Patent Publication Number: US-9903113-B2

Title: Thermal break for curtain wall

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 14/365,559, filed Jun. 13, 2014, which is a National Stage 371 Application of International Application No. PCT/US2012/069223, filed Dec. 12, 2012, which claims the benefit of priority to U.S. Provisional Application No. 61/570,638, filed Dec. 14, 2011, all of which are incorporated herein by reference in their entirety. 
    
    
     BACKGROUND 
     A curtain wall is a thin, usually aluminum-framed wall, containing in-fills of glass, metal panels, or thin stone. The framing is attached to a building structure and generally does not carry floor or roof loads of the building structure. Wind and gravity loads of the curtain wall are transferred to the building structure, typically at the floor line. 
     SUMMARY 
     The invention pertains to a curtain wall panel that includes a thermally insulating structural spacer. In some embodiments, a curtain wall panel includes a frame that is configured to be secured to an exterior surface of a building structure. The frame includes a first mullion, a second mullion, a sill and a head. A first insert is secured to the frame. A first structural space secures the first insert to the frame and supports the weight of the first insert. The structural space is formed of a thermally insulating material. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view of a first panel of a curtain wall system, according to some embodiments. 
         FIG. 2  is a sectional view of the first panel along line  2 - 2  of  FIG. 1 , according to some embodiments.  FIG. 2A  is an enlarged view of a portion of  FIG. 2 , according to some embodiments. 
         FIG. 3  is a sectional view of the first panel along line  3 - 3  of  FIG. 1 , according to some embodiments.  FIG. 3A  is an enlarged view of a portion of  FIG. 3 , according to some embodiments.  FIG. 3B  shows a camming, assembly action of spacers used in the first panel of  FIG. 1 , according to some embodiments. 
         FIG. 4  is a transverse cross-section of a spacer of the first panel of  FIG. 1 , according to some embodiments. 
         FIG. 5  shows a mullion interface of the first panel of  FIG. 1  and an adjacent panel of a curtain wall system, according to some embodiments. 
         FIG. 6  shows a sill and head interface of the first panel of  FIG. 1  and a stacked panel of a curtain wall system, according to some embodiments. 
         FIG. 7  is a front view of a second panel of a curtain wall system, according to some embodiments. 
         FIG. 8  is a sectional view of the second panel along line  8 - 8  of  FIG. 7 , according to some embodiments. 
         FIG. 9  is a sectional view of the second panel along line  9 - 9  of  FIG. 7 , according to some embodiments. 
         FIG. 10  shows a mullion interface of the second panel of  FIG. 7  and an adjacent panel of a curtain wall system, according to some embodiments. 
         FIG. 11  shows a sill and head interface of the second panel of  FIG. 7  and a stacked panel of a curtain wall system, according to some embodiments. 
         FIG. 12  shows a pultrusion profile of a first mullion spacer of the first panel of  FIG. 1 , according to some embodiments. 
         FIG. 13  shows a pultrusion profile of a first mullions spacer of the second panel of  FIG. 7 , according to some embodiments. 
     
    
    
     The figures are meant to be illustrative in nature and are not to be read as limiting the scope of invention. Additional or alternate features to those shown are contemplated, as understood with reference to the disclosure as a whole. 
     DETAILED DESCRIPTION 
     Various embodiments relate to curtain wall systems including a plurality of panels or units assembled together. Such systems are optionally described as “unitized” systems, although a variety of other types of systems are contemplated. Curtain wall systems include individual curtain wall panels, accessories for securing the panels relative to one another, accessories for securing the panels to a building structure (such as the columns and floors of a building structure), as well as other components as desired. 
