U.S. patent application number 14/460705 was filed with the patent office on 2014-12-04 for trailer door seal.
This patent application is currently assigned to Press-Seal Gasket Corporation. The applicant listed for this patent is Katherine A. Bergfeld, Andrew J. Happel, Myron S. Worley. Invention is credited to Katherine A. Bergfeld, Andrew J. Happel, Myron S. Worley.
Application Number | 20140352227 14/460705 |
Document ID | / |
Family ID | 45525271 |
Filed Date | 2014-12-04 |
United States Patent
Application |
20140352227 |
Kind Code |
A1 |
Happel; Andrew J. ; et
al. |
December 4, 2014 |
TRAILER DOOR SEAL
Abstract
A one-piece seal is used between the rear doors of a
semi-trailer truck and the rear frame of the truck, the seal having
a good compression set resistance. The seal is made from multiple
extrusion members that are fused, welded, or otherwise integrally,
monolithically connected at corner joints to form a central
opening. The extrusion members have a sealing profile, or
cross-section, that allows for the compression and deflection of a
pair of sealing lobes to create inner and outer seals,
respectively, between the trailer frame and the door structure at
the rear of a semi-trailer truck, as well as between the doors
themselves.
Inventors: |
Happel; Andrew J.; (Fort
Wayne, IN) ; Worley; Myron S.; (Middlebury, IN)
; Bergfeld; Katherine A.; (Waterville, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Happel; Andrew J.
Worley; Myron S.
Bergfeld; Katherine A. |
Fort Wayne
Middlebury
Waterville |
IN
IN
OH |
US
US
US |
|
|
Assignee: |
Press-Seal Gasket
Corporation
Fort Wayne
IN
|
Family ID: |
45525271 |
Appl. No.: |
14/460705 |
Filed: |
August 15, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13193268 |
Jul 28, 2011 |
8839564 |
|
|
14460705 |
|
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|
|
61368353 |
Jul 28, 2010 |
|
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61430356 |
Jan 6, 2011 |
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Current U.S.
Class: |
49/506 ;
29/428 |
Current CPC
Class: |
B29C 48/09 20190201;
E06B 7/22 20130101; E06B 7/2307 20130101; E06B 7/2312 20130101;
Y10T 29/49826 20150115; B29C 48/0021 20190201; B29C 48/12 20190201;
B60J 10/86 20160201 |
Class at
Publication: |
49/506 ;
29/428 |
International
Class: |
E06B 7/22 20060101
E06B007/22; E06B 7/23 20060101 E06B007/23 |
Claims
1.-11. (canceled)
12. A method of producing a door seal, the method comprising:
procuring a first seal portion holder, the first seal portion
holder comprising: a first recess defining a longitudinal axis, and
a first inner face defining an angle with respect to the
longitudinal axis of the first recess; procuring a second seal
portion holder, the second seal portion holder comprising: a second
recess defining a longitudinal axis, and a second inner face
defining a second angle with respect to the longitudinal axis of
the second recess; placing a first seal portion into the first seal
portion holder, the first seal portion having a miter-cut end, said
step of placing the first seal portion including placing the
miter-cut end substantially flush with the first inner face;
placing a second seal portion into the second seal portion holder,
the second seal portion having a miter-cut end, said step of
placing the second seal portion including placing the miter-cut end
substantially flush with the second inner face; and fusing the
first seal portion to the second seal portion.
13. The method of claim 12, wherein said step of fusing comprises:
placing a ribbon between the miter-cut ends of the first and second
seal portions; and heating the miter-cut ends and the ribbon.
14. The method of claim 12, further comprising, prior to said
fusing step, the additional step of: moving said first seal portion
holder inward toward said second seal portion holder.
15. The method of claim 13, further comprising the additional step
of: repeating said fusing step on additional seal portions to
create a seal with a closed profile.
16. The method of claim 15, wherein the additional seal portions
comprise two additional seal portions, and the closed profile
defines a rectangular profile.
17. The method of claim 15, further comprising the additional step
of: installing the seal onto a door having a profile corresponding
to the closed profile.
18. The method of claim 17, wherein said step of installing further
comprises: stretching the seal over edges and corners of the
door.
19. A method of sealing an opening, the method comprising:
procuring a monolithic, elastically deformable first seal, the
first seal comprising: a first plurality of seal portions; a first
plurality of seal corners, each of the seal corners integrally
joining two of the first plurality of seal portions; and the first
plurality of seal portions joined by the seal corners to form a
closed profile, the first plurality of seal portions cooperating to
define at least one sealing lobe extending continuously around a
periphery of the first seal; attaching a first one of the first
plurality of seal corners to a corresponding first corner of a
first door, the first door movable between a closed position and an
open position; stretching one of the first plurality of seal
portions to align a second one of the first plurality of seal
corners with a corresponding second corner of the first door;
attaching the second one of the first plurality of seal corners to
the corresponding second corner of the first door; and repeating
said attaching and stretching steps for the remainder of the first
plurality of seal corners such that the first seal fully
encapsulates a periphery of the first door.
20. The method of claim 19, further comprising the additional step
of: attaching each of the first plurality of seal portions to a
corresponding edge of the first door, such that the corresponding
edge occupies a space defined by the respective seal portion.
21. The method of claim 19, wherein said stretching step comprising
stretching the respective seal portion by as little as 3% and as
much as 30%.
22. The method of claim 19, further comprising the additional steps
of: procuring a monolithic, elastically deformable second seal, the
second seal comprising: a second plurality of seal portions; a
second plurality of seal corners, each of the seal corners
integrally joining two of the second plurality of seal portions;
and the second plurality of seal portions joined by the seal
corners to form a closed profile, the second plurality of seal
portions cooperating to define at least one sealing lobe extending
continuously around a periphery of the second seal; attaching a
first one of the second plurality of seal corners to a
corresponding first corner of a second door, the second door
movable between a closed position and an open position, the first
and second doors adjacent to one another when in their respective
closed positions; stretching one of the second plurality of seal
portions to align a second one of the second plurality of seal
corners with a corresponding second corner of the second door;
attaching the second one of the second plurality of seal corners to
the corresponding second corner of the second door; and repeating
said attaching and stretching steps for the remainder of the second
plurality of seal corners such that the second seal fully
encapsulates a periphery of the second door.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser.
No. 13/193,268, filed Jul. 28, 2011, entitle TRAILER DOOR SEAL,
which claims the benefit under Title 35, U.S.C. .sctn.119(e) of
U.S. Provisional Patent Application Ser. No. 61/368,353, filed on
Jul. 28, 2010 and entitled TRAILER DOOR SEAL, and U.S. Provisional
Patent Application Ser. No. 61/430,356, filed on Jan. 6, 2011 and
entitled TRAILER DOOR SEAL, the entire disclosures of which are
hereby expressly incorporated by reference herein.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates to seals, and in particular,
to seals that are adapted to seal doors such as semi-trailer
trucks, boxcars, shipping containers, building doors, etc.
[0004] 2. Description of Related Art
[0005] Known seals for use on, for example, the doors of
semi-trailer trucks are made from a thermoplastic that is not able
to withstand extreme hot or cold temperatures. Usually, such seals
are used for only one or two seasons before seal replacement is
needed. Thus, such known seals are short-term in use.
