U.S. patent application number 11/924541 was filed with the patent office on 2008-02-21 for drywall bead with knurled paper flaps.
This patent application is currently assigned to CONTINUOUS COATING CORPORATION. Invention is credited to Kenneth N. Harel.
Application Number | 20080041006 11/924541 |
Document ID | / |
Family ID | 25463585 |
Filed Date | 2008-02-21 |
United States Patent
Application |
20080041006 |
Kind Code |
A1 |
Harel; Kenneth N. |
February 21, 2008 |
DRYWALL BEAD WITH KNURLED PAPER FLAPS
Abstract
A drywall joint assembly strip device comprised of an elongate
core having a cover bonded to its exterior surface and extending
beyond its longitudinal edges to form flexible flaps in which
longitudinal, parallel grooves and ridges and/or spaced-apart
perforations are formed for flow of joint compound during the
installation process.
Inventors: |
Harel; Kenneth N.; (Anaheim,
CA) |
Correspondence
Address: |
FULWIDER PATTON LLP
200 OCEANGATE, SUITE 1550
LONG BEACH
CA
90802
US
|
Assignee: |
CONTINUOUS COATING
CORPORATION
520 West Grove Avenue
Orange
CA
92865
|
Family ID: |
25463585 |
Appl. No.: |
11/924541 |
Filed: |
October 25, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09933229 |
Aug 20, 2001 |
|
|
|
11924541 |
Oct 25, 2007 |
|
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|
Current U.S.
Class: |
52/465 ;
52/745.2 |
Current CPC
Class: |
E04F 13/068 20130101;
B32B 27/10 20130101; B32B 1/00 20130101; B32B 2037/1215 20130101;
B32B 15/12 20130101; E04F 13/06 20130101; B32B 15/08 20130101; E04F
2013/063 20130101; B32B 38/1866 20130101; Y10T 428/28 20150115;
B32B 2607/00 20130101; Y10T 428/2839 20150115; B32B 3/266
20130101 |
Class at
Publication: |
052/465 ;
052/745.2 |
International
Class: |
E04B 1/68 20060101
E04B001/68 |
Claims
1. A protective drywall joint strip device comprising: a rigid
elongated core of a predetermined width, configured with
longitudinal edges and having an outer surface and an inner
surface; a cover bonded to said core and configured to project
laterally beyond at least one of said longitudinal edges to form at
least one flexible flap; and said flap formed with elongated,
lengthwise grooves with ridges interposed therebetween.
2. The drywall joint assembly strip device of claim 1, wherein:
said core is constructed of metal.
3. The drywall joint assembly strip device of claim 2, wherein:
said core is constructed of galvanized steel.
4. The drywall joint assembly strip device of claim 1, wherein:
said core is constructed of plastic.
5. The drywall joint assembly strip device of claim 1, wherein:
said core is configured with a curved lengthwise cross-section such
that said outer surface is generally convex and said inner surface
is generally concave.
6. The drywall joint assembly strip device of claim 1, wherein:
said flap is constructed with perforations extending therethrough
for flow of joint compound from one side to the other.
7. The drywall joint assembly strip device of claim 6, wherein:
said flap is constructed with said perforations formed with at
least one transverse cross-sectional dimension of at least 1/64th
of an inch.
8. The drywall joint assembly strip device of claim 1, wherein:
said cover is paper.
9. The drywall joint assembly strip device of claim 8, wherein:
said cover is constructed of at least three layers.
10. The drywall joint assembly strip device of claim 1, wherein:
said flap includes at least three said grooves and four said
ridges.
11. The drywall joint assembly strip device of claim 10, wherein:
said flap is formed with perforations along said grooves.
12. The drywall joint assembly strip device of claim 1, wherein:
said cover is wider than said predetermined width to include said
flaps projecting laterally beyond both said longitudinal edges and
formed with said grooves and ridges.
13. The drywall joint assembly strip device of claim 6, wherein:
said flap is formed with said perforations spaced therealong
throughout its length.