       FIG. 1  is a front view of a first panel  10  of a curtain wall system, according to some embodiments.  FIG. 2  is a sectional view of the first panel  10  along line  2 - 2  in  FIG. 1  and  FIG. 3  is a sectional view of the first panel  10  along line  3 - 3  in  FIG. 1 , according to some embodiments. As shown, the first panel  10  includes a first insert  12 , a second insert  14 , and a frame assembly  16  supporting the first and second inserts  12 ,  14 . In some embodiments, the first and second inserts  12 ,  14  are secured into the frame assembly  16  (e.g., in a factory or remote site from a building site) and then the entire first panel  10 , along with a plurality of substantially similar panels are shipped to an installation site and secured to a building structure to form the curtain wall system. 
     As shown, the first and second inserts  12 ,  14  are insulated glass units, or IG units including one or more opposed glazing sheets separated by spacer and sealant systems with an insulating gas or a vacuum between the glazing sheets ( FIGS. 2 and 3  only show an end portion of each of the first and second inserts  12 ,  14 ). The inserts  12 ,  14  are optionally of different sizes, as shown, though similarly sized inserts are contemplated. Additionally, although the inserts  12 ,  14  are optionally IG units, a variety of other inserts are contemplated, including stone veneer, metal or plastic panels, louvers, and vent inserts, for example. 
     As shown, the frame assembly  16  includes first and second mullions  20 ,  22 , a sill  24 , a head  26 , an intermediate member  28 , first and second mullion spacers  30 ,  32 , a sill spacer  34 , a head spacer  36 , an upper intermediate spacer  37 , and lower intermediate spacers  38 . As shown in one of  FIGS. 2 and 3 , the frame assembly  16  also includes a first mullion cover  40 , a second mullion cover  42 , a sill cover  44 , a head cover  46 , and an intermediate cover  48  (the covers are not shown in  FIG. 1 ). The mullions  20 ,  22 , sill  24 , head  26 , intermediate member  28 , and covers  40 ,  42 ,  44 ,  46  are optionally formed of extruded aluminum material or other material as desired. In some embodiments, one or more of the spacers act as structural components that help support the inserts  12 ,  14 . As described in greater detail, one or more of the spacers  30 ,  32 ,  34 ,  36 ,  37 ,  38  are formed of a thermal insulating material (e.g., as opposed to metals such as aluminum or steel, which are generally considered thermally conductive) in the field of fenestration products. 
     As shown in  FIG. 2 , the first mullion  20  includes a first interlocking tang  50 , a second interlocking tang  52 , and a spacer lock  54 . As described in greater detail, the first and second interlocking tangs  50 ,  52  are configured to form a complementary fit with a laterally adjacent panel ( FIG. 5 ), according to some embodiments. 
       FIG. 2A  is an enlarged view of the first mullion  20  near the spacer lock  54 , according to some embodiments. As shown, the spacer lock  54  includes a rear wall  56  and a front wall  58  combining to define a spacer channel  60  for receiving a portion of the first mullion spacer  30 . As shown, the rear wall  56  includes a step, or recess  62  that is configured to form an interlocking fit with a portion of the first mullion spacer  30 . 
     As shown in  FIG. 2 , the second mullion  22  includes a first interlocking tang  70 , a second interlocking tang  72 , and a spacer lock  74  that is substantially similar to the spacer lock  54  of the first mullion  20 . The interlocking tangs  70 ,  72  are complementary in nature to the interlocking tangs  50 ,  52  and, in a curtain wall system, facilitate assembly of the first panel  10  to adjacent panels. 
     As shown in  FIG. 3 , the sill  24  forms a pocket  80  and includes a spacer lock  84 . The spacer lock  84  optionally includes front and rear walls that define a spacer channel substantially similar to the spacer channel  60  of the first mullion  20 , where the head  26  includes a neck  90  and spacer lock  94 . The neck  90  is optionally adapted to carry one or more weather seals and is adapted to be received in a pocket, such as the pocket  80 , of an adjacent panel in a panel stack of a curtain wall system. The spacer lock  94  optionally includes front and rear walls that define a spacer channel substantially similar to the spacer channel  60  ( FIG. 2A ) of the first mullion  20 . As shown, the intermediate member  28  includes oppositely facing spacer locks  104 ,  106  that optionally each respectively include front and rear walls that define a spacer channel substantially similar to the spacer channel  60  of the first mullion  20 . 
