U.S. patent application number 11/679562 was filed with the patent office on 2007-08-02 for lath with barrier material.
Invention is credited to Harold Davis, Abraham Jacob Sacks, Jeffrey Leonard Sacks, William Spilchen.
Application Number | 20070175145 11/679562 |
Document ID | / |
Family ID | 46327390 |
Filed Date | 2007-08-02 |
United States Patent
Application |
20070175145 |
Kind Code |
A1 |
Sacks; Abraham Jacob ; et
al. |
August 2, 2007 |
Lath with Barrier Material
Abstract
A rigid wire lath product having a backing material which may be
used to reinforce coatings, such as stucco, applied to building
surfaces. The product comprises a mesh of longitudinal wires and
transverse wires having a plurality of spaced indentations. A layer
of backing material having apertures which straddle the
indentations is interwoven in the mesh by longitudinal retaining
wires extending along the bottom of the indentations. A method of
manufacturing the product by providing a mesh of longitudinal and
transverse wires welded together at their intersections
substantially in a plane, and forming rows of spaced indentations
in the transverse wires. A planar material is overlaid on the mesh
such that said portions of the indentations protrude through
apertures in the material. A plurality of wires are welded along
respective rows of the protruding indentations to sandwich the
material between the mesh and the wires.
Inventors: |
Sacks; Abraham Jacob;
(Vancouver, CA) ; Sacks; Jeffrey Leonard;
(Vancouver, CA) ; Davis; Harold; (Vancouver,
CA) ; Spilchen; William; (White Rock, CA) |
Correspondence
Address: |
GEORGE S. LEVY
3980 DEL MAR MEADOWS
SAN DIEGO
CA
92130
US
|
Family ID: |
46327390 |
Appl. No.: |
11/679562 |
Filed: |
February 27, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10935821 |
Sep 8, 2004 |
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11679562 |
Feb 27, 2007 |
|
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09927544 |
Aug 13, 2001 |
6820387 |
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10935821 |
Sep 8, 2004 |
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Current U.S.
Class: |
52/408 |
Current CPC
Class: |
E04C 5/0627 20130101;
E04F 13/047 20130101; E04C 5/04 20130101; E04F 13/04 20130101; B21F
27/20 20130101 |
Class at
Publication: |
052/408 |
International
Class: |
E04B 5/00 20060101
E04B005/00 |
Claims
1. Welded wire lath comprising: a mesh formed from a plurality of
longitudinal wires and a plurality of transverse wires, said
longitudinal wires and said transverse wires being welded at their
intersections to form a mesh having a plurality of cells, said mesh
having at least two opposed ends, each end being defined by a row
of cells sharing at least one common longitudinal wire; said
transverse wires having indentations at spaced intervals, and
longitudinal retaining wires being welded to said indentations to
form rows of indentations coinciding with said longitudinal
retaining wires; a planar barrier layer of material having a
plurality of apertures with webs therebetween, said material being
interwoven with said mesh, said indentations extending through said
apertures, and said longitudinal retaining wires spanning portions
of said webs to retain said material to said mesh; said material
having two opposed ends each end comprising a row of end webs
extending between a plurality of openings, at least one of said end
webs being folded over and around a common longitudinal wire and
being secured back onto itself about said common longitudinal
wire.
2. The lath of claim 1 wherein said apertures are spanned by said
longitudinal retaining wires but not by any other ones of said
longitudinal wires.
3. The lath of claim 1 wherein each of said end webs is folded over
and around a common longitudinal wire and each of said end webs is
secured back onto itself about its respective common longitudinal
wire.
4. The lath of claim 1 wherein said openings at said ends of said
material define apertures bounded by a closed curve prior to said
end webs being folded over.
5. The lath of claim 1 wherein said openings at said ends of said
material define unclosed gaps along an edge prior to said end webs
being folded over.
6. The lath of claim 1 wherein said common longitudinal wire around
which said end webs are folded over is one of said longitudinal
retaining wires welded to said indentations.