14. A drywall joint assembly strip device for protecting a drywall
corner joint, comprising: an elongated core formed with angular
flanges terminating in longitudinal edges; a cover bonded to said
core and projecting laterally beyond said longitudinal edges to
form flexible flaps, each having an outwardly-facing surface and an
inwardly-facing surface; said flaps being formed with elongated,
lengthwise grooves and ridges disposed in alternating fashion along
at least one of said surfaces to provide linear stiffness in said
flaps; and said flaps being further formed with spaced-apart
perforations along said grooves of sufficient size to provide for
the communication of uncured joint compound between said
outwardly-facing surfaces and said inwardly-facing surfaces during
the installation of said drywall joint assembly strip device onto
said drywall corner joint.
15. A drywall trim device for protecting a drywall corner joint,
comprising: a relatively rigid elongated core having a curved
lengthwise cross-section so as to have a convex outer surface and a
concave inner surface and including a pair of flanges terminating
in respective longitudinal edges; a paper cover bonded to said
outer surface and extending beyond said longitudinal edges of said
core to form flexible flaps; and said flaps being formed with
elongated grooves with spaced-apart perforations and elongated
ridges formed lengthwise along said flaps in parallel, alternating
relationship.
16. A drywall corner protection strip device for protecting a
drywall corner joint, comprising: an elongated metal core having
first and second longitudinal edges; a paper cover bonded to said
metal core and extending beyond said first and second longitudinal
edges to form flexible flaps each having an outwardly-facing
surface and an inwardly-facing surface; said flaps being formed
with elongated grooves and ridges in alternating relationship in
said outwardly-facing surfaces to provide linear stiffness in said
flaps; and said flaps being further formed with spaced-apart
perforations formed along said grooves to provide for the
communication of uncured joint compound between said
outwardly-facing surfaces and said inwardly-facing surfaces during
the installation of said drywall corner protection strip device
onto said drywall corner joint.
17. A drywall joint assembly strip device to be covered by flowable
joint compound and comprising: an elongated core; a paper cover
bonded to said core so as to extend beyond the longitudinal edges
of said core to form flexible flaps, said flaps being formed on at
least one side with longitudinal rib means for, when said joint
compound is applied thereto, afford a mechanical barrier to
shifting relative to such compound; and said flaps formed with
compound-directing means and communication means to provide for the
communication of said flowable joint compound between said
outwardly-facing surfaces and said inwardly-facing surfaces to,
when set up, fill the respective said perforations with compound
posts.
18. A drywall assembly strip device for protecting a drywall joint,
comprising: core means for spanning said drywall joint; cover means
bonded to said core means and projecting laterally therefrom to
form at least one flexible flap; said flaps being formed with
reinforcing means extending lengthwise along said flap to resist
longitudinal fluting; moisture-directing means interposed between
said reinforcing means along said flap; and said flap formed with a
plurality of communication means spaced therealong and configured
to provide for passage thereunto of uncured joint compound to, when
cured, form respective posts.
19. The drywall assembly strip device of claim 18, wherein: said
communication means are formed along said moisture-directing
means.
20. A drywall corner protection strip device, comprising: an
elongated, continuous metal core configured with a lengthwise
central portion arcuate in cross-section and terminating on each
longitudinal core edge in a generally planar, lengthwise flange
portion, said core thus having a generally convex outer surface and
a generally concave inner surface; a paper cover centrally bonded
to said outer surface and configured such that the longitudinal
edges of said cover extend beyond said longitudinal core edges to
form respective flexible flaps having respective outwardly-facing
and inwardly-facing surfaces; elongated grooves and ridges
permanently formed in alternating relationship along said
outwardly-facing surfaces to provide linear stiffness for said
flaps; and spaced-apart perforations formed along said grooves to
provide for the communication of uncured joint compound between
said outwardly-facing surfaces and said inwardly-facing surfaces
during the installation of said drywall corner protection strip
device onto a drywall corner joint.
21. A method of making a drywall joint protection strip device,
including the following steps: selecting a core having an elongate
outer surface; selecting a cover such that the width of said cover
is greater than the width of said outer surface; forming said core
with a desired cross-section; bonding said cover centrally on said
outer surface such that said cover extends beyond the longitudinal
edges of said core to form flexible flaps; and forming lengthwise
grooves and lengthwise ridges in parallel, alternating relationship
along said flaps such that said grooves are further configured with
spaced-apart perforations therealong.
