Note: Descriptions are shown in the official language in which they were submitted.
CA 02600598 2007-09-07
CORNER JOINING OF STRUCTURAL MEMBERS
Related Applications
This application claims the benefit of U.S. Provisional Application No.
60/842,720 filed
September 7, 2006.
Field of the Invention
The present invention relates generally to methods for joining lineal
structural members,
and, more particularly, to joining the corners of structural members for use
in fenestration, such
as windows and doors.
Background of the Invention
The advantages of hollow lineal structural members for use in fenestration are
well
known. For example, economically produced window sashes made from hollow
extrusions of
polymeric materials, such as PVC, provide adequate strength and appearance for
many
applications. A hollow extruded polymeric lineal member requires less material
than would a
comparable solid member, yet in many cases still provides adequate structural
strength. In
addition, once the extrusion die is in place, lineal meinbers having even the
most complex cross
sectional profiles can be produced at a high rate, with relatively little
waste. When greater
structural strength is needed, as might occur in door panels, for example,
reinforced polymeric
materials, such as glass fiber reinforced hollow pultrusions, can be used.
The advantages of hollow polymeric lineals notwithstanding, the use of members
made
from such materials has presented some challenges, particularly in joining of
such members to
form a complete structure. This has been especially true in the joining of
hollow pultruded
members, since an advantage of pultruded members is that they can be made with
relatively thin
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CA 02600598 2007-09-07
walls. Additionally, pultruded members typically utilize thermosetting
polymers, which often
tend to be brittle, and are typically not weldable. As a result, pultruded
members may not be
readily fastenable by conventional mechanical fasteners. In cases where a
mitered corner can be
used, right angle inserts, or corner keys, have proven useful. The corner keys
are inserted into
the ends of the lineal members and attached to the members by adhesives,
mechanical fasteners,
or combinations thereof. There are cases, however, in which mitered joints are
not desirable.
For example, it is often desirable to produce a fenestration component, such
as a door panel or a
window sash, from hollow structural members that maintain a traditional wood
appearance,
more specifically, the appearance of a wooden structure joined by mortise and
tenon joints.
Summary of the Invention
The present invention provides a system for joining hollow structural members
in a
mortise and tenon manner. The system is particularly useful for joining thin
walled lineal
polymeric members, in particular pultruded lineal members, wherein a high
level of joint
strength and closeness of fit is required. In forming a joint according to the
present invention, an
end portion of a first lineal structural member is abutted to a side portion
of a second lineal
structural member. Joining is accomplished by the use of a coupling member in
the form of an
insert having a base plate adapted to engage the internal profile of the first
structural member,
with a first, internal, web attachment portion attached to a first side of the
base plate and a
second, external, tenon portion, attached to a second side of the base plate.
The first structural
member is adapted to receive, in one end, the first web attachment portion of
the insert, while the
second structural member is adapted to receive the tenon portion of the insert
through one or
more transverse, mortise-like, openings.
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Particularly useful embodiments of the system are those in which the second
lineal
structural member has a cross sectional profile comprising features such as
channels or
projections with which the mating end of the first member can be fabricated to
fit. The first
structural member may further comprise one or more internal longitudinal webs
adapted to
receive the attachment portions of the insert member. The attachment portions
of the insert
member, along with the receiving portions of the first structural member, are
adapted to provide
a maximum load bearing area, with a minimum of stress concentration, thereby
increasing the
load bearing capacity of the joint. A particularly useful insert is one having
a hook-like first
attachment portion that is resiliently moveable so as to allow it to hook into
an opening in an
internal web of the first lineal member.
It will be understood that while the embodiments disclosed herein involve
lineal
members, other types of members can also be joined, provided they incorporate
the appropriate
hollow spaces for receiving and engaging the coupling inserts. As used herein,
the term hollow
member will refer to a member having hollow portions in areas that receive
coupling inserts.
Such members may have other portions, not involved with the coupling inserts,
that are not
hollow.
Description of the Drawings
Figure 1 is an exploded view of a structure for joining two hollow lineal
members having
rectangular cross sectional profiles.
Figure 2 is a partially assembled exploded view of the structure portrayed in
Figure 1.
Figure 3 portrays the structure shown in Figure 1 after assembly but prior to
installation
of screws.
Figure 4 is a sectional view of the structure shown in Figure 3.
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Figure 5 is a sectional view of a structure for joining two hollow lineal
members at an
angle other than 90 .
Figure 6 is sectional view of a structure for joining two hollow members using
a coupling
insert having solid alignment arms to enhance alignment of the insert relative
to a lineal member.
Figure 7 is a sectional view of a structure for joining two hollow lineal
members using a
coupling insert having two hook portions.
Figure 8 is a sectional view of a structure for joining two hollow lineal
members using a
coupling insert having two hook portions and a detent portion.
Figure 9 is a sectional view, prior to assembly, of a structure for joining a
first hollow
lineal member to a second hollow lineal member using a coupling insert
attached to the first
member, wherein the coupling insert has an extended portion that engages a
channel portion in
the second member.