7. The lath of claim 1 wherein said apertures are circular.
8. The lath of claim 1 wherein said openings are larger than said
apertures.
9. The lath of claim 1 wherein the apertures along at least one
longitudinal row of indentations are sufficiently small that
opposed edges of the apertures are in simultaneous contact with
said indentation to retain said material against transverse
displacement.
10. Welded wire lath comprising: a mesh formed from a plurality of
longitudinal wires and a plurality of transverse wires, said
longitudinal wires and said transverse wires being welded at their
intersections to form a mesh having a plurality of cells, said mesh
having at least two opposed ends, each end being defined by a row
of cells sharing at least one common longitudinal wire; said
transverse wires having indentations at spaced intervals, said
indentations coinciding with parallel rows of said intersections
and spaced ones of said longitudinal wires being welded to said
indentations to form rows of indentations along said spaced
longitudinal wires; a planar barrier layer of material having a
plurality of apertures with webs therebetween, said support
material and being interwoven with said mesh, said indentations
extending through said apertures and said spaced longitudinal wires
spanning portions of said webs to retain said material to said
mesh; said material having two opposed ends each being defined by a
row of end webs extending between a plurality of openings each
bounded by a closed curve and being larger in diameter than said
apertures; and, said end webs being folded over and around a common
longitudinal wire that is welded to a row of said indentations, and
being secured back onto themselves about said common longitudinal
wire.
11. A method of manufacturing a welded wire lath, comprising the
steps of: providing a mesh of longitudinal and transverse wires
welded together at their intersections substantially in a plane;
forming rows of spaced indentations in said transverse wires, said
indentations having portions extending out of said plane; after
said step of forming rows, providing a planar material having a
plurality of apertures being spaced from one another in a pattern
corresponding to the locations of said indentations and overlaying
said planar material on said mesh such that said portions of said
indentations protrude through said apertures; after said step of
overlaying said planar material, welding a plurality of elongated
wires along respective rows of said protruding portions of said
indentations to thereby sandwich said planar material between said
mesh and said elongated wires.
12. The method of claim 11 wherein: said planar material is
provided in sheets, said sheets including interconnected webs of
material between said apertures, and further including a row of end
webs at least one side of said sheets said end webs extending
between a row of end openings, and further including the step of:
folding and securing each of said end webs over onto itself around
a common one of said elongated wires.
13. The method of claim 11 wherein said planar material further
includes a plurality of holes, each of said holes having a diameter
smaller than the diameter of said apertures and is sufficiently
small that opposed edges of said holes are in simultaneous contact
with its respective indentation to retain said planar support
material against transverse displacement.
14. The method of claim 12 wherein said end openings in said planar
material are bounded by a closed curve and said end openings are
larger than said apertures.
15. A method of manufacturing a welded wire lath, comprising the
steps of: providing a mesh of longitudinal and transverse wires
welded together at their intersections substantially in a plane;
forming rows spaced indentations in said transverse wires, said
indentations having portions extending out of said plane; providing
a plurality of sheets of planar material each of said sheets:
having a plurality of apertures being spaced from one another in a
pattern corresponding to the locations of said indentations;
including interconnected webs of material between said apertures;
having a row of end webs at least one side of said sheet, said end
webs bounded by a closed curve and extending between a row of end
openings, said end openings being larger than said apertures;
having a plurality of holes, each of said holes having a diameter
smaller than the diameter of said apertures and sufficiently small
that opposed edges of said holes will be in simultaneous contact
with its respective indentation to retain said planar support
material against transverse displacement when said sheet of planar
material is overlaid on said mesh; overlaying one of said sheets of
planar material on said mesh such that said portions of said
indentations protrude through said apertures; welding a plurality
of elongated wires along respective rows of said protruding
portions of said indentations to thereby sandwich said planar
material between said mesh and said elongated wires; folding and
securing each of said end webs over onto itself around a common one
of said elongated wires; and, shearing said mesh into sheets of
lath.