22. The method of claim 21, wherein: said core is selected to be
metal.
23. The method of claim 21, wherein: said core is selected to be
rigid plastic.
24. The method of claim 21 for use with flowable uncured joint
compound and that includes: forming perforations spaced along the
respective said flaps of a size sufficient for flow therethrough of
said flowable compound.
25. The method of claim 21, wherein: the step of forming said
cross-section is performed by passing said core through an
extrusion die.
26. The method of claim 25, wherein: the step of forming said
cross-section includes forming said core arcuate such that at least
one surface thereof is generally convex.
27. The method of claim 21, wherein; the step of bonding said cover
on said core is performed using a hot melt glue.
28. The method of claim 21, wherein the step of forming lengthwise
grooves and lengthwise ridges in parallel, alternating relationship
comprises: selecting a mating roller device such that a first
roller and a second roller are rigidly mounted in rolling
engagement and wherein said first roller is configured with axially
spaced-apart circumferential channels and said second roller is
configured with axially spaced-apart circumferential rings
positioned to mate with said channels and having radially
spaced-apart pyramidal spikes thereabout; and passing each said
flap longitudinally through said mating roller device with said
outwardly-facing surface oriented toward said second roller so as
to form said grooves with spaced-apart perforations and said ridges
in said outwardly-facing surface of each said flap.
29. A method of making a drywall corner protection strip device,
including the following steps: selecting an elongated metal core
having a convex outer surface; selecting a paper cover such that
the width of said cover is greater than the transverse distance
along said outer surface; bonding said cover centrally on said
outer surface so that said cover extends beyond the longitudinal
edges of said core to form flexible flaps; forming alternating
lengthwise grooves and ridges in said flaps; and forming
spaced-apart perforations along said grooves.
30. A protective drywall joint strip device comprising: an
elongated rigid core of a predetermined width and terminating in
opposite longitudinal edges; a paper cover bonded to said core and
configured to project laterally beyond the respective said edges to
form respective flexible flaps; said flaps being formed on at least
one side with at least four parallel elongated grooves defining
therebetween respective reinforcing ribs, said grooves being spaced
1/8.sup.th of an inch apart and said ribs being raised outwardly
from the bottoms of the respective said grooves at least
1/64.sup.th of an inch; and said flaps being further formed with
respective perforations spaced equidistant along the respective
said grooves and projecting extending through said flaps to form
open flow apertures at least 1/64th of an inch in transverse cross
action for flow therethrough of joint compound.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to drywall finish trim devices
typically utilized in finishing a drywall installation at a corner
joint or other terminus.
[0003] 2. Description of the Prior Art
[0004] Drywall, sometimes also referred to as wallboard, is a
staple in the construction industry as an economical alternative to
plaster for forming the interior walls and ceilings of rooms in
residential, commercial, and industrial buildings. The materials
used in drywall construction include gypsum board, plywood,
fibre-and-pulp boards, and asbestos-cement boards. The large, rigid
sheets are fastened directly to the frame of a building with nails,
screws, or adhesives, or are mounted on furring (strips of wood
nailed over the studs, joists, rafters, or masonry, which allow
free circulation of air behind the interior wall). A significant
advantage of drywall construction is that the craftsman is not
required to delay his or her finish work while the plaster spread
over the interior support structure dries. Wallboard is
manufactured in both finished and unfinished forms, and in its
finished form may be faced with vinyl or other materials in a
variety of permanent colors and textures so that they do not need
to be painted when installed.
[0005] Drywall construction allows the drywall hanger to easily cut
the panels to many different shapes and sizes for assembly and
hanging from the building frame. However, workmen face a challenge
in finishing drywall panels at an edge or corner. It is very
difficult, if not impossible, to cut the edges of such panels with
the precision, straightness, and smoothness required to abut the
edges of adjoining panels in a sufficiently straight corner to
provide an aesthetic finish. Additionally, cut edges expose the
soft, raw cores of the drywall panels, thus requiring some sort of
covering or treatment to afford a finished appearance.