Figure 10 is a sectional view of the structure shown in Figure 9 after
assembly, but prior
to installation of screw(s).
Figure 11 portrays a cross sectional profile of a lineal member suitable for
use as a top
rail or a bottom rail of a door panel frame.
Figure 12 portrays a coupling insert suitable for use with the lineal member
portrayed in
Figure 11.
Figure 13 portrays the coupling insert shown in Figure 12 after installation
in the lineal
member shown in Figure 11.
Figure 14 is a sectional view of the coupling insert and lineal member shown
in Figure
13.
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Figure 15 portrays a cross sectional profile of a lineal member suitable for
coupling to the
lineal member portrayed in Figures 11 and 13.
Figure 16 portrays an assembled structure for coupling the Iineal member
portrayed in
Figure 11 to the lineal member portrayed in Figure 15, using the coupling
insert portrayed in
Figure 12.
Figure 17 portrays the assembled structure shown in Figure 16, with a cutaway
view of a
channel for receiving a sealant for sealing an exterior joint.
Figure 18 portrays a structure having a coupling insert utilizing two tenon
portions.
Figure 19 portrays a coupling insert suitable for use in the structure shown
in Figure 18.
Figure 20 portrays an alternative embodiment of a coupling insert.
Figure 21 is a sectional view of a structure utilizing the coupling insert
shown in Figure
20.
Figure 22 portrays a structure utilizing an alternative embodiment of a
coupling insert for
coupling two hollow lineal members.
Figure 23 is a side view of the coupling insert shown in Figure 22.
Figure 24 portrays yet another embodiment of a coupling insert.
Figure 25 poi-trays a door panel frame utilizing the joining structures
disclosed herein.
Figure 26 portrays a door panel frame utilizing the joining structures
disclosed herein and
further incorporating a midrail.
Figure 27 portrays a cross sectional view of a hollow lineal member suitable
for use as a
midrail for the door panel frame portrayed in Figure 26.
Figure 28 portrays a door panel frame utilizing the joining structures
disclosed herein and
further incorporating a midrail and a center stile.
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Figure 29 is a sectional view of a structure using a coupling insert to join
two lineal
members, with provision for injecting a flowable foaming material.
Figure 30 portrays a door panel frame prepared for foam injection into the
stiles.
Detailed Description
In the embodiment portrayed in Figures 1-4, a first hollow lineal structural
member 10 is
joined perpendicularly to second hollow lineal member 12, in a mortise and
tenon manner, by
coupling insert 13. As used herein, the term lineal member will refer to an
elongated member
having a substantially constant cross section over its length. Lineal members
may be stock
materials of indefinite length, from which members of a predetermined length
can be cut, or may
be members of a defined length. Also, as used herein, "hollow" means that at
least some portion
of the lineal member comprises an inner space or cavity. The ends of lineal
members may be cut
at any suitable angle to the longitudinal direction, in a smooth single cut
fashion, or may be cut
in a manner defining a variety of shaped end cuts, or end fabrications, that
may be needed, for
example, to fit an end portion of a first lineal member to a side portion of a
second lineal member
having a particular, perhaps complex, cross sectional profile. In the
embodiment portrayed in
Figure 1, the cross sectional profile of lineal member 12 is a simple
rectangle, and member 10 is
to be joined perpendicularly to member 12, so that end portion 11 of lineal 10
can be formed in a
simple, single cut, manner, in a plane oriented at 90 to the longitudinal
direction of member 10.
Referring to Figure 2, a first member 10 is joined to second member 12 by
first installing
insert 13 in end portion 11 of member 10. Referring to Figures 3 and 4, first
member 10 is then
assembled with second member 12 by inserting tenon portions 136 and 138 of
insert 13 into
transverse openings 122 and 124 provided in member 12. Additionally, a solid
core member, or
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CA 02600598 2007-09-07
core block, 21, is inserted into cavity 123 of member 12. Referring to Figure
4, insert 13 is held
in place by hook portion 132, which is fixedly attached to hook arm 133, which
is in turn fixedly
attached to base plate 134. Hook arm 133 is adapted to resiliently hold hook
portion 132 in a
position that enables it to snap into web opening 103 upon insertion of insert
13 to a suitable
depth, so as to hold insert 13 in place under tensile loads tending to pull it
out from member 10.
Insert 13 is held in alignment relative to lineal member 10 by base plate 134,
which is adapted to
match at least a portion of the profile of internal surface 101 of lineal
member 10. Tenon portions
136 and 138 are fixedly attached to base plate 134 so as to extend from end 11
of member 10. It
will further be noted that internal web 106 has been cut back to surface 107
to allow space for
insert 13 to be installed.
Opening 103 can be produced by a drill that first drills access hole 102, and
then drills
through web 106 to produce opening 103. While it is not required that opening
103 be circular
in shape, the circular shape is convenient, in that it can be produced by a
simple drilling
operation. The circular shape has the further advantage that it avoids sharp
corners that could
produce stress concentrations that might cause breakage of web 106. It will be
recognized that
alternative methods of producing opening 103 may be used. For example, a right
angle punch or
other suitable cutting device, of one of the various types known to those
skilled in the art, could
be inserted through end 11 to punch out or otherwise produce aperture 103.
