Note: Descriptions are shown in the official language in which they were submitted.
CA 02227069 1998-O1-16
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PROCESS OF MAKING H-PIhhAR COVERB
AND COVERS PRODUCED THEREBY
This application relates to vehicle parts
and more particularly to improvements in plastic door
pillar covers and the method of making such covers.
It is well known that many vehicles mask the
portion of the door B-pillar which is coextensive with
the window so as to provide edge coverage as well as
color contrast. Heretofore, covers of this type have
been injection molded of a suitable plastic material.
In order to achieve a high gloss f finish, the molded
article is either injection molded over a preformed
paint film laminate inserted in the mold or painted in
. conventional fashion after molding with the required
number of coats. This method of making the covers
resulted in the formation of wall thickness greater
than required because of the necessity to practice
efficient mold filling procedures. The cost of
providing excess material and the added cost of
finishing the part created a particular need for cost
effectiveness in producing the part.
An object of the present invention is to
satisfy the need identified above. In accordance with
the principles of the present invention, this
objective is achieved by providing a method of making
thin wal7.ed covers with the use of a vacuum mold
assembly. Each of the thin walled covers is shaped to
fit over a vehicle part having an exterior surface
canfiguration defined along an elongated peripheral
extent th~areof by a thin sheet metal marginal edge and
along an opposed elongated peripheral extent thereof
by an in~turned surface. The vacuum mold assembly
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includes a plurality of molding horns, each having a
surface configuration molding surface corresponding in
shape substantially to the shape of a vehicle part
surface configuration, a thin marginal edge molding
surface corresponding in shape substantially to the
shape of a vehicle part thin sheet metal marginal edge
and an inturned surface molding surface corresponding
in shape substantially to the shape of a vehicle part
inturned surface. The plurality of molding horns are
movably mounted in the vacuum mold assembly. The
method comprises the steps of providing a thin sheet
of thermoplastic material of generally uniform
thickness and placing the thin sheet of thermoplastic
material in a heated condition in operative relation
with the plurality of molding horns of the vacuum mold
assembly so that spaced main body portions of the
sheet are disposed in spaced coextensive relation with
the surface configuration molding surfaces of the
molding horns and adjacent portions of the heated
sheet extend beyond the thin marginal edge molding
surfaces and the inturned surface molding surfaces of
the molding horns. A relative movement between the
sheet and the vacuum mold assembly is effected and
thereafter a vacuum is applied to the vacuum mold
assembly sufficient to form a peripheral seal with a
surface area of the sheet which includes the surface
configuration providing and adjacent portions thereof
and to cause the main body portions of the heated thin
sheet of thermoplastic material to move into
engagement with the surface configuration molding
surfaces of said molding horns in a direction
generally perpendicular thereto and the adjacent
portions of the heated thin sheet of thermoplastic
material to move into engagement around the thin
marginal edge molding surfaces of the molding horns '
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and into engagement with the inturned surface molding
surfaces of the molding horns so as to form within the
peripher2il seal of the thin sheet of thermoplastic
material a plurality of thin walled covers each
comprisir.~g a main body portion having a U-shaped
marginal edge along one elongated peripheral extent
thereof of a shape to snugly receive therein the sheet
metal marginal edge of a vehicle part and an inturned
flange a7.ong an opposed elongated peripheral extent
thereof of a shape to be adhered to the inturned
surface of the vehicle part. Thereafter, the thin
sheet of thermoplastic material with the thin walled
covers therein in a cooled condition is separated from
the vacuum mold assembly during which the molding
horns move so that the surface configuration providing
portions of the thin sheet of thermoplastic material
engaged with the surface configuration molding
surfaces of the molding horns move relatively away
from the latter in an angular direction having a
component in a direction to withdraw the thin marginal
edge mold~Lng surfaces of said molding horns relatively
out of they U-shaped marginal edges of the formed thin
walled corers. Finally, the formed thin walled covers
are cut from the sheet after being separated from the
vacuum mo:Ld assembly.