[0006] As a result, several different devices and techniques have
been developed in effort to produce a structurally sound corner or
other joint that exhibits a smooth and seamless intersection.
Devices proposed to achieve this result include drywall tape, trim
and corner beads. Conventional drywall tape may be applied to the
joints and edges of abutting panels to be covered by wet joint
compound that is feathered and smoothed to cover the newly created
seams. When the joint compound has dried, the tape and drywall can
be sanded, painted, covered, or otherwise finished in whatever
manner is desired. Great deal of skill is required, however, to
apply and form the joint compound to create a sufficiently straight
intersection that will exhibit, when taped and sanded to a finish,
no evidence of scuffing and tearing in the tape.
[0007] In light of the limitations on use of drywall tape to trim a
joint, trim strips or corner beads are often utilized to cover a
joint and produce a seamless and aesthetically pleasing edge trim
or intersection at the corners of drywall panels.
[0008] Such trim strips may take many different configurations and
are typically in the form of an angle corner bead having diverging
flanges or may be, for instance, a J strip to cap the edge of a dry
wall panel. For the purposes of this invention, the particular
configuration is not critical and use in conjunction with numerous
different configurations is contemplated. For instance, the trim
may be flat or configured with any one of a number of well known
configurations, including corner trim with perpendicular flanges,
corner trim with a rib formed at the juncture of the flanges
defining a bead, flanges angled at 135.degree. to one another,
those configured with somewhat of a Z shape, those with soft line
or rounded corners, and those with offsets or other configurations
traditionally used in the trade and known to those skilled in the
art.
[0009] One common feature of many of the trim strips or corner
beads currently available is the use of a rigid or semi-rigid core
that caps the drywall corner joint to provide support and to
prevent the drywall from being chipped or cracked along the
otherwise exposed edges of the panels. Typical materials known and
used in the art for such cores include galvanized steel, aluminum,
plastic, and sometimes stiff, thick paper. A disadvantage of these
cores is that they must be anchored in some way as by nailing,
screwing, or otherwise fastening to the drywall panels. A further
disadvantage of such cores is that the drywall finishing compound
applied to the corner joints to complete the assembly may not
readily adhere to such rigid and semi-rigid core materials or
easily conceal nail or screw heads, making it difficult to cover,
sand, paint or otherwise finish out the corner joint in an
aesthetically-pleasing manner.
[0010] To enhance the function and finished appearance of drywall
corner joints configured with corner beads, efforts have been made
to provide such beads with an exterior covering of some other
material such as paper or fabric to facilitate both installation
and application of the joint compound to the exterior surfaces
thereof. The challenge is to provide such an exterior covering that
is substantial enough to secure the inner core in position while
being thin enough to create a smooth transition between the cover
and the underlying drywall. One bead developed to address some of
the problems with the prior art is a corner bead with a metal core,
covered on its exterior with a paper cover which projects beyond
the opposite lateral edges to form flexile, flaps to be secured in
place as by nailing and embedding in joint compound. I have
discovered that such flaps often fail to securely anchor the corner
bead device in place thus allowing for shifting of the bead
relative to the drywall thereby producing an irregular
appearance.
[0011] It has been common practice to form such flaps with small
holes for communication of moisture during the curing process for
the joint compound. Oftentimes, such holes are formed by punching
chads from one side of the flap often leaving one side of the chad
attached. Consequently, some of the attached chads end up acting as
flaps which close over the holes upon installation thus serving to
block communication of joint compound through the respective chad
holes.
[0012] It has also been discovered that prior art corner beads
suffer the shortcoming that such flaps are often wavy throughout
their length, making it difficult to effectively cover the flap
material with a smooth layer of joint material to adequately
securely anchor them in the joint compound.
[0013] Because these features have not been optimally satisfied in
a single drywall bead design, there still exists a need for such a
finishing bead that addresses each of these challenges. The present
invention is directed to just such a drywall bead.