     As shown in  FIG. 1 , in terms of length, the first and second mullion spacers  30 ,  32  correspond generally in length to the first and second mullions  20 ,  22 , the sill spacer  34  corresponds generally in length to the sill  24 , and the head spacer  36  corresponds generally in length to the head  26 . The upper intermediate spacer  37  generally spans the intermediate member  28  while the lower intermediate spacers  38  are a plurality of shorter spacers secured to the intermediate member  28  at discrete locations. 
       FIG. 4  is a transverse cross-section of the first mullion spacer  30 , according to some embodiments. In some embodiments, the various spacers  30 ,  32 ,  34 ,  36 ,  37 ,  38  have substantially similar cross-sections and thus are described collectively with spacer  30 . As shown, the first mullion spacer  30  is substantially L-shaped or is hook shaped and includes a first end  110 , a body  112 , and a second end  114 . The first end  110  forms the hook end, or lower bar of the L-shape and includes a shoulder or catch  120  and a nose  122  with a rounded tip  124 . The body  112  is substantially planer and defines an inward face  130  and an outward face  132 . The second end  112  is chamfered and also defines an inward catch  136  in the form of an inward projection and an outward catch  140  in the form of a recess into the second end  112 . As shown, at the second end  112  the outward face  132  forms a T-shaped channel for receiving one or more assembly accessories, such as a weather seal. 
     As previously referenced, in some embodiments at least a portion of the first mullion spacer  30  (e.g., the body  112 ) is formed of a thermal insulating material, such as a polymeric material. In some embodiments, the entire first mullion spacer  30  is formed as a single, monolithic piece of material. One or more of the spacers also optionally provide substantial structural load bearing in the X, Y, and Z axis in the first panel  10 . As such, a material with sufficient structural strength is selected according to various implementations. For example, one material that has been found to be particularly suitable for such applications is fiberglass material including a reinforcing mat sold under the trade name “DURACAST” fiberglass composite material by Pella Corporation, of Pella, Iowa. Examples of suitable fiberglass materials and associated methods of making can also be found in U.S. Pat. No. 7,276,132 to Davies et al., “Method of Making a Reinforcing Mat for a Pultruded Part,” issued Oct. 2, 2007, the entire contents of which are incorporated herein by reference for all purposes. Other materials are also contemplated, for example co-extruded aluminum and vinyl spacers, where the aluminum serves as a structural core. 
     In some embodiments, the first and second mullion covers  40 ,  42 , sill cover  44 , and the head cover  46  are substantially similar. As shown in  FIG. 2A , the first mullion cover  40  includes a first catch  150  and a wall  152  terminating at a second catch  154 . The first mullion cover  40  also includes a gasket catch  156  for receiving and securing a gasket  160 . The first mullion cover  40  is optionally adapted to be cammed, or rotated and slid, onto the second end  114  ( FIG. 4 ) of the first mullion spacer  30 . The second mullion cover  42 , the sill cover  44 , and the head cover  46  are similarly adapted to cammed onto the second mullion spacer  32 , sill spacer  34 , and head spacer  36 , respectively. As shown in  FIG. 3A , the intermediate cover  48  defines an enlarged channel  170  with opposing walls  172 ,  174  adapted to be cammed onto the intermediate spacers  37 ,  38 . 
