Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02197533 2004-06-21
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PAT NT
INSULATED PLASTIC MOLDED DOOR WITH INTEGRAL HINGE
This invention relates to an improvement on a hollow
rotationally molded and foamed filled high impact resistant
insulated door. Specifically, a molded door is disclosed
which includes a hinge bar integrally molded to the plastic
door to both simplify door construction and obviate through
bolting of cast hinge members to the finished door product.
An improved air barrier is disclosed for use with the door to
provide an air barrier in the vicinity of the integrally
attached hinge member as it protrudes at the corners of the
door adjacent the edge of the integrally molded hinge member.
This invention provides
further improvements including the expedient of venting a
rotationally molded door during the rotational molding process
through an integrally molded hinge edge reinforcing member.
This same venting scheme is utilized for enabling improved
cooling of the door once molding of the hollow door shell has
occurred. Further, the rotationally molded door keys with
improved efficiency to subsequently injected foam at the
manifold outlets.
BACKGROUND OF THE INVENTION
In Brown U.S. Patent 4,084,347 issued April 13, 1978
entitled HIGH IMPACT RESISTANCE DOOR, there is described a
rotationally molded hollow body door which is foamed-in-place
in the interior of the hollow door with insulating material.
A gasket construction is shown molded into the door edges.
This door requires the use of an integral two part
mold which anticipates window placement. Further, reinforcing
- members are inserted through cuts within the rotationally
molded structural skin of the door after rotational molding
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but before foaming to inhibit door warpage. After foaming,
and during completion of the door assembly, the structural
skin of the door is again cut at the door hinge corners and
cast and molded hinge members are placed on the door. While
the disclosed door is of sturdy construction, what follows is
a simplified construction method and resultant door having
greater flexibility, lower cost and higher commercial
applicability.
In the rotational molding of doors, it has been
required to vent molds during the rotational molding process.
Specifically, an aperture is placed in the rotational mold
typically in the vicinity of the hinge recess in the upper and
lower hinge corners of the door. Because such vents have a
tendency to discharge unconsolidated powder plastic charges
placed within the rotational mold, such vents are filled with
glass fibers. These fibers enable the desired venting to
occur without permitting excessive release of the
unconsolidated powder plastic charge -- especially during the
early stages of the rotational molding process.
When cooling of a rotational mold is desired, the
vent tubes are typically removed. During the cooling of the
mold, air can enter the otherwise hollow part preventing
collapse due to atmospheric pressure.
We have fabricated doors utilizing the rotational
molding process. In our fabrication process, we utilize the
holes of the vent tubes as an entry point for routing out
apertures for the insertion of steel members to our
rotationally formed doors. Specifically, and for our most
robust industrial doors, we route square apertures having a
cross section sufficient to fit the corresponding square cross
section of a steel bar inserted along the hinge side edge of
the door. In this prior art construction, once these
apertures are routed, a steel bar is threaded through the
apertures along the door hinge axis and taped in place.
After, this taping has occurred, the door is placed in a press
with its hir~ge edge vertically upward and has foam injected to
the hollow interior. Curing occurs in the mold. The tape
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holding the reinforcing bar is removed and conventional
finishing assembly of the door follows.
SUMMARY OF THE INVENTION
A high impact resistant rotationally molded door and
process for molding the door is disclosed in which a hinge
member is integrally molded to the door along one edge only.
This hinge member forms to the hollow door edge without door
warpage during curing and shrinking of rotationally molded
plastic door body. Door warpage is avoided by delaying full
integral attachment of the hinge member to the door until
curing of the injected foam interior which both bonds to the
interior of the door and the hinge member.
Accordingly, the present invention provides a high
impact resistant door comprising in combination:
a rotationally molded six sided plastic door body
including;
a front door surface;
a rear door surface;
a top door edge;
a bottom door edge;
a hinge door edge; and,
an opening door edge;
said surfaces and edges forming an integral hollow
cavity in the interior of said plastic door body;
an upper hinge cavity defined in an upper corner of
said door at said hinge door edge in said front door
surface, rear door surface, top door edge and hinge door
edge;
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a lower hinge cavity defined in a lower corner of said
door at said hinge door edge in said front door surface,
rear door surface, bottom door edge and hinge door edge;
an elongate hinge member rotationally molded to said
door and extending along said hinge door edge within said
upper hinge cavity and said lower hinge cavity free of the
rotationally molded plastic of said door;
said elongate hinge member having two end portions
adjacent to but not within said upper and lower hinge
cavities molded about but not integrally attached to said
rotationally molded plastic of said door body; and,
a foam filler interior of said door integrally bonded
within said integral hollow cavity and said elongate hinge
member of said door.