Producing aperture
103 using a tool that could be inserted through end 11 of member 10 would have
the advantage
of eliminating the need for hole 102.
Second member 12 is adapted to receive tenon members 136 and 138 through
transverse
openings 122 and 124, respectively. Member 12 is further adapted to receive
screws 302
through clearance holes 211 and 212 in edge web 1202 and clearance holes 213
and 214 in core
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block 21, and through clearance holes 426 and 428 of internal web 126. Screws
302 are thus
able to self-thread into tenon portions 136 and 138, respectively. It will be
recognized that while
screws 302 are portrayed as self threading in this embodiment, alternative
embodiments in which
tenon portions 136 and 138 contain pre-threaded holes are also contemplated.
It will be further
recognized that while screws 302 are portrayed in the various drawings
contained herein as
flathead screws, other types of screws may also be useful in certain
applications. For example,
holes 211, 212, 213, and 214 may be counterbored and round or hex headed
screws used.
Counterboring also provides the opportunity for covering the heads of screws
302 with plugs,
sealant, or other covering materials. It will also be recognized, however,
that when the heads of
screws 302 seat against outer web 1202 rather than against core block 21, the
load imposed by
screws 302 is shared between web 1202 and core block 21.
It will also be recognized that tenon portions 136 and 138 need not be
circular in cross
section. Tenon portions could be rectangular in cross section, or could be of
a variety of other
cross sectional shapes. The space between tenon portions 136 and 138 could be
filled with a
connecting web, so as to produce a single tenon portion. Circular cross
sections, on the other
hand, provide the advantage that openings for receiving the tenon portions can
also be circular,
thereby reducing the likelihood of breakage due to stress concentrations and
allowing convenient
production by simple drilling operations.
Insert 13 can be conveniently produced by injection molding of a thermoplastic
polymeric material. The polymers suitable for insert 13 are not particularly
limited, though
materials that are capable of forming strong couplings with self threading
screws are often
preferred. Fillers and other additives may be used in the resin formulation,
as would be apparent
to one of ordinary skill in the art. A particularly useful property of
materials for insert 13 is the
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CA 02600598 2007-09-07
ability to provide good adhesion to commonly used adhesives and sealants.
Since insert 13 is
typically not visible in the finished product, appearance of the part may be
of less importance,
compared to the importance of mechanical strength or robustness under extreme
environmental
conditions such as extreme ranges of temperatures. A particularly useful
polymeric material for
insert 13 is glass filled polyamide.
Other materials and manufacturing methods for insert 13 are also contemplated.
For
example, metal inserts could be incorporated into a molded part, to achieve
greater mechanical
strength or improved thread holding. In another embodiment, insert 13 could be
made from a
thermosetting, rather than a thermoplastic material. In yet another
embodiment, die cast metal
could be used in place of injection molded polymeric materials. Inserts
assembled from more
than one piece are also contemplated. In still another embodiment, the insert
could be made of
one or more pieces of sheet metal by, for example, stamping, bending, and
possibly welding.
It is typically preferred that end surface 1200 of member 12 match side
surface 1000 of
member 10, to form a smooth continuous surface. The matching of surfaces 1000
and 1200 can
be controlled by the location and sizing of openings 122 and 124 in member 12.
Openings 122
and 124 can, for example, be precisely located and sized to provide a
relatively snug fit so as to
assure alignment of surface 1000 and end 1200.
Core block 21 serves to support outer web 1202 and to distribute the load of
screws 302
over a wider area of web 126, thereby reducing the likelihood of failure due
to breakage of web
126, and allowing it to be made thinner, in some instances. Core block 21 also
serves to receive
fasteners such as screws for attaching hinges and other fittings. Materials
suitable for core block
21 are not particularly limited, though preferred materials are those of
moderate elastic modulus,
so as to enable them to conform sufficiently to surface 127 of web 126 to
distribute effectively
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CA 02600598 2007-09-07
load stresses over the surface 127 of web 126. It is further preferred that
core block 21 be
formable and drillable by conventional methods. It has been found that a
particularly useful and
cost effective material for core block 21 is wood. While core block 21 is
portrayed in Figure 4 as
a relatively short member, it will be recognized that it could extend for a
greater distance, and
may serve the additional function of stiffening member 12. It will also be
recognized that while
core block 21 is shown as being rectangular in shape, other suitable shapes
may also be useful.
For example, portions of the cross section of core block 21 may be removed to
limit contact with
the interior surface of member 12 to only selected areas, for example, those
areas that might be
best able to withstand stress without excessive deformation or breakage. It
may also be useful to
remove certain portions of the cross section of core block 21 to ease its
insertion into member 12.
Referring to Figure 5, lineal members can be joined at angles other than 90 .