     In some embodiments, assembly of the panel  10  includes assembling the first and second mullions  20 ,  22 , the sill  24 , the head  26 , and the intermediate member  28  of the frame assembly  16  into the desired (e.g., rectangular) shape. Typically, the partially assembled frame assembly  16  is placed in a horizontal position and gaskets G ( FIGS. 2 and 3 ) are installed into the frame assembly  16  and the first and second inserts  12 ,  14  are received against the gaskets G. The various spacers are then installed in the frame assembly  16  by camming the spacers into the various spacer locks (see,  FIG. 2A  and  FIG. 3B ), which provides an effective manner for assembling the components. For example, with respect to the first mullion spacer  30  and the first mullion  20 , the first end  110  is inserted into the spacer channel  60  and as indicated in  FIG. 2A , with the nose  122  in the channel  60 , and the body  112  is rotated in the direction R to cam the catch  120  into the recess  62  to secure the first mullion spacer  30  to the first mullion  20 , for example in an interference, cammed relationship. 
     Similarly, the second mullion spacer  32  is assembled to the second mullion  22 , the sill and head spacers  34 ,  36  are secured to the sill and head  24 ,  26 , and the intermediate spacers  37 ,  38  are secured to the intermediate member  28 . The covers are then fit onto the spacers to capture and secure the inserts  12 ,  14  in place. In particular, as shown in  FIG. 2A , the first mullion cover  40  is cammed onto the second end  114  of the first mullion spacer  30  with the first catch  154  engaging the inner catch  136  of the spacer  30  and the second catch  150  of the cover  40  engaging the outward catch  140  of the spacer  30 . The gasket  160  is then inserted between the cover  154  and the insert  12  to help secure the insert in place. Similarly, the covers  42 ,  44 ,  46 ,  48  are secured to the second mullion spacer  32 , the sill spacer  34 , the head spacer  36 , and the intermediate spacers  37 ,  38 . Gaskets are received in the covers  42 ,  44 ,  46 ,  48  to form a captured assembly, with the inserts  12 ,  14  captured between the covers, gaskets, and the mullions  20 ,  22 , sill  24 , head  26 , and intermediate member  28 . 
     Thus, the various spacers  30 ,  32 ,  34 ,  36 ,  37 ,  38  provide an integral portion of the structure, and maintain structural integrity for securing the inserts  12 ,  14  to the frame assembly  16 . Additionally, in some embodiments, at least some of the weight of the first insert  12  is supported on the inward face of the sill spacer  34  and at least some of the weight of the second insert  14  is supported on the inward face of the upper intermediate spacer  37 . In other words, the spacers  34 ,  37  are load bearing in the sense that those spacers  34 ,  37  bear the weight of the inserts  12 ,  14 , including after installation to the building structure. Additionally, the inserts  12 ,  14  are retained in position within the frame assembly  16  by the spacers. As shown in  FIGS. 2 and 3 , when formed of a thermally insulating material, such as “DURACAST” fiberglass composite material, the spacers  30 ,  32 ,  34 ,  36 ,  37 ,  38  provide an effective thermal break between the outer portion of the frame assembly  16  (e.g., the various covers  40 ,  42 ,  44 ,  46 ,  48 ) and the inner portion of the frame assembly (e.g., the mullions  20 ,  22 , sill  24 , head  26 , and the intermediate member  28 ). In other words, the spacers are in a position to block the flow of heat between the interior and exterior of the frame assembly  16  from an exterior of the structure to which the first panel  10  is secured. 
       FIGS. 5 and 6  show the first panel  10  in a unitized curtain wall system  200 , where  FIG. 5  is downward-looking cross-sectional view showing the first panel  10  assembled mullion-to-mullion with a second, laterally adjacent panel  10 B and  FIG. 6  is a sideways-looking cross-sectional view showing the first panel  10  assembled head-to-sill to a vertically adjacent, or stacked, panel  10 C, where the panels  10 ,  10 B, and  10 C are substantially similar. As shown in  FIG. 5 , during assembly to the building structure (not shown) the first mullion  20  is engaged with a second mullion  22 B of the laterally adjacent panel  10 B. As shown, a weather seal  210  is optionally secured to the first mullion spacer  30  and engaged with a second mullion spacer  32 B of the adjacent panel  10 B. Similarly, as shown in  FIG. 6 , during assembly to the building structure (not shown) the head  26  is engaged with a sill  24 C of the vertically adjacent panel  10 C. As shown, a weather seal  212  is optionally secured to a sill spacer  34 C of the adjacent panel  10  and engaged with the head spacer  36  of the first panel  10 . 
