Thermally improved curtain wall connection system

Various disclosures of a horizontal stack joint system for a curtain wall is disclosed. In certain embodiments, the joint system comprises a lower subsystem having a dual member projection and an upper subsystem having a channel sized to receive the dual member projection.

TECHNICAL FIELD

The invention relates in general to metal fabrication of curtain wall systems, and in particular to thermally improved curtain wall connection systems.

BACKGROUND INFORMATION

The use of structural steel and reinforced concrete in construction has allowed for large buildings to be supported by a system of columns rather than their exterior walls. Curtain walls are non-structural walls placed on the exterior of multi-story buildings. The primary purpose of a curtain wall is to provide a barrier between building inhabitants and the outside elements. These curtain walls are traditionally aluminum frames filled with sheets of glass, metal, or stone. Glass is a popular choice because of the added benefit of allowing in natural light.

Curtain walls can be classified by their method of fabrication and installation into the following general categories: stick systems and unitized (also known as modular) systems. In the stick system, the curtain wall frame (mullions) and glass or opaque panels are installed and connected together piece by piece. In unitized systems, the curtain wall is composed of large units that are assembled and glazed in the factory, shipped to the site and erected on the building. Vertical and horizontal mullions of the modules mate together with the adjoining modules. Modules are generally constructed one story tall and one module wide but may incorporate multiple modules. Typical units are five to six feet wide.

Water penetration resistance is a function of glazing details, drainage details, sealants, and frame construction. Water can enter the exterior wall system by means of five different forces: gravity, kinetic energy, air pressure difference, surface tension, and capillary action. To mitigate water infiltration, all of these forces are usually accounted for in the curtain wall system design.

Unlike discontinuous windows, which are smaller units and can rely to a high degree on sill flashings to capture frame corner leakage, curtain walls cover large expanses of wall without sill flashings at each glazed opening. Water penetration of curtain wall frame corners is likely to leak to the interior and/or onto insulating glass below. Watertight frame corner construction and good glazing pocket drainage are critical for reliable water penetration resistance. Additionally, due to the reduction or lack insulation in curtain wall systems, the construction materials may conduct the heat or cold from the exterior of the building, and condensation can form as a result and may create internal weepage within the system.

Typically, curtain wall systems transfer their own dead load plus any live loads (which consist primarily of positive and negative wind loads) back to building structure or intermediate framing. In certain situations, the curtain wall system may demonstrate movement caused by thermal changes and wind significantly different than movement of the building structure. Therefore the connections to anchor the curtain wall must be designed to allow differential movement while resisting the loads applied while at the same time allow for weepage and the control of thermal transfers between the outside and inside of the building.

What is needed, therefore, is a device to act as an insulating frame and provide an effective gutter system for exterior condensation or rainwater while minimizing any weepage from reaching the interior and offering protection at the weak point of the seal.

SUMMARY

In response to these and other problems, in one embodiment, there are various disclosures of a horizontal stack joint system for a curtain wall disclosed. In certain embodiments, the joint system comprises a lower subsystem having a dual member projection and an upper subsystem having a channel sized to receive the dual member projection. In certain embodiments, the joint system includes male and female front legs, a gutter, male and female split mullions, a mullion splice, a female joint, sill trim members, mullion fins, horizontal fins, a gasket, a thermal isolator, silicone boot, a shop applied silicone seal and a field applied silicone seal.

These and other features, and advantages, will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings. It is important to note the drawings are not intended to represent the only aspect of the invention.

DETAILED DESCRIPTION

When directions, such as outer, inner, exterior, interior, upper, lower, top, bottom, clockwise, counter-clockwise, are discussed in this disclosure, such directions are meant to only supply reference directions for the illustrated figures and for orientated of components in the figures. The directions should not be read to imply actual directions used in any resulting invention or actual use. Under no circumstances, should such directions be read to limit or impart any meaning into the claims.

Prefabricated or unitized curtain wall systems are usually designed to accommodate the differential movement between the structure and the thermal movement of the frame at the joints between each curtain wall unit. Because these units are frequently custom designed, the amount of movement to be accommodated can be carefully engineered into the system. Anchoring of unitized curtain wall typically consists of a proprietary assembly with three-way dimensional adjustability. For instance,FIG. 1illustrates a portion102of a unitized curtain wall system100.

Typically, a plurality of anchors spaced at a predetermined distance, such as anchors104aand104b, attach the portion102of the curtain wall system100to a building structure such as a spandrel beam or floor slabs106aand106b. As illustrated inFIG. 1, there is typically a plurality of curtain wall units, such as unit108(only a portion of unit108is illustrated inFIG. 1) and unit110hung from the edge of the floor slab106a. A unit112is about to be hung, and is thus shown positioned away from the floor slab106a. Typically, differential movement between the curtain wall units is accommodated at the vertical and horizontal unit joints.