First lineal
member 59 is cut at angle 0 to produce the joint portrayed. Openings 553, 554,
557, and 559 are
provided to receive tenon portions 556 and 558. It will be appreciated that
while tenon portions
556 and 558 are portrayed as being of different lengths, there may be
situations in which they
could be of the same length, with the depths of openings 557 and 559 being
adjusted to properly
accommodate them. Clearance holes 560 and 562 are drilled concentric with
holes 571 and 572
of tenon poi-tions 556 and 558, and counterbores 564 and 566 are drilled
concentric to holes 560
and 562. The holes can be located using appropriate locating fixtures or other
locating devices,
as would be apparent to one skilled in the art. Holes 571 and 572 in tenon
portions 556 and 558
are sized to allow threading of screws 302 into them, while holes 560 and 562
are sized to
provide clearance for screws 302, and counterbores 564 and 566 are sized to
allow clearance for
the heads of screws 302. While counterbores 564 and 566 are shown as being
relatively deep, it
CA 02600598 2007-09-07
is contemplated that they need not be of the depth shown, and could instead be
only deep enough
to provide adequate seating of the heads of screws 302.
In a third embodiment, portrayed in Figure 6, alignment of insert 63 relative
to first lineal
member 61 is enhanced by solid alignment arms 640 and 642, which engage
internal surface 601
of member 61. Additionally, alignment and positioning of lineal member 62
relative to member
61, both during and after assembly, can be enhanced by additional internal web
622. It will be
recognized that while added web 622 and alignment arms 640 and 642 are shown
together in
Figure 6, they are separate features that need not be used together in the
same joint.
In yet another embodiment, portrayed in Figure 7, the strength of the joint
between lineal
members 71 and 74 is enhanced by dual hook portions 732 and 734 of insert 73,
which distribute
the tensile load over two webs, rather than one, as in previous embodiments.
This embodiment
has the disadvantage, in some applications, of having hook 734 exposed to the
exterior of
member 71.
The external surface of the joint can be made smoother by the embodiment shown
in
Figure 8, wherein detent portion 836 partially, or in some embodiments,
completely, fills
opening 802, while providing a relatively smooth surface and, in addition,
sharing the tensile
load with hook portions 832 and 834. On the other hand, protrusion of hook
portion 832 may, in
some instances, serve a useful purpose. For example, if members 81 and 84 are
part of a frame
surrounding a glazing unit or other panel, protruding portion 833 may serve as
a spacer, or
setting block, to aid in centering the glazing unit in the opening formed in
part by frame
members 81 and 84.
In yet another embodiment, the inserts of the present invention can align the
members to
be joined in an alternative manner. Referring to Figures 9 and 10, lineal
member 92, shown in
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CA 02600598 2007-09-07
an end view, is provided with channel 921, which receives extended portion 910
of insert 93,
thereby keying members 91 and 92 together in an aligned manner, while still
allowing end
portion 911 to be a simple flat end. When this configuration is used, it may
not be necessary to
use the dual tenon system of previous embodiments, since the alignment
provided by the two
tenons is now provided by the fitting of extended portion 910 into channel
921. In yet another
embodiment, end portion 911 could itself be fabricated to a profile that would
fit directly into
channel 921, thereby making extended portion 910 optional.
A significant advantage of hollow lineal members produced by extrusion or
pultrusion is
that they can be economically made in the complex profiles useful in
fenestration, wherein a
single profile can contain many features that enable it to serve a range of
functions. For example,
referring to Figure 11, the cross sectional profile of lineal member 100,
which can be used as a
top or bottom rail of a door panel frame, includes grooves 1102 and 1104 for
receiving weather
stripping, when used as a top rail of a door panel. Member 100 can also be
used as a bottom rail
of a door panel, in which case grooves 1102 and 1104 can receive a bottom
sweep. Groove 1106
can be provided for receiving a glazing bead, and edge wall 1108 and bedding
surface 1110 can
be provided for receiving a glazing unit. End portion 1111 has been fabricated
to mate with a
side portion of a stile of a door panel frame. In addition, internal web 1105
has been cut back to
surface 1109 to provide room for a coupling insert.
Referring to Figure 12, an insert, 1220, for joining first member 100 to a
suitably adapted
second hollow structural member is portrayed. Insert 1220 comprises base plate
1221, which has
first side 1223 and second side 1225. First hook portion 1224, second hook
portion 1226, and
detent portion 1228 extend from first side 1223 of base plate 1221. Tenon
portion 1229 extends
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CA 02600598 2007-09-07
from second side 1225 of base plate 1221. Referring to Figure 13, the external
periphery 1227 of
base plate 1221 is adapted to be received by the internal profile of lineal
member 100.
Referring to Figure 14, first member 1400 is further adapted to receive insert
1220 by
openings1441, 1443, and 1445, which can be produced by drilling transversely
through lineal
100, at locations suitable for producing a predetermined protrusion of tenon
portion 1229 from
end portion 1411 of member 1400. The diameters of apertures 1441, 1443, and
1445 should be
sufficient to allow them to receive hook portions 1224 and 1226, and detent
portion 1228 of
insert 1220, but not so large as to harm the overall integrity of first member
100. It is further
useful for the radii of surfaces 1224, 1226, and 1228 of insert 1220, which
engage openings
1441, 1443, and 1445, respectively, to match the radii of those openings, at
least in the area of
contact, so as to maximize the contact area between the hook portions and the
apertures and
minimize local stresses. It will also be noted that internal web 1105 has been
cut back to surface
1109 to allow space for base plate 1221. A second insert 1220', not shown, may
be installed in
the second end of first member 100. Installation of inserts 1220 and 1220' may
be performed by
grasping tenon portion 1229, orienting the insert so as to match the
peripheral profile of base
plate 1221 with the interior profile of first member 100, and sliding it in
until the hooks and
detent snap into place.
Referring to Figure 15, an embodiment of a second lineal member 150, to which
first
lineal member 100 can be joined, is portrayed. Second member 150 comprises a
first, or interior
facing wall 1562 and a second, parallel, facing wall 1564, joined by first
edge web 1561 and
second edge web 1567, along with first internal web 1563 and second internal
web 1565. Core
block 1568 is provided between edge web 1561 and first internal web 1563. In
one embodiment,
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core block 1568 is a solid member that extends for some length along lineal
150. As discussed
hereinabove, core block 1568 can conveniently be made of wood.
Referring to Figure 16, screw clearance hole 1671 is drilled through web 1561,
core
block 1568, and web 1563. Openings 1672 and 1674 are provided in webs 1565 and
1567,
respectively, for the purpose of receiving tenon portion 1229. Joining of
first member 100, in
which insert 1220 has been installed, to second member 150, is performed by
first inserting
tenon portion 1229 through openings 1672 and 1674, thereby bringing end
portion 1111 of first
member 100 into engagement with web 1567 of second member 150. Screw 302 is
then
installed through clearance hole 1671, into a threadable pilot hole in tenon
portion 1229.
Tightening of screw 302 couples tenon portion 1229 to first member 100,
thereby pulling first
member 100 tightly against second member 150 to form the completed joint.
Referring to Figure 17, base plate 1221 of insert 1220 may be further adapted
to provide
one or more flow channels for the injection of sealants or adhesives. A
particularly useful flow
channel is channel 1710, which allows sealant 1712 to seal exterior joint 1720
between first
member 100 and second member 150. After assembly, sealant 1712 can be injected
into channel
1710 through a hole drilled at a suitably inconspicuous location, such as one
that will later be
covered by a glazing unit or other member. Suitable sealants can be chosen
from commercially
available flowable and curable materials, such as hot melt adhesives, or other
sealing materials.
In another embodiment, portrayed in Figures 18 and 19, a wider first member
200 can be
joined by a coupling member having two tenon portions 192 and 193, such as
insert 190, shown
in Figure 19. Second member 220 is adapted to receive tenon portions 192 and
193 by providing
two transverse openings 221 and 223. This embodiment is useful, for example,
in a door panel
having a bottom rail that is of greater height, in conformity with traditional
door styling.
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Bottom cover 195, shown in Figure 18, can also be added to close the open end
of
member 220. Cover 195 can be held in place by conventional means, such as
detents, screws,
adhesives, combinations thereof, or other suitable fasteners. Cover 195 may
also be provided
with drain or vent holes to allow drainage of any water that may have leaked
into the various
members, and ventilation to allow drying and pressure relief.
Referring to Figure 20, an alternative insert is portrayed. Insert 2113
comprises base
plate 2110 having first side 2109 and second side 2111. Coupling arms 2117 and
2119 extend
from first side 2109 and further incorporate bosses 2116 and 2118,
respectively. Clearance hole
2114 extends through arm 2119, and concentric threaded hole 2115 extends
through arm 2117,
so that screw 2102 can pass through hole 2114 and be threaded into hole 2115.
Alternatively,
screw 2102 may be self threading. As will be apparent to one skilled in the
art, threading may
alternatively be provided by a threaded metal insert, or a nut. Insert 2113
can be conveniently
made by injection molding of a thermoplastic material, though other materials
and fabrication
methods are also contemplated, as discussed hereinabove.
Figure 21 shows the installation of insert 2113 in lineal member 220, and its
use in
coupling member 220 to member 230. Insert 2113 is slid into lineal member 220
until bosses
2116 and 2118 snap into opening 221. It will be noted that interior web 226 is
cut back to
surface 2127 to allow space for insert 2113. Screw 2102 is then installed to
pinch clamping
surfaces 2121 and 2122 together onto interior web 226. Clamping internal web
226 between
surfaces 2121 and 2122 may improve the dimensional stability of the joint
between members 220
and 230, and may further help to stabilize web 226 against crushing or tearout
under conditions
of heavy pulling on insert 2113, particularly when web 226 is relatively thin.