     Although the first panel  10  is optionally a captured construct, or a construct in which structural adhesives are not utilized to maintain the inserts  12 ,  14  (e.g., a “dry glaze” construct), constructs including structural adhesive are also contemplated. For example,  FIGS. 7-11  show a second panel  310  of a curtain wall system, according to some embodiments.  FIG. 7  is a front view of the second panel  310 ,  FIG. 8  is a sectional view of the second panel  310  along line  8 - 8  in  FIG. 7 , and  FIG. 9  is a sectional view of the second panel  310  along line  9 - 9  in  FIG. 7 , according to some embodiments. As shown, the second panel  310  includes a first insert  312 , a second insert  314 , and a frame assembly  316  supporting the first and second inserts  312 ,  314 . In some embodiments, the first and second inserts  312 ,  314  are secured into the frame assembly  316  (e.g., in a factory or remote site from a building site) and the entire second panel  310  along with a plurality of substantially similar panels forming the curtain wall system are secured to the building structure. 
     Various components of the second panel  310  are optionally substantially similar to the first panel  10 , although the second panel  310  is optionally assembled with a structural adhesive SA (also called a structural sealant) securing the inserts  312 ,  314  to the frame assembly  316 . As shown, the frame assembly  316  includes first and second mullions  320 ,  322 , a sill  324 , a head  326 , an intermediate member  328 , first and second mullion spacers  330 ,  332 , a sill spacer  334 , a head spacer  336 , and an intermediate spacer  337 . The frame assembly  316  also includes a first mullion cover  340 , a second mullion cover  342 , a sill cover  344 , a head cover  346 , and an intermediate cover  348  (the covers are not shown in  FIG. 7 ). The mullions  320 ,  322 , sill  324 , head  326 , intermediate member  328 , and covers  340 ,  342 ,  344 ,  346  are optionally formed of extruded aluminum material, or other material as desired. In some embodiments, one or more of the spacers act as structural components that help support the inserts  312 ,  314 . As described in greater detail, one or more of the spacers  330 ,  332 ,  334 ,  336 ,  337 ,  338  are formed of a thermal insulating material (e.g., as opposed to metals such as aluminum or steel, which are generally considered thermally conductive). 
       FIGS. 10 and 11  show the second panel  310  in a unitized curtain wall system  500 , where  FIG. 10  is downward-looking cross-sectional view showing the second panel  310  assembled mullion-to-mullion with a laterally adjacent panel  310 B and  FIG. 11  is a sideways-looking cross-sectional view showing the second panel  310  assembled head-to-sill to a vertically stacked, panel  310 C, wherein the panels  310 ,  310 B,  310 C are substantially similar. 
     As shown in  FIG. 10 , the first mullion spacer  330  has a first end  410  and a body  412  that are substantially similar to that of the spacer  30 , although a second end  414  of the first mullion spacer  330  defines a generally bulbous shape. As shown in  FIGS. 7-9 , the other spacers  332 ,  334 ,  336 ,  337  are similarly shaped. In turn, the covers  340 ,  342 ,  344 ,  346 ,  348  are also substantially similar and are configured to slide onto the spacers to form an interference fit with the second ends of the respective spacers  330 ,  332 ,  334 ,  336 ,  337 . As with the first panel  10 , in some embodiments at least a portion of the spacers of the second panel  310  are formed of a thermal insulating material. 