Each unit, such as unit112, comprises framing members. In the illustrated situation, the unit112comprises a pair of vertical mullions114and116and two or more horizontal framing members, such as a top framing member118, an intermediate framing member120, and a bottom framing member122. The vertical mullions114and116attach to the anchors104aand104b, respectively. When assembled, the bottom framing member122is positioned upon the top framing member124of the lower adjacent unit126. Thus, when in place, the unit112spans horizontally from the anchor104ato the anchor104bwhich as explained above are positioned horizontally along the slab106a. The unit112spans vertically from the top framing member124of the lower adjacent unit126to the anchors104aand104b, the unit112cantilevers above the slab106ato a predetermined distance (for instance, desk height above the floor). Another unit (not shown) may then be placed adjacent to the vertical mullion116of the unit112. Yet, another unit (not shown) may then be placed on the top framing member118of unit112.

A horizontal stack joint128connects the units together to form the curtain wall system100. The horizontal stack joints are designed to resist lateral loads while the two floor anchors resist gravity and lateral loads. Usually, at least one of the floor anchors104aor104bwill allow movement in plane with the unitized system.

FIG. 1illustrates the horizontal stack joint128completed where all adjacent units are in place and an open or incomplete stack joint130which will be formed once unit112is stacked on top of unit126.

In the illustrated situation ofFIG. 1, the units108,110, and112are composed of a lower panel132of “vision glass” and an upper panel134of an opaque glass or a glazed spandrel shadow box. In certain embodiments, the upper panel134may have an insulated back pan. Surrounding the lower panel132and the upper panel134are framing members as discussed above. Of course, the vision glass may be in the upper panel in other situations. Additionally, in yet other situations, the units may contain more than two panels.

Stack Joint System:

Turning now toFIG. 2, there is illustrated an exemplary stack joint system200generally comprising a lower subsystem202(which may be an upper framing member of a curtain wall unit, e.g. top framing member118of unit112or top framing member124or unit126) and an upper subsystem204(which may be a lower or bottom framing member of a curtain wall unit, e.g. lower or bottom framing member122of unit112).

FIG. 2is a section view of a stack joint system200where the lower subsystem202is coupled to the upper subsystem204to form a completed stack joint system such as illustrated when inFIG. 1unit112is positioned above unit126. For instance, the lower panel132of vision glass may be coupled and supported by the upper subsystem204which is essentially the bottom framing member122of an upper unit, such as unit112(FIG. 1). In certain embodiments, the upper portion of opaque glass, such as panel134of the unit112or a panel136of the unit126(FIG. 1) may be coupled to and laterally supported by the lower subsystem202(which is essentially the top framing member of the respective curtain wall unit).

As will be apparent when the details of the stack joint system200are discussed below, in certain embodiments, the stack joint system200creates an airtight or pressurized chamber209. The pressurized chamber209may act as an air barrier of the curtain wall. To prevent rain infiltration through the curtain wall, it may be desirable to have an air tight or pressurized chamber, such as pressurized chamber209. If the air that leaks in and through cracks and crevices of a curtain wall during a rain storm were limited or stopped, most of the water impinging on the curtain wall would migrate straight down the surface and little would penetrate the wall. Thus, if an airtight or pressurized element is positioned behind the exterior surface of a curtain wall, the chamber formed between the exterior cladding and the airtight element may reach the same air pressure level as is exerted on the cladding surface, thus removing the force which causes air to flow through any curtain wall opening. The “Rain Screen Wall,” therefore is characterized by a chamber behind the exterior surface of the wall that is connected to the exterior but sealed tightly, or as tightly as reasonably possible to the interior.

the Lower Subsystem:

FIGS. 3A through 3Dare various views of the lower subsystem202of the horizontal stack joint system200.FIG. 3Ais a section view illustrating the “structural” primary elements of one embodiment of the lower subsystem202. The lower subsystem202comprises a male front leg206, a male back leg208, and a joint gutter210. The male front leg206comprises an extruded metal member generally formed in the shape of an “L” with a horizontal leg212and a vertical leg214. A curved protrusion216extends away from a lower surface or face218of the horizontal leg212. As will be explained below, in certain embodiments, the curved protrusion216forms a male portion of a connection220between the horizontal leg212and the joint gutter210.

A generally horizontal protrusion222extends from a back or interior face224of the vertical leg214. In certain embodiments, the horizontal protrusion222may have one or more screw holes226for an assembly screw228(seeFIG. 3B). In certain embodiments, a groove protrusion230extends from the top portion of a front face231of the vertical leg214. The groove protrusion230is sized to allow a gasket318(seeFIG. 3B) to fit within a groove234formed by the groove protrusion230.

The male back leg208comprises a vertical leg236, a front protrusion238, an intermediate section240, and a back portion242. In certain embodiments, the back portion242comprises a horizontal portion244which connects to a vertical portion246.

In certain embodiments, the vertical leg236may also include a groove protrusion248containing a groove250. In certain embodiments, the groove protrusion248is essentially a mirrored protrusion of the groove protrusion230. Thus, the groove protrusion230faces towards the exterior of the system and the groove protrusion248faces towards the interior of the system and/or building. The front protrusion238also has a screw hole252such that when the primarily components are assembled into a stack joint, the screw hole252aligns with the screw hole226of the male front leg206, such that the assembly screw228can couple the male front leg206to the male back leg208.