[0006] Some known seals are formed as a plurality of separate
pieces that are not joined to one another. These separate members
can be joined at their respective corners using separate molded
corner blocks that must be sealed to the separate members via glue
or silicone caulk, for example. Not only are these multi-piece
seals expensive, the multi-piece seals are also difficult to
install and maintain.
[0007] Further, some known thermoplastic seals rely on a flap that
seals via bending against the rear frame of a trailer. However,
thermoplastic has poor performance in compression set, which is the
measure of the material's ability to maintain deformation force
over a long period of time. Therefore, over time, the thermoplastic
flap of the known seal will not maintain a sealing force against
the frame of a semi-trailer truck.
[0008] Still other seals are pre-formed to fit a given truck door
size. These seals normally cannot be deformed without compromising
the effectiveness of the seal, and are therefore shipped as a
single, door-shaped piece in a large, flat shipping container
having approximately the same dimensions as the door to which the
seal will be mounted.
[0009] A need exists for a new seal design that has an improved
compression set performance and that may withstand extreme seasonal
temperature changes to reduce the need for replacement of the seal
after a short period of use.
SUMMARY
[0010] The present disclosure provides a one-piece seal for use
between the rear doors of a semi-trailer truck and the rear frame
of the truck, the seal having a good compression set resistance.
The seal is made from multiple extrusion members that are fused,
welded, or otherwise integrally, monolithically connected at corner
joints to form a central opening that extends continuously around
the corner joints. The extrusion members have a sealing profile, or
cross-section, that allows for the compression and deflection of a
pair of sealing lobes to create inner and outer seals,
respectively, between the trailer frame and the door structure at
the rear of a semi-trailer truck, as well as between the doors
themselves.
[0011] The seal is formed from an elastomeric material that is
elastically deformable, resilient, compressible and packable by
rolling, stuffing or folding into a compact space. The seal
material retains a constant deformation force over an extended
period of time, and accommodates repeated deformations while
maintaining a fluid-tight seal that seals the inside of the trailer
from the outside environment. The elastic deformation and
monolithic, one-piece design simplifies installation as the seal
will stretch over the door and hold itself in place. Moreover, the
seal is both weather resistant in subzero temperatures and
resistant to degradation by UV exposure.
[0012] In one form thereof, the present disclosure provides a door
seal for use in sealing a periphery of a door, the seal comprising:
a monolithic seal made of a resilient, elastically deformable
material, the seal including: a plurality of seal portions; a
plurality of seal corners, each of the seal corners integrally
joining two of the plurality of seal portions; and the plurality of
seal portions joined by the seal corners to form a closed profile,
the seal portions cooperating to define at least one sealing lobe
extending continuously around a periphery of the seal.
[0013] In another form thereof, the present disclosure provides a
door seal for use in sealing a gap between a periphery of a door
and an opening, the door having a door edge extending between
corners formed on a periphery of the door, the seal comprising: a
first seal portion made of a resilient, elastically deformable
material, the first seal portion having a first cross-sectional
profile comprising: a first mounting portion defining a first space
sized to receive a portion of the edge of the door; and a
deformable, first sealing lobe extending away from the first
mounting portion, the first sealing lobe adapted to create a
compression seal between the edge of the door and the opening; a
second seal portion made of a resilient, elastically deformable
material, the second seal portion having a second cross-sectional
profile comprising: a second mounting portion defining a second
space sized to receive a portion of the edge of the door; and a
deformable, second sealing lobe extending away from the second
mounting portion, the second sealing lobe adapted to create a
compression seal between the edge of the door and the opening, the
second seal portion fused to the first seal portion at an angle
relative to the first seal portion, the first sealing lobe joined
to the second sealing lobe to form a continuous lobe corner
extending around a corner of the door, the continuous lobe corner
dimensioned to provide a compression seal between the corner of the
door and an adjacent corner of the opening.
[0014] In yet another form thereof, the present disclosure provides
a method of producing a door seal, the method comprising: procuring
a first seal portion holder, the first seal portion holder
comprising: a first recess defining a longitudinal axis, and a
first inner face defining an angle with respect to the longitudinal
axis of the first recess; procuring a second seal portion holder,
the second seal portion holder comprising: a second recess defining
a longitudinal axis, and a second inner face defining a second
angle with respect to the longitudinal axis of the second recess;
placing a first seal portion into the first seal portion holder,
the first seal portion having a miter-cut end, the step of placing
the first seal portion including placing the miter-cut end
substantially flush with the first inner face; placing a second
seal portion into the second seal portion holder, the second seal
portion having a miter-cut end, the step of placing the second seal
portion including placing the miter-cut end substantially flush
with the second inner face; and fusing the first seal portion to
the second seal portion.
[0015] In still another form thereof, the present disclosure
provides a method of sealing an opening, the method comprising:
procuring a monolithic, elastically deformable first seal, the
first seal comprising: a first plurality of seal portions; a first
plurality of seal corners, each of the seal corners integrally
joining two of the first plurality of seal portions; and the first
plurality of seal portions joined by the seal corners to form a
closed profile, the first plurality of seal portions cooperating to
define at least one sealing lobe extending continuously around a
periphery of the first seal; attaching a first one of the first
plurality of seal corners to a corresponding first corner of a
first door, the first door movable between a closed position and an
open position; stretching one of the first plurality of seal
portions to align a second one of the first plurality of seal
corners with a corresponding second corner of the first door;
attaching the second one of the first plurality of seal corners to
the corresponding second corner of the first door; and repeating
the attaching and stretching steps for the remainder of the first
plurality of seal corners such that the first seal fully
encapsulates a periphery of the first door.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The above-mentioned and other features and advantages of
this disclosure, and the manner of attaining them, will become more
apparent and the invention itself will be better understood by
reference to the following descriptions of an embodiment of the
invention taken in conjunction with the accompanying drawings,
wherein:
[0017] FIG. 1 is a rear perspective view of a semi-trailer truck
including doors that are fitted with seals according to the present
disclosure;
[0018] FIG. 2A is a fragmentary view of a corner of the rear frame
and door structure of the semi-trailer truck of FIG. 1;
[0019] FIG. 2B is a fragmentary view of a right-door seal according
to the present disclosure, illustrating an inside-facing portion of
the seal corner prior to a fusing process;
[0020] FIG. 2C is a section view of the right-door seal shown in
FIG. 2B, in which the section line bisects a hollow formed in a
seal lobe;
[0021] FIG. 2D is a perspective view of a fusing apparatus operable
to fuse mitered seal corners;
[0022] FIG. 3 is a cross-sectional view of a truck door seal in
accordance with the present disclosure, taken along line 3-3 of
FIG. 1;
[0023] FIG. 4 is another cross-sectional view of the seal shown in
FIG. 3, taken along line 4-4 of FIG. 1, in which one of a pair
doors is illustrated in a closed position and the other of the pair
of doors is approaching a closed position;
[0024] FIG. 5 is another cross-sectional view of the seal shown in
FIG. 4, taken along line 4-4 of FIG. 1, in which both of the pair
of doors are shown in a fully closed position;
[0025] FIG. 6 is cross-sectional view of an outer door seal of FIG.
