Patent Publication Number: US-5829216-A

Title: Seismic facade support

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention broadly concerns a device for supporting building facades where the facade may be subject to movement relative to the supporting structure. More particularly, it is concerned with a device which supports building facades for translational or pivoting movement relative to the supporting building or buildings to withstand seismic stresses. 
     2. Description of the Prior Art 
     The use of facades in the construction field has as its purpose the enhancement of the aesthetic appearance of a structure, or possibly the provision of thermal or sound isolation to the interior rather than functioning as a load-bearing member. Facades, as used herein, refers to panels or structures attached to the exterior of a structure or structures, and may be made of stone, masonry, metal, or other materials, or combinations thereof. 
     In the wake of recent earthquakes in California and elsewhere, architects and engineers are compelled to consider the ability of a structure to withstand small and moderate earthquakes with only minor damage. In many regions lying astride active fault lines, architects and engineers are cognizant of increased concern and new regulations concerning the resistance or accommodation of buildings to seismic activity. However, the concept of enhancing the resistance of building facades to seismic activity is a new one. 
     SUMMARY OF THE INVENTION 
     The problem of developing a system for mounting a facade to a building with increased resistance to seismic disturbance is largely solved by the present invention. That is to say, the present invention provides a system which permits a facade to be supported from a building, or between two buildings, in a manner which allows limited movement of the facade relative to the building or buildings, thus reducing stress on the mounting system during earthquakes and the like. 
     The system of the present invention advantageously includes a support which connects the facade to the building in a manner which permits relative movement therebetween. In many applications, the facade will connect or span a gap between two or more buildings, and must accommodate relative movement between the two buildings. In preferred embodiments, the system may permit both limited translational and pivotal movement, and in particularly preferred embodiments, the movement may be translational in three orthogonal axes and pivotal about the three rotational axes. The capability of permitting translational and pivotal movements minimizes the effect of building movement on the facade and its supports when the building or buildings oscillate in unpredictable patterns as a result of e.g., slip, strike-slip, oblique slip or separation type faults. 
     The system hereof includes a coupler, a mount complementally configured to the coupler and shiftable interconnected to the coupler, and means for connecting the mount and the coupler respectively to at least one building and a facade. The coupler may be in the form of a track element a projecting member and the mount providing a receiving member complementally configured to the projecting member for permitting relative movement, such as shiftable movement therebetween. In the case of the track and guide element slidably mounted thereon, the shiftable movement is translational. Another type of coupler having a projecting member is a hinge presenting a pin, with the mount presenting a recess for receiving the hinge pin. In the present invention, the hinge hereof is operatively coupled to the facade and a building and configured to permit both limited pivoting and limited translational movement between the coupler and mount. 
     In particularly preferred embodiments where the facade spans two buildings, multiple tracks may be employed and oriented along either parallel or perpendicular axes. For example, multiple parallel tracks would be employed to provide adequate support for a medium or large facade, while tracks oriented perpendicular thereto would permit movement of the facade along a different orthogonal axis. Moreover, the system may employ link pins to interconnect system components, providing additional pivoting, typically in the range of at least about 6 degrees. In addition, panels of rubber or synthetic resin such as polyvinyl chloride may be employed to provide environmental protection to the components against rain and wind-borne grit, but which will resiliently yield during seismic disturbances to permit relative movement between the facade and supporting buildings. The vinyl strips or panels are placed to permit the facade or system components to move thereagainst and to yield before the metal components of the system are permanently deformed or fail. 
     The system hereof is particularly useful in buildings which are separated by a gap of two feet, or more commonly four feet or more, and which employ a facade to conceal the separation. Such gaps permit the adjacent buildings to move relative to one another, and the system hereof permits the facade to span the gap and move in relationship to one or both buildings to minimize stress, damage or even separation of the facade. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front perspective view of the facade support hereof spanning a gap between two adjacent buildings, with portions of the facade and part of the support removed for clarity; 
     FIG. 2 is a top plan view of the support hereof, showing the buildings and facade and angle irons secured to the building for carrying the support hereof; 
     FIG. 3 is an enlarged, fragmentary view of the facade support hereof, with one track only partially shown and the facade foreshortened; 
     FIG. 4 is a vertical cross-sectional view of the facade support taken along line 4--4 of FIG. 2 to illustrate the facade and a track portion of the support; 
     FIG. 5 is a vertical cross-sectional view of the facade support taken along line 5--5 of FIG. 2 to illustrate the second track portion of the support oriented perpendicular and along a second building respective to the track of FIG. 4; 
     FIG. 6 is an end elevational view taken along line 6--6 of FIG. 3 with portions of the track shown in phantom; and 
     FIG. 7 is an enlarged, fragmentary perspective view of the hinge of the support. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawing, a seismic facade support 10 broadly includes hinge 12 and tracks 14a and 14b for movably supporting a facade 16 between a first building 18 and a second building 20 as is shown in FIG. 3. While a facade support 10 may be employed to support a facade 16 on only a single building, the use of the support on two adjacent buildings 18 and 20 separated by a gap 22 which is typically in excess of four feet (about 1.25 meters) presents an advantageous use as demonstrated in the figures. The support 10 also preferably includes a seal cap 24 and end cap 26 which are useful both aesthetically and for limiting access of precipitation and grit to the support 10 located behind the facade 10. Angle irons 28 are secured to the buildings 18 and 20, typically by mortar or welding, to carry the support 10 and therefore the facade 16. It may be readily appreciated that beams incorporated in the buildings&#39; structural frame or other structural components are an acceptable alternative to the angle irons 28. The buildings 18 and 20 may be of any suitable construction, and may be specially constructed to meet local building codes or requirements in earthquake-prone areas. 