SUMMARY OF THE INVENTION
[0014] The present invention provides a drywall bead which is
convenient to install and still effective to attractively cover and
protect the drywall panel joint. The drywall joint assembly strip
device of the present invention is characterized by lengthwise,
longitudinal flexible flaps projecting from at least one side and
configured with one or more longitudinal grooves and ridges to
provide a mechanical anchor in the joint compound when covered
therewith.
[0015] The strip device core is generally elongate and has exterior
and interior surfaces. Preferably, a continuous cover having a
width greater than the width of the core is bonded to the core's
exterior surface such that the edges of the cover extend beyond the
longitudinal edges of the core to form flexible flaps. As such, the
lengthwise, alternating grooves and ridges are then formed along
the flaps in a secondary operation. In one embodiment, lengthwise,
spaced-apart perforations are formed along the grooves as well, as
by knurling.
[0016] In use, then, the flaps of the drywall joint assembly strip
device of the present invention provide flexibility about the
longitudinal edges of the core, while the grooves and ridges
cooperate to provide linear stiffness along the length of the flaps
to maintain them flat during installation so that the device is
convenient to use. In this regard, grooves and ridges, when
embedded in the joint compound, serve to facilitate anchoring of
the device in place in covering relationship over the joint.
Additionally, in embodiments where the flaps are knurled with
perforations of sufficient size for flow of the joint compound,
such compound, when cured, will form a plurality of small columns
or posts through such perforations to facilitate the anchoring of
the flaps. Finally, by placing such perforations in the grooves
formed in such flaps, the grooves themselves will serve to direct
the joint compound through the spaced-apart perforations to the
underside of the flaps to thus create a series of respective
bridges through such flaps defining respective anchoring posts.
[0017] Other features and advantages of the invention will become
apparent from the following detailed description, taken in
conjunction with the accompanying drawings, which illustrate, by
way of example, the features of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a partial perspective view of a drywall bead
device embodying the present invention;
[0019] FIG. 2 is a transverse sectional view, in enlarged scale,
taken along line 2-2 of FIG. 1;
[0020] FIG. 3 is a detailed view, in enlarged scale, taken from the
oval identified by the numeral 3 in FIG. 2;
[0021] FIG. 4 is a perspective view, in reduced scale, of the
drywall bead device shown in FIG. 1, partially in section, and
covering a corner joint;
[0022] FIG. 5 is a detailed view, in enlarged scale, taken from the
oval identified by the numeral 5 in FIG. 4; and
[0023] FIG. 6 is a partial perspective view, in reduced scale, of a
method of producing the drywall bead device shown in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] As shown in the drawings for purpose of illustration, the
present invention provides generally for an improved drywall bead
10 that is comprised of an elongate core 20 having a cover 40
bonded to the outside surface thereof to extend beyond the
longitudinal side edges of the core to provide flexible flaps 50 in
which longitudinal grooves 56 and ridges 58 are formed. Some
embodiments include a longitudinal pattern of compound
communicating perforations 60. While the present invention is
described and depicted in detail as a drywall bead having a core
with a curved cross-section and mounted on the typical vertical
drywall corner joint, it will be appreciated by those skilled in
the art that the invention can be used in conjunction with cores of
most any cross-section on virtually any drywall joint.
[0025] Referring to FIGS. 1 and 2, in one embodiment elongate core
20 is formed having a generally curved transverse cross-section to
form what is known as a bull nose shape defining a convex outer
surface 22 and a concave inner surface 24. The elongate flanges 26
project laterally beyond the longitudinal edges of the core. In the
embodiment of the strip device shown, transitions are formed at the
opposite sides of the bull nose curve to define slight bends
serving to direct the respective flanges outwardly away from each
other at an angle of about ninety degrees. The core may be made of
a number of rigid or semi-rigid materials such as galvanized steel,
aluminum, and a variety of plastics, including vinyl, nylon, and
PVC. In a preferred embodiment, I have found that from parallel
groove 56 and ridges 58 perform satisfactorily. A representative
embodiment is formed with the grooves spaced laterally apart a
distance of about 1/8.sup.th of an inch and the ribs formed to bow
outwardly in transverse cross section as described below. Thus,
once embedded such ribs present respective barriers against lateral
shifting of the respective flanges relative to the joint compound
embedded in the respective grooves. Depending on the material
selected and the core cross-section desired, the core may be formed
through a variety of processes known in the art, including casting,
molding, extruding, or roller-forming.
[0026] The elongate cover 40 is configured having a length
substantially equal to that of the core 20 but with a greater
transverse width. It is preferably made of a paper material, but
may be made of other thin, flexible materials such as textiles and
synthetic fabrics. In the preferred embodiment, the selected
material is to have sufficient tensile strength to resist tearing
or chafing, while being sufficiently flexible to facilitate
installation, all the while having absorptive and surface
characteristics that allow it to be effectively bonded both to the
core and to a drywall surface and to, upon curing of the joint
compound, provide an appearance complimentary to that of the
adjacent drywall surface. It has been discovered that, in one
embodiment these objectives are satisfied in a paper cover
fabricated by mixing fibers and strengthening compound to
encapsulate the fibers with a thin film and then combining three or
more layers of such a film to produce a tear- and
temperature-resistant paper cover material, as described in
copending U.S. patent application Ser. No. 09/825,766, filed on
Apr. 3, 2001, and now U.S. Pat. No. ______. While ideal for this
application, it will be appreciated by those skilled in the art
that other conventional stiff paper such as the covering paper
typically used to cover the surface of drywall panels will suffice
in this invention.
[0027] The paper defining the cover 40 is bonded to the outer
surface 22 of the formed core 20, using a hot melt glue or other
such adhesive known in the art. Such cover is wider than such core
so that the opposite margins 42 project laterally beyond the
longitudinal edges 30 of the core to form the flaps 50. In one
embodiment, such cover is bonded centered on the core so that the
flaps are symmetrical on the opposite sides thereof. Generally, the
cover is rectangular so that the longitudinal edges extend parallel
to the respective longitudinal edges of the core. By extending
beyond the edges of the underlying rigid core, both the
outwardly-facing surfaces 52 and inwardly-facing surfaces 54 of the
flaps are exposed free of such core. Based on the grooved
construction described and the thin, fibrous material from which
the flaps are made, it will be appreciated that the flaps may be
formed with a relatively straight longitudinal configuration and
will resist flexing along the longitudinal axis while being
somewhat flexible relative to the longitudinal edges of the core to
facilitate conforming to the drywall surface projecting from the
opposite edges of such core.
[0028] Referring now to FIG. 3, the elongate, flexible flaps 50 are
configured along their length with one or more of the parallel
grooves 56 and ridges 58. The ridges 58 are interposed lengthwise
between the grooves and are generally parallel to them. In one
embodiment, three grooves and four ridges are formed in each flap.
As noted, such lengthwise grooves and ridges cooperate to serve the
purpose of reinforcing ribs and to provide linear stiffness for the
flaps, thereby minimizing longitudinal fluting or waviness in such
flaps along their respective lengths while still allowing each flap
to bend or flex relatively freely about an axis parallel to the
respective longitudinal edges 30 of the core 20. It will be
appreciated that this configuration maximizes the workability of
the drywall joint assembly strip device 10 of the present
invention, as the flaps are held straight in the longitudinal
direction but are free to flex about vertical axes to lay down flat
over the marginal edges of the joining drywall panels.
[0029] With continued reference to FIG. 3, in the preferred
embodiment the spaced-apart perforations 60 are formed of
sufficient size to communicate uncured joint compound between the
outwardly-facing surfaces 52 and the inwardly-facing surfaces 54 of
the flaps. In a preferred embodiment, I have found these
perforations formed in longitudinal grooves arranged in a uniform
pattern and having an opening of about 1/64 of an inch wide, about
1/16 of an inch long and spaced longitudinally apart about 3/32 of
an inch from end to end work well. In this embodiment the center of
the respective ribs 58 (FIG. 2) rise up about 1/64th of an inch
from the bottom of the respective grooves thus making such its
respective grooves about that deep. As will be appreciated by those
skilled in the art, the cross sectional area of such perforations
and density thereof may vary, it only being important that they
allow for flow therethrough of the compound of the particular
viscosity to be used to complete the joint and that such
perforations be sufficiently dense in the flap to provide for a
sufficient number of resultant compound posts to securely anchor
the flap in the finished joint. The cross sectional area of such
perforations for use with conventional compound can vary from about
0.0006 to about 0.05 square inches or even more depending on the
characteristics of the compound used. The side walls of the ribs
taper toward the grooves and the perforations themselves are
generally tapered to narrow from the outside to the inside surface
(FIG. 3), such that the opening of each perforation at the
outwardly-facing surface is larger than the opening where each
perforation intersects the inwardly-facing surface to compliment
the shape of tapered side walls of such ribs in providing a funnel
effect inwardly toward the body of the respective drywall panels.
