exterior surface of a lower
interconnecting side 12 of the first
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stage extruded bracket, so that the extending end 28 of the arcuate portion 24
does not initially
contact the edge profile 22 of the upper first bracket side 14. Other steps
include cooling the two
stage extruded bumper and sectioning into given lengths.
[0053] Other process steps drawn from the above assembly include inducing a
negative
pressure within the chamber, flattening first and second cross sectional
locations of the first stage
"L" bracket (if needed) prior to the step of extruding the arcuate/parabolic
shaped portion 24, and
cooling the first stage "L" bracket 12/14 prior to extruding the second stage
and flexible
arcuate/parabolic portion 24. Additional steps include independently
controlling a temperature
of each individual forming portion integrated within the elongated forming
mandrel, this forming
a portion of a crosshead die associated with the second stage extrusion, such
including the use of
coolant and thermos-electric coupling devices (or Thermalators0), and
transitioning the co-
extruded bumper from the elongated lobe forming mandrels to a plurality of
spaced apart pairs of
supporting spindles during traversing of the elongated coextruded article
through a second
chamber downstream from the crosshead die. Final process steps also include
cooling the two
stage extruded bumper.
[0054] Having described our invention, other and additional preferred
embodiments will
become apparent to those skilled in the art to which it pertains, and without
deviating from the
scope of the appended claims.
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