16. The method of claim 15 wherein said step of providing a mesh
comprises providing a mesh of longitudinal and transverse wires
welded together at their intersections substantially in a plane,
wherein groups of said longitudinal wires are spaced from one
another by a first amount and said longitudinal wires within each
group are spaced from another by a second amount that is greater
than said first amount to provide gaps between said groups and such
that when said step of forming rows of indentations is said
transverse wires is performed, said groups are drawn toward one
another to substantially eliminate said gap.
17. A wire fabric lath comprising: a mesh formed from a plurality
of longitudinal wires and a plurality of transverse wires arranged
to form a mesh having a plurality of cells, said mesh having at
least two opposed ends, each end being defined by a row of cells
sharing at least one common longitudinal wire; a planar layer of
material having a plurality of apertures with webs therebetween,
said material being interwoven with said mesh; said material having
two opposed ends each being defined by a row of end webs extending
between a plurality of openings, at least one of said end webs
being folded over and around a common longitudinal wire and being
secured back onto itself about said common longitudinal wire.
18. The wire fabric lath of claim 17 wherein each of said end webs
is folded over and around a common longitudinal wire and each of
said end webs is secured back onto itself about its respective
common longitudinal wire.
19. The wire fabric lath of claim 17 wherein said openings at said
ends of said material define apertures bounded by a closed curve
prior to said end webs being folded over.
20. The wire fabric lath of claim 17 wherein said openings at said
ends of said material define unclosed gaps along an edge prior to
said end webs being folded over.
21. The wire fabric lath of claim 17 wherein said openings are
larger than said apertures.
22. Welded wire lath comprising: a mesh formed from a plurality of
longitudinal wires and a plurality of transverse wires, said
longitudinal wires and said transverse wires being welded at their
intersections to form a mesh having a plurality of cells, said mesh
having at least two opposed ends, each end being defined by a row
of cells sharing at least one common longitudinal wire; said
transverse wires having indentations at spaced intervals, and
longitudinal retaining wires being welded to said indentations to
form rows of indentations coinciding with said longitudinal
retaining wires; a planar barrier layer of material having a
plurality of apertures with webs therebetween, said material being
interwoven with said mesh, said indentations extending through said
apertures, and said longitudinal retaining wires spanning portions
of said webs to retain said material to said mesh; and, said
apertures being circular.
23. The lath of claim 22 wherein the apertures along at least one
longitudinal row of indentations are sufficiently small that
opposed edges of the apertures are in simultaneous contact with
said indentation to retain said material against transverse
displacement.
24. The lath of claim 22 wherein a plurality of first longitudinal
rows of said apertures are of a first size and at least one second
longitudinal row of said apertures are of a second size that is
smaller than said first size.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation in part of U.S. patent
application Ser. No. 10/935,821 entitled Self Stiffened Welded Wire
Lath Assembly by Abraham Sacks et al. filed Sep. 8, 2004, which was
a continuation in part of U.S. patent application Ser. No.
09/927,544 filed on Aug. 13, 2001.
FIELD OF THE INVENTION
[0002] This invention relates to building technology, and in
particular to wire lath which may be used to reinforce coatings,
such as stucco, applied to soffits and other building surfaces.
BACKGROUND OF THE INVENTION
[0003] Some building construction techniques involve the
application of a coating, such as stucco, to a surface. The coating
may be desired, for example, to improve appearance, enhance fire
resistance or to comply with building or fire codes. In the
following disclosure the term "stucco" is used generally to apply
to cementitious plasters or gypsum plasters, including stuccos as
defined in applicable building codes.
[0004] When applying a coating of stucco (or other similar
material) it is generally desirable to provide a lath on the
surface. The lath provides reinforcing for the stucco and holds the
stucco in place while it cures.
[0005] Typical construction usually involves wood or metal framing
without sheathing, referred to as open frame construction. On
vertical surfaces, horizontal strands of 18 gauge tautened wire
backing are attached to the surfaces of the vertical supports. A
weather-resistant barrier is then installed which is usually a
Grade D asphalt building paper. For plaster cladding, wire fabric
lath is then attached to the framing over the building paper and
backing wires. The backing wires provide sufficient rigidity to
permit proper plaster application without damaging the paper and
achieving consistent plaster thickness between framing members.