In certain embodiments, the intermediate section240may also have a screw hole254. In certain embodiments, the intermediate section240may have a downward vertical portion256which joins the intermediate section to the back or interior portion242. In certain embodiments, the various legs206,208, or joint gutter210may have screw splines for connecting screws (not shown) to out of plane members (not shown), such as screw spline258.

In certain embodiments, the joint gutter210may be extruded into a shape which generally comprises a vertical leg260joined to an inclined leg or member262. In certain embodiments, at a top end of the vertical leg260, there may be a groove portion264forming a longitudinal groove266. At the bottom of the vertical leg260, there may be a groove portion268, containing a longitudinal groove270designed to couple with a gasket (not shown). As discussed above, various screw splines, such as screw spline272and screw spline274may be formed along the inclined member262to couple out-of-plane members (not shown). In certain embodiments, extension members, such as extension member276, may be formed to position the screw spline274in the correct horizontal and vertical position. The inclined leg262may end with a connecting portion278. A screw hole280may be defined within the connecting portion278. When the subsystem202is assembled, the screw hole280may be aligned with the screw hole254of the back leg208such that a assembly screw282(FIG. 3B) can couple the back leg208to the joint gutter210.

Now that exemplary features and geometry of the front leg206, the back leg208, and the joint gutter210have been described, attention will be directed toFIGS. 3B,3C, and3D.FIG. 3Bis a section view of the stack joint lower subsystem202cut at a where the subsystem202from one of units meets a similar subsystem from an adjacent unit at a stack joint.FIG. 3Cis a top isometric view of a lower subsystem202for the entire stack joint which is formed by two adjacent subsystems202. Similarly,FIG. 3Dis a side isometric view of the lower subsystem202for the entire stack joint.

Turning now toFIGS. 3B,3C, and3D, as discussed above, the lower subsystem202comprises the male front leg206, the male back leg208, and the joint gutter210. As illustrated inFIGS. 3C and 3D, when the units are assembled, the male front leg206is positioned adjacent to a female front leg306of an adjacent subsystem of an adjacent unit. Similarly, the male back leg208couples with a female back leg308of an adjacent subsystem of the adjacent unit.

As illustrated inFIGS. 3B,3C and3D in certain embodiments, the top surfaces of the male front leg206and the female front leg306may be coupled to a silicone boot312at the joint. Once the male front leg206and male back leg208are assembled, the vertical leg214and the vertical leg236form a channel314. At the joint, the interior of the channel314may be lined with a second silicone boot316. The silicone boot312prevents water from running down the joint created by the male front leg206and the female front leg306. Similarly, the silicone boot316prevents water from running down the joint created by the male back leg208and the female back leg308.

A weather seal, such as a gasket318may be inserted into the groove234defined within the vertical leg214. Similarly, a second weather seal, such as a gasket320may be inserted into the groove250defined within the vertical leg236of the male back leg208. In certain embodiments, another thermal isolator, such as a rigid PVC spacer strip322may be inserted horizontally into grooves defined within the bottom face of the horizontal protrusion222of the male front leg206and defined within the top face of the front protrusion238of the male back leg208. In certain embodiments, the PVC spacer strip322may have openings (not shown inFIG. 3B) sized to allow one or more assembly screw228to pass through the openings. In certain embodiments, the PVC spacer strip322is positioned such that the openings of the PVC spacer strip align with the screw holes226and252. Thus, the assembly screw228may extend into the screw hole226of the horizontal protrusion222through the PVC spacer strip322and through the screw hole252of the front protrusion238of the back leg208. In other words, the front leg206and the back leg208may be connected, but remain relatively thermally isolated.

In certain embodiments, another thermal isolator, such as a rigid PVC spacer strip330may be inserted horizontally into grooves defined within the bottom face of the intermediate section240of the male back leg208and defined within the top face of the connecting portion278of the joint gutter210. In certain embodiments, the PVC spacer strip330has one or more openings sized to allow one or more assembly screws282to pass through the opening. In certain embodiments, the PVC spacer strip330is positioned such that the PVC spacer strip openings align with the screw holes254and280. Thus, the assembly screw282may extend into the screw hole254of the intermediate section240through the PVC spacer330and through the screw hole280of the connecting portion278of the joint gutter210. In other words, the back leg208and the joint gutter210may be connected, but remain relatively thermally isolated.

A third thermal isolator, such as a rigid PVC tubular member336may be inserted into the groove266defined within the vertical leg260of the joint gutter210to form a third thermal isolating connection. A circular end portion338of the curved protrusion216may be inserted into the tubular member336as illustrated inFIG. 3D. Thus, the front leg206and the joint gutter210may be connected, but remain relatively thermally isolated.

Thus, the lower joint subsystem202includes the male front leg206(having a first vertical leg214) which is coupled to the male back leg208(having a second upper or vertical leg236) via a thermal isolation joint (e.g., the assembly screw228and the PVC spacer322). The subsystem202also includes a joint gutter210which couples to the front leg206via a second thermal isolation joint (e.g., the curved protrusion216and the PVC tubular member336which allows some rotation) and couples to the back leg208via a third isolation joint (e.g., the assembly screw282and the PVC spacer330).