Another object of the present invention is
to provide a more cost effective cover of the type
described. In accordance with the principles of the
present invention, this objective is achieved by
3o providing a cover for a vehicle part which has an
exterior surface configuration defined along an
~ elongated peripheral extent thereof by a thin sheet
metal marginal edge and along an opposed elongated
~ .peripheral. extent thereof by an inturned surface. The
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cover comprises a thin sheet of thermoplastic material
of generally uniform thickness vacuum molded to
provide a main body portion defined along a first
elongated peripheral extent thereof by a first vacuum
formed transverse bend in the thin sheet of
thermoplastic material having a first integral vacuum
formed strip extending transversely therefrom in
generally parallel coextensive relation to a margin of
the main body portion extending along the first
peripheral extent thereof. The first transverse bend
and strip defines with the margin a marginal edge of
U-shaped cross-sectional configuration. The main body
portion is defined along a second generally opposed
elongated peripheral extent by a second vacuum formed
transverse bend in the thin sheet of thermoplastic
material which has a second integral vacuum formed
strip extending therefrom to form an inturned flange.
The first and second bends extend in the same general
transverse direction with respect to the main body
2o portion. The thin sheet of thermoplastic material is
vacuum molded to have an interior surface shaped (1)
along the U-shaped marginal edge thereof to snugly
receive therein the sheet metal marginal edge of the
vehicle part (2) along the main body portion thereof
to be adhered to the exterior surface configuration of
the vehicle part and (3) along the inturned flange
thereof to be adhered to the inturned surface of the
vehicle part.
These and other objects of the present
invention will become more apparent during the course
of the following detailed description and appended
claims:
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PCT/IB96 /Q:.005
The invention may beet be understood with
reference; to the accompanyir~g drawings w?~.erein an
illuet.rat.ive embodiment is shown.
ID1 TH~ DFAWI~IGB
g Figure 1 is a perspective view looking
downward7.y and to the front of the exterior side of a
cover fc~_~ a right-front door H-pillar constructed in
accordance with the principles o= the present
invent icn;
1o Figure 2 is a perspective view of the cover
shown in rig~are 1 looking down and to the rear of the
interior Bide thereof;
Figure 3 is an enlarged fragmentary
eectiana:L v_ew taker. alcrsg the line 3-3 of B'igure 1;
Z5 Figure 4 is a eome~uhat schematic side
el evational view of an apparatus for ~~racticing the
method c~f making the cover in accordance with the
principl~=a of the present invention;
Figure 5 ie a fragmer_tary esctiar_al view
20 taken along the direction cf movement of the sheet
through a molding hcrn pivot ehawincf the initial
position of the upper and lower parts of the vacuum
mold ase~=mbly after a heated sheet has been positioned
therebetween;
25 Figure 6 ie a view similar to Figure 5
showing the position of the parts dur:_ng the vacuum
forming procedure;
AMENDED SHEET
~,."~"r,.,~-.T _..___,_._..-
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Figure 7 is a view similar to Figure 6,
showing the position of the parts as the molded sheet
begins to be separated therefrom;
Figure 8 is a view similar to Figure 7
showing the position of the parts after separation of .
the mold sheet therefrom;
Figure 9 is a fragmentary sectional view
taken along the line 9-9 of Figure 6; and
Figure 10 is a fragmentary sectional view
taken along the line 10-10 of Figure 8.
Referring now more particularly to the
drawings, there is shown in Figures 1-3 thereof a
vehicle part cover, generally indicated at 10, which
embodies the principles of the present invention. The
cover 10 is made of a thin sheet of thermoplastic
material of uniform thickness by a vacuum forming
process. Preferably, the process includes steps in
accordance with the principles of the present
invention.
As best shown in Figures 1-3, the cover 10
includes a main body portion 12 having an elongated
marginal edge portion, generally indicated at 14,
along one elongated peripheral extent thereof which is
of generally U-shaped cross-sectional configuration
and a flange, generally indicated at 16, extending
along an opposed elongated peripheral extent thereof.
The U-shaped marginal edge portion 14 includes a short
rather sharp transverse bend 18 which extends from the
peripheral extent of the main body portion 12, the
transverse bend 18 having an integral strip 20
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extending therefrom which is disposed in generally
'parallel relation with an edge margin 22 of the main
body porltion. The flange 16 includes a transverse
bend 24 which extends from the main body portion 12 in
the same general direction as the bend 18 and a strip
26 which extends from the bend 24.
The cover 10, as best shown in Figure 1, is
shaped to be applied to the portion of the B-pillar of
a right hand vehicle door which is generally
1o coextensive with the window area. The U-shaped
marginal .edge portion 14 is shaped to receive therein
the sheet metal marginal edge of the portion of the
rear extremity of the door which is coextensive with
the window area. The main body portion 12 of the
caver 10 is shaped to be adhered to the exterior
surface c~~nfiguration of the portion of the B-pillar
of the veahicle door which is coextensive with the
window. 9'he flange 14 of the cover 10 is shaped to be
adhered to the inturned surface of the portion of the
B-pillar of the vehicle door which is coextensive with
the windom. When actually mounted on the vehicle, the
flange 14 of the cover 10 will have a trim strip
secured tc~ the exterior thereof and there will be trim
strips along the upper edge and lower edge of the main
body portLon 12. In this regard, it will be noted
that the upper edge includes an indented portion which
is adapted. to receive the upper trim strip.
As best shown in Figure 2, each cover 10,
prior to :its application to a vehicle part, has an
adhesive layer 28 adhered to the interior surface of
the interior surface of the body portion 12 thereof
and to the interior surface of the flange 16 thereof.
. Each adhesive layer 28 forms a part of a composite
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tape, generally indicated at 30. Each composite tape
30 is of known constructions and includes a non-
adhesive release layer 32 adhered to the opposite
surface of the adhesive layer 28. It will be
understood that, just prior to the application of the
cover to the vehicle part, the release layers 32 of
the composite tapes 30 are removed leaving the
opposite surfaces of the adhesive layers exposed. The
cover 10 is applied by moving the marginal edge
1o portion 14 of the cover 10 over the sheet metal
marginal edge of the door so that the latter is snugly
received with the U-shaped marginal edge portion 14.
The main body portion 12 and flange 14 are then
applied to the main surface configuration and inturned
surface respectively of the vehicle part so that
adhesive layers 28 retain the cover 10 in operatively
engaged covering relation to the vehicle part.
Figure 4 illustrates somewhat schematically
an apparatus, generally indicated at 34, which can be
used in performing the preferred method of the subject
matter. As shown, the apparatus 34 includes a main
frame assembly, generally indicated at 36, which
includes a pair of transversely spaced main horizontal
frame members 38 supported by a series of
longitudinally spaced legs 40. As shown in Figure 4,
one end of the main frame assembly 36 has mounted
thereon supports 42 for rotatably supporting a
continuous roll 44 of thermoplastic material having a
generally uniform width and generally uniform
3o thickness. A predetermined length of the continuous
roll 44 constitutes a sheet of thermoplastic material
which is processed in accordance with the principles '
of the present method. As shown, there are provided
in the main frame members 38 suitable power operated '
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conveying mechanisms, generally indicated at 46. The
conveying mechanisms 46 are schematically illustrated
in Figure=s 5-9 as including a series of pinlike rotors
48 which are capable of engaging openings punctured in
apposite marginal edges of the continuous sheet by
puncturing mechanism 50 located forwardly of the
supports 42. The subsequently spaced rotors 48 serve
to advance the continuous sheet 44 intermittently
forward a distance equal to the aforesaid
predetermined length. The dwell time between
movement: is, for example, 25 seconds. The forward
advance of the continuous roll 44 so moves successive
predetermined lengths thereof are moved intermittently
through a multiplicity of stations provided on the
main frame assembly 36. It will be understood that
other ty~~es of conveying mechanisms may be used such
as endle~~s chains with pins and the like.
The first three stations in which the
predetermined lengths of the roll 44 are advanced
consist of three ovens o.r oven chambers 52, 54 and 56
which arEa capable of being maintained at different
temperatures. The temperatures which are utilized in
the ovens will be dependent upon the. particular
thermoplastic material which is utilized in the
continuous roll 44.
The continuous roll 44 is preferably formed
as a thin. coated substrate of thermoplastic material
of unifa~rm thickness, as, for example, 2 mm.
Exemplary thermoplastic materials for the substrate
are polyc;3rbonates or acrylonitrile butadiene styrene
. (ABS) or polyvinyl chloride (PVC) or blends thereof.
The coating is preferably paint material of the dry
paint film laminate type. Examples of such coatings
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include a acrylic polyvinylidene difluoride (PVDF)
clear coat of 1 to 2 mils, a PVDF acrylic base color
coat of .6 to 1.2 mils, and a thermoplastic adhesion
promoter size coat of .1 mils. The particular
formulation of the coating is dependent upon the color
and the surface gloss which is desired for the
finished cover 10 and the coating will, of course, be
on the exterior surface of the finished cover so as to
provide the desired color and gloss when applied to
the vehicle part. While the use of a color and gloss
providing coating is greatly preferred, the broadest
aspects of the present invention contemplates the use
of a substrate alone and conventional painting after
vacuum forming. Examples of the oven temperatures
when utilizing an ABS substrate suitably coated with
dry paint material is for the first stage 52
approximately 450° F., the second stage 54
approximately 480° F., and the third and final stage
56 approximately 520° F. These temperatures are
related to the exemplary intermittent speed of
operation of 25 seconds.