[0006] The building paper application starts at the bottom and each
succeeding course overlaps the previous course by a minimum of 2
inches, and usually is approximately 4 inches. This ensures proper
shingling of the paper to ensure that any moisture that penetrates
the cladding is directed downward and away from the building
structure. The wire fabric lath has to be lapped not less than one
mesh at the sides and ends. Since the building paper and wire
fabric lath are applied independently, there is no difficulty in
achieving the proper overlapping of each element.
[0007] This practice is referred to as a 3 step
process--installation of backing wires, installation of building
paper, and installation of lath. To overcome this inefficiency,
paper backed lath products have been developed that are one step
products. These products incorporate the backing wire, the building
paper and the wire lath into a single product. An example of such a
product is available from K-Lath Corp. of Fontana, Calif. referred
to as Stucco Rite.RTM.. Stucco Rite.RTM. is a 2'' by 2'' welded
wire mesh with a slot-perforated absorptive, separator paper, and
with a sheet of Grade D building paper adhered to the separator
paper. Another manufacturer, Davis Wire Corp of Irwindale, Calif.
manufactures a similar product called Best-Lath "D" Welded Wire
Fabric Lath.
[0008] As seen in both of these products, a perforated separator
paper is incorporated between the longitudinal and cross wires of
the lath. The function of this separator paper is to provide a
means of attaching the building paper to the lath. The building
paper must remain intact so holes or perforations cannot be
incorporated into the building paper itself. Therefore, the
separator paper is required since it can be perforated so that it
may be mechanically attached to the wire lath. This sheet provides
a suitable base for attachment of the building paper.
[0009] In the installation of these one step products, care must be
taken to achieve the proper lapping of the building paper and of
the wire lath. ASTM C-1063 "Standard Specification for Installation
of Lathing and Furring to Receive Interior and Exterior Portland
Cement-Based Plaster" states in Section 7.8.3 "Where metal plaster
base with backing is used, the vertical and horizontal lap joints
shall be backing on backing and metal on metal". To achieve this,
the manufacturers of the above products have carefully sized the
building paper sheet size and sheet location on the wire mesh
sheet, so that proper lapping of both the building paper and the
wire lath can be achieved. Since the building paper is adhered to
the separator sheet, the interwoven wires are trapped between these
two papers. As a result, the position of the papers in relation to
the wire lath is maintained during handling and installation.
[0010] Further, since the separator paper is only required to
provide an adhesive base for the building paper, it need not extend
all the way to the edges of the lath sheet. Therefore, it is sized
so that it does not encroach on the overlaps and is not a hindrance
factor in achieving the proper metal on metal contact. Usually,
this separator paper is kept back two to three inches from all
edges of the wire lath.
[0011] Since the building paper provides support for the edges of
the separator paper, there is no need to firmly attach the edges of
the separator paper to the lath. When the product is applied on the
wall, the building paper prevents the separator paper from being
displaced into the wall cavity with the pressure of the applied
plaster. Further, since the building paper extends past the lath
overlaps in all directions, there are no gaps in the backing where
plaster can flow past the lath into the wall cavity.
[0012] However, there are applications where building paper is not
required or not desired. Such applications would be on horizontal
surfaces such as undersides of soffits or porticos, or on vertical
surfaces such as rain screen walls. Rain screen walls are
constructed with building paper installed over the framing and then
a furring spacer, usually 3/4 inch thick, is installed vertically
over the building paper. A lath with backing is attached to these
furring spacers. A lath with building paper is not desirable in
this instance since any moisture traveling downward within the
drainage cavity could be caught by the edge of the building paper
and deflected out of the rain screen cavity. The design intent is
to keep the moisture within the cavity and then discharge it at the
bottom through a proper flashing.