1 mounted on the edge of a door;
[0026] FIG. 7 is a cross-sectional view of another truck door seal
in accordance with the present disclosure, taken along line 3-3 of
FIG. 1;
[0027] FIG. 8 is another cross-sectional view of the seal shown in
FIG. 7, taken along line 4-4 of FIG. 1, in which one of a pair
doors is shown in a closed position and the other of the pair of
doors is approaching a closed position;
[0028] FIG. 9 is another cross-sectional view of the seal shown in
FIG. 8, taken along line 4-4 of FIG. 1, in which both of the pair
of doors are shown in a fully closed position and define a
relatively narrow door gap therebetween;
[0029] FIG. 10 is another cross-sectional view of the seal shown in
FIG. 8, taken along line 4-4 of FIG. 1, in which both of the pair
of doors are shown in a fully closed position and define a
relatively wide door gap therebetween;
[0030] FIG. 11 is a cross-sectional view of another truck door seal
in accordance with the present disclosure, taken along line 4-4 of
FIG. 1, in which one of a pair doors is shown in a closed position
and the other of the pair of doors is approaching a closed
position;
[0031] FIG. 12 is another cross-sectional view of the seal shown in
FIG. 11, taken along line 4-4 of FIG. 1, in which both of the pair
of doors are shown in a fully closed position and define a
relatively narrow door gap therebetween;
[0032] FIG. 13 is another cross-sectional view of the seal shown in
FIG. 11, taken along line 4-4 of FIG. 1, in which both of the pair
of doors are shown in a fully closed position and define a
relatively wide door gap therebetween;
[0033] FIG. 14 is a cross-sectional view of another truck door seal
in accordance with the present disclosure, taken along line 4-4 of
FIG. 1, in which one of a pair thick trailer doors is shown in a
closed position and the other of the pair of doors is approaching a
closed position;
[0034] FIG. 15 is a cross-sectional view of an outer door seal
mounted on the vertical edge of a first closing door in accordance
with an additional embodiment of the present disclosure; and
[0035] FIG. 16 is a cross-sectional view of an outer door seal
mounted on the vertical edge of a first closing door in accordance
with a still further embodiment of the present disclosure.
[0036] Corresponding reference characters indicate corresponding
parts throughout the several views. The exemplifications set out
herein illustrate an exemplary embodiment of the invention, and
such exemplifications are not to be construed as limiting the scope
of the disclosure in any manner.
DETAILED DESCRIPTION
[0037] Large trucks, such as semi-trailer trucks, often need
sealing units between rear door structures and a rear frame of the
truck, as well as between the rear doors themselves. The present
one-piece seal designed for installation on trailer doors for
semi-trailer trucks is made of four individually extruded sections,
or extrusion members. The extrusion members are heat fused or
welded together to form a four-sided, one-piece, monolithic design
having a closed profile. This one-piece design ensures that there
is no leak path across the seal when the seal is placed on the
semi-trailer truck.
[0038] While the seals of the present disclosure are discussed in
terms of semi-trailer truck doors, other uses are also
contemplated. For example, shipping containers, railroad boxcars
and building doors may be used with seals made in accordance with
the present disclosure. Moreover, any aperture or opening which is
sealingly blocked with a cover of comparable size and shape may
benefit from the application of such seals.
[0039] Referring now to FIG. 1, trailer 10 of a semi-trailer truck
is shown as having leg prop assembly 12, wheel assembly 14, and
cargo box 15. Cargo box 15 has five sides sealed to one another to
define a cargo space therein, with the sixth side of cargo box 15
open for transferring cargo to and from the cargo space. The open
sixth side is selectively closed by a rear door assembly including
a generally rectangular rear frame 16, doors 18 and 20, latch
assemblies 22, and seals 24, 24'. As discussed in detail below,
seals 24, 24' span the gaps between rear frame 16 and doors 18, 20,
as well as the gap between left door 18 and right door 20.
[0040] 1. Seal Configurations and Characteristics
[0041] Referring still to FIG. 1, left seal 24 mounts to left door
18, and right seal 24' mounts to right door 20. Left and right
seals 24, 24' are generally similar in structure, except where left
and right seals 24, 24' interact with one another to seal the gap
between left and right doors 18, 20 (described below and shown,
e.g., in FIGS. 8-10). More particularly, seals 24, 24' each include
identical upper seal portions 21, outer seal portions 23, and lower
seal portions 25, which are respectively sized and adapted to mate
with the top, outside and bottom edges of doors 18, 20. Seals 24,
24' also include inner seal portions 27, 27' which may differ from
one another to facilitate sealing engagement between seals 24, 24'
as described in detail below.
[0042] The inner, outer, upper and lower portions of seals 24, 24'
are fused to one another at the seal corners to create a one-piece,
monolithic seal for each of doors 18, 20. In one example, best
shown in FIGS. 2A-2C, the corner of seal 24 is formed by a fused,
mitered joint between upper seal portion 21 and outer seal portion
23. For a rectangular door, the mitered joint is formed by two
45-degree miter cuts to accommodate the 90-degree angle of the door
corners. The other three seal corners are similarly mitered and
fused together at generally right angles, such that seal 24 defines
a generally rectangular central opening 28 sized and shaped to fit
tightly over left door 18. Alternatively, the corners of seals 24,
24' may be formed by an injection-molding process. Such methods are
described in detail in the "Methods of Production" section
below.
[0043] Several embodiments of cross-sections which may be used for
seals 24, 24' are shown and described herein. A first embodiment,
shown in FIGS. 3-6, include reference numerals ending in "A," such
that seals 24, 24' having a cross section in accordance with the
first embodiment can be said to include seal portions 21A, 23A,
25A, 27A and 27A'. FIGS. 7-10 similarly illustrate a
cross-sectional view of a second embodiment of seals 24, 24', with
reference numerals ending in "B". FIGS. 11-13 illustrate yet
another cross-sectional view of a third embodiment of seals 24,
24', with reference numerals ending in "C." FIGS. 14, 15 and 16
illustrate still other cross-sectional views of a third, fourth and
fifth embodiment of seals 24, 24', with reference numerals ending
in "D," "E" and "F" respectively.
[0044] Each of the six embodiments described herein include a set
of seal portions with analogous functions and structures, and are
generally similar except as described below. As used herein, "seal
24" and "seal 24'" may refer to seals having any such set of seal
portions. By extension, generic reference to a seal portion implies
that any exemplary set may be used, such that "seal portion 21" may
refer to any of seal portions 21A, 21B, 21C, 21D, 21E and 21F.
Similarly, "seal portion 23" may refer to any of seal portions
23A-23F, "seal portion 25" may refer to any of seal portions
25A-25F, "seal portion 27" may refer to any of seal portions
27A-27F, and "seal portion 27'" may refer to any of seal portions
27A'-27F'.
[0045] In an exemplary embodiment, upper, outer, and lower portions
21, 23, 25 of seals 24, 24' share a common cross-section. For one
of seals 24, 24' (i.e., left seal 24 of FIG. 1) inner portion 27
has a unique cross-section adapted to mate with inner portion 27'.