It will be appreciated that, as discussed below in more detail, in
use, the grooves, ridges, and perforations cooperate to
conveniently effectuate the installation of the joint assembly
strip device 10 over a drywall corner joint.
[0030] Referring now to FIGS. 4 and 5, a typical drywall corner
joint consists of a first drywall panel 90 and a second drywall
panel 92 being mounted vertically to meet at a corner at
approximately right angles to one another. The panels are installed
on an internal wall support structure 94, such as framing, studs,
joists, furring, or other such support structure known in the art,
using a conventional fastening technique, such as nails, screws, or
adhesives. The panels are configured to be substantially planar,
such that the first drywall panel has a first exterior surface 96
and the second drywall panel has a second exterior surface 98
wherein both exterior surfaces face outwardly away from the
building frame. The panels are further configured such that a first
vertical edge 100 and a second vertical edge 102 of the respective
first and second panels meet at right angles to form a drywall
corner joint 104.
[0031] In use, the drywall joint assembly strip device 10 of the
present invention is installed vertically in covering relationship
over the drywall corner joint 104 such that the concave interior
surface 24 of the core 20 is adjacent to the corner joint.
Typically, the strip device is cut to a length substantially equal
to the length of the corner joint so as to completely cover and
protect the entire corner joint. Wet drywall joint compound is
applied to the exterior surface of the strip and blended with the
strip device 11 whether manually or by an application. The strip
device is then applied to the desired corner juncture and a
finishing layer compound applied to the exterior drywall surfaces
all along the joint using a conventional troweling or other such
technique known in the art in order to produced a smooth,
aesthetically-pleasing, finished corner joint.
[0032] It will be appreciated by those skilled in the art that
several beneficial and novel features of the drywall joint assembly
strip device 10 of the present invention become evident in the
installation process. First, as the strip device is positioned over
the corner joint, the lengthwise grooves 56 and ridges 58 formed in
the flaps 50 serve to provide linear stiffness so that the flaps
minimize any waviness or fluting along their respective lengths.
This allows the worker to easily vertically align the strip device
over the drywall corner joint with such flaps relatively flat on
the drywall surface. Moreover, because the grooves and ridges are
configured lengthwise and generally parallel to the longitudinal
edges 30 of the core 20, the flaps are still free to bend and flex
and curve relative to their respective vertical planes. In this
way, the grooves and ridges cooperate to provide both the
flexibility relative to the edges of the core and the linear
stiffness needed to allow a worker to position the strip device on
the drywall corner with such flaps flat against the drywall surface
while he or she applies the joint compound over such flaps to
anchor them to the drywall panels themselves.
[0033] Second, on the respective one sides of the flaps, the joint
compound will be worked into the grooves 56 between the ridges 58
to create compound ribs and will be worked into the undulations
formed by the ridges on the opposite sides of such flaps to thus
cooperate in mechanically trapping such flaps in the joint compound
to anchor them solidly in place.
[0034] Third, for those embodiments where the perforations 60 are
formed in spaced-apart relationship along the flaps 50 they provide
for the wet joint compound to actually flow through to the
inwardly-facing flap surfaces 54 and the underlying drywall
exterior surfaces 96 and 98 to enhance the communication of
compound from one side to the other and to construct small pins or
posts in the respective such perforations. In this way, when the
joint compound dries and cures, the drywall joint assembly strip
device 10 is integrally locked in place by the mechanical
entrapment of the ribs and grooves and also by the compound posts
through the perforations.