[0013] A lath as disclosed in U.S. Pat. No. 6,820,387 to Sacks et
al discloses a lath with a separator paper only without the
building paper which is intended for such applications. However,
when the building paper is omitted, several deficiencies become
evident. In the prior art as disclosed by Sacks, the separator
paper (referred to as a barrier paper in the Sacks prior art) does
not extend all the way to the edges of the wire lath. If the
separator paper did extend all the way to the edge, it would
firstly interfere with achieving metal to metal contact. Secondly,
it would not be secured at the edges and would give way when
plaster pressure was applied. This would result in uneven thickness
of plaster which could cause a plaster fall out due to additional
weight of wet plaster, or be the cause of potential cracks in the
future. Further, since there is no building paper adhered to the
separator paper, the separator is not held firmly in position
relative to the wire. Therefore, since the paper may shift during
handling and installation, it could the also interfere in obtaining
metal to metal contact without any paper in between the overlapping
joint.
[0014] In addition, the longitudinal wires forming part of the
Sacks truss extend across the slots thereby impeding to some extent
the keying of the stucco through the slot. The elongated slots in
the separator layer also result in movement or play between the
separator layer and the wire mesh that can cause displacement of
the separator layer.
[0015] An additional problem arises from the use of paper backed
lath arises from the manner in which the paper is terminated at the
sides of the lath. The paper is provided with apertures for keying
of the stucco. The areas between the apertures form interconnected
webs of material. At the sides of the lath, the paper includes an
unattached flap of material that does not provide effective
resistance to the application of stucco, resulting in difficulty of
application.
[0016] It is the objective of the present invention to provide an
improved backed lath with a barrier layer that avoids the
disadvantages of the prior art paper backed laths.
SUMMARY OF THE INVENTION
[0017] This invention provides a rigid wire lath product having a
backing material that overcomes a number of disadvantages of prior
art wire fabric laths.
[0018] According to the invention, the principal plane of the wire
fabric comprises a mesh of longitudinal and transverse wires
forming columns and rows. The transverse wires have a plurality of
spaced indentations. A planar barrier layer of material is
interwoven in the mesh by longitudinal retaining wires extending
along the bottom of the indentations. The barrier layer is provided
with apertures enabling the indentations to be straddled by the
apertures such that the material forming the barrier layer is
retained between the principal plane of the wire fabric on one side
and the longitudinal retaining wires on the other side. This
arrangement allows all of the intersections of the principal plane
of the wire fabric to be welded before applying the barrier layer
and the longitudinal retaining wires. Preferably the apertures may
be circular so as to more closely abut the indentations in all
directions, thereby limiting relative displacement of the barrier
layer in relation to the wire mesh.
[0019] In one aspect of the invention, the longitudinal wires
forming the principal plane of the wire fabric are arranged such
that they do not extend across the apertures thereby ensuring that
they do not impede the keying of the stucco into the apertures.
[0020] In another aspect of the invention, the barrier layer
includes webs at the sides of a sheet between end rows of cells,
each of the webs being folded over a common longitudinal wire and
being secured back unto itself about the longitudinal wire thereby
avoiding unattached flaps.
[0021] In another aspect of the invention, the barrier layer
includes a plurality of apertures overlapping the indentations and
wherein each of the apertures in at least one row has a diameter
substantial equal to or less than the maximum span of the
indentations.
[0022] In another aspect of the invention, at least one rows of
apertures are smaller than the other rows of apertures and are
sufficiently small that opposed edges of the apertures in the at
least one row are in simultaneous contact with the indentation
about which it is seated so as to retain the barrier material
against transverse displacement.
[0023] According to a method aspect of the invention, the
manufacture of a welded wire lath comprises providing a mesh of
longitudinal and transverse wires welded together at their
intersections substantially in a plane, and forming rows spaced
indentations in the transverse wires, the indentations having
portions extending out of the plane. A planar material is provided,
the material having a plurality of apertures being spaced from one
another in a pattern corresponding to the locations of the
indentations. The planar material is overlaid on the mesh such that
said portions of the indentations protrude through the apertures. A
plurality of elongated wires are then welded along respective rows
of the protruding portions of the indentations to thereby sandwich
the planar material between the mesh and the elongated wires.