For the other of seals 24, 24', (i.e., right seal 24' of FIG. 1),
inner portion 27' may have the same cross-section as upper, outer,
and lower portions 21, 23, 25, or may have a unique cross-section
specifically adapted to mate with inner portion 27. Particular
cross-sectional geometries of seals 24, 24' are discussed in detail
below.
[0046] Referring now to FIG. 3, outer portion 23A of seal 24 is
shown disposed between right door 20 and wall 19 of rectangular
frame 16 (FIG. 1). As noted above, outer portion 23A has the same
cross sectional geometry as upper and lower portions 21A, 25A. For
purposes of simplicity, outer portion 23A is described below, it
being understood that upper and lower portions 21A, 25A interact
similarly with respective adjacent portions of frame 16 when doors
18, 20 are closed.
[0047] Outer portion 23A has a generally deformable, pliable body
including mounting portion 31 and sealing portion 33 which are
integrally and monolithically formed with one another. Mounting
portion 31 includes inside wall 30 and a substantially parallel
outside wall 32 defining space 35 for receipt of door 20
therebetween. Sealing portion 33 includes first and second
deformable sealing lobes 41, 42, which elastically deform to
sealingly engage with adjacent surfaces and provide a fluid-tight
seal between door 20 and wall 19, as described below.
[0048] In the installed and sealed state shown in FIG. 3, first
sealing lobe 41 is substantially aligned with the outer one of the
pair of parallel walls 30, 32 of mounting portion 31. First sealing
lobe 41 has an elongate, arcuate profile that spans the gap between
door 20 and wall 19, and extends further from mounting portion 31
to overlap wall 19, when door 20 is in a closed position (and
second sealing lobe 42 is therefore in contact with inner surface
wall 17, as shown). In this configuration, sealing lobe 41 is
sealing seated upon wall 19. Outer wall 32 is sealingly affixed to
the adjacent surface of door 20. Thus, outer wall 32 and sealing
lobe 41 cooperate to present an initial, outer barrier to ingress
of fluid into cargo box 15 through the gap between door 20 and wall
19.
[0049] Sealing portion 33 of outer seal portion 23A further
includes second sealing lobe 42 which provides a second, inner
fluid barrier against such fluid ingress. As best seen in FIG. 6,
the cross-section of second sealing lobe 42 of sealing portion 33
includes diagonal wall 34 extending from inside wall 30. Convex
hemispherical wall 36 is disposed between diagonal wall 34 and
concave hemispherical wall 37, and first sealing lobe 41 extends
from concave hemispherical wall 37. Diagonal wall 34 and convex
hemispherical wall 36 cooperate to define deformable inner lobe tip
44, which sealingly biases against inner surface 17 of rear frame
16 as shown in FIG. 3. Second sealing lobe 42 includes cylindrical
hollow 46, which aids in producing a controlled, repeatable
compression of second sealing lobe 42 against inner surface 17 when
doors 20 of trailer 10 is closed.
[0050] In use, as shown in FIG. 3, first and second sealing lobes
41, 42 cooperate to form redundant, inner and outer fluid-tight
seals between the inside and outside of cargo box 15. More
particularly, when doors 18 and 20 are closed, second sealing lobe
42 is compressed such that lobe tip 44 elastically deforms. This
elastic deformation biases lobe tip 44 against inner surface 17 of
rear frame 16 to create an inner fluid-tight seal between doors 18
and 20 and the inner surfaces of the top, side, or bottom portions
of rear frame 16. Advantageously, this creates a reliably
fluid-tight seal even if the seal is jostled or vibrated (such as
during transport).
[0051] Concurrently with deformation of second sealing lobe 42 to
create an inner seal, deformation of first sealing lobe 41 creates
an outer seal. When door 20 is closed, tip 40 of first sealing lobe
41 is deflected from a first position to a second position along a
deflection direction D having deflection magnitude B (FIG. 6). By
comparison with the undeformed state shown in FIG. 6, it can be
seen in FIG. 3 such deflection elastically deforms first sealing
lobe 41. This elastically deformation biases deflectable tip 40
toward wall 19, such that lobe 41 is pressed against rear frame 16
to form an outer fluid-tight seal between doors 18 and 20 and the
inner surfaces of the top, side, or bottom portions of rear frame
16.
[0052] Thus, three sides of doors 18, 20, are redundantly sealed
against ingress of fluid by first and second sealing lobes 41, 42.
To complete the seal of the rear door assembly shown in FIG. 1, the
gap between left and right doors 18, 20 is sealed by left and right
inner portions 27A, 27A', which cooperate to form a redundant inner
and outer seal as described in detail below. To form this redundant
seal, inner seal portion 27A may have a unique cross-section
different from seal portion 27A', while inner portion 27A' has the
same cross-section as upper, outer and lower portions 21A, 23A,
25A. It is, however, contemplated that a unique cross-section may
be used for both of inner seal portions 27A and 27A'.
[0053] Inner seal portion 27A sealingly engages inner seal portion
27A' as shown in FIGS. 4 and 5. FIG. 4 illustrates a
cross-sectional view of doors 18 and 20 in a partially-open
configuration, with door 18 in a closed position and door 20
approaching a closed position. Door 20 pivots between the open and
closed positions along the direction of arrow A (e.g., around a
hinge disposed near outer seal portion 23A). Left door 18 similarly
pivots between open and closed positions. In the illustrated
embodiment, right door 20 is closed after left door 18 to ensure
proper engagement of seals 24, 24', such that a moving right inner
seal 27A' (attached to an inner edge of right door 20) engages a
stationary left inner seal 27A (attached to an inner edge of left
door 18) as shown in FIG. 5 and described in detail below. Of
course, left and right seals 27A, 27A' may be interchanged to
provide for left door 18 to be closed upon right door 20 as
required or desired.
[0054] The unique cross-section of left inner seal 27A includes
mounting portion 47 and sealing portion 49. As with the
cross-section of outer seal portion 23A described above, mounting
portion 47 includes inner and outer walls 48, 50 defining space 51
for receipt of left door 18 therebetween. Sealing portion 49
includes a generally triangular sealing lobe 52 which extends from
walls 48, 50. Sealing lobe 52 is includes diagonal walls 54 and 56
that meet at inner lobe tip 58. Sealing lobe 52 also includes
cylindrical hollow 60 that aids in facilitating compression of
triangular sealing lobe 52, as further described below, when doors
18 and 20 are closed.
[0055] FIG. 5 illustrates left and right doors 18, 20 in a fully
closed position, with left door 18 having in profile the
cross-section of left inner seal portion 27A and second closing
door 20 having in profile the cross-section of inner seal portion
27A'. In this fully closed position, inner lobe tip 44 of seal
portion 27A' deforms against triangular inner lobe tip 58 of seal
portion 27A, such that tips are mutually deformed to define an area
of contact. Meanwhile, first sealing lobe 41 of seal portion 27A'
deflects to bias against outer wall 50 of seal 27A in a similar
manner as described above. In this manner, inner lobes 42, 52
deform against one another to form a first, inner seal within the
gap between the doors, while first sealing lobe 41 biases against
wall 50 of the adjacent seal 27A to form a second, redundant outer
seal between the closed doors.