CA 02600598 2007-09-07
Alternative embodiments are also contemplated for the attachment of the tenon
portions
of the inserts to the second member. In particular, screws 302 may be replaced
by transverse
wedging devices. Referring to Figures 22 and 23, insert 235 joins first member
240 to second
member 245. Tenon portions 2352 and 2354 are provided with notches for
receiving keys 242
and 244, which can be driven or pressed in from end 2311 of second member 245.
Keys 242 and
244 can be provided in the form of two pronged forks, with one prong of key
242 engaging notch
2351 and the other prong engaging notch 2355. In like manner, one prong of key
244 engages
notch 2353 and the other prong engages notch 2357. The reliability of the
engagement can be
improved by dimensioning the width of keys 242 and 244 sufficiently large to
enable them to fit
snugly against front wall 2420 and back wall 2422 of member 245.
In yet another embodiment, portrayed in Figure 24, tenon portion 2550 of
insert 2500 is
provided with openings 2552 and 2554, which are able to receive transverse
keys that rest
against webs of a lineal member to hold insert 2500 in place, thus forming a
complete joint
between two hollow lineal members.
Referring to Figure 25, panel frame members 2502, 2504, 2506, and 2508 are
hollow
lineals of the type disclosed hereinabove and are joined in a side to end
manner by the joining
system disclosed hereinabove. First stile 2502 has been joined to bottom rail
2508, and this
assembly has been joined to top rail 2504, to which second stile 2506 is then
joined, to form a
rectangular door panel frame defining opening 2510. Opening 2510 is further
defined by
bedding surface 2520 and edge wall 2560, which enable it to receive a glazing
unit, thereby
forming a windowed door.
The joining system disclosed herein can also be used for other parts of a door
panel.
Referring to Figure 26, first stile 2602 is joined to bottom rai12608, as well
as to top rail 2604,
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CA 02600598 2007-09-07
thereby forming an assembly to which second stile 2606 is joined, thus forming
a frame for a
door panel. Rails 2604 and 2608 are hollow lineals of the type disclosed
hereinabove, and are
joined to stiles 2602 and 2606 by suitable adaptations of the joining system
disclosed
hereinabove. In the embodiment portrayed in Figure 26, midrail 2630 is
provided to improve the
structural strength of door 260 and to define an upper opening 2610 and a
lower opening 2620,
either or both of which may be adapted to hold a glazing unit, a screen, an
opaque panel, or other
suitable component.
Referring to Figure 27, midrail 2630 can have a cross sectional profile
adapted to receive
glazing units or other like members. Bedding surfaces 2742 and 2742' are
adapted to match up
with the bedding surfaces of the stiles and rails of door panel frame 260 so
as to form continuous
bedding surfaces surrounding openings 2610 and 2620, respectively. In like
manner, edge walls
2740 and 2740' are adapted to match up with the edge walls of the rails and
stiles of door panel
260 so as to form continuous edge walls around openings 2610 and 2620
respectively. The ends
of midrail 2630 are fabricated to fit the profiles of stiles 2602 and 2606, in
the manner that the
ends of top and bottom rails 2604 and 2608 fit stiles 2602 and 2606. Midrail
2630 can be
provided with inserts of the general type provided for top rail 2604, having
baseplates adapted to
be received by the internal profile of member 2630. Suitable openings can be
provided in stiles
2602 and 2606 for receiving the tenon portions of the inserts, along with
openings for screws for
holding stiles 2602 and 2606 tightly against the ends of midrail 2630.
Additionally, midrai:l 2630
can be provided with an internal core block for supporting screw head and
other structural loads.
In yet another embodiment, portrayed in Figure 28, center stile 2832 is
provided, in
addition to midrail 2830. Center stile 2832 can be provided with suitably
fabricated ends and
can be provided with inserts of the type disclosed hereinabove for holding
midrail 2630 in place.
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CA 02600598 2007-09-07
Bottom rai12808 and midrail 2830 can be provided with openings for receiving
the tenon
portions of the inserts from center stile 2832, as well as screws for holding
the various members
in place. It is useful for the openings in stiles 2802 and 2806 that receive
the tenon portions of
the inserts in midrail 2830 to be slightly elongated in the vertical
direction, to allow midrail 2830
to adjust its position so as to fit tightly against center stile 2832. It will
be appreciated that while
midrail 2830 and center stile 2832 are portrayed in Figure 28 as being of
substantially the same
width, this need not be the case. Center stile 2832 could, for example, be
made narrower, so as
to appear less bulky in relation to openings 2820 and 2825, if such a
configuration appears
desirable. Additionally, midrail 2830 can be provided with an internal core
block for supporting
screw loads and other structural loads.
While the use of hollow lineal members in the production of door panel frames
provides
many advantages, as disclosed hereinabove, still other advantages can be
gained by filling the
hollow spaces in the door panel frame with suitable filling materials, such as
foam or other like
material. Such materials can be provided in preformed shapes, such as flexible
foam core blocks
or fiberglass insulating bats, or injected as a reactive flowable material
that expands to fill the
hollow spaces in the panel. Combinations of preformed members and injected
foam can also be
used. Flowable foam materials are commercially available and can be formulated
to provide
such desirable performance properties as improved structural strength, heat
insulation, air and
moisture sealing, and sound deadening, as well as combinations thereof.
