PRECAST PANEL MOUNTING SYSTEM

FIELD OF THE INVENTION

The present invention relates to precast cladding panels mounted to supporting structures, and relates in particular to mounting brackets cast into precast panels.

BACKGROUND OF THE INVENTION

Precast panels of various sizes and shapes are widely used as cladding on building walls, serving as components of building envelope systems intended to prevent infiltration of rain and outside air into the building. Precast cladding panels are commonly made of concrete, but may also be made with other cast materials known in the construction field. Concrete cladding panels are common on large structures such as office buildings, but they are also used on residential housing structures as an alternative to traditional cladding materials such as wood siding and brick.

Whether installed on large or small buildings, it is desirable for cladding panels to be mounted in such a way that there will be a continuous air space between the rear (i.e., inner) faces of the panels and the supporting structure, while at the same time providing reliable structural support for the panels, both to transfer the vertical weight of the panels to the supporting structure and to provide anchorage against lateral forces (such as wind) that may act on the panels.

The purpose of the air space is to provide a passage through which any water or moisture vapour that gets behind the cladding can be directed away from the building envelope before it infiltrates other parts of the building. Although caulking or other sealant materials are typically used to seal the spaces between cladding panels, the possibility of moisture infiltration behind the cladding - as a result of vapour migration, direct penetration of rainwater (due to sealant deterioration or other factors), or leakage at roof- to-wall junctures - cannot be entirely eliminated. If such moisture is not removed from the building envelope fairly promptly, it will tend to migrate further into the building, potentially causing a variety of problems that could entail costly maintenance and repairs

and could detract from the building's overall durability and value. Such problems may include drywall damage due to moisture absorption, rot and mold in wooden construction components (e.g., studs and sheathing), corrosion of non-rust-resistant construction hardware, and staining on interior building finishes.

When an air space is provided behind the cladding, moisture can run downward behind the cladding to exit points such as weepholes built into the cladding system at appropriate locations. The air space also facilitates or enhances air circulation behind the cladding, helping to remove moisture vapour before it can condense inside the wall structure, and helping to dry out any wall structure components that may have become damp due to moisture infiltration.

The essential problem facing designers of cladding panel support systems is to provide hangers or brackets that can adequately support weight of the panels at a distance away from the face of the supporting structure (i.e., so as to provide the desired air space), without significantly impeding the passage of water or water vapour through the air space. In this regard, it is particularly desirable to avoid or minimize hanger-to-panel connection details where moisture might become trapped or its vertical flow impeded.

One approach to this problem is to use vertically-oriented hangers cast into the rear faces of the cladding panels, as in Canadian Patent No. 2,169, 585 issued to Kuelker on February 3, 2004, and similarly in U.S. Patent No. 6,253,515 issued to Kuelker on July 3, 2001. The hangers used in this system accomplish the desired objectives of providing good structural support without significantly impeding air circulation behind the panels. It is important, of course, for these hangers to be cast into the panels within fairly close tolerances to facilitate uniform vertical alignment of the panels when they are mounted to a supporting structure. As well, when using vertically-oriented panel hangers of this or similar type, it will often be desirable or necessary to control the horizontal location of the hangers within close tolerances, such as when it is desired to attach the hangers directly to primary structural elements (e.g., wall studs) rather than to secondary elements (e.g., wall sheathing or strapping). It is readily apparent that cladding panels using vertical hangers of this general type cannot be effectively used on unsheathed walls unless the hangers coincide with stud locations, or unless horizontal strapping is installed across the studs at

specific vertical intervals (and at additional cost) to receive the hanger fasteners.

It is desirable for concrete cladding panels to be stackable as compactly as possible to minimize space requirements during storage and shipping. When the panels have embedded hangers that project from the panels' rear faces, there will always be a space between the stacked panels equal to at least the thickness of the hangers. Accordingly, the total height of a stack of panels may be as much as 20% to 30% greater than the sum of the thicknesses of the panels, depending on the relative thickness of the panels and the hanger members. It is desirable, therefore, to have a hanger system that reduces or substantially eliminates the space between stacked cladding panels, thus significantly reducing storage space requirements .

The prior art discloses a number of additional examples of hanger systems for mounting precast cladding panels to vertical supporting structures, including:

- German Patent Application No. DE 3209746 (Wϋnsch), filed March 17, 1982;

- French Patent Application No. 82 14147 (Michelet et al.), filed August 16, 1982 - U.S. Patent No. 4,553,366 (Guerin), issued November 19, 1985; and

- European Patent Application No. 89115208.4 (Isele), filed August 18, 1989.

However, none of these prior art systems addresses all of the problems and desirable features discussed above. Moreover, these systems are primarily intended for use in the construction of curtain wall systems or mounting large, heavy concrete cladding panels on large buildings, and are not conveniently adaptable for use with comparatively small and light concrete cladding panels for residential housing structures.

For the foregoing reasons, there is a need for an improved precast panel support system that facilitates secure mounting of panels at a uniform distance away from a vertical supporting structure without introducing significant impediments to air flow through the air space thus created between the rear faces of the panels and the supporting structure. There is a further need for a panel support system that facilitates accurate positioning of the hangers in the panels during panel casting operations, so as to minimize the likelihood of misalignment of the mounted panels. There is an additional need for a panel hanger system in which lateral location of the hangers in the panels is not critical in order for the

panels to be conveniently and securely anchored to vertical support elements, such as sheathed or unsheathed wall studs. In addition, there is a need for a panel hanger system that facilitates more compact stacking and storage of panels, with the space between stacked panels reduced or eliminated. The present invention is directed to these needs.

BRIEF SUMMARY OF THE INVENTION

In general terms, the present invention is a mounting system for precast cladding panels featuring as its main component a mounting bracket that can be cast into a precast cladding panel adjacent to the panel's upper or lower edge. One end or portion of the bracket is intended for embedment in a precast panel, while the other end or portion is intended to extend or project at an angle both rearwardly and laterally away from the rear face of the panel. The mounting bracket is configured such that when cast into a precast panel in an appropriate angular orientation, the end of the extension portion of the bracket will be disposed at a distance away from the rear face of the panel corresponding to the desired air space. At least one fastener hole is provided in the extension portion of the bracket, for receiving a fastener such as a wood screw to attach the panel to a supporting structure. The bracket also incorporates abutment means which, when the bracket is embedded in a panel as described above, will be substantially in alignment with the rear face of the panel.

In a typical application, two or more mounting brackets are cast into a panel adjacent its upper edge, with two or more brackets being cast into the panel adjacent its lower edge. The upper brackets are used to fasten the panel to a supporting structure (such as a sheathed stud wall, for instance, in a residential construction scenario), using screws, spikes, or other suitable fasteners driven through the fastener openings in the upper brackets. The upper brackets thus support the full suspended weight of the panel, while also positioning the rear face of the panel at a desired distance away from the face of the supporting structure (i.e., corresponding to the desired air space). After a first panel has been thus fastened to the support structure, a second similar panel is positioned above the first panel, with the lower brackets of the second panel extending downward behind the first panel. By virtue of their inherent configuration and the orientation at which they are cast into the panel, the lower brackets of the second panel dispose the rear face of the

second panel at the desired distance (i.e., air space thickness) away from the face of the supporting structure. At the same time, the abutment means of the lower brackets of the second panel extend below the upper edge of the first panel and engage the rear face of the first panel, thus effectively locking the second panel behind the first panel, and preventing the bottom of the second panel from being displaced outward away from the structure, without any direct connection between the bottom of the second panel and the supporting structure.

Accordingly, in one aspect the present invention is a mounting bracket for partial embedment in a precast panel having a front face, a generally planar rear face, an upper edge, and a lower edge, said bracket comprising:

(a) a rigid, elongate main body having an outer side, an inner side, and two longitudinal edges, said main body also defining:

a.l an embedment portion; and

a.2 an extension portion contiguous with the embedment portion, said extension portion having an inner end; and

(b) abutment means associated with the outer side of the extension portion, said abutment means having an outer edge;

wherein when the embedment portion is embedded in a precast panel such that the extension portion projects from the rear face of the panel so as to form an obtuse angle between the inner side of the extension portion and the rear face of the panel, the outer edge of the abutment means will substantially coincide with the plane of the rear face of the panel.

In a second aspect, the invention is a precast panel having a front face, a generally planar rear face, an upper edge, and a lower edge, and further having at least two mounting brackets embedded in spaced-apart relation adjacent a selected one of said upper and lower edges of the panel, each said mounting bracket comprising:

(a) a rigid, elongate main body having an outer side, an inner side, and two

longitudinal edges, said main body also defining:

a.1 an embedment portion; and

a.2 an extension portion contiguous with the embedment portion, said extension portion having an inner end; and

(b) abutment means associated with the outer side of the extension portion, said abutment means having an outer edge;

wherein the embedment portion of each mounting bracket is embedded in the panel such that:

(c) the extension portion projects from the rear face of the panel so as to form an obtuse angle between the inner side of the extension portion and the rear face of the panel;

(d) the outer edge of the abutment means substantially coincides with the plane of the rear face of the panel; and

(e) at least a portion of the abutment means is disposed outboard of the associated panel edge;

and wherein the outer edges of the abutment means of each bracket is disposed at a substantially uniform distance from the inner ends of their corresponding extension portions, as measured perpendicular to the plane of the rear face of the panel.

In a third aspect, the invention is a forming system that facilitates accurate placement of mounting brackets in precast panels to ensure the creation of a substantially uniform air space behind the panels after they are mounted on a supporting structure.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described with reference to the accompanying figures, in which numerical references denote like parts, and in which:

FIGURE 1 is an isometric view of a mounting bracket in accordance with a first embodiment of the invention.

FIGURE 2 is an isometric view of a mounting bracket in accordance with a second embodiment.

FIGURE 3 is an elevation of a precast panel with mounting brackets in accordance with the invention.

FIGURE 4 is an end view of the precast panel of Figure 3.

FIGURE 5 is an elevation of an assembly of precast panels as in Figure 3, mounted to a vertical supporting structure.

FIGURE 6 is an end view of the assembly of Figure 5.

FIGURE 7A is a sectional detail illustrating a typical field connection of an upper mounting bracket in accordance with the embodiment of Figure 1.

FIGURE 7B is a sectional detail as in Figure 7A, additionally illustrating the optional use of an auxiliary fastener.

FIGURE 7C is a sectional detail illustrating a typical field connection of an upper mounting bracket in accordance with the embodiment of Figure 2.

FIGURE 8A is a sectional detail of a horizontal joint between two mounted precast panels having mounting brackets in accordance with the embodiment of Figure 1.

FIGURE 8B is a sectional detail of a horizontal joint between two mounted precast panels having mounting brackets in accordance with the embodiment of Figure 2.

FIGURE 9 illustrates a preferred detail for supporting the uppermost panel in a mounted assembly of precast panels in accordance with the invention.

FIGURE 10 illustrates a preferred detail for supporting the lowermost panel in a mounted assembly of precast panels.

FIGURE 11 is an elevation of a precast panel in accordance with the invention, mounted to an unsheathed wall using a corrugated strapping member.

FIGURE HA is a cross-section of an exemplary embodiment of the strapping member shown in Figure 11.

FIGURE 12 illustrates a number of precast panels with mounting brackets in accordance with the invention, stacked with protective cushioning material disposed between panels.

FIGURE 13 is a perspective view of a multi-cell formwork assembly for casting multiple panels, with pockets for receiving mounting bracket inserts in accordance with the invention.

FIGURE 14 illustrates the formwork assembly of Figure 13, showing mounting brackets with corresponding inserts positioned in one formwork cell, ready to receive fluid concrete, and showing one formwork cell already filled with concrete.

FIGURE 15 is a sectional detail of a formwork cell filled with concrete as in Figure 14.

FIGURE 16 illustrates a mounting bracket in accordance with a third embodiment of the invention, in which the bracket is fashion from wire.

FIGURE 17 is a sectional detail of a horizontal joint between two mounted precast panels having mounting brackets in accordance with the embodiment of Figure 16.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to Fig. 1, a rigid, elongate mounting bracket 10 in accordance with a first embodiment of the invention has an embedment portion 11 and a contiguous extension portion 13. The point of demarcation between embedment portion 11 and extension portion 13 is not precisely defined, but will coincide with the rear face of a precast cladding panel in which bracket 10 is embedded, as will be described in detail herein. Bracket 10 is preferably fashioned from a corrosion-resistant metal, such as stainless steel, galvanized steel, or plated steel, but other materials may also be used provided they have suitable physical properties. Persons skilled in the art will appreciate that bracket 10 could be fashioned in accordance with any of several known fabrication methods. In the preferred embodiment shown in Fig. 1, however, bracket 10 is cold- formed from sheet stock. Bracket 10 will preferably be formed with side edge flanges 14 for increased stiffness, but these are not essential to the invention.

Embedment portion 11 preferably has supplementary anchorage means such as anchor tab 12, to enhance the strength and security of the bracket's embedment in a precast panel. As shown in Fig. 1, anchor tab 12 may be formed by cutting or punching the partial outline of anchor tab 12 and bending it back from the main body of embedment portion 11 to a desired orientation.

Extension portion 13 has an outer end 15, which is preferably formed with an angled lip 16. A primary fastener opening 30 is provided in extension portion 13 adjacent to outer end 15. In preferred embodiments, an auxiliary fastener opening 32 is also provided, and preferably disposed between primary fastener opening 30 and embedment portion 11. Extension portion 13 is formed with abutment means, for helping to maintain an air space of substantially uniform width between precast panels having mounting brackets 10 and a supporting structure to which the panels are mounted (as will be described in greater detail herein). In the embodiment shown in Fig. 1, the abutment means is provided in the form of an angled tab 20 which is cut or punched from the main body of extension portion 13 and formed in a desired configuration.

The specific physical dimensions of bracket 10 may be varied to suit the requirements of a given application, taking into consideration various factors including the dimensions and weight of the cladding panel in which bracket 10 is to be cast. To provide only one example, brackets 10 approximately 15 mm wide and formed from 24 gauge sheet steel (approximately 0.024 inches or 0.61 millimeters thick) have been successfully used with precast concrete panels measuring up to 460 mm square and having an approximate thickness of 15 mm thick.

Fig. 2 illustrates a mounting bracket 110 in accordance with a second embodiment. Bracket 110 has several features in common with bracket 10, as indicated by the use of common reference numerals. What distinguishes bracket 110, however, is that the abutment means is provided as a shoulder 120 formed integrally with bracket 110. For greater clarity in differentiating bracket 110 from bracket 10, the embedment portion and extension portion of bracket 110 are indicated by reference numerals 111 and 113 respectively, with shoulder 120 forming part of extension portion 113.

Fig. 3 is an elevation of a typical precast cladding panel 50 formed with mounting brackets 10 in accordance with the present invention; Fig. 4 is an end view (or side view) of the panel of Fig. 3. As illustrated, panel 50 has a front face 52 (which may be flat or textured as desired), a generally planar rear face 54, two longitudinal edges 56 (which may be upper or lower edges, depending on the orientation of panel 50), and side edges 58. As shown in the Figures, panel 50 may be rectilinear in shape, but this is not essential; panel 50 could take other geometric shapes without departing from the present invention. For example, either or both of longitudinal edges 56 could be partially or completely curvilinear. Longitudinal edges 56 and side edges 58 are preferably beveled as illustrated in the Figures, but this feature is not essential for purposes of the present invention; longitudinal edges 56 and side edges 58 could also be formed at substantially right angles relative to front face 52 and rear face 54 of panel 50.

In a typical arrangement, as shown in Fig. 3, at least two brackets 10 are cast into panel 50 along each of its longitudinal edges 56. As shown in Fig. 4, each bracket 10 extends at an angle rearward and laterally away from panel 50, such that each bracket 10 has a maximum rearward extension distance 62, as measured perpendicular to rear face 54,

substantially equal to a desired air space width. By way of example only, an air space of approximately 0.375 inches (10 mm) is commonly used for cladding panels in residential and light commercial construction; other air space widths may be desirable or necessary depending on specific building requirements.

Brackets 10 may be positioned in a variety of patterns along longitudinal edges 56.

In the preferred configuration shown in Fig. 3, brackets 10 are in vertical alignment, but they are offset different dimensions from each of the side edges 58. This is an advantageous arrangement in that it makes panels 50 reversible, as can be best seen from Fig. 5, which is a representative elevation of three panels 50 arrayed in vertically adjacent fashion. Panels 50 are all the same, but because of the reversible orientation of their brackets 10 as described above, adjacent panels are simply rotated 180 degrees relative to each other so that their respective brackets 10 do not interfere.

The specific bracket layouts shown in Figures 3 and 5 are exemplary only, and persons skilled in the art of the invention will readily appreciate that brackets 10 can be arranged in a variety of alternative manners without departing from the present invention. It is not necessary for brackets 10 to be positioned along longitudinal edges 56 of panels 50 in any particular manner or relationship, provided of course that there is no interference between the brackets 10 of adjacent panels when they are mounted to a support structure.

Fig. 6 is an end view (or side view) of the panel arrangement in Fig. 5, mounted on a vertical support structure 70. As can be seen from Fig. 6, when panels 50 are placed against support structure 70, they create an air space 60 having a substantially uniform width 62, due to the rigidity of brackets 10 and the angular orientation at which they are cast into panels 50. Fig. 6 also illustrates how it is only necessary to connect the uppermost brackets 10 of each panel 50 to support structure 70. This feature is illustrated with greater clarity in other Figures, as will now be described in detail.

Fig. 7 A is an enlarged detail showing how a typical bracket 10 at an upper longitudinal edge 56 is connected to support structure 70. It can also be seen from Fig. 7A that bracket 10 is cast into panel 50 such that the abutment means (in the form of angled tab 20) is substantially in alignment with rear face 54 of panel 50; in other words, angled tab 20 is disposed at a distance 62 from the point of maximum rearward extension of

extension portion 13. To mount panel 50 to support structure 70, a suitable primary fastener 40 (such as a wood screw, lag screw, or spike) is driven through primary fastener opening 30 of each of the brackets 10 along upper longitudinal edge 56 of panel 50, and into support structure 70.

In the Figures, support structure 70 is conceptually illustrated as comprising vertical structural members 71 (such as wood or steel studs) with exterior structural sheathing 73 (such as plywood or oriented strand board) in accordance with well-known construction techniques. This form of construction is particularly compatible with the present invention since the structural sheathing 73 will provide a suitable substrate to receive primary fasteners 40 regardless of the relative lateral positions of brackets 10 relative to vertical members 71. It is therefore unnecessary for brackets 10 to be in alignment with vertical members 71. As will be seen, however, it is not essential to have a support structure 70 of this specific construction in order to use the panel mounting brackets of the present invention, and in fact they can be readily used with support structures 70 that do not have exterior sheathing, or that have non-structural sheathing (such as foam insulation panels).

As shown in Fig. 7B, an auxiliary fastener 42 may be driven through auxiliary fastener opening 32 to provide a more robust structural connection. When auxiliary fastener opening 32 is disposed close to embedment portion 11 as shown in Fig. 7A, auxiliary fastener 42 can have the additional beneficial effect of creating a moment arm that urges the lower longitudinal edge 56 of panel 50 against support structure 70.

Fig. 7C illustrates a connection much the same as in Fig. 7A, except that in this case panel 50 has alternative brackets 110 with integrally- formed abutment shoulder 120. In a fashion analogous to angled tabs 20 of brackets 10, shoulder 120 is disposed at a distance 62 from the point of maximum rearward extension of extension portion 13. Alternative brackets 110 are connected to support structure 70 in the same manner as brackets 10 in Figs. 7 A and 7B.

Fig. 8A is a section through a typical horizontal field joint between two cladding panels 50 having brackets 10 in accordance with the invention. For convenient reference in Fig. 8A (and in other Figures), the panel above the horizontal joint is referred to as

upper panel 5OU, and the panel below the joint is referred to as lower panel 5OL. Similarly, the suffix "U" or "L" has been added to the reference numerals of various panel and bracket features to indicate that they are referable to upper panel 5OU or lower panel 5OL (and/or their respective brackets 1OU and 10L) as the case may be.

At a typical horizontal joint as shown in Fig. 8 A, lower panel 5OL is mounted to support structure 70 by connecting brackets 1OL (disposed along the upper longitudinal edge 56L of lower panel 50L) to support structure 70 as previously described with reference to Fig. 7A (and, optionally, Fig. 7B). Lower panel 5OL is thus disposed with its rear face 54L at a distance 62 from the face of support structure 70 (creating desired air space 60). Upper panel 5OU is then installed by sliding extension portions 13U of brackets 1OU (disposed along the lower longitudinal edge 56U of upper panel 50U) behind lower panel 5OL and into air space 60, until lower edge 56U of upper panel 5OU abuts upper edge 56L of lower panel 5OL as shown. Alternatively, upper panel 5OU may be positioned so as to leave a narrow vertical space between upper edge 56L and lower edge 56U, if desired. Because of the substantially identical configuration and orientation of brackets 1OU and 1OL (relative to upper panel 5OU and lower panel 5OL respectively), extension portions 13U of upper panel 5OU will abut support structure 70, and angled tabs 2OU of brackets 1OU will abut rear face 54L of lower panel 5OL, while rear face 54U of upper panel 5OU will abut angled tabs 2OL of brackets 1OL, thus bringing rear faces 54U and 54L into substantial alignment. Upper panel 5OU may then be physically connected to support structure 70 as previously described with reference to Fig. 7 A (and, optionally, Fig. 7B).

Particular advantages of the present invention may be readily appreciated from the foregoing discussion of Fig..8A. There is no physical connection between lower brackets 1OL of upper panel 5OU and support structure 70. Upper panel 5OU is effectively locked in lateral position behind lower panel 5OL, so there is no need for additional means to provide lateral stability to the lower portion of upper panel 5OU. Upper panel 5OU preferably rests upon lower panel 5OL during installation, thus facilitating both horizontal and vertical alignment of the panels. Rear panel faces 54U and 54L are automatically brought into substantial alignment when upper panel 5OU is positioned above lower panel 5OL as described; this is beneficial to facilitate relatively unimpeded drainage of moisture down the rear faces of the panels.

Because as few as two brackets 10 can be used along each longitudinal edge 56 of a typical cladding panel 50 (or, for small or narrow panels, only a single bracket 10 on each edge), and since brackets 10 are fairly narrow in width, brackets 10 present minimal impedance to the movement of moisture within air space 60, whether in either liquid or vapour form.

An additional advantage is obtained in preferred embodiments of bracket 10 in which outer end 15 of extension portion 13 is formed with an angled lip 16. As may be appreciated from Fig. 8A, angled lip 16U of bracket 1OU may be configured to act as a drip edge, so that moisture will drip off of angled lip 16U in approximately the middle of air space 60, with the desirable effect of minimizing moisture contact with support structure 70.

A further advantage is that the foregoing and other practical benefits are achieved using the same mounting bracket 10 on both the upper and lower edges of cladding panels 50. As a matter of convenience, all brackets 10 are preferably fabricated with primary fastener opening 30 (and, optionally, auxiliary fastener opening 32), even though in practice these openings will typically not be required for those brackets 10 that will be on lower panel edges. This simplifies fabrication and ensures that the required fastener openings will be present regardless of the orientation of the panels 50.

Fig. 8B illustrates a typical horizontal field joint similar to that shown in Fig. 8A, but with cladding panels 5OU and 5OL having brackets 11 OU and 11 OL in accordance with the alternative embodiment shown in Fig. 2. The integrally-formed shoulders 120U and

120L of brackets 11 OU and 11 OL function is substantially the same fashion as angled tabs

2OU and 2OL in Fig. 8A.

Fig. 9 is a sectional detail illustrating a preferred method for mounting the uppermost (or top) cladding panel in an assembly of cladding panels on a building wall, such as below a soffit or eave. In the illustrated detail, top panel 5OT has brackets 1OT along its lower longitudinal edge 56T, but requires no brackets 10 along its upper edge. A spacer channel 74 is attached to support structure 70 near the top of the wall in conjunction with a cap flashing 75, using flashing fastener 44 as shown. Cap flashing 75 is proportioned to allow for a space 75A above top panel 5OT. Top panel 5OT is mounted

after the panel below it has been mounted, by temporarily positioning top panel 5OT at an angle (with its lower edge disposed outwardly away from the wall) and sliding its upper edge upward between spacer channel 74 and cap flashing 75, until brackets 1OT are above the upper edge of lower panel 5OL. The lower edge of top panel 5OT is moved inward and then lowered so that it is supported on the upper edge of lower panel 5OL, with cap flashing 75 providing lateral support to the upper edge of top panel 5OT. Cap flashing 75 will have sufficient strength and flexibility to tolerate outward elastic deformation during the installation of top panel 5OT, such that it will spring back to the position shown in Fig. 9 after top panel 5OT has been positioned.

The installation of top panel 5OT may be facilitated by folding angled lips 16T of brackets 1OT upward as indicated in Fig. 9. This step reduces the distance that top panel 5OT must be raised above lower panel 5OL in order for brackets 1OT to be able to slide behind lower panel 5OL. At the same time, this allows cap flashing 75 to be somewhat narrower in width.

Persons skilled in the art will readily appreciate that other methods for mounting top panel 5OT are possible. For example, top panel 5OT could have brackets 10 on both longitudinal edges, with the uppermost brackets mounted to support structure 70 in the same way as for the lower panels, thereby eliminating the need for spacer channel 74, and with a cap flashing installed if necessary or desired after top panel 5OT has been mounted. The suitability of this or any other method of mounting top panel 5OT will depend on the specific architectural details of the structure in question.

Fig. 10 is a sectional detail illustrating a preferred method for mounting the lowermost (or bottom) cladding panel in an assembly of cladding panels on a building wall. In the illustrated detail, bottom panel 5OB has brackets 1OB along its upper longitudinal edge 56B, but requires no brackets 10 along its lower edge. Bottom panel 5OB is mounted to support structure 70 before upper panel 5OU above it. A spacer channel 74 is first attached to support structure 70 near the bottom of the wall, using spacer fastener 46 as shown. Preferably, a continuous or intermittent bead of mastic 76 or other suitable adhesive material is deposited on flange 74A of spacer channel 74. Bottom panel 5OB is then mounted to support structure 70 using primary fastener 40 in the manner previously

described.

Because the center of gravity of bottom panel 5OB is disposed at a distance away from the face of support structure 70 (and from the point at which brackets 1OB are connected thereto), the weight of bottom panel 5OB induces a counterclockwise moment (as viewed in Fig. 10) urging the lower portion of bottom panel 5OB against flange 74A of spacer channel 74 and the mastic 76 deposited thereon. This gravity-induced moment and mastic 76 both help to maintain the lower portion of bottom panel 5OB in lateral position against support structure 70 without need for direct mechanical fastening. It can be readily appreciated from Fig. 10 that the use of auxiliary fastener 42 in conjunction with brackets 1OB will induce a second counterclockwise moment which enhances the lateral stability of the lower portion of bottom panel 5OB against support structure 70. For this reason, it is particularly preferable to use auxiliary fasteners 42 when mounting bottom panels 5OB in a cladding panel assembly, especially for exterior installations in which the panel assembly may be subject to outwardly-acting negative pressures (due to wind or other factors).

After bottom panels 5OB have been mounted, additional panels may be mounted thereabove in the usual manner, as shown in Fig. 10 (for purposes of which panels immediately above bottom panels 5OB are referenced as upper panels 50U).

Persons skilled in the art will readily appreciate that other methods for mounting bottom panel 5OB are possible. For example, bottom panel 5OB could have brackets 10 on both longitudinal edges, thereby eliminating the need for spacer channel 74. In such alternative methods, it may be desirable or necessary to provide an additional flashing or other means for covering or protecting the brackets on the lower edges of bottom panel 5OB. The suitability of this or any other method of mounting bottom panel 5OB will depend on the specific architectural details of the structure in question.

Fig. 11 illustrates how strapping members 80 may be used to facilitate the mounting of cladding panels having brackets 10 on a support structure 70 that incorporates spaced vertical studs 71 but has no exterior structural sheathing. Strapping members 80 are positioned horizontally across studs 71 and fastened thereto using strapping fasteners 82. As may be seen from Fig. 11, strapping members 80 have a sufficient width W so that when positioned straddling intended horizontal panel joint locations, they will provide a

surface against which the extension portions 13 of brackets 10 can abut, and into which primary and auxiliary fasteners 40 and 42 may be driven as required (in lieu of structural sheathing).

In the preferred embodiment shown in Fig. 11 (and in cross-section in Fig. HA), strapping members 80 are cold-formed channels made from rust-resistant sheet steel, with closely-spaced perforations to facilitate installation of fasteners 82, 40, and 42 without need for field drilling. However, regular dimension lumber (e.g., one-by-threes) or alternative cold-formed metal shapes could be used instead of the illustrated strapping members 80.

Where stud walls are sheathed with exterior foam insulation panels, strapping members 80 may be applied against the exterior faces of the foam panels, with strapping fasteners 82 passing through the foam panels before engaging studs 71. Where strapping members 80 are channels as in Figs. 11 and 1 IA, the channel flanges 8OA will be pressed into the foam.

Fig. 12 illustrates how the use of mounting brackets 10 in accordance with the present invention facilitates compact stacking of cladding panels 50 on a pallet 84 (or other supporting surface) for purposes of storage and shipping. Because of their angular orientation, as well as their positioning very close to the longitudinal edges of panels 50, brackets 10 present little or no interference with adjacent stacked panels. Therefore, panels 50 can be stacked with little or no space between them. It will generally be desirable, however, to provide cushioning means 86 between panels in a stack, to prevent panel damage during shipping and handling (especially to the outer panel faces, which typically will be exposed to view after installation). The cushioning means 86 could be in the form of resilient matting, heavy cardboard, wood lath strips, or other material that will not mar cladding panel surfaces.

Figs. 13, 14, and 15 illustrate a preferred forming system for casting cladding panels having brackets 10 in accordance with the present invention. Although individual panel forms could be used, it is preferable and more efficient to use a multi-panel forming frame 90 as shown in Figs. 13 and 14. Forming frame 90 has multiple casting cells 92, typically with two (or more) bracket pockets 94 formed into frame 90 in desired positions

along opposing edges 93 (corresponding to the longitudinal edges of the panels 50 to be cast in cells 92). As best seen in Fig. 15, each bracket pocket 94 has a bearing surface 94A for receiving angled tab 20 of a typical bracket 10. Bearing surface 94 A also serves as a casting line guide; i.e., when a casting cell 92 is filled to the level of bearing surfaces 94A of its corresponding bracket pockets 94, rear face 54 of the resultant precast panel 50 will substantially coincide with angled tab 20, thus helping to ensure that extension portions 13 of brackets 10 will extend perpendicular to rear face 54 a distance 62 corresponding to the desired air space width, as previously described.

To facilitate the casting of bracket 10 into panel 50 at a desired angular orientation, bracket 10 preferably will have an anchor tab 12 as previously described, dimensioned and configured such that it will rest against the inner surface of casting cell 92 so as to help maintain bracket 10 in the desired orientation during the panel casting operation, with the fluid pressure of the concrete (or other casting material) tending to hold anchor tab 12 in position against the casting cell surface.

As illustrated in Figs. 14 and 15, the maintenance of the bracket position during panel casting may be further facilitated by encasing part of the extension portion 13 of each bracket 10 in a resilient plug 96 that helps to hold bracket 10 in the desired angular orientation. This preferred feature may be achieved using a bracket plug mold (not shown) having appropriately shaped casting cells into each of which a bracket 10 may be positioned, whereupon the casting cells may be filled with a suitable liquid compound (e.g., latex or silicone) that will cool or cure to form resilient plug 96 partially encasing extension portion 13 as shown in Fig. 15. Brackets 10 with resilient plugs 96 may then be positioned in bracket pockets 94 as illustrated by way of example with reference to casting cell 92 A in Fig. 14. The next step is to fill casting cells 92 with concrete (or other casting material) to form cladding panels 50 as illustrated in plan view with reference to casting cell 92B in Fig. 14 and in section in Fig. 15. After panels 50 have cured, resilient plugs 96 may be easily pulled off of brackets 10 and discarded.

Figs. 16 and 17 illustrate a third embodiment of the mounting bracket of the present invention. As shown in Fig. 16, alternative bracket 210 is formed from metal wire of a gauge suitable to provide the structural strength and stiffness required for specific panel

applications. Bracket 210 has embedment portion 211 and extension portion 213 analogous to embedment portion 11 and extension portion 13 of the previously-described bracket 10. Bracket 210 is twist-formed to create a fastener opening 30 analogous to that of bracket 10, and to form abutment means in the form of a shoulder 220 analogous to shoulder 120 of alternative bracket 110.

It will be readily appreciated by those skilled in the art that various modifications of the present invention may be devised without departing from the essential concept of the invention, and all such modifications are intended to be included in the scope of the claims appended hereto.

In this patent document, the word "comprising" is used in its non- limiting sense to mean that items following that word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article "a" does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one such element.