As illustrated inFIGS. 3C and 3D, the male front leg206is positioned longitudinally adjacent to the female front leg306. A field applied silicone seal340may be applied between the male front leg206and the female front leg306. Similarly, the male back leg208is positioned longitudinally adjacent to the female back leg308. A field applied silicone seal342may be applied between the male back leg206and the female back leg306.

In certain embodiments, there may be one or more weep holes defined with a lower surface of the joint gutter, a baffle344may be positioned at the weep hole in order to minimize air from infiltrating the joint (SeeFIG. 3B). In certain embodiments, a baffle, such as baffle346may be positioned within the channel314(seeFIG. 3Cor3D).

In certain embodiments, there may also be vertical mullion splice members348and350which may also function as lifting lugs. The vertical mullion splice member348may be coupled to a vertical split mullion male member352(seeFIG. 3D). Similarly, the vertical mullion splice member350may be coupled to a vertical split mullion female member354(seeFIG. 3D). In certain embodiments, a shop applied silicone seal356may be applied between the male back leg208and the vertical splice member348. Similarly, a shop applied silicone seal (not shown) may be applied between the female back leg308and the vertical mullion splice member350to prevent water from seeping through the joint. In various locations, other gaskets and seals may be used to prevent water infiltration such as glazing seal358or gasket360as is known in the art. Additionally, field applied caulking or sealing may also be employed, such as390a,390b, and390c.

Turning back toFIG. 3D, three thermal isolation members (e.g., PVC spacer322, PVC spacer330, and PVC tubular member336) isolate the interior male back leg208from the exterior elements: front leg206and joint gutter210. Additionally, the vertical leg214of the front leg206and the vertical leg236of the back leg208along with the gaskets318and320proved a dual line of defense for the stack joint. The subsystem202also provides for internal weepage through weep holes and baffles, such as baffle344(not shown). Additionally, the vertical mullion splice members348and350are positioned behind the vertical legs236.

the Upper Subsystem:

FIG. 4Ais a section view through certain horizontal members of the upper subsection204ofFIG. 2(or lower framing member of a curtain wall unit). As illustrated, in certain embodiments, a stack joint female member402may have a plurality of downward pointing vertical members or legs, such as vertical leg416, vertical leg418, vertical leg420and vertical leg422. Vertical leg418and vertical420form the channel404and are spaced such that they can accept the vertical legs214and236of the lower subsystem202(SeeFIG. 2andFIG. 3B) to create an air tight or pressurized chamber (chamber209ofFIG. 2). In certain embodiments, the stack joint female member402may also have screw splines424and426for coupling with out of plane screws (not shown).

In certain embodiments, a groove portion428forming a longitudinal groove430may be defined at the lower end of the vertical leg418. The vertical leg416may have a connecting portion432. In certain embodiments, one or more screw hole(s)434is defined within the connecting portion432.

A horizontal fin440may be used to support a lower panel of glass, such as lower panel132of vision glass which may be part of an upper unit, such as top framing member118(FIG. 1). In certain embodiments, a gasket442may be coupled to the upper stack joint female member402and positioned such that the gasket442is between the upper stack joint member402and the lower panel132of vision glass. A backer rod444and seal446may be positioned between the lower panel132and the horizontal fin440as illustrated inFIG. 4A. In certain embodiments, there may be a longitudinal groove448for accepting and coupling with a gasket450that is positioned between the horizontal fin440and the male front leg206of the lower subsystem202.

In section, an interior end452of the horizontal fin440is circular and is designed to fit within a thermal isolator, such as a rigid partially tubular PVC member454. In turn, the rigid PVC tubular member454may be sized to be inserted into the groove430defined within the vertical leg418of upper stack joint member402to form a thermal isolating connection. Thus, the vertical leg418and the horizontal fin440may be connected, but remain relatively thermally isolated.

In certain embodiments, the horizontal fin440may have one or more screw holes456such that when the horizontal fin is coupled to the stack joint member402, the screw hole456and screw hole434align so that an assembly screw458may be placed in the screw holes to couple the connecting portion432of the vertical leg416to the horizontal fin440. The assembly screw458may go through a thermal isolating member, such as a PVC spacer strip460which may be positioned between the horizontal fin440and the connecting portion432of the vertical leg416.

In certain embodiments, the PVC spacer strip460may be inserted horizontally into grooves defined within the bottom face of the connecting portion432of the vertical leg416and defined within the top face of the horizontal fin440. In certain embodiments, the PVC spacer strip460may have openings (not shown inFIG. 4B) sized to allow one or more assembly screw(s)458to pass through the openings. In certain embodiments, the PVC spacer strip460is positioned such that the openings of the PVC spacer strip align with the screw holes434and456. Thus, the stack joint member402may be coupled and supports the horizontal fin440, but is thermally isolated from the horizontal fin via the PVC spacer strip460and the rigid tubular PVC tubular member454.