A mold fabricated from back side reinforced aluminum
sheet is disclosed. This mold has an interior for defining
a hollow rotationally molded six sided door. A mold cavity
is provided including a front door surface, a top door edge,
a bottom door edge, a hinge door edge, and an opening door
edge. The mold is closed and opened at a flat plat surface
which also forms the rear door edge. When closed, the
surfaces of the mold form an integral hollow cavity.
Plastic, when placed into this hollow cavity and
rotationally molded, forms a hollow plastic door body on the
interior surface of the mold with the inner portion of the
plastic door body being hollow.
The mold further defines an upper hinge cavity in the
upper door corner in the front door surface, rear door
surface, top door edge and hinge door edge. A lower hinge
cavity is defined in the lower door corner by the mold in
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the front door surface, rear door surface, bottom door edge
and hinge door edge. An elongate hinge member is place in
the mold extending along the hinge door edge within the
integral hollow cavity of the door and extending into the
upper hinge cavity and the lower hinge cavity.
In a further aspect, the present invention provides a
process of molding a high impact resistant door comprising
the steps of:
providing a mold having an interior for defining a
hollow rotationally molded six sided door including;
a front door surf ace ;
a rear door surface;
a top door edge;
a bottom door edge;
a hinge door edge; and
an opening door edge;
said surfaces and edges of said provided mold forming
an integral hollow cavity in the interior of said door;
said mold further defining an upper hinge cavity
defined in said upper corner of said door at said front door
surface, rear door surface, bottom door edge and hinge door
edge;
placing an elongate hinge member to said mold extending
along said hinge door edge within said integral hollow
cavity of said door and extending into said upper hinge
cavity and said lower hinge cavity;
coating said elongate hinge member with a release agent
to prevent integral plastic bonding to said hinge member
interior of said integral hollow cavity of said door, said
coating extending interior of said integral hollow cavity of
said door adjacent said upper hinge cavity and said lower
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hinge cavity, said elongate hinge member having an uncoated
portion between said coated portions of said hinge member;
placing plastic in said mold and rotationally molding
said plastic to the interior of said mold to form a hollow
plastic door having said front surface, said rear surface,
said top door edge, said bottom door edge, said hinge door
edge, and said opening door edge with said upper and lower
hinge member cavities defined in said door; and,
injecting a foam filler interior of said door
integrally bonded within said integral hollow cavity of said
door.
A release agent coating is applied to extend interior
of the integral hollow cavity of the door adjacent the upper
hinge cavity and the lower hinge cavity. The portion of the
hinge member in the middle of the door is left uncoated. In
the preferred embodiment, the hinge member includes an
attached protruding portion -- such as hollow square bar --
for secure attachment to the door when subsequently filled
with foam.
Plastic is placed in the mold and rotationally molded.
The plastic adheres to the interior surfaces of the mold to
form a hollow plastic door body having the front surface,
the rear surface, the top door edge, the bottom door edge,
the hinge door edge, and the opening door edge with the
upper and lower hinge member cavities defined in the door.
Such integral bonding does not occur to the release agent
coated portions of the hinge member adjacent the upper and
lower hinge cavities. The door can then shrink relative to
the hinge member during curing of the outer plastic body of
the door. The result is that the rotationally molded hollow
door is not warped or bent out of a plane configuration by
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the attached hinge member along only one edge of the door
during curing and shrinking of the hollow plastic body of
the door.
Thereafter, a foam filler is injected interior of the
door integrally bonded within the integral hollow cavity of
the door. At this time, the hinge member and its attached
protruding portion integrally bond to the door. There
results the simplified integral hinge member bonded to the
finally fabricated foam enclosing door.
The present invention also provides a high impact
resistant insulated door having a door sill mounted hinge
attached side for closure on hinge members urging door
closure assisted by the gravity of the door, said door
including:
a f ront door surf ace ;
a rear door surface;
a top door surface;
a bottom door surface;
a hinge door edge; and,
an opening door edge;
an upper hinge cavity defined in an upper corner of
said door at said hinge door edge in said front door
surface, rear door surface, top door edge and hinge door
edge;
a lower hinge cavity defined in a lower corner of said
door at said hinge door edge in said front door surface,
rear door surface, bottom door edge and hinge door edge;
at least one elongate hinge member attached to said
door and extending into said upper hinge cavity and said
lower hinge cavity free of the rotationally molded plastic
of said door; and,
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means for sealing said upper and lower hinge cavity
against air flow during movement of said door; the
improvement to said means for sealing including:
a channel affixed to said door at said hinge cavity
parallel to said elongate hinge member of said door; and,
a semi-rigid arcuate member having a first end portion
attached to said sill adjacent said hinge member, a second
portion attached to said sill adjacent said hinge member,
and extending arcuately between said first and second
portions into contact with said channel affixed to said door
to form an air barrier.
The present invention also provides a process of
rotationally molding a panel with an integral side edge
reinforcing member comprising the steps of:
providing a rotational mold defining a front panel
surface, a rear panel surface, a top edge, a bottom edge,
and side edges for defining an interior surface to which an
exterior surface of a rotationally molded panel can form
during rotational molding;
providing a hollow edge reinforcing member having at
least one end for protruding from the rotational mold;
placing a powdered plastic molding charge interior of
the rotational mold;
manifolding the hollow edge reinforcing member with
spaced apart apertures interior of the rotational mold to
permit the hollow edge reinforcing member to form a vent
path to and from the interior of the rotational mold; and,
rotationally molding the rotational mold to permit exit
of gas formed during molding into the hollow edge
reinforcing member and outward of the rotational mold
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through the vent path provided by the hollow edge
reinforcing member.
There is also disclosed an improved hinge seal for use
with the door. Simply stated, and in the vicinity of the
upper and lower hinge cavities, there is attached to the
sill a semi-rigid arcuate member. This semi-rigid arcuate
member mates with a door mounted channel contained within
the hinge cavity. As the door opens and closes, an air seal
is maintained between the semi-rigid arcuate member and
channel, effectively providing an air barrier at the hinge
recess.
Also disclosed is a manifolded reinforcing side hinge
edge member integrally formed with door at the hinge edge of
the door. As before, mold release agent is applied to a
typically square section manifolded steel bar placed through
the rotational mold and extending out either end of the
rotational mold. When rotational molding occurs, the
manifold in square section
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steel bar forms a convenient gas escape path with a sufficient
circuitous gas path to prevent discharge of substantial
quantities of uncoalesced plastic powder charge. During
cooling of the product in the mold, gas can enter through the
5 manifolded hinge member to prevent collapse due to atmospheric
pressure. Upon demolding of the product, cooling air can be
introduced and expelled through the manifolded hinge edge
reinforcing member to assure uniform part cooling without
differential contraction that can lead to deformation of the
molded part. Finally, and during the door foaming process,
penetration of the foam to the interior of the square
sectioned manifolded steel reinforcing bar indicates flooding
of the door with a sufficient level of foam as well as
enabling improved keying of the hinge edge reinforcing bar to
the door through the foam.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view of a turret type
station apparatus including a first station for loading the
mold of this invention, a second station for the oven
contained rotational molding of the loaded mold, a third
station for the cooling of the mold; and a fourth station for
unloading and storing the mold;
Fig. 2 is a perspective view of the mold only with
the top plate shown in exploded relation overhead illustrating
the placing and spreading of plastic within the mold and the
integrally fastened hinge bar placed to the mold with the top
and bottom areas of the hinge having mold release being
differentiated from the rest of the hinge bar;
Fig. 3 is a view of the rotationally molded and
removed door being injected with foam within a schematically
indicated press to preserve the linearity of the door, the
press here being illustrated including a group of doors;
Fig. 4 is a perspective view of a section of the
door at the upper hinge corner having an edge for receiving a
gasket shown with the inserted and replaceable gasket and
illustrating a hinge member air dam channel adjacent the
protruding integral hinge bar at the upper portion thereof;
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Fig. 5 is a perspective view of the upper hinge
corner shown in Fig. 3 with the hinge member air dam mounted
to the door shill and co-acting with the hinge member air dam
channel to provide insulation of the interval at the hinge to
enable working insulation of the door at the hinge interval;
- Fig. 6 is a perspective view of a window being
installed to the foam filled rotationally molded door;
Fig. 7 is a perspective view of a completed and
installed door according to this invention;
Fig. 8 is a detail of the mold of this invention at
the integrally fastened hinge member illustrating the coating
of the hinge member and its placement to the mold;
Fig. 9 is a view of an alternate cylindrical hinge
edge reinforcing member which can be placed and subsequently
through bolted between the door sides of the rotationally
molded door; and,
Fig. l0A and lOB are respective side elevation
section and plan views of a rotational mold formed in
accordance with this invention illustrating a manifolded hinge
edge reinforcing member being placed for integral formation
with the rotationally molded door shell, it being noted that
spaced manifolding apertures along the edge of the door permit
the entry and exit of gas from the door.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Fig. 7, door D is shown mounted to sill
S along hinge axis A. Door D includes front surface 14, rear
surface 24, and respective hinge edge 16, opening edge 18, top
edge 20, and bottom edge 22. A single hinge member H is
integrally molded to the hollow door body Y (the door body
shown in Fig. 3). This hinge member H protrudes into upper
hinge cavity 26 at the upper hinged corner of the door and
lower hinge cavity 28 at the lower corner of the door.
Opening and closing of door D is conventional and
can be easily understood. Specifically, bottom hinge member
portion 30 protrudes into a conventional hinge bearing where
hinge member H at bottom hinge member portion 30 can rise and
fall as door D respectively opens and closes. Top hinge
~T.,
t_
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member portion 32 is conventionally attached to a conventional
V-cam door closure mechanism. This mechanism causes the door
D to raise upon opening, and descend upon closing against a
conventional V-cam door closure mechanism. Such a mechanism
can be obtained from Chase-Durus Industries of Bend, Oregon
under the product designation 5508.
It will therefore be understood that upper hinge
cavity 26 and lower hinge cavity 28 are necessary so that door
D can rise and fall during opening on hinge member H. This
being the case, these respective hinge cavities must be
prevented from venting air through sill S when door D is in
the closed position. To prevent this from occurring, door
attached U-shaped flange F and sill attached arcuate air stop
R is utilized.
Having generally described the door product of this
invention as installed, and description of the process of
manufacture of door D can now be set forth.
Referring to Fig. 2, mold M for rotational molding
of door D is set forth. The two major surfaces of door D
including front surface 14 and rear surface 24 are molded
across front surface aluminum sheet 44 and rear surface
aluminum sheet 54. Each of these sheets is~reinforce on the
reverse side by longitudinal reinforcing members 45 and
transverse reinforcing members 46, such reinforcing members
only visible with respect to front surface aluminum sheet 44.
Rear surface aluminum sheet 54 has attached thereto
U-shaped channels forming mold opening side edge 48, mold
hinge side edge 50, mold top edge 51, and mold bottom edge 52.
It will thus be seen that rear surface aluminum sheet 54 with
its respective fastened edges forms cavity C into which
plastic P can be placed for rotationally molding door D. It
will be realized that when mold M is closed by front surface
aluminum sheet 44 that hollow mold M will be formed.
It is required that hinge member H be integrally
molded to hollow door body Y. To understand this feature of
the invention, reference must be made to Fig. 8.
Referring to Fig. 8, hinge member H is shown placed
interior of mold M. Hinge member H includes 1; inch diameter
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bar having square key section 55 welded thereto (See Fig. 2).
Mold M defines an inner dimension of iZ inches. It is
important that hinge member H having those portions of the bar
adjacent upper hinge cavity 26 and lower hinge cavity 28
coated with release agent.
- Accordingly, hinge member H at upper member section
56 and lower member section 58 is coated with release agent.
As is conventional, the interior of mold M is also coated with
a release agent. Medial portion 60 of hinge member H
including square key section 55 is left uncoated. The effect
of this release agent coating of upper member section 56 and
lower member section 58 during conventional rotational molding
is easy to understand.
Specifically, plastic P molds to all interior
portions of mold M. Such molding of plastic will also occur
around hinge member H at the borders of mold M. Molding of
plastic will generally not occur to portions of hinge member H
between upper member section 56 and lower member section 58.
Plastic attaching to hinge member H at upper member
section 56 and lower member section 58 will be free to move.
The result is that when rotational molding has occurred,
hollow door body Y and hinge member H will form an integral
linear member with only local attachment of hinge member H at
those portions of hollow door body Y through which hinge
member H protrudes. Final, integral attachment of hinge
member H to door D will await filling of hollow.door body Y
with foam.
It will be understood that molding a member such as
door D with integrally molded hinge member H has not
heretofore been possible without significant warping of the
molded member, here door body Y. Specifically, and in absence
of both the release agent here utilized and the disclosed
foaming sequence, such a single side member would cause door
warpage upon curing of the door.
Referring to Fig. 1, rotational molding is
relatively easy to understand. Schematically, a turret type
multiple station rotational molding station 64 is illustrated.
It includQS maid loading station 70, mold rotating station 72,
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mold cooling station 74, and product discharge station 76. At
the end of rotational molding, there is discharged hollow door
body Y having hinge member H integrally molded thereto.
Typically, and after rotational molding of hollow
door body Y, the door product is allowed to sit for a period
of 24 hours. Thereafter, and as shown in Fig. 3, foam
injections occur through aperture 80 and hose 82 from
conventional foam producing apparatus (not shown). Such foam
injection finally causes hinge member H to integrally bond to
door D.
Once this has occurred, door D filled with foam is
allowed to sit further for 24 hours. Thereafter, the
respective hinge edge 16, opening edge 18, top edge 20, and
bottom edge 22 are milled to receive gasket molding 85. As
can be seen in Fig. 4, gasket molding 85 has door edge side 86
configured to fit to the milled door edges. Further, gasket
molding 85 defines gasket receiving slot 87 to receive gasket
90 at the respective hinge edge 16, opening edge 18, top edge
20, and bottom edge 22.
Once gasket 90 has been installed, window W is
placed in door D. Specifically, window hole 100 is first
placed in door D and drilled with bolt apertures 101.
Thereafter, front window flange member 104, and rear window
flange member 105 trap window pane 106 therebetween.
In observing the installation of window W, it will
be understood that placement of window W is independent of the
construction of mold M. This being the case, the size, shape,
and location of window W can be varied to suit customer
preference on a special order basis.
It will be noted that door D includes an installed
bumper B in Fig. 7. Such bumpers B are conventional; they
will not be further discussed here. Having set forth the door
construction, attention can now be devoted to sill attached
arcuate air stop R.
Referring to the perspective detail of Fig. 5, door
D at upper hinge cavity 26 is illustrated. Door D on vertical
cavity edge 110 includes U-shaped flange F. Sill S has fixed
thereto sill attached arcuate air stop R. This sill attached
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arcuate air stop R fastens at first arcuate end 112 to sill S,
extends around hinge member H, and fastens at second arcuate
end 114 to sill S. In such extension, sill attached arcuate
air stop R is given a length so that it contacts U-shaped
5 flange F. Thus during opening and closing of door D, contact
of sill-attached arcuate air stop R with U-shaped flange F
will continuously occur.
It will be remembered that door D rises and falls
during respective opening and closing. This being the case,
10 some provision at sill attached arcuate air stop R is
desirable. Accordingly, slotted skirt 120 is placed adjacent
the lower edge of upper hinge cavity 26. Similarly, a slotted
skirt 120 is placed at the upper portion of sill attached
arcuate air stop R on lower hinge cavity 28. It will be
understood that at upper hinge cavity 26, conventional V-cam
door closure mechanism is enclosed by sill attached arcuate
air stop R. As this conventional V-cam door closure mechanism
is conventional, it is not here illustrated.
It will be understood that a particularly
advantageous door construction is illustrated. Over the prior
art, both door construction and cost of manufacture are
simplified and lowered.
Referring to Fig. 9, square stock hinge member H is
shown in partial longitudinal section. As can be seen, square
stock hinge member H' is manifolded at apertures 101 and is
open at its respective ends 102. Typically, square stock
hinge member H' is a 1" by 1" steel tube.
Referring to Figs. 10A and lOB, placement of square
stock hinge member H' within mold M' can be easily understood.
square stock hinge member H' is positioned relative to mold M'
so that manifold apertures 101 communicate to the interior of
the mold and end apertures 102 communicate exterior of mold
M'
Function of square stock hinge member H' and its
apertures 101 and open ends 102 during the molding process can
be easily understood. First, and as in the previous
embodiments, square stock hinge member H' forms a manifolded
reinforcing side hinge edge member. This side hinge edge
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member will be integrally formed with door at the hinge edge
of the door.
As before, mold release agent is applied to the
typically 1" by 1" square section manifolded steel bar placed
through rotational mold M and extending out either end of the
rotational mold. When rotational molding occurs, the manifold
in square section steel bar forms a convenient gas escape path
through apertures 101 and out ends 102 with a sufficient
circuitous gas path to prevent discharge of substantial
quantities of uncoalesced plastic powder charge.
Additionally, and during cooling of the product in
the mold, gas can enter through square stock hinge member H'
to prevent collapse due to atmospheric pressure.
Upon demolding of the product, cooling air can be
introduced and expelled through the manifolded hinge edge
reinforcing member to assure pniform part cooling without
differential contraction that can lead to deformation of the
molded part. It is to be noted that the "manifolded
construction" of square stock hinge member H' effects a
uniform distribution of cooling air interior of the recently
molded door article; differential cooling which might
otherwise warp of the door will be held to a minimum.
Finally, and during the door foaming process,
penetration of the foam to the interior of the square
sectioned manifolded steel reinforcing bar indicates flooding
of the door with a sufficient level of foam as well as
enabling improved keying of the hinge edge reinforcing bar to
the door through the foam. Further, apertures 101 form points
for square stock hinge member H' to key to injected foam,
further giving a sturdy door construction.
It is to be understood that square stock hinge
member H' will typically be through bolted to the rotationally
molded door body.