[0056] Referring now to FIGS. 7-10, a cross-section of a second
exemplary embodiment of seals 24, 24' is shown. Seals 27B, 27B' are
similar to seals 27A, 27A' described above, and reference numbers
in FIGS. 7-10 refer to analogous structures shown in FIGS. 3-6 and
described above with respect to seals 27A, 27A'. Similarly to outer
seal portion 23A, the cross sectional geometry of outer portion 23B
discussed herein may also be used for upper and lower seal portions
21B, 25B, as well as for one of inner seal portions 27B, 27B'. For
purposes of the present discussion, right inner seal portion 27B'
(FIG. 8) is taken to have the same cross section as outer seal
portion 23B (FIG. 7). Advantageously, using a common cross section
around the entire periphery of seal 24 facilitates continuity of
lobe 142 and provides an enhanced seal as described below.
[0057] Referring to FIGS. 7 and 8, outer seal portion 23B includes
mounting portion 131 and sealing portion 133. Mounting portion 131
includes inside wall 130 and outside wall 132 defining space 35 for
receipt of door 20 therebetween. Sealing portion 133 includes first
and second deformable sealing lobes 141, 142, which cooperate with
adjacent surfaces to provide a fluid-tight seal between door 20 and
wall 19. Mounting portion 131 and first sealing lobe 141 are
generally similar to mounting portion 31 and first sealing lobe 41
(discussed above) in structure and function, such that repeated
discussion of same is not necessary here. However, second sealing
lobe 142 of sealing portion 133 is differently shaped and
positioned to provide an enhanced inner seal between door 20 and
inner surface 17 of rear frame 16.
[0058] As shown in FIG. 8, a generally triangular second sealing
lobe 142 includes diagonal wall 134 formed on the inside surface
thereof, with a generally identical, mirror-image diagonal wall 138
formed opposite the inside surface and facing the outside surface,
such that second sealing lobe is generally symmetrical. A
deformable inner lobe tip 144 joins diagonal walls 134, 138.
Instead of cylindrical hollow 46 described above, a generally
triangular hollow 146 is bounded by walls 134 and lobe tip 144,
such that the cross-section of second sealing lobe 142 has a
substantially constant wall thickness T.sub.1. In the illustrated
embodiment, wall thickness T.sub.1 is about the same as the
corresponding thicknesses of walls 130, 132.
[0059] Inner wall 134 of second sealing lobe 142 extends outwardly
from inner wall 130, such that sealing lobe 142 may be said to join
mounting portion 131 at the one end of inner wall 134. On the other
hand, outer wall 138 of second sealing lobe 142 joins mounting
portion 131 at a location approximately halfway between inner wall
130 and outer wall 132. Put another way, second sealing lobe 142 is
"off-center" or asymmetrically disposed with respect to centerline
C bisecting seal portion 27B' (FIG. 8) while outer wall 138 runs
substantially along centerline C. As discussed below, this
asymmetric orientation provides an enhanced liquid-tight seal.
[0060] Rather than concave hemispherical wall 37 (discussed above),
outer and inner seal portions 23B, 27B' define pocket 137 extending
from outer wall 132 of mounting portion 131 to outer wall 138 of
second sealing lobe 142. As shown in FIG. 7, for example, pocket
137 is sufficiently large to accommodate lobe tip 144 when second
sealing lobe 142 is severely deformed into a sealing configuration.
The relatively large size of triangular hollow 146 and the uniform
wall thickness of second sealing lobe 142 (described above)
facilitate such deformation, so that when outer seal portion 23B is
pressed against inner surface wall 17 of rear frame 16, second
sealing lobe 142 folds into pocket 137.
[0061] As illustrated in FIG. 7, inner wall 134 presents a large
surface area for contact with inner surface wall 17, thereby
creating a robust liquid-tight seal therebetween. At the same time,
pocket 137 is large enough to allow second sealing lobe 142 to
elastically deform into the "folded" configuration illustrated in
FIG. 7 without pressing against the inner surface of first sealing
lobe 141, thereby ensuring that first sealing lobe 141 will remain
fully sealingly biased toward wall 19 of rectangular frame 16 even
when second sealing lobe 142 is in its fully deformed or "folded"
state.
[0062] Referring back to FIG. 8, left inner seal portion 27B has a
unique profile as compared to the other seal portions of seal 24
(i.e., seal portions 21, 23 and 25). This unique profile allows
left inner seal portion 27B to cooperate with right inner seal
portion 27B' to redundantly seal the gap between doors 18, 20.
[0063] More particularly, left inner seal portion 27B lacks first
sealing lobe 141. In all other respects, the profile of left inner
seal portion 27B is similar to right inner seal portion 27B'. Thus,
left inner seal portion 27B includes mounting portion 131 having
inside and outside walls 130, 132 defining space 35 for receipt of
door 18 therebetween. Second sealing lobe 142 again includes lobe
tip 144 joining inside and outside walls 134, 138, which cooperate
to define a generally triangular hollow 146.
[0064] The lack of an outer sealing lobe in seal portion 27B
facilitates the redundantly sealed configuration shown in FIG. 9
Inner seal portion 27B', which has the same cross-section as outer
seal portion 23B of FIG. 7, allows severe deformation of lobe 142
into pocket 137 when doors 18, 20 are moved from the open
configuration (FIG. 8) to the closed configuration (FIG. 9). In the
case of inner seal portion 27B', however, this deformation is
caused by interaction between the pair of second sealing lobes 142
of left and right inner seal portions 27B, 27B', rather than
interaction between second sealing lobe 142 and wall 17 (FIG.
7).
[0065] As illustrated in FIG. 9, this lobe-on-lobe interaction
causes mutual elastic deformation, resulting in a tortuous, arcuate
contact profile therebetween. The contacting portions of the pair
of lobes 142 also occupies a large proportion of the area between
inside wall 134 of right-side lobe 142 (of right inner seal portion
27B') and outside wall 138 of the left-side lobe 142 (of left inner
seal portion 27B), as illustrated. Advantageously, this tortuous,
large-area contact provides a robust liquid-tight inner seal
between doors 18, 20 which is resistant to outside forces such as
vibration, shock and wind. In addition to the seal provided by
interaction between the pair of sealing lobes 142, first sealing
lobe 141 of seal portion 27B' also cooperates with outer wall 132
of seal portion 27B to create an outer seal, as noted above,
thereby isolating the inner seal from most or all of the elements
outside cargo box 15 (FIG. 1).
[0066] In FIG. 9, a relatively narrow gap width G.sub.N is shown
between left door 18 and right door 20. However, seals 24, 24' are
capable of providing a liquid-tight seal across a range of gap
widths between doors 18, 20. Referring to FIG. 10, a much wider gap
width G.sub.W is shown in conjunction with inner seal portions 27B,
27B'. As illustrated, lobe-on-lobe interaction still causes mutual
elastic deformation, such that contact between inside wall 134 of
right-side lobe 142 (of right inner seal portion 27B') and outside
wall 138 of the left-side lobe 142 (of left inner seal portion 27B)
still occurs. Further, it can be seen that first sealing lobe 141
is long enough to ensure that deflectable tip 140 can still
contact, and bias against outside wall 132 in similar fashion to
first sealing lobe 41 described above. In an exemplary embodiment,
the gap widths G.sub.N, G.sub.W accommodated by inner seal portions
27B, 27B' may be as small as 0.20 inches, 0.25 inches, or 0.30
inches or as large as 0.63 inches, or any range defined by any of
the foregoing values.