The female or upper stack joint female member402may be made of extruded aluminum. In certain embodiments, the stack joint female member402may be coupled to a split male mullion406as illustrated inFIG. 4B. A split female mullion408may be coupled to a stack joint female member410of an adjacent unit. If required, the stack joint female members402and410may be coupled to snap on sill trim members412and414, respectively.

The Vertical Mullion System:

FIG. 5Ais a detailed section view showing a mullion joint system500formed from certain vertical members or mullions. For instance, inFIG. 4B, mullions406and408are coupled to the upper subsystems204, respectively of adjacent units.FIG. 5Bis an enlarged detailed portion of the section view illustrated inFIG. 5A.

Turning now toFIGS. 5A and 5B, there is illustrated in section the interconnection between the split male mullion406and the split female mullion408. As illustrated, the split male mullion406may include a lateral member502, a lateral member504, a lateral member506, and a lateral member508.

In certain embodiments, the lateral member502may have a connecting end portion510with a vertical groove512. The lateral member504may have a side groove portion514and a connecting end portion516with a circular groove513defined on one face and a snap or hook element515extending laterally outward. A portion of a flexible member or gasket537may be inserted vertically into the circular groove513such that the gasket537is coupled to the end portion516of the lateral member504.

The lateral member506has a connecting end portion517with a circular groove519defined on one face and a small engagement extension521extending laterally outward. A portion of a flexible member or gasket539may be inserted vertically into the circular groove519such that the gasket539is coupled to the end portion517of the lateral member506. The lateral member508has a connecting end portion518with a snap or hook element523extending laterally outward.

Similarly, the split female mullion408may include a lateral member522, a lateral member524, a lateral member526, and a lateral member528. The lateral member522may have a connecting end portion530with a vertical groove532. The lateral member524may have a side groove portion534and a connecting end portion536. In some embodiments, in section the end portion536is shaped to engage a portion of the snap or hook portion515of the lateral member504. The end portion536is also shaped to engage the gasket537which is coupled to the end portion516of the lateral member504so that the connection between the end portion536and the end portion516is hermetically sealed.

In certain embodiments, the lateral member526may have a connecting end portion527which may be shaped to engage the gasket539(which is coupled to the connecting end portion516of the member506) so that the connection between the end portion527of the lateral member526and the end portion517of the lateral member506is hermetically sealed. Thus, a vertical pressurized or airtight chamber436is formed because the connection between lateral members504and524and the connection between lateral members506and526are sealed. The airtight chamber436is open to and in hermetic communication with airtight chamber209(discussed in reference toFIG. 2). A rectangular airtight chamber, therefore, is created for the unit as the units are positioned to create the curtain wall system.

In certain embodiments, a mullion fin540and a mullion fin560may be positioned within the space between the connecting portions510and530of the lateral members502and522, respectively. Generally, the mullion fins540and560extend from the vertical grooves514and534, to approximately the exterior face of the glass panels (e.g., the glass panels134and136ofFIG. 1). The mullion fins540and560may comprise a series of “step sections” in cross-section to allow their interior ends to clear the connection between the lateral members504and524.

The mullion fin540may have a vertical groove542for securing a gasket543. The opposing face of the mullion fin540may have vertical groove544defined therein. The interior end of the mullion fin540may also be circular in shape to couple with a thermal isolator, such as a rigid PVC vertical tubular member546which may be inserted into the side groove portion514of the lateral member504. Similarly, the mullion fin560may have a vertical groove562for securing a gasket563. Thus, as illustrated, gasket543and gasket563are aligned and are pressed against each other.

The opposing face of the mullion fin560may have a vertical groove564defined therein. The interior end of the mullion fin560may also be circular in shape to couple with a thermal isolator, such as a rigid PVC vertical tubular member566which may be inserted into the groove portion534of the lateral member524.

A thermal isolator, such as a rigid PVC vertical member548may be formed to be coupled with a vertical groove544defined within the mullion fin540and the vertical groove512defined within the connecting end portion510of the lateral member502. In certain embodiments, one or more assembly screws501may secure the mullion fin540to the connecting end portion510of the lateral member502. Thus, although the lateral member502is mechanically coupled to the mullion fin540, the lateral member502is thermally isolated from the mullion fin via the PVC vertical member548.

Similarly, a thermal isolator, such as a rigid PVC vertical member568may be formed to be couple with the groove564defined within the mullion fin560and a groove532defined within the connecting end portion530of the lateral member522. In certain embodiments, one or more assembly screws561may secure the mullion fin560to the connecting end portion530of the lateral member522. Thus, although the lateral member522is mechanically coupled to the mullion fin560, the lateral member522is thermally isolated from the mullion fin via the PVC vertical member568.

The exterior corner of the split male mullion406may be formed to engage and couple with a gasket570. Similarly, the exterior corner of the split female mullion408may be formed to engage and couple with a gasket572. As illustrated, the gaskets570and572are positioned between the respective mullions and the glass panels (e.g., the glass panels134and136ofFIG. 1).