[0024] In a more particular aspect, the planar material is provided
in sheets having end webs that are folded over a common elongated
wire of the mesh and are secured to themselves about that wire.
[0025] In a still more particular aspect, the planar material is
provided with holes having a smaller diameter than the diameter of
the apertures such that opposed edges of each hole are in
simultaneous contact with its respective indentation to retain the
planar support material against transverse displacement.
[0026] The foregoing summary of the invention does not necessarily
include all aspects of the invention. Further features and aspects
of the invention will be more fully understood by reference the
following description of the preferred embodiments and to the
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The preferred embodiment of the invention will be described
by reference to the drawings in which:
[0028] FIG. 1 is a schematic front perspective view of a welded
wire mesh lath in accordance with the invention;
[0029] FIG. 2 is a schematic cross-sectional view of the welded
wire mesh lath of FIG. 1;
[0030] FIG. 3 is a diagrammatic side elevation of the manufacturing
process of welded wire mesh lath according to the invention;
[0031] FIG. 4A is a diagrammatic plan view of a first part of the
manufacturing process according to the invention;
[0032] FIG. 4B is a diagrammatic plan view of a second part of the
manufacturing process according to the invention; and
[0033] FIG. 4C is a diagrammatic plan view of a third part of the
manufacturing process according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] Referring to FIGS. 1 and 2, there is shown a lath 10
according to the preferred embodiment comprising a wire mesh 12 and
a planar barrier layer of material 14. The material 14 may comprise
a suitable building paper, such as kraft paper, which may be
surface treated to improve the adhesion of stucco. Alternatively it
may comprise asphalt-coated paper or such an asphalt-coated paper
adhered to another layer, such as kraft paper.
[0035] Wire mesh 12 is fabricated by welding the intersections 18
of a plurality of transverse wires 20 and a plurality of
longitudinal wires 22 that are perpendicular to the transverse
wires 20. The wires 20 and 22 and their intersections lie
substantially in plane 24, best seen in FIG. 2. Each of the
transverse wires 20 has a plurality of spaced indentations 26
arranged in rows and columns across the lath. Indentations 26 are
preferably generally V-shaped and provide rigidity to the lath.
[0036] A set of longitudinal retaining wires 28 are welded to the
indentations 26 at the apices of the indentations (as best seen in
FIG. 2) so that the indentations are formed in rows coinciding with
the longitudinal retaining wires 28. Each transverse wire 20 lies
within a plane that includes indentation 26. That plane, which is
the plane of FIG. 2, is generally perpendicular to plane 24. In the
preferred embodiment, longitudinal wires 18 are located so as to
avoid spanning the openings of the apertures 30 in the support
material 14, which apertures are described in more detail
below.
[0037] A wire lath 10 can be produced in any desired dimensions but
is preferably provided in sheets of widths and lengths that can be
easily handled. For example, the sheets may have a width in the
range of 2 to 5 feet. Sheets of wire lath 10 can be compactly
stacked together with the indentations 26 of one sheet being
received within those of the next sheet in the stack.
[0038] The combination of the longitudinal and transverse wires
welded at their intersections forms a mesh comprising rows of
cells, including opposed end rows 32, 34 at opposed transverse ends
36, 38 of the mesh. The cells comprising end row 32 share at least
one common longitudinal wire 40 while the cells comprising end row
34 share at least one common longitudinal wire 42. In the preferred
embodiment, wires 40 and 42 are the endmost ones of longitudinal
retaining wires 28, i.e. they extend along the apices of
indentations 26 in a plane 44 that is defined by the plurality of
longitudinal retaining wires 28.
[0039] Lath 10 may be applied over framing members, which are
typically 16 inches or 24 inches on center. It can be attached to
the framing members at the bottom of indentations 26. In horizontal
applications, building codes generally require that a lath be
attached every 3 inches. In vertical applications, the codes
generally require attachment to the framing members every 6 inches.