[0067] Advantageously, maintaining a common cross section of lobe
142 around the entire periphery of seals 24, 24' may cooperate with
the use of miter-cut edges (shown in FIGS. 2A-2C and described in
detail below) to create continuity of walls 134, 138 and tip 144 at
the corners of seals 24, 24'. Put another way, hollows 146 may
create a continuously sealed cavity around the entire periphery of
seals 24, 24', including the corners thereof. Thus, a continuous
lobe extends uninterrupted around the entire periphery of doors 18,
20, eliminating potential leak paths at the corners of doors 18,
20, in the same manner as along the edges of doors 18, 20. The
cavity defined by hollows 146 similarly extends uninterrupted
around the entire periphery of seals 24, 24'.
[0068] However, it is contemplated that special unique cross
sections may be used for both left and right inner seal portions
27B, 27B'. For example, second sealing lobe 142 may be shortened on
right inner seal portion 27B', i.e., the inner seal portion of the
later-closed truck door, which is right door 20 in the illustrated
embodiment. Shortening this second sealing lobe 142 while leaving
all other second sealing lobes the same height may, for example, be
employed where narrow gap width G.sub.N (FIG. 9) is observed, in
order to avoid impingement of lobe 142 on outside wall 132 of left
inner seal portion 27B as right door 20 is closed. Similarly, left
inner seal portion 27B may have a different, unique cross-section
as compared to all other sealing portions, such as by relocating or
reconfiguring the geometry of second sealing portion 142, in order
to optimize the fluid-tightness of the seal. It is contemplated
that continuity of lobes 142 around the periphery of seals 24, 24'
may also be maintained with alternative manufacturing methods, such
as injection-molded corners (as described below).
[0069] Referring now to FIGS. 11-13, a cross-section of another
exemplary embodiment of seals 24, 24' is shown. Seals 27C, 27C' are
similar to seals 27B, 27B' described above, and reference numbers
in FIGS. 11-13 refer to analogous structures shown in FIGS. 8-10
and described above with respect to seals 27B, 27B'. However, lobes
242 define thickness T.sub.2 which is less than thickness T.sub.1,
and is less than the corresponding thicknesses defined by mounting
portion 231. In an exemplary embodiment, thickness T.sub.2 is about
0.085 inches. This reduced thickness T.sub.2 facilitates easier
elastic deformation of the pair of lobes 242 when doors 18, 20 are
in the closed position, as shown in FIGS. 12 and 13. Thus, the
tortuous, arcuate path defined by contact between inside wall 234
of right-side lobe 242 (of right inner seal portion 27B') and
outside wall 238 of the left-side lobe 242 defines an even larger
contact area therebetween.
[0070] Further, the embodiment illustrated 11-13 includes a longer,
more inwardly curved first sealing lobe 241. This additional length
and curve increases the biasing force applied by sealing lobe 241
against outer wall 232 when doors 18, 20 are in the closed
configuration, as shown in FIGS. 12 and 13.
[0071] Referring now to FIG. 14, a cross-section of yet another
exemplary embodiment of seals 24, 24' is shown. Seals 27D, 27D' are
similar to seals 27C, 27C' described above, and reference numbers
in FIGS. 11-13 refer to analogous structures shown in FIGS. 11-13
and described above with respect to seals 27C, 27C'. However, inner
and outer walls 330, 332 of mounting portions 331 are spaced
farther apart to accommodate larger doors 18A, 20A. For example,
doors 18, 20 may have a thickness of about 0.50 inches, while doors
18A, 20A may have a thickness of about 0.75 inches. Outer walls 332
of seals 27D, 27D' also include a chamfered edge 339, which avoids
or minimizes application of forces to outer wall 339 (such as by a
truck operator opening and closing doors 18A, 20A which might
otherwise urge seals 27D, 27D' to "roll off" of doors 18A, 20A.
Seals 27A, 27A', 27B, 27B', 27C and/or 27C' may include similar
such chamfers.
[0072] Lobes 342 of seals 27D, 27D' may define thickness T.sub.2'
which is less than thickness T.sub.2 described above with respect
to seals 27D, 27D', and is less than the corresponding thicknesses
defined by mounting portion 331. In an exemplary embodiment,
thickness T.sub.2.sup.' is about 0.054 inches.
[0073] Referring now to FIGS. 15 and 16, cross-sections of two
additional exemplary embodiments of seals 24, 24' is shown. Seals
27E and 27F are similar to seals 27A, 27A' described above, and
reference numbers in FIGS. 15 and 16 refer to analogous structures
shown in FIGS. 3-6 and described above with respect to seals 27A,
27A'. Seals 27E and 27F are adapted to be fitted onto a
first-closed door of a pair of trailer doors, such as left door 18
in the illustrated embodiment. Each of the illustrated inner seal
portions includes an additional feature adapted to reinforce the
sealing lobe of the seal and to prevent or restrict a rolling
motion of the seal inwardly in a direction toward the interior of
the trailer upon closing of the second door as the sealing lobes of
the pair of seals engage one another.
[0074] Referring to FIG. 15, for example, inner seal portion 27E
includes auxiliary reinforcement lobe 70 adapted to face the
interior of cargo box 15 (FIG. 1). Reinforcement lobe 70 is
disposed substantially at the junction between wall 48 and diagonal
wall 54 of sealing lobe 52. Auxiliary reinforcement lobe 70
provides additional material at this junction, which strengthens
seal portion 27E and acts to prevent the above-described rolling of
seal portion 27E upon contact with seal portion 27A' (FIG. 5) as
sealing lobe 42 of seal portion 27A' engages sealing lobe 52 of
seal portion 27E.
[0075] Referring to FIG. 16, in a still further embodiment, wall 48
of inner seal portion 27F may include a pocket or hollow portion 72
disposed proximate the junction between wall 48 and diagonal wall
54 of sealing lobe 52. A reinforcing strip of steel 74, or other
rigid material such as a rigid plastic, for example, may be
received within pocket 72, which reinforces wall 48 of seal portion
27F and aids in preventing the above-described rolling of seal
portion 27F upon contact with seal 27A' (FIG. 5) as sealing lobe 42
of seal portion 27A' engages sealing lobe 52 of seal portion
27F.
[0076] 2. Seal Installation and Use
[0077] As noted above, seals 24, 24' are unitary, monolithic seals
having upper, outer, lower and inner seal portions 21, 23, 25, 27
(or 27') joined by fused corners. In an exemplary embodiment, seals
24, 24' are also made from a resiliently elastically deformable
material, such as EPDM (see also "Methods of Seal Production"
section below).
[0078] For simplicity, installation will be discussed with respect
to left seal 24 on left door 18. Installation of any seal made in
accordance with the present disclosure to any door or panel can be
accomplished in a similar manner.