Referring to Figure 29, heat insulation can be improved by installing foam
members in
hollow spaces 2933 and 2934 of bottom rai1292 prior to installation of inserts
298. Such foam
members can be preformed core blocks of flexible foam or rigid foam core
blocks configured so
that they do not interfere with the installation of inserts 298. It is
contemplated that
18
CA 02600598 2007-09-07
combinations of rigid and flexible foams may also be used. It may also be
useful to attach foam
pieces to insert 298 prior to installation into bottom rail 292. It is also
contemplated that in some
instances, fiberglass or other suitable non-foam insulation may be used to
fill spaces 2933 and
2934.
In an alternative embodiment, hollow spaces 2933 and 2934 of bottom rail 292
can be
injected with one of the commercially available flowable foams that cure to a
solid, closed cell
structure. One method of carrying out the injection is to first install a
first insert 298 into a first
end of rail 292, then install a second insert 298 into a second end of rail
292, and finally inject
the reactive foaming composition through injection ports 2966 and 2968, which
have been
provided for this purpose. Apparatus for performing the injection is
commercially available, for
example from Graco Incorporated of Minneapolis, Minnesota, and typically
comprises a gun-like
device having an extended injector tube which can first extend through ports
2966 and 2968 to
first inject foam into hollow space 2933, and then be retracted to inject foam
into hollow space
2934. The injector tube is then retracted from rail 292 and port 2966 is
plugged with an
appropriate plugging member, such as a screw or snap-in plug. After injection,
the foaming
material reacts chemically, with the blowing agent contained in the foaming
material generating
gas bubbles that produce expansion of the foam, thereby producing flow of the
material to
various parts of hollow spaces 2933 and 2937. Simultaneously, the curing
process proceeds to
finally form a solid structure that substantially fills hollow spaces 2933 and
2934.
The siinultaneous expansion, flow, and curing of the foam material is a
complex process
that entails significant unpredictability. Certain measures can be taken,
however, to improve the
quality of filling and hence the quality of the finished product. One such
measure is to provide
venting, so that air or other gases do not become trapped in pockets that
might inhibit the
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CA 02600598 2007-09-07
expansion of foam into these areas, resulting in voids in the finished
product. Openings 2921
and 2923 in rail 292, along with openings 2981 and 2982 in insert 298, serve
as vents.
Generally, it is useful for the vents to be as far as possible from the
injection ports, and to be
relatively small, compared to the size of the injection ports, so as to allow
adequate exit of gases,
but limited flow of foaming material. It will also be appreciated that some
leakage of foaming
material from the vents is usually acceptable, since leaked amounts of the
types of foam typically
used are easily scraped off or otherwise removed. It will further be
appreciated that vents 2921,
2923, 2981, and 2982 are merely examples of vents that would be useful, and
that further
analysis or experimental runs of foaming may lead to more optimal venting
arrangements.
Another measure that can be taken is to provide gaps between parts within the
spaces to
be foamed, wherein the gaps provide sufficient clearance to allow foam to more
easily flow
between and around parts, so as to maximize the contact area with all of the
parts. Maximizing
contact area is particularly useful when the foaming material exhibits
adhesive properties. In
particular, gaps 2991, 2992, and 2993 are provided to allow foam to flow
between parts of insert
298 and the webs of rail 292, so as to provide increased bonding area between
insert 298 and rail
292. More generally, if complex spaces are to be filled with foam, a useful
principle is to
provide flow paths with the maximum cross sectional area, so as to cause the
minimum
restriction to the flow of the foaming material.
In cases wherein the fit of insei-t 298 into rail 292 is relatively loose, so
that movement of
insert 298 relative to rail 292 is possible, it may be useful to provide a
fixture for liolding tenon
portions 2983 and 2986 in a precisely deterinined position relative to rail
292 during foaming
and curing, so as to produce a more precise product. Providing a predetermined
looseness of fit,
CA 02600598 2007-09-07
followed by fixturing and foaming, may be useful, in some instances, to
compensate for
manufacturing tolerances in rail 292 and insert 298.
Another type of fixturing may also be usefiil in some cases. Since the
expansion of the
foaming material can produce significant internal pressures in the spaces
being filled, even with
venting, there is the possibility that bulging and other distortions of the
walls of the space being
filled may occur. It is useful, in such instances, to provide clamping
fixtures to hold the walls of
the space in predetermined positions until curing has been completed.
An alternative method of injecting foaming material into rail 292 is to first
install one
insert 298, followed by injection of a measured amount of foaming material
into hollow spaces
2933 and 2934 of rail 298, followed by quickly inserting the second insert,
and allowing the
foam to expand and cure. This method of foaming would have the advantage of
avoiding
injection ports and the subsequent need to plug them. It would also have the
advantage of
providing large venting areas, prior to insertion of second insert 298. It may
further be useful to
provide vents in second insert 298 to enable the final foam expansion to
proceed to completion.
Suitable injectable foaming materials, such as reactive polyurethane foaming
materials,
are commercially available from a variety of sources, and foaming materials
suitable for
improving heat insulation, structural strength, sound attenuation, as well as
other desirable
properties, and combinations thereof, may be chosen from a variety of
formulations, based upon
foam manufacturer recommendations, as well as on the experience of those
skilled in the art.
Foam materials that are particularly useful are those that adhere well to the
interior surfaces of
rail 292 and insert 298, so as to enhance structural strength and rigidity of
the assembled rail, as
well as to seal the bottom rail assembly against moisture intrusion.
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CA 02600598 2007-09-07
It is also useful to fill the stiles of a door panel frame with a foam
material. Injection of
foaming material into first stile 294 can be performed by several alternative
methods. In one
embodiment, bottom rail 292 is first produced as a foamed assembly comprising
rail 292 and
inserts 298, installed in each end by one of the methods described
hereinabove. An assembled
and foamed top rail is produced in a similar manner. First stile 294 is then
prepared for assembly
and foaming by first inserting core block 295, followed by drilling the
appropriate holes to
produce openings 2985, 2987, 2988, and 2989, for receiving tenon portions 2983
and 2986 of
insert 298. Clearance holes are also drilled in stile 294, through core block
295, to receive
screws 2902. In this embodiment, core block 295 extends for the full length of
first stile 294.
First stile 294 is then installed onto bottom rail 292 by insertion of tenon
portions 2983 and 2986
into first into 2985 and 2987, and then into openings 2988 and 2989, so that
the end of rail 292
engages the side of stile 294.
Referring to Figure 30, top rail 392 is installed onto stile 394 in a manner
similar to
installation of bottom rail 292. Finally, second stile 394 is installed onto
rails 292 and 392.
Assembly is completed by installing screws 2902 at the four corners of the
frame to form
completely assembled frame 300. Bottom covers 296 are then installed by
attaching, for
example, with screws extending into core blocks 295. Other attachment methods,
involving
detents, snaps, and other like devices, may also be used. It will be
appreciated that the expansion
of the foaming material may generate significant internal pressure in the
stiles, so that the
attachment of covers 296 nlay need to be fairly robust, as would be apparent
to one skilled in the
art.
In this embodiment, foaming is performed by injecting the foaming material
into the top
ends 3060 and 3062 of first and second stiles 294 and 394. A suitable
apparatus for injecting the
22
CA 02600598 2007-09-07
foam comprises a relatively long tube that extends for some distance into the
stiles, with a foam
source having sufficient pressure to project the foaming material to the
bottom of each stile, and
the capability of providing a measured quantity of foaming material. Once the
foam has been
injected, vented top covers can be installed onto top ends 3060 and 3062 of
stiles 294 and 394, so
that the foaming material can expand to fill the stiles and cure to a solid
structure.
In yet another embodiment, stiles can be provided in extended stock lengths,
from which
two or more stiles can be cut. The stock lengths are first foamed and cured,
after which
individual stiles are cut from the foamed stock. Any inserted core blocks can
be installed either
before or after cutting to length. The stock len.gths can be made somewhat
longer than needed
for the number of stiles to be cut, so that the end of the stock length, which
includes the final free
surface of the foam, can be discarded.
Referring again to Figure 29, surface 2999 of base plate 2980 has been located
at a slight
distance from the side of stile 294, thereby creating gap 297, and allowing
screws 2902 to pull
rail 292 into tighter contact with stile 294, without interference from insert
298. Gap 297 may
also be injected with a foaming material through, for example, opening 2965. A
particularly
useful type of foaming material is an expanding adhesive, many of which are
commercially
available. A method of producing an expanding adhesive from a conventional hot
melt adhesive
is disclosed in U.S. Patent 4,778,631, assigned to Nordson Corporation.
Door panel frames typically provide cavities or mortises for such things as
locks and door
closers. Such cavities can be created by partitioning off areas of the stiles
or rails, prior to
foaming, so as to exclude foam during the foaming process, or by filling the
entire panel frame
with foam, and using a router or other like device to remove foam and other
material in the
desired locations.
23
CA 02600598 2007-09-07
The invention has been described herein in terms of embodiments and
methodologies
considered by the inventors to be the best mode of carrying out the invention.
It will be
understood by those skilled in the art that various modifications, variations,
changes and
additions can be made to the illustrated embodiments without departing from
the spirit and scope
of the invention. For example, while lineal members have been illustrated in
the embodiments
described herein, other types and shapes may be provided so long as they
incorporate at least
some hollow portion for receiving and engaging coupling inserts with a
coupling portion and a
tenon portion. Further to the methods of firmly fastening the lineal members
described herein,
other suitable fasteners and/or adhesives are envisioned. The various
components can have
configurations other than the generally flat or planar configurations shown in
the preferred
embodiments, such* as undulating, cupped, serrated, or the like. These and
other modifications
are possible and within the scope of the invention as set forth in the claims.
24