[0035] A fourth beneficial installation feature of the drywall
joint assembly strip device 10 relates to both the parallel grooves
56 and ridges 58 and the perforations 60. It will be appreciated
that as wet joint compound is applied to the outwardly-facing
surfaces 52 of the flaps 50, the grooves and ridges in the flaps
cooperate to direct moisture along the grooves and into the
perforations. Thus, the grooves, ridges and perforations cooperate
to more effectively direct the wet joint compound toward the flaps'
inwardly-facing surfaces 54 and the underlying exterior surfaces 96
and 98 of the drywall panels.
[0036] The drywall corner joint is finished out by applying and
smoothing, or feathering, a sufficient amount of wet joint compound
to the exterior surfaces of the drywall joint assembly strip device
10 so as to completely cover the strip device and blend the
compound with the exposed exterior surfaces 96 and 98 of the
drywall panels.
[0037] It will be appreciated that the drywall joint assembly strip
device 10 of the present invention, with its longitudinally grooved
flaps, provides for effective and efficient installation onto a
typical drywall corner joint. For those embodiments with the
knurling is operative to form perforations for communication of
compound, the anchoring posts formed therein will further
facilitate the anchoring function. Furthermore, it will be
appreciated by those skilled in the art that any number of core
configurations may be formed in producing the strip device
described, causing the device to be versatile and suitable for use
in a wide variety of drywall joint applications.
[0038] In an exemplary embodiment, the grooves 56, ridges 58, and
perforations 60 on each flap 50 of the drywall joint assembly strip
device 10 of the present invention are formed in a single
operation. As shown in FIG. 6, one such means for forming all three
features in one step is a mating roller device, or knurling machine
70. The machine generally has two parallel shafts aligned in a
vertical plane: an upper shaft 72 and a lower shaft 74. An upper
roller 76 and a lower roller 78 are mounted in rolling contact on
the distal ends of the upper and lower shafts, respectively. The
upper roller is configured with one or more axially spaced-apart
circumferential rings 80 having radially spaced-apart pyramidal
spikes, or knurling points 82, thereabout. The lower roller is
configured with axially spaced-apart circumferential channels 84
positioned to accommodate the spiked rings of the upper roller.
[0039] The upper and lower shafts 72 and 74 rotate in opposite
directions relative to one another, so that the upper roller 76 and
lower roller 78 turn on each other and allow the flaps 50 to be fed
between them one at a time. The shafts may be manually rotated or
be driven by the knurling machine. In either case, a dry paper flap
may be fed between the mating, rotating rollers to pass between
them such that its outwardly-facing surface 52 faces the upper
roller so that each ring 80 on the upper roller forces the flap
material into the corresponding channel 84 on the lower roller to
permanently deform the paper and form the respective grooves 56. At
the same time, in those embodiments which are perforated, knurling
teeth define points 82 to make multiple punctures in the respective
flap along each groove to form the spaced-apart perforations 60.
The flap material is forced by the rings into the engaging channels
with sufficient force to permanently deform the paper forming such
flaps to define on one side thereof high areas, defining the ridges
58, on either side of each groove. In this way, through a single
operation, a knurled surface comprised of lengthwise grooves,
ridges, and perforations is permanently formed along the
outwardly-facing surface of each flap, thus completing the strip
device 10. Therefore, it will be appreciated by those skilled in
the art that the drywall joint assembly strip device of the present
invention is capable of being produced in a convenient and
cost-effective manner by being made of relatively common and
inexpensive materials and by employing methods that are efficient
and utilize equipment that is generally known in the art.
[0040] From the foregoing, it will be appreciated that the drywall
joint assembly strip device of the present invention provides an
effective and economical strip device for covering and protecting
an underlying drywall joint. The strip device may be formed in many
different configurations to suit a variety of drywall joint
applications and optimizes the ease and effectiveness of installing
the strip device on a drywall joint through its novel flexible
flaps having lengthwise grooves and ridges and/or spaced-apart
perforations for flow of joint compound to anchor such flaps.
[0041] Various modifications and changes may be made with regard to
the foregoing detailed description without departing from the
spirit of the invention.
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