[0079] To install seal 24 to left door 18 (FIG. 1), any two
adjacent corners of seal 24, such as the top corners, are attached
to the appropriate corresponding corners of door 18. Opposing
corners may also be used as the first two corners of attachment. In
an exemplary embodiment, seal 24 may be sized to require a slight
stretch of seal 24 to bring the second seal corner into alignment
with the second door corner. For example, the seal may be stretched
as little as 3% or as much as 15% or 30%, or may not be stretched
at all. The third and fourth corners are similarly attached to
their respective door corners, leaving seal 24 loosely attached to
door 18.
[0080] Next, one of seal portions 21, 23, 25, 27, such as upper
seal portion 21, is attached to the corresponding edge of door 18.
To effect such attachment, inside and outside walls 30, 32 are
aligned with door 18 and worked until space 35 is fully occupied by
door 18. Once fully installed, door 18 is encapsulated by the
closed profile of seal 24, i.e., the entire outer periphery of door
18 is covered over by seal 24. As a result of this encapsulation,
no leak paths are present around the periphery of the door.
[0081] Optionally, adhesive may be applied to space 35 prior to,
during or after the seal portion is attached to the door edge. In
one exemplary embodiment, a special spreader tool with an adhesive
nozzle may simultaneously seat space 35 on door 18 while applying a
layer of adhesive therebetween. In another embodiment, seals 24,
24' may be mechanically fastened to doors 18, 20, such as by
driving screws through seals 24, 24' and into respective doors 18,
20. For example, screws may be driven through inside or outside
walls 30, 32 (or 130, 132) of mounting portion 31 (or mounting
portion 131), through concave hemispherical wall 37, or through
pocket 137.
[0082] Advantageously, the attachment of seal portions 21, 23, 25,
27 to corresponding door edges after the securement of the seal
corners to the door corners ensures even tension throughout the
seal material (provided such tension is imparted to the seal
material, i.e., by stretching). This even tension promotes even
seal seating against the adjacent surfaces of rear frame 16, as
described above, which in turn promotes a long-lasting fluid-tight
seal.
[0083] Right seal 24' is then installed to right door 20 in a
similar manner. With both of seals 24, 24' so installed, effecting
the seal is accomplished by simply closing doors 18, 20 in the
designated order. The first door to be closed is the door with
inner seal portion 27, i.e., the inner seal portion lacking either
of first sealing lobes 41, 141. In the illustrated embodiment shown
in the figures, this is left door 18. The first door may be secured
in the closed position, such as by activating latch assembly 22.
The second door is then closed over the first door, which engages
right inner seal portion 27' with left inner seal portion 27 as
described above. The second door may similarly be locked by
activating the other of latch assemblies 22.
[0084] Where inner seal portion 27F with solid strip 74 (FIG. 16)
is used, solid strip 74 may be made shorter than the final
stretched length of seal portion 27F (i.e., the seal length after
installation on one of doors 18, 20). As seal portion 27F is
stretched during installation, solid strip 74 can move within
pocket 72 to effectively allow pocket 72 to lengthen while solid
strip 74 maintains its original length. Thus, solid strip 74 will
still provide additional support to most of the seal portion in
which it is installed.
[0085] Advantageously, the range of gap widths accommodated by
seals 24, 24', (i.e., gaps between narrow gap width G.sub.N and
wide gap width G.sub.W described above and illustrated in FIGS. 9
and 10) allows seals 24, 24' to be retrofitted on a wide variety of
trailers in differing states of repair. Moreover, seals 24, 24' can
be used as frame seals for many applications, such as for overseas
shipping containers, exterior doorways, or any other application in
which a door must sealingly engage a correspondingly sized
aperture.
[0086] As noted herein, seals 24, 24' are unitary, monolithic and
elastically deformable devices. These unique qualities allow seals
24, 24' to be collapsed into a small package, such as a typical
cube-type shipping box, without compromising the integrity or
effectiveness of seals 24, 24'. In an exemplary embodiment, a
shipping box sized to fit both seals 24, 24' is approximately 13
inches wide, 13 inches long and 13 inches tall. Advantageously,
seals 24, 24' may be folded, rolled, or stuffed into such a box,
and the box may then be shipped to a remote location where the seal
is unfolded, unrolled or unstuffed to be applied to a flat panel
(such as rectangular doors 18, 20) defining a maximum dimension
substantially larger than the maximum dimension of the shipping
box. Advantageously, seals 24, 24' do not permanently deform (i.e.,
no deformation set occurs) in the shipping box, such that seals 24,
24' easily "spring back" into their originally formed shape after
being removed from the package.
[0087] In addition, the packability of seals 24, 24' allow extra
seals 24, 24' to be compactly stored and procured on short notice.
For a seal having inner seal portion 27F (FIG. 16) having solid
strip 74, solid strip 74 may be pliable enough to be folded or
rolled, or may be installed separately within pocket 72 after
unpacking the seal with seal portion 27F.
[0088] 3. Methods of Seal Production
[0089] In an exemplary embodiment, each of the seal portions 21,
23, 25, 27, 27' are produced independently by extruding pliable
material at an elevated temperature through an appropriately shaped
die. As noted above, a common extrusion may be used for upper,
outer, and lower seal portions 21, 23, 25. A single continuous
strip of extruded material may therefore be produced and cut to
length for these three seal portions, with the same or a unique
extrusion profile used for the fourth, inner seal portion 27 or 27'
as described above. Respective ends of the four seal portions are
then fused to one another to form seals 24, 24' into unitary,
monolithic truck door seals having a generally rectangular central
opening 28 (FIG. 1). Methods of fusing the corners in accordance
with the present disclosure are discussed in detail below.
[0090] As mentioned above, seals 24, 24' may be made of a
resilient, elastically deformable/compressible material. Such
materials may include natural rubber, silicone, isoprene, ethylene
propylene ("EPM") or ethylene propylene diene monomer ("EPDM")
rubber, a mixture of cross-linked EPDM rubber and polypropylene,
such as SANTOPRENE.RTM. (SANTOPRENE.RTM. is a registered trademark
of the Exxon Mobil Corporation of Irving, Tex.), or any other
suitable material. In an exemplary embodiment, the material used
for seals 24, 24' has good resistance to compression set, resists
degradation from exposure to UV light and other environmental
impacts, and remains pliable in cold temperatures.
[0091] In the illustrated embodiment of the present disclosure, the
seal material is made from EPDM, which has been found exhibit the
above-mentioned exemplary qualities for superior longevity in the
environments normally encountered by shipping trailers. For
example, normal use of a truck door seal made in accordance with
the present disclosure may subject the seal to repeated
deformations over time, such as by repeated opening and closing of
the doors to which the seal is attached, or to vibrations and
deformations resulting from movement of the vehicle with which the
doors are associated. Forming the seal from a material highly
resistant to compression set, such as EPDM, renders the seal
well-suited for use in the potentially harsh service environments
encountered in the shipping industry. Even after repeated
deformations, the above-mentioned seal materials maintain their
original shape and elasticity and are therefore able to maintain
the desired sealing effect over time. In an exemplary embodiment
EPDM having a durometer of about 60 may be used. When the seals are
monolithic, the durometer of the entirety of such seals is the same
throughout respective seal cross sections.