     In some embodiments, assembly of the second panel  310  includes assembling the first and second mullions  320 ,  322 , the sill  324 , the head  326 , and the intermediate member  328  of the frame assembly  316  into the desired (e.g., rectangular) shape. The partially assembled frame assembly  316  is placed in a horizontal position and weathering gaskets WG ( FIGS. 2 and 3 ) are installed into the frame assembly  316  and the first and second inserts  312 ,  314  are received against the gaskets WG. In some embodiments, a structural adhesive SA is applied between the inserts  312 ,  314  and the first and second mullions  320 ,  322 , the sill  324 , the head  326 , and the intermediate member  328 . Similarly to the first panel  10 , the various spacers  330 ,  332 ,  334 ,  336 ,  337  are assembled to the frame assembly  316  by camming the spacers into spacer channels of the mullions  320 ,  322 , sill  324 , head  326 , and intermediate member  328 . The covers  34 ,  342 ,  344 ,  348  are added to the spacers before or after installation into the frame assembly  16 . One or more backer rods BR are installed between the spacers and the inserts  312 ,  314  as shown. Additional sealant and weather stripping is applied as desired. 
     As shown, the various spacers  330 ,  332 ,  334 ,  336 ,  337  provide an integral portion of the structure, and maintain structural integrity for securing the inserts  312 ,  314  to the frame assembly  316 . For example, in some embodiments, immediately following assembly, the structural adhesive SA is not fully cured and does not provide substantial structural support; it may take days for a full cure. In some embodiments, during at least that cure time, the spacers provide structural support to the second panel  310 . As such, the second panel  310  is able to be more easily moved and stored (e.g., in a vertical configuration) immediately following assembly. Moreover, when formed of a thermally insulating material, such as DURACAST fiberglass composite material, the spacers  330 ,  332 ,  334 ,  336 ,  337  provide an effective thermal break between the outer portion of the frame assembly  316  (e.g., the various covers  340 ,  342 ,  344 ,  346 ,  348 ) and the inner portion of the frame assembly (e.g., the mullions  320 ,  322 , sill  324 , head  326 , and the intermediate member  328 ). 
     As previously described, in some embodiments, the various spacers are pultruded parts of a fiberglass composite.  FIG. 12  is a pultrusion profile of the first mullion spacer  30  of the first panel  10 , according to some embodiments. As shown, the pultruded profile includes a plurality of reinforcing structures, or reinforcing mats M 1 -M 11  that provide structural support to the part. Suitable reinforcing structures are available from Pella Corporation of Pella Iowa. Suitable reinforcing structures are also disclosed in U.S. Pat. No. 7,276,132 to Davies et al., “Method of Making a Reinforcing Mat for a Pultruded Part,” issued Oct. 2, 2007 (previously incorporated). As shown, the pultrusion profile also includes a plurality of rovings R located in the core of the profile as well as a plurality of rovings R of various diameters and texo yarns T adjacent a perimeter of the pultrusion profile. The profile also optionally includes a heat set resin coating on an exterior surface of the part, according to some embodiments. 
       FIG. 13  is a pultrusion profile of the first mullion spacer  330  of the first panel  10 , according to some embodiments. As shown, the pultruded profile includes a plurality of reinforcing structures, or reinforcing mats M 1 -M 8  that provide structural support to the part. Suitable reinforcing structures are available from Pella Corporation of Pella Iowa. Suitable reinforcing structures are also disclosed in U.S. Pat. No. 7,276,132 to Davies et al., “Method of Making a Reinforcing Mat for a Pultruded Part,” issued Oct. 2, 2007 (previously incorporated). As shown, the pultrusion profile also includes a plurality of rovings R of multiple diameters located in the core of the profile as well as a plurality of rovings R of various diameters and texo yarns T adjacent a perimeter of the pultrusion profile. The profile also optionally includes a heat set resin coating on an exterior surface of the part, according to some embodiments. 
     Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present invention. For example, while a camming or interference fit has been described for installing the spacers and covers, additional methods and associated spacer configurations for fastening are contemplated, such as slide in, snap fits, mechanical fasteners, bonding (e.g., chemical or thermal), or combinations thereof. While the embodiments described above refer to particular features, the scope of this invention also includes embodiments having different combinations of features and embodiments that do not include all of the above described features.