Turning back toFIG. 1, it is apparent that most of the units (e.g. unit112) in the curtain wall system100comprise a top or upper horizontal system which is similar to the lower subsystem202ofFIG. 2; a bottom or lower horizontal system which is similar to the upper subsystem204ofFIG. 2, a side mullion system which contains the mullion406, and a side mullion system which contains the mullion408. As the units are positioned or “stacked” adjacent to and above one another, joint systems are formed between the units. For instance, stack joint systems200(FIG. 2) are formed horizontally between the respective units and mullion joint systems500(FIGS. 5A and 5B) are formed vertically between the respective units.

Stack Joint System (Alternative Embodiment):

Turning now toFIG. 6, there is illustrated an exemplary stack joint system1200generally comprising a lower subsystem1202(which may be an upper framing member of a curtain wall unit, e.g. top framing member118of unit112or top framing member124or unit126(FIG. 1)) and an upper subsystem1204(which may be a lower or bottom framing member of a curtain wall unit, e.g. lower or bottom framing member122of unit112(FIG. 1)).

FIG. 6is a section view of a stack joint system1200where the lower subsystem1202is coupled to the upper subsystem1204to form a completed stack joint system such as illustrated when inFIG. 1unit112is positioned above unit126. For instance, the lower panel1132of vision glass may be coupled and supported by the upper subsystem1204which is essentially the bottom framing member122of an upper unit, such as unit112(FIG. 1). In certain embodiments, the upper portion of opaque glass, such as panel1134of the unit112or a panel136of the unit126(FIG. 1) may be coupled to and laterally supported by the lower subsystem1202(which is essentially the top framing member of the respective curtain wall unit).

As will be apparent when the details of the stack joint system1200are discussed below, in certain embodiments, the stack joint system1200creates an airtight or pressurized chamber1209. The pressurized chamber1209may act as an air barrier of the curtain wall. To prevent rain infiltration through the curtain wall, it may be desirable to have an air tight or pressurized chamber, such as pressurized chamber1209. If the air that leaks in and through cracks and crevices of a curtain wall during a rain storm were limited or stopped, most of the water impinging on the curtain wall would migrate straight down the surface and little would penetrate the wall. Thus, if an airtight or pressurized element is positioned behind the exterior surface of a curtain wall, the chamber formed between the exterior cladding and the airtight element may reach the same air pressure level as is exerted on the cladding surface, thus removing the force which causes air to flow through any curtain wall opening. The “Rain Screen Wall,” therefore is characterized by a chamber behind the exterior surface of the wall that is connected to the exterior but sealed tightly, or as tightly as reasonably possible to the interior.

The Lower Subsystem (Second Embodiment):

FIGS. 7A through 7Dare various figures illustrating various aspects of the lower subsystem1202.FIG. 7Ais a section view illustrating the primary “structural” elements of one embodiment of the lower subsystem1202. The lower subsystem1202comprises a male front leg1206, a male back leg1208, and a joint gutter1210. The male front leg1206comprises an extruded metal member generally formed in the shape of an “L” with a horizontal leg1212and a vertical leg1214. A curved protrusion1216extends away from a lower surface or face1218of the horizontal leg1212. As will be explained below, in certain embodiments, the curved protrusion1216forms a male portion of a connection1220between the horizontal leg1212and the joint gutter1210.

In certain embodiments, the horizontal leg1212may have one or more screw holes1226for an assembly screw1228(not shown). In certain embodiments, a groove protrusion1230extends from the top portion of a front face1231of the vertical leg1214. The groove protrusion1230is sized to allow a gasket1318(seeFIG. 7B) to fit within a groove1234formed by the groove protrusion1230.

The male back leg1208comprises a vertical leg1236, a front protrusion1238, an intermediate section1240, and a back portion1242. In certain embodiments, the back portion1242comprises a horizontal portion1244which connects to a vertical portion1246.

In certain embodiments, the vertical leg1236may also include a groove protrusion1248containing a groove1250. In certain embodiments, the groove protrusion1248is essentially a mirrored protrusion of the groove protrusion1230. Thus, the groove protrusion1230faces towards the exterior of the system and the groove protrusion1248faces towards the interior of the system and/or building.

In certain embodiments, the intermediate section1240may also have a screw hole1254. In certain embodiments, the intermediate section1240may have a downward vertical portion1256which joins the intermediate section to the back or interior portion1242. In certain embodiments, the various legs1206,1208, or joint gutter1210may have screw splines for connecting screws (not shown) to out of plane members (not shown), such as screw spline1258.

In certain embodiments, the joint gutter1210may be extruded into a shape which generally comprises a vertical leg1260joined to an inclined leg or member1262. In certain embodiments, at a top end of the vertical leg1260, there may be a groove portion1264forming a longitudinal groove1266. At the bottom of the vertical leg1260, there may be a groove portion1268, defining a longitudinal groove1270designed to couple with a gasket (not shown). In certain embodiments, an extension member1276may project upwards and contain a horizontal connecting portion1277. One or more screw holes1252may be defined within the horizontal connecting portion1277. As noted above, the horizontal leg1212may have one or more screw holes1226which may align with the screw holes1252when the primary components are assembled into a lower subsystem1202of the stack joint1200.