[0092] Two exemplary methods of fusing the seal portion corners
include fusing the seal portions at a miter cut and injection
molding the seal corners. In the first method, seals 24, 24' are
miter cut at their edges at 45.degree. angles and heat fused. The
heat fusing of the extrusion members may be effected in various
ways including fusing of mitered edges and injection molding.
[0093] In an exemplary embodiment, the extrusion members may be
extruded from compressible, resilient elastomeric material that is
cut to have mitered ends, as noted above. Referring to FIG. 2D,
showing an apparatus for fusing miter seal corners to one another,
these mitered ends are then inserted into seal portion holders 504,
which each include lower block 506, upper block 508, and center
block 510. When assembled as shown in FIG. 2D, blocks 506, 508, 510
cooperate to define mirror-image apertures 512 corresponding to the
cross-section of a seal portion, such as seal portions 21, 23. When
seal portions 21, 23 are disposed within respective apertures 512,
each seal portion 21, 23 is well-supported such that the shape is
maintained through the rest of the fusing process.
[0094] Apertures 512 each define a longitudinal axis A (FIG. 2D)
corresponding to a longitudinal axis of seal portions 21, 23. The
longitudinal axis of seal portions 21, 23 may be considered to be,
for example, an axis parallel to the direction of extrusion of seal
portions 21, 23. In the case of seal portions The ends of seals
portions 21, 23 are miter-cut at a certain angle, such as
45-degrees as discussed above, such that the pair of longitudinal
axes A form a 90-degree angle when the ends are abutted to one
another as shown in FIGS. 2A-2C. Inner faces 514 of seal holders
504 each define the same angle with respect to the respective
longitudinal axes of apertures 512, such that end surfaces 516, 518
of seal portions 21, 23 are flush with inner faces 514 when seal
portions 21, 23 are secured within apertures 512.
[0095] With seal portions 21, 23 secured within apertures 512,
ribbon 502 is positioned between seal holders 504, and seal holders
504 are then moved inwardly (e.g., along slide 505) toward one
another into abutting contact, and are held together. Heat is
locally applied to simultaneously heat end faces 516, 518 of seal
portions 21, 23 and melt ribbon 202, such as by direct conduction
through seal holders 504, for example. This heat operates to fuse
the mitered ends together. Alternatively, an uncured liquid may be
applied to one or both of seal portions in lieu of ribbon 202. As
illustrated in FIG. 2C, the material of ribbon 202 may melt away
within cavity 146 such that the pair of cavities 146 of seal
portions 21, 23 form one continuous cavity traversing the newly
formed corner between seal portions 21, 23.
[0096] Once the material has sufficiently hardened and/or cured and
with seal holders 504 still in abutting contact, upper blocks 508
are moved upwardly (e.g., along slides 509) and center block is
moved or pivoted away, leaving seal portions 21, 23 exposed. The
fused seal portions may then be removed by lifting away from lower
block 506.
[0097] In some instances, the extrusion members may retain a
residual heat from the extrusion process, which allows the mitered
ends of separate extrusion members to fuse to one another when the
ends are held together without the use of ribbon 202.
[0098] The one-piece monolithic seal, after heat fusing, may then
be installed onto a semi-trailer truck door by stretching the seal
around the edges of the door as described above.
[0099] In the second method of fusing the seal portion corners,
each seal portion may have regular or plain-cut ends, i.e., the cut
face may be transverse to the direction of extrusion. These cut
ends may then be placed adjacent one another beneath an injection
molding head and adjacent an injection-molding die, with a corner
of the cuts touching or nearly touching. The void at the seal
corner is then filled by injecting molten seal material into the
injection-molding die, and allowing such molten rubber to contact
and fuse to each seal end.
[0100] However the corners are fused, the first and second sealing
lobes 41, 42 (or 141, 142, 241, 242, etc.) form a continuous and
uninterrupted "bulbs" around the entire periphery of the seal. To
create this continuity of the sealing lobes, the material of one
seal portion lobe is directly joined to the material of another
seal portion lobe by the corner structure. In the case of a mitered
joint, for example, the sealing lobes of one seal portion extend
outwardly at 45-degrees to meet and are directly fused to
complementary sealing lobes also extending at 45-degrees. In the
case of an injection-molded corner, the cross-sectional geometry of
the corners is controlled by the injection-molding die for a given
corner to ensure that the lobes are similarly continuous through
the corners.
[0101] The injection-molding die may have a different
cross-sectional geometry compared to the two adjacent seal portion
cross-sections (which may be different from one another, as
discussed above). However, an exemplary injection-molding die is
formed to create corners having substantially the same
cross-sectional area as the adjacent seal portions. Keeping the
cross-sectional area constant throughout the corners, whether by
injection molding or fusing mitered corners, prevents the formation
of "harder" or otherwise dissimilar material properties at the seal
corners, and ensures that the seal will have consistent stretch,
deformability and pliability throughout. To further enhance this
consistency in the physical properties of seals 24, 24', the
injection-molded corners will have voids adjacent to cylindrical
and/or triangular hollows 46, 146 (FIGS. 4 and 8). The voids leave
an absence of material next to hollows 46, 146 to ensure that
second deformable sealing lobes 42, 142 will deform near the
corners in the same manner as in the middle of a respective seal
portion.
[0102] To produce seals 24, 24' with injection-molded corners, up
to six separate dies may be used. An upper/outside die is formed to
fuse the corners between upper portion 21 and outer portion 23 of
seals 24, 24'. A lower/outside die is a mirror image of the
upper/outside die and forms the corners between lower portion 25
and outer portion 23 of seals 24, 24'. A left upper/inside die is
specially adapted to merge the dissimilar cross-sections of upper
portion 21 and inner portion 27 of seal 24. A left lower/inside die
is a mirror image of the left upper/inside die and forms the corner
between lower portion 25 and inner portion 27 of seal 24.
[0103] It is also contemplated that the lower/outside and
upper/outside corners may be formed by a single die, bringing the
total number of dies down to five. Further, an identical
cross-section can be used for all four sides on one of seals 24,
24', potentially allowing the upper/inside and lower/inside corners
to be formed by the same die used for the corresponding outside
corners. In this case, the total number of dies required for the
corners may be as few as three.
[0104] A right upper/inside die is optional, and is used where
right inner seal portion 27' has a different, unique
cross-sectional geometry as compared to the other portions of seal
24'. Where used, the right upper/inside is specially adapted to
merge the dissimilar cross-sections of upper portion 21 and inner
portion 27' of seal 24'. A right lower/inside die is used in
conjunction with the right upper/inside die, and is a mirror image
of the right upper/inside die for forming the corner between lower
portion 25 and inner portion 27' of seal 24'. Where a uniform
cross-sectional seal geometry is used for all four sections of
right seal 24', the upper/outside die can be used for the
lower/inside corner of right seal 24', and lower/outside die can be
used for the upper/inside corner of right seal 24'.
[0105] While this invention has been described as having an
exemplary design, the present invention can be further modified
within the spirit and scope of this disclosure. This application is
therefore intended to cover any variations, uses, or adaptations of
the invention using its general principles. Further, this
application is intended to cover such departures from the present
disclosure as come within known or customary practice in the art to
which this invention pertains and which fall within the limits of
the appended claims.
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