In either case, a 3 inch spacing of the indentations 26 allows
appropriate attachment points. Lath 10 is preferably applied in an
orientation such that the side of lath 10 bearing longitudinal
retaining wires 26 faces the framing members, each of the
longitudinal retaining wires crosses a plurality of the framing
members, and longitudinal wires 22 are spaced from the faces of the
framing members by the indentations 26. The portions of lath 10
between the framing members can be substantially unsupported.
[0040] A planar barrier layer of material 14 is disposed between
plane 24 and plane 44. Barrier layer 14 includes apertures 30
through which the indentations 26 protrude to allow the
longitudinal wires 22 to lie on one side of support layer 14 and
longitudinal retaining wires 28 to lie on the other side of layer
14. The barrier layer 14 is thereby interwoven with the mesh,
straddling the indentations 26 and being sandwiched between the
principal plane 24 of the mesh and the longitudinal retaining wires
28. This arrangement allows all of the other intersections of the
mesh to be welded and the indentations 26 to be formed in advance
of applying the barrier layer 14 and welding the longitudinal
retaining wires 28 to the indentations 26.
[0041] According to the prior art approach disclosed in U.S. Pat.
No. 6,820,387, certain ones of the longitudinal wires 22 are
provided on the shoulder portions of the indentations 26. This
sometimes results in such longitudinal wires spanning and
obstructing a portion of the opening of the apertures 30. However,
according to the present invention, the longitudinal wires 22 are
positioned in relation to the indentations 26 so that none of them
spans the apertures 30 as best seen in FIG. 1.
[0042] In the known prior art, the perforations in the barrier
layer are elongated to form slots. This can result in displacement
or floating of the support layer in relation to the wire mesh in
the direction of elongation of the slots. In order to avoid such
effect, the present invention provides apertures 30 that are
circular so as to more closely abut the indentations in all
directions, thereby limiting relative displacement of the support
material in relation to the wire mesh. Preferably, all of the
apertures 30 have diameters substantial equal to or less than the
span D of the indentations at their base, i.e. where the transverse
wires 20 begin to leave plane 24.
[0043] In the preferred embodiment, at least one of the rows of
apertures comprises holes 46 that are smaller in diameter than the
maximum span D of the indentations (at the base of the
indentations). This results in holes 46 snugly engaging the
indentations at some point between the base and the apices of the
indentations, thereby more effectively resisting displacement of
the support material in relation to the wire mesh. In the preferred
embodiment, holes 46 are between 1/4'' and 3/4'' in diameter,
preferably about 1/2'' in diameter, while the apertures 30 are
between 3/4'' and 11/4'' in diameter, preferably about 7/8'' in
diameter. Such an arrangement of two sets of apertures allows snug
retention of the support material to the wire mesh on the one hand,
by means of the smaller holes, while also allowing effective
mushrooming of the stucco through the larger apertures.
[0044] The arrangement of apertures 30 in the barrier layer forms a
matrix of interconnected webs of support material between the
apertures. It will be appreciated that the longitudinal retaining
wires 28 span portions of these webs to retain the barrier layer 14
between the longitudinal retaining wires 28 on the one hand and a
combination of the transverse wires 20 and the longitudinal wires
22 on the other hand. The barrier layer of the preferred embodiment
has two opposed ends 48 and 50 that extend generally to the opposed
sides of the wire mesh. At least one of such ends, for example end
50, comprises a row of end webs 52 extending between a plurality of
end openings 54. The end webs 52 are folded over and secured to
themselves about and around common longitudinal wire 56 and each of
said end webs 52 is secured back onto itself around common
longitudinal wire 56. Preferably the same is done at opposed end 48
of the support material.
[0045] Prior to being folded over, the end openings 54 comprise
apertures bounded by a closed curve, however it is contemplated
that prior to being folded over, the end openings 54 may simply
present unclosed gaps in the end of the support material. In the
preferred embodiment, end openings are larger in their aperture
area than aperture 30. When the end openings are folded over
themselves, there is a possibility that the webs of material
between the openings will not line up perfectly so that the facing
webs combine to increase the surface area available to obstruct the
passage of stucco. This may be compounded when adjacent sheets of
lath are brought into edge to edge engagement during installation.
Thus it is desirable to have openings that are as large as feasible
to maximize the keying of stucco once the webs are folded over and
secured to themselves.
[0046] It will be appreciated that various modifications to the
preferred embodiment may be practised without changing the
underlying structure and effectiveness of the invention. For
example, additional longitudinal or transverse wires might be added
and additional apertures might be provided in the barrier layer.
Other such changes can be made that do not depart from the
principles of the invention.
[0047] The manufacture of the lath 10 of the preferred embodiment
will now be described by reference to FIGS. 3, 4A, 4B and 4C.
[0048] A matrix of perpendicular transverse 60 and longitudinal 62
wires are welded (64) at their intersections 66 in a continuous
process to produce a rectangular mesh 68. Transverse wires 60 are
spaced about 1.6'' from one another while longitudinal wires 62 are
nominally spaced about 0.6'' from one another. At regular intervals
of three longitudinal wires, one of the longitudinal wires is
omitted as indicated by the numeral 70 so that gaps are provided
between groups of otherwise equally spaced longitudinal wires. The
gaps 70 left by the omitted wires are made to be of such dimensions
that when a fur indentation 72 is made in the transverse wires by
indentation former 74, the groups of longitudinal wires are drawn
towards one another across the gaps so that the spacing between the
groups is brought to approximately the regular longitudinal
interval spacing of 0.6''. The drawing in of the longitudinal wires
is shown at 76 in FIG. 4A. Each of two transverse feed strands is
turned back on itself at the sides of the lath to form adjacent
transverse wires at a spacing of about 1.6''. The turning back on
themselves at the sides of the lath results in the formation of
ears 78 (shown in FIG. 1 as ears 37, 39).
[0049] The resulting mesh 68 is then formed as at 74 to provide fur
indentations 72 at spaced intervals along the transverse wires 60,
the indentations 72 corresponding in position to the omitted
longitudinal wires from gaps 70.
[0050] A support material 80, preferably kraft paper, having
apertures 82 and 84 corresponding to the pattern of indentations 72
is then applied over the mesh workpiece such that each of apertures
82 and 84 straddles one of the fur indentations 72.
[0051] A plurality of longitudinal retaining wires 86 are then
welded (88) to the apices of the indentations 72 to sandwich the
support material 80 between the principal plane of the mesh and the
longitudinal retaining wires 86.
[0052] Pinch feed rolls 95 draw the mesh along to a shearing
station 90 where the mesh is sheared into sheets 92 having
approximately the desired dimensions of the lath 10.
[0053] Glue is then sprayed (94) by an applicator 96 onto the end
webs 98 of the sheets 92 and the sheets are then fed to a folding
station 100 where the end webs 98 are folded over and around the
terminal longitudinal retaining wires 102 that are at the sides of
the sheets. Additional feed pinch rolls 104 deliver the sheets to a
stack 106 for transport.
[0054] It should be appreciated that the invention as described
herein comprising a number of aspects, each of which might
independently be applied. For example, the aspect of the invention
involving the folding over of the end webs of the barrier material
may be practised on a mesh that does not necessarily include
indentations or furring spacers. Similarly, the method of
manufacturing involving the formation of a planar mesh, followed by
the formation of indentations and the application of longitudinal
retaining wires over a barrier layer may be practised without
necessarily folding over the end webs of the barrier layer. Further
still, providing a mesh wherein the longitudinal wires do not span
the apertures may be practised without necessarily including the
other aspects of the invention.
[0055] As will be apparent to those skilled in the art in the light
of the foregoing disclosure, many alterations and modifications are
possible in the practice of this invention without departing from
the spirit or scope thereof. Accordingly, the scope of the
invention is to be construed in accordance with the substance
defined by the following claims.
* * * * *