In certain embodiments, the inclined leg1262may end with a connecting portion1278and may be formed to position the screw spline1274. A screw hole1280may be defined within the connecting portion1278. When the subsystem1202is assembled, the screw hole1280may be aligned with the screw hole1254of the back leg1208such that an assembly screw1282(FIG. 7B) can couple the back leg1208to the joint gutter1210.

As discussed above, various screw splines, such as screw spline1272and screw spline1274may be formed along the inclined member1262to couple out-of-plane members (not shown).

Now that exemplary features and geometry of the front leg1206, the back leg1208, and the joint gutter1210have been described, attention will be directed toFIGS. 7B,7C and7D.FIG. 7Bis a section view of the stack joint lower subsystem1202cut at where the subsystem1202from one of units meets a similar subsystem from an adjacent unit.FIG. 7Cis a top isometric view of a lower subsystem1202for the entire stack joint which is formed by two adjacent subsystems1202. Similarly,FIG. 7Dis a side isometric view of the lower subsystem1202for the entire stack joint.

Turning now toFIGS. 7B,7C, and7D, as discussed above, the lower subsystem1202comprises the male front leg1206, the male back leg1208, and the joint gutter1210. As illustrated inFIGS. 7C and 7D, when the units are assembled, the male front leg1206is positioned adjacent to a female front leg1306of an adjacent subsystem of an adjacent unit. Similarly, the male back leg1208couples with a female back leg1308of an adjacent subsystem of the adjacent unit.

As illustrated inFIGS. 7B,7C and7D in certain embodiments, the top surfaces of the male front leg1206and the female front leg1306may be coupled to a silicone boot1312at the joint. Once the male front leg1206and male back leg1208are assembled, the vertical leg1214and the vertical leg1236form a channel1314. At the joint, the interior of the channel1314may be lined with a second silicone boot1316. The silicone boot1312prevents water from running down the joint created by the male front leg1206and the female front leg1306. Similarly, the silicone boot1316prevents water from running down the joint created by the male back leg1208and the female back leg1308.

A weather seal, such as a gasket1318may be inserted into the groove1234defined within the vertical leg1214. Similarly, a second weather seal, such as a gasket1320may be inserted into the groove1250defined within the vertical leg1236of the male back leg1208. In certain embodiments, a thermal isolator, such as a rigid PVC spacer strip1322may be inserted horizontally into space defined by the lower surface1218of the horizontal leg1212of the male front leg1206and the top face of the connecting portion1277of the extension member1276of the joint gutter1210. In certain embodiments, the PVC spacer strip1322may have openings (not shown inFIG. 7B) sized to allow one or more assembly screws (not shown) to pass through the openings. In certain embodiments, the PVC spacer strip1322is positioned such that the openings of the PVC spacer strip align with the screw holes1226and1252. Thus, the assembly screw1228may extend into the screw hole1226of the horizontal leg1212through the PVC spacer strip1322and through the screw hole1252of the connecting portion1277of the front leg1206. In other words, the front leg1206and the joint gutter1210may be connected, but remain relatively thermally isolated.

In certain embodiments, another thermal isolator, such as a rigid PVC spacer strip1330may be inserted horizontally into the space defined by the bottom face of the intermediate section1240of the male back leg1208and the top face of the connecting portion1278of the joint gutter1210. In certain embodiments, the PVC spacer strip1330has one or more openings sized to allow one or more assembly screws1282to pass through the opening. In certain embodiments, the PVC spacer strip1330is positioned such that the PVC spacer strip openings align with the screw holes1254and1280. Thus, the assembly screw1282may extend into the screw hole1254of the intermediate section1240through the PVC spacer1330and through the screw hole1280of the connecting portion1278of the joint gutter1210. In other words, the back leg1208and the joint gutter1210may be connected, but remain relatively thermally isolated.

A third thermal isolator, such as a rigid PVC tubular member1336may be inserted into the groove1266(FIG. 7A) defined within the vertical leg1260of the joint gutter1210to form a third thermal isolating connection. A circular end portion1338of the curved protrusion1216may be inserted into the tubular member1336as illustrated inFIG. 7D. Thus, the front leg1206and the joint gutter1210may be connected, but remain relatively thermally isolated.

Thus, the lower joint subsystem1202includes the male front leg1206(having a first vertical leg1214) which is coupled to the male back leg1208(having a second upper or vertical leg1236) via a thermal isolation joint (e.g., the assembly screw1228and the PVC spacer1322). The subsystem1202also includes the joint gutter1210which couples to the front leg1206via a second thermal isolation joint (e.g., the curved protrusion1216and the PVC tubular member1336which allows some rotation) and couples to the back leg1208via a third isolation joint (e.g., the assembly screw1282and the PVC spacer1330).

As illustrated inFIGS. 7C and 7D, the male front leg1206is positioned longitudinally adjacent to the female front leg1306. A field applied silicone seal1340may be applied between the male front leg1206and the female front leg1306. Similarly, the male back leg1208is positioned longitudinally adjacent to the female back leg1308. A field applied silicone seal1342may be applied between the male back leg1206and the female back leg1306.