     In greater detail, the hinge 12 of the support includes a hinge plate 30 which includes a hinge pin 32 projecting therefrom, the hinge plate 30 serving as a coupler 34. The hinge pin 32 is preferably elongated and circular in cross section, and may be fabricated of a suitable material such as aluminum. The junction 36 between the hinge pin 32 and the flattened portion of the hinge plate 30 is beveled to present a reduced transverse dimension adjacent the hinge pin 32. The hinge 12 also includes a mounting bracket 38 which includes a receiver 40 including an elongated slot 42 complementally configured to receive the hinge pin 32 therein. The receiver 40 includes shoulders 44 which are beveled to greater degree than the junction 36 of the hinge plate 30, whereby the hinge plate 30 is free to shift or pivot through a limited range of motion relative to the mounting bracket 38. Preferably, the difference in the beveling of the hinge plate 30 and the shoulders 44 permits at least a 6° range of pivoting movement. Wheel bearing grease or other suitable lubricant aids in the movement. It may also be appreciated from FIG. 7 that the configuration of the hinge 12 enables the hinge pin 32 to shift or move translationally relative to the receiver 40. That is to say, if the hinge pin 32 is oriented substantially vertically as shown in the drawing, the receiver 40 and thus the facade 16 connected thereto is permitted limited up and down movement relative thereto because of the configuration of the support 10 as set forth herein. 
     The hinge plate 30 is connected to the track 14a by hinge bracket 46 and link 48. The hinge bracket 46 presents a pair of spaced-apart, parallel flanges 50 and 52 which extend on either lateral side of the hinge plate 30. Each of the flanges 50 and 52 include a plurality of circular, opposed and aligned holes 54 for receiving link 48 therethrough and through a corresponding aligned hole in the hinge plate 30. The link 48 is retained in position by an enlarged head portion and a cotter pin 56 as is conventional. As shown in FIG. 3, the hinge plate 30 includes an end wall 58 which is spaced from the opposing surface of the hinge bracket 46 whereby the space therebetween enables the hinge plate limited pivotal movement about an axis defined by the link 48. That portion of the hinge bracket 46 remote from the flanges 50 and 52 is welded or otherwise secured by suitable fasteners to track 14 and thus fixed relative to the track 14 but capable of limited movement relative to mounting bracket 38. 
     Mounting bracket 38 includes a pair of spaced-apart, opposed arms 60 and 62 each provided with a circular, opposed hole 64. Link 66, similar to link 48, passes through the holes 64 and through corresponding aligned holes in the facade 16 for pivotally supporting facade 16 between the arms 60 and 62. It may be seen that there is a slight clearance 68 between the facade 16 and the wall 70 of the mounting bracket 38 between the arms 60 and 62, which enables the facade 16 to pivot about the link 66 through a limited range similar to the limited pivoting action of the hinge plate 30 and hinge bracket 46. A cotter pin 72 passes through the link 66 opposite its head to hold the link in position. 
     Tracks 14a and 14b are similar in enabling translational movement of the facade 16 relative to a building. Tracks 14a and 14b each include a track element 74 serving as a coupler and presenting opposed, divergent and outwardly projecting rails 76 and 78 and a recessed bight 80, and a guide 82 slidably carried by the track element 74. The guide 82 serves as a mount for carrying the facade 16 in the case of track 14a, while in the case of track 14b, a modified double guide 84 carries hinge bracket 46, which as explained above, is operatively connected to and functionally mounts the facade 16. The guide 82 and the double guide 84 are complementally configured with the track element 74 to be slidingly carried thereon and include a central wall 86 connecting opposed legs 88 and 90 presenting inwardly oriented convergent feet 92 and 94 respectively to define therein a receiving area 96. As may be seen from FIG. 1, a plurality of tracks 14a or 14b may be mounted in parallel to provide sufficient support for a facade of the size and weight selected. Additionally, it may be appreciated that the tracks 14 may be oriented at angles to one another to provide translational movement along different axes, such as the perpendicular orientation between the tracks 14a and 14b as shown in FIG. 2. 
     The track elements 74 are preferably positioned with their longitudinal axes substantially horizontal as shown in FIG. 1, although other orientations are entirