The present invention relates to glazed panel wall constructions, such as curtain walls, storefronts, and the like and more specifically, to a pressure plate for retaining glazing panels in place against a frame in a weather-tight manner.
Glazing systems for curtain walls, storefront framing systems, and the like are known wherein a pressure plate retains a glazing panel in place against a frame member, such as a mullion. The mullions are anchored to the building and run between the floor slabs in a window wall application or past the floor slabs in a curtain wall application. Typically, a pair of gaskets is installed within grooves in the pressure plate, which is then fastened to the outer face of the frame member by screws. The gaskets bear against adjacent glazing panels, providing a seal against air and water leakage. A third gasket installed near the center of the pressure plate between the pressure plate and the frame member may also be utilized to provide an additional weather and thermal barrier, e.g., to prevent water and air from migrating from one side of the mullion to the other and providing a thermal barrier between the pressure plate and the mullion. This type of glazing system is labor-intensive to install, requiring multiple separate components to be assembled. Over time, the gaskets may shrink, compromising the integrity of the installation.
A co-extruded pressure plate made from polymer materials is disclosed in U.S. Pat. No. 5,592,795 as an alternative to the more common use of multiple separate gaskets with a metal pressure plate. In order for the pressure plate to be extruded integrally with the gaskets, it must be made of a material that is compatible with the elastomeric gaskets. It is challenging to utilize a compatible combination of currently available polymers for co-extrusion that have sufficient strength through the temperature extremes experienced by buildings for this application. Fiberglass pultrusions have been proposed for pressure plate applications to reduce thermal transfer, but are not as strong and or as easy to fabricate as aluminum pressure plates. Aluminum alloy pressure plates have desirable mechanical and manufacturing properties, despite having greater thermal conductivity. Aluminum provides the integrity and stiffness to maintain clamping pressure during all extremes of weather that are experienced by the exterior of a building. Alternative glazing systems to those presently known therefore remain desirable for different applications and requirements.
The disclosed subject matter relates to a pressure plate for holding a glazing unit to a frame member, including: an elongated metal plate; and an elongated composite plate formed from a material having a thermal conductivity less than the metal plate, the composite plate and the metal plate aligned and coupled together to form a pressure plate assembly, the pressure plate assembly fastened to the frame member with the composite plate proximate the frame member and the metal plate distal to the frame member, the pressure plate assembly pressing the glazing unit toward the frame member.
In another embodiment, the composite plate has a pair of gaskets and a central isolator attached to and extending longitudinally and parallel to the composite plate along a length thereof.
In another embodiment, the composite plate has at least one rib extending therefrom toward the metal plate and the metal plate has a slot receiving the rib therein to couple the composite plate to the metal plate.
In another embodiment, the composite plate has a pair of ledges extending along opposing side edges of the composite plate, the ledges embracing the metal plate there between.
In another embodiment, further including a cap, the cap attaching to the pressure plate assembly distal to the frame member.
In another embodiment, the frame member has a tongue and the pressure plate assembly has at least one aperture therein and further comprising a threaded fastener, the threaded fastener extending through the at least one aperture and being threadedly received in the tongue, the threaded fastener pushing the pressure plate assembly toward the glazing unit.
In another embodiment, further including a cap with peripheral edges, the cap covering the pressure plate assembly, the pressure plate assembly having a pair of opposed grooves, the opposed grooves receiving corresponding ones of the peripheral edges of the cap.
In another embodiment, the ledges are disposed at an acute angle relative to the composite plate and point in a converging direction.
In another embodiment, each ledge has a land at a tip thereof extending toward the metal plate.
In another embodiment, the ribs have teeth disposed at an orientation that resists withdrawal of the ribs from engagement with the slot.
In another embodiment, the isolator abuts against the tongue dividing the space between adjacent glazing units.
In another embodiment, the composite plate has a pair of extensions extending from the isolator.
In another embodiment, further including a pair of ribs extending from a surface of the composite plate in a perpendicular direction, the ribs running lengthwise along the composite plate parallel to edges of the composite plate and the metal plate has a pair of receivers, the receivers receiving the pair of ribs, the metal plate nesting between the ledges.
In another embodiment, the metal plate has a central offset, the offset receiving a portion of the isolator therein while the pair of extensions abut flat portions of the metal plate on either side of the central offset.
In another embodiment, the central offset has a thicker wall than the flat portions of the metal plate.
In another embodiment, the gaskets and the isolator are adhered to the pair of extensions by an adhesive.
In another embodiment, the gaskets and the isolator are co-extruded with the pair of extensions.
In another embodiment, a glazing system for holding glazing units to a frame member, includes: an elongated metal plate; and an elongated composite plate formed from a plurality of polymers having a thermal conductivity less than the metal plate, the composite plate having a pair of gaskets and a central isolator attached to and extending longitudinally and parallel to the composite plate along a length thereof, the composite plate and the metal plate aligned and coupled together to form a pressure plate assembly, the composite plate having a pair of ribs extending therefrom toward the metal plate and the metal plate having a pair of slots receiving the pair of ribs therein to couple the composite plate to the metal plate, the composite plate having a pair of ledges extending along opposing side edges of the composite plate, the ledges embracing the metal plate there between, wherein the frame member has a tongue and the pressure plate assembly has a plurality of apertures therein and further comprising a plurality of threaded fasteners, the threaded fasteners extending through corresponding ones of the plurality of apertures and being threadedly received in the tongue, the threaded fastener pushing the pressure plate assembly toward the glazing unit, a cap with peripheral edges, the cap covering the pressure plate assembly, the pressure plate assembly having a pair of opposed grooves, the opposed grooves receiving corresponding ones of the peripheral edges of the cap, the pressure plate assembly fastened to the frame member with the composite plate proximate the frame member and the metal plate distal to the frame member, the pressure plate assembly pressing the glazing unit toward the frame member.
In another embodiment, the composite plate has a pair of extensions extending from the isolator and the metal plate has a central offset, the offset receiving a portion of the isolator therein while the pair of extensions abut flat portions of the metal plate on either side of the central offset, the central offset having a thicker wall than the flat portions of the metal plate and wherein the gaskets and the isolator are co-extruded with the pair of extensions.
In another embodiment, the ledges are disposed at an acute angle relative to the composite plate and point in a converging direction, each ledge having a land at a tip thereof extending toward the metal plate, each of the gaskets covering an outside surface of a corresponding one of the ledges, surmounting an upper edge of the ledge and returning in a downward direction on an inside surface of the ledge, including the land, the gaskets sealing between the metal plate and the lands, the isolator abutting against the tongue dividing the space between adjacent glazing units.
For a more complete understanding of the present disclosure, reference is made to the following detailed description of exemplary embodiments considered in conjunction with the accompanying drawings.
Gaskets 22, 24 made from an elastomeric material such as TPE, flexible polyvinyl chloride, DuPont Alcryn®, or other suitable elastomer are formed, e.g., co-extruded, on the extensions 16, 18 proximate the ledges 16L, 18L on surfaces 16D, 18D distal to the ribs 16R, 18R, respectively. In another embodiment, the gaskets 22, 24 may be separately formed and then adhered to the extensions 16, 18 by an adhesive or thermal welding. The gaskets 22, 24 have varying thickness over the width thereof and faces 22F, 24F permitting increased contact area with a glazing panel (
The metal plate 12 has a central offset 12C between flat portions 12F1, 12F2. The offset 12C may have a greater wall thickness than the flat portions 12F1, 12F2 to provide greater rigidity for the metal plate 12. The offset 12C also accommodates a portion of the thermal isolator 20, such that the body of the thermal isolator 20 can accommodate the inner ends 16E, 18E of the extensions 16, 18 therein, while the extensions 16, 18 abut against the flat portions 12F1, 12F2 of the metal plate 12. The registration of the offset 12C with the thermal isolator 20, the ribs 16R, 18R with the slots 12S1, 12S2 and the ledges 16L and 18L embracing the metal plate 12 proximate the receivers 12R1, 12R2, all contribute to establishing a pre-determined relative orientation between the metal plate 12 and the composite plate 14.
The composite plate 14 may be pre-assembled in a manufacturing facility rather than at the job site. Similarly, the composite plate 14 and the metal plate 12 may be assembled to form the pressure plate assembly 10 in a manufacturing facility. Alternatively, the composite plate 14 and the metal plate 12 may be assembled to form the pressure plate assembly 10 in the field, since assembly may be accomplished by a press-fit. In one alternative, the composite plate 14 and the metal plate 12 may be adhered to one another by an adhesive. The parts of the composite plate 14, such as a extensions 16, 18, the thermal insulator 20 and the gaskets 22, 24 may be produced separately and then assembled and adhered to one another using adhesives or thermal (plastic) welding. In another alternative, the parts of the composite plate 14, such as extensions 16, 18, the thermal insulator 20 and the gaskets 22, 24 may be produced and adhered to one another simultaneously by co-extrusion. Co-extrusion techniques are known to those skilled in the art wherein pellets of the different polymers, e.g. flexible polyvinyl chloride and glass-reinforced polyvinyl chloride, are placed in separate screw presses, heated, and forced as molten material through separate cavities of an extrusion press. The different polymers are forced through different ports of an extrusion die and brought together as they exit the die to form a unitary extrusion (co-extrusion).
In another alternative, the composite plate 14 may be produced by additive manufacturing (3D printing) methods.
A cap 44 may be placed over the pressure plate assembly 10 to provide a finished look and improve thermal and weather resistance. The cap 44 is made from a material, such as an aluminum alloy or a polymer that has a degree of elasticity sufficient to allow the cap 44 to deform, permitting the edges 44E to slip over the metal plate 12, and enter and grip the grooves 12G1, 12G2. In one embodiment, the gasket surfaces 22T and 24T may seal against the edges 44E of the cap 44 to reduce air and water intrusion into the space under the cap 44, providing a weather and thermal barrier. The pressure plate assembly 10 aids in reducing thermal transfer and weather infiltration through and around the cap 44 as indicated diagrammatically by arrow T1, through the pressure plate assembly 10, (T2), between the glazing units 30, 32 and the pressure plate assembly 10 (T3), through the glazing units 30, 32 and pressure plate assembly 10 (T4) and by convection on either side of the tongue 36 (T5 and T6).
An aspect of the present disclosure is to produce a pressure plate assembly 10 that combines the beneficial attributes of a aluminum pressure plate (metal plate 12) with those of a co-extruded polymer pressure plate (composite plate 14), which features the gaskets 22, 24 and the central thermal isolator 20. The metal plate 12 provides the structural support associated with traditional pressure plates, while the composite plate 14 provides the desired sealing and thermal isolation properties, while simultaneously allowing easy and reliable installation. The composite plate 14 (with lower thermal conductivity) is integrated into a single unit (is unitized), providing a continuous, uninterrupted thermal barrier across its width and across the width of the metal plate 12, which is embraced by the ledges 16L, 18L. When the composite plate 14 is assembled to the metal plate 12 and occupies a position between the metal plate 12 and the frame member 34, it reduces thermal transfer there between. The composite plate 14 insures proper positioning of the isolator 20 and gaskets 22, 24 when first installed, firmly holding same in position relative to the metal plate 12. The integral composite plate 14 also resists shrinkage and movement of the isolator 20 and gaskets 22, 24 relative to the extensions 16, 18 and the metal plate 12 after installation, thereby preserving weather-tightness and extending the useful life of the glazing system. The reduction in the number of parts required to assemble the glazing system simplifies assembly and reduces the inventory storage and processing required for a system with a greater number of parts, as well as, the staging required in preparing for an installation.
It will be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the claimed subject matter. All such variations and modifications are intended to be included within the scope of the appended claims.