With the materials, temperatures and times
noted above, the sheet of thermoplastic material will
be moved out of the third oven stage at a temperature
of about 340° F. Each successive predetermined length
is moved from the third oven stage 56 into a forming
station which includes a vacuum mold assembly,
generally indicated at 58. The vacuum mold assembly
58 includes a pair of upper and lower mold parts 60
and 62 which are suitably mounted in the main frame
assembly 36 for relative movement in a direction
toward and away from each other between opened and
closed positions.
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As best shown in Figures 5-9, the upper mold
part 60 is of generally hollow configuration and
includes an upper peripheral seal element 64 in the
lower peripheral edge thereof. As shown in Figure 4,
the hollow upper mold part 60 carries a blower
assembly 66 which, for example, may have the
capabilit;Y of moving 2, 000 cubic feet per minute of
ambient air through the hollow upper mold part 60.
The blower assembly 66 is positioned to blow ambient
1o air into t:he mold part 60 down on the upper surface of
the sheet 44 after the vacuum molding procedure has
been comp:Leted and the upper seal 64 has moved away
from the periphery of the sheet 44.
The lower mold part 62 is likewise in the
form of a hollow member. However, the mold part 62
has mounted thereon a frame structure 68 for applying
a source of vacuum to the area of the sheet 44 engaged
by the upper seal 64 and a corresponding lower seal
element 70. Seal element 70 faces upwardly and is in
20. generally coextensive relation with the peripheral
seal 64 0~: the upper mold part 60. Mounted on the
frame structure 68 of the lower mold part 62 is a
plurality of molding horns 72. In the embodiment
shown, there are eight molding horns 72 provided so
that, during each vacuum molding operation, eight
covers 10 can be formed in the sheet 44. It will be
understood that, in a four door sedan, there will most
likely be four different covers required in that the
portions o:E the B-pillars which are coextensive with
3o the windows in the two front doors will be most likely
mirror images of one another and the portions of the
B-pillars c~f the rear doors which are coextensive with
the window: will be mirror images of one another but
- also will vary with respect to the other two covers
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because of the orientation of the U-shaped edges and
flanges of the body portions. With the use of eight
molding horns 72, each sheet 44 can be molded to
provide two sets of four covers for a four door car.
It will be noted that each of the molding
horns 72 have in common the provision of a main body
which presents a main body forming surface 74
conforming in shape substantially to the surface
conf iguration of the vehicle part over which the cover
10 is to be mounted. Moreover, each molding horn 72
also has formed along one elongated peripheral extent
thereof a marginal edge forming surface 76 which
conforms substantially in shape to the sheet metal
marginal edge of the vehicle part. Similarly, each
molding horn 72 also includes a flange forming surface
78 which is shaped substantially the same as the
inturned surface of the vehicle part.
Where two or more molding horns 72 are
provided in the vacuum mold assembly 58, the procedure
for applying the heated sheet 44 to the molding horns
72 and removing the formed sheet after the vacuum has
been applied presents a problem due to the
configuration of the cover and the need to provide an
exterior surface which is free of freeze marks.
Freeze marks can be prevented by applying the heated
sheet 44 to the major body forming surface 74 in a
general perpendicular direction. It is noted that the
surfaces 74 are somewhat bowed in the elongated
direction but the bowing is not sufficient to cause a
problem in the application of the sheet to the
surfaces from a freeze mark point of view. Freeze '
marks may well occur as the sheet is applied around
the elongated edge forming surfaces 76 or the flange
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forming surfaces 78. However, freeze marks on these
areas of the cover do not seriously hamper the
appearance because these areas are more or less hidden
by trim strips or other door edges or pillar edges in
operation. It can be seen that, where there are two
' molding horns which require a certain initial
orientai~ion of the sheet 44 and a predetermined
relative. movement between the sheet 44 and molding
horns 7:: to apply the sheet to the surfaces 74, there
will be a difficult problem in removing the formed
sheet 49. after the vacuum forming as been accomplished
because of the edge forming surfaces 76 which are
within U'-shaped sections of the sheet after formation.
In order to accommodate these considerations, the
molding horns 72 are movably mounted on the frame
structure 68. As shown, each molding horn 72 has a
pair o;f depending legs 80 spaced along the
longitudinal extent thereof and the legs 80 are
mounted in the frame structure 68 by pivot pins 82
(see Figure 9) which serve to mount the molding horns
72 for pivotal movement about the aligned axis of the
pins 82.
Each molding horn 72 is also provided with
an electric heater element 84 which, in operation, is
controlled to maintain the molding horns 72 at a
generally constant temperature within the range of
220°-230° F.
In accordance with the principles of the
present invention, as each successive length of the
continuous roll 44 is moved into the molding station,
- the sheen will assume a supported position on the main
frame members 38 extending horizontally within the
- molding :station. The mold assembly 58 is in its open
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position with the upper mold part 60 raised and the
lower mold part 62 lowered, as shown in Figure 5. As
soon as the length of thermoplastic material 44 has
been moved into the aforesaid horizontal position, the
two mold parts 60 and 62 are moved in a direction
relatively toward one another until the peripheral
seals 64 and 70 respectively thereof engage the upper
and lower surfaces of the sheet 44 so as to provide a
peripheral seal over an area of the sheet which is to
be molded. During the upward movement of the lower
mold part 62, the lower surface of the sheet will be
engaged with the main body forming surfaces 74 of the
molding horns 72. This engagement is essentially a
movement in a direction generally perpendicular to the
surfaces 74 so that the sheet is distributed
essentially on the surfaces without significant
stretching.
With the seal in place and the sheets
engaged at least partially on the surfaces 74, the
vacuum source is communicated with the vacuum channels
in the frame structure 68 which, in turn, communicate
with interior channels in each of the molding horns.
The application of the vacuum to the openings causes
the interior surface of the heated sheet 44 to conform
with the surfaces provided by the molded horns 72. In
this way, a plurality of covers 10 are molded within
the area defined by the peripheral seal.
After the molding step has been completed,
the upper mold part 60 is moved upwardly so that its
seal 64 leaves the upper surface of the sheet 44.
During this movement, the fan assembly 66 directs
ambient air onto the upper surface of the sheet 44 in
its molded condition. At the same time, the lower
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mold part: 62 moves downwardly and the support of the
sheet provided by the frame members 38 and moving
mechanisms 48 initially cause the molding horns to
pivot about the pivot pins 82 thereof . The pivotal
movement of the molding horns 72 causes the surface 74
' to be moved away from the body portions 12 of the
covers 10 which have been formed in an angular
direction which has a component allowing the marginal
edge surfaces 76 of the molding horns to be moved out
of the U--shaped marginal edge portions 14 formed in
the covers 10. In this way, the molding horns 72 are
disengaged from the covers 10 which are molded into
the sheet 44 within the area defined by the peripheral
seal. When the mold parts 60 and 62 reach their full
open position, the drive mechanisms 48 are activated
to move tike sheet having the covers 10 molded therein
into the next station which constitutes a cooling
station. As best shown in Figure 4, an air
conditioning and blower assembly 86 is provided at the
cooling si=ation. The assembly 86 is operable to cause
chilled a,ir at a temperature of approximately 15° C.
to be directed at the upper surface of the molded
sheet 44 at a rate of about 1,000 cubic feet per
minute. After the cooling has taken place, each
successivEa length of continuous roll 44 is advanced
into the next station which constitutes a rough
cutting si~ation. The rough cutting station includes
a vertically movable shear assembly 88 which
cooperate: with a stationary shear frame 90 to form a
3o rough cut around each of the covers 10 which have been
molded wii:hin the sheet 44. After the rough cut has
been accomplished, the separated covers 10 are then
- sorted and given a final trim to the final dimensions
periphera7.ly. The final step with respect to the
formation of the covers is to apply the tapes 30 to
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the interior surfaces of the body portion 12 and the
flanges 26. The remainder of the sheet 44 which is
left after the covers have been separately rough cut
therefrom is then moved into a final stage indicated
schematically at 92 where the remaining thermoplastic
material is cut into small pieces for recycling.
Any United States patent applications or
patents mentioned or cited hereinabove are hereby
incorporated by reference into the present
specification.
It thus will be seen that the objects of
this invention have been fully and effectively
accomplished. It will be realized, however, that the
foregoing preferred specific embodiment has been shown
and described for the purpose of this invention and is
subject to change without departure from such
principles. Therefore, this invention includes all
modifications encompassed within the spirit and scope
of the following claims.
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