In certain embodiments, there may be one or more weep holes defined with a lower surface of the joint gutter, a baffle1344may be positioned at the weep hole in order to minimize air from infiltrating the joint (SeeFIG. 7B).

In certain embodiments, there may also be vertical mullion splice members1348and1350which may also function as lifting lugs. The vertical mullion splice member1348may be coupled to a vertical split mullion male member1352(seeFIG. 7D). Similarly, the vertical mullion splice member1350may be coupled to a vertical split mullion female member1354(seeFIG. 7D). In certain embodiments, a shop applied silicone seal1356may be applied between the male back leg1208and the vertical splice member1348. Similarly, a shop applied silicone seal (not shown) may be applied between the female back leg1308and the vertical mullion splice member1350to prevent water from seeping through the joint. In various locations, other gaskets and seals may be used to prevent water infiltration such as glazing seal1358or gasket1360as is known in the art (FIG. 7B). Field applied seals or caulking may also be used such as1390a,1390b, and1390c.

Turning back toFIG. 7D, three thermal isolation members (e.g., PVC spacer1322, PVC spacer1330, and PVC tubular member1336) isolate the interior male back leg1208from the exterior elements: front leg1206and joint gutter1210. Additionally, the vertical leg1214of the front leg1206and the vertical leg1236of the back leg1208along with the gaskets1318and1320proved a dual line of defense for the stack joint. The subsystem1202also provides for internal weepage through weep holes and baffles, such as baffle1344(not shown).

The Upper Subsystem (Second Embodiment):

FIG. 8Ais a section view through certain horizontal members of the upper subsection1204ofFIG. 6(or lower framing member of a curtain wall unit). As illustrated, in certain embodiments, a stack joint female member1402may have a plurality of downward pointing vertical members or legs, such as vertical leg1416, vertical leg1418, vertical leg1420and vertical leg1422. Vertical leg1418and vertical1420form the channel1404and are spaced such that they can accept the vertical legs1214and1236of the lower subsystem1202(SeeFIG. 6andFIG. 7B) to create an air tight or pressurized chamber (chamber2209ofFIG. 6). In certain embodiments, the stack joint female member1402may also have screw splines1424and1426for coupling with out of plane screws (not shown).

In certain embodiments, a groove portion1428forming a longitudinal groove1430may be defined at the lower end of the vertical leg1418. The vertical leg1416may have a connecting portion1432. In certain embodiments, one or more screw hole(s)1434is defined within the connecting portion1432.

A horizontal fin1440may be used to support a lower panel of glass, such as lower panel132of vision glass which may be part of an upper unit, such as top framing member118(FIG. 1). In certain embodiments, a gasket1442may be coupled to the upper stack joint female member1402and positioned such that the gasket1442is between the upper stack joint member1402and the lower panel132of vision glass. A backer rod1444and seal1446may be positioned between the lower panel132and the horizontal fin1440as illustrated inFIG. 8A. In certain embodiments, there may be a longitudinal groove1448for accepting and coupling with a gasket1451that is positioned between the horizontal fin1440and the male front leg1206of the lower subsystem1202.

In section, an interior end1452of the horizontal fin1440is circular and is designed to fit within a thermal isolator, such as a rigid partially tubular PVC member1454. In turn, the rigid PVC tubular member1454may be sized to be inserted into the groove1430defined within the vertical leg1418of upper stack joint member1402to form a thermal isolating connection. Thus, the vertical leg1418and the horizontal fin1440may be connected, but remain relatively thermally isolated.

In certain embodiments, the horizontal fin1440may have one or more screw holes1456such that when the horizontal fin is coupled to the stack joint member1402, the screw hole1456and screw hole1434align so that an assembly screw1458may be placed in the screw holes to couple the connecting portion1432of the vertical leg1416to the horizontal fin1440. The assembly screw1458may go through a thermal isolating member, such as a PVC spacer strip1460which may be positioned between the horizontal fin1440and the connecting portion1432of the vertical leg1416.

In certain embodiments, the PVC spacer strip1460may be inserted horizontally into grooves defined within the bottom face of the connecting portion1432of the vertical leg1416and defined within the top face of the horizontal fin1440. In certain embodiments, the PVC spacer strip1460may have openings (not shown inFIG. 8B) sized to allow one or more assembly screw(s) (not shown) to pass through the openings. In certain embodiments, the PVC spacer strip1460is positioned such that the openings of the PVC spacer strip align with the screw holes1434and1456. Thus, the stack joint member1402may be coupled and supports the horizontal fin1440, but is thermally isolated from the horizontal fin via the PVC spacer strip1460and the rigid tubular PVC tubular member1454.

The female or upper stack joint female member1402may be made of extruded aluminum. In certain embodiments, the stack joint female member1402may be coupled to a split male mullion1406as illustrated inFIG. 8B. A split female mullion1408may be coupled to a stack joint female member1410of an adjacent unit. If required, the stack joint female members1402and1410may be coupled to snap on sill trim members1412and1414, respectively.

The foregoing description of the embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many combinations, modifications and variations are possible in light of the above teaching. Undescribed embodiments which have interchanged components are still within the scope of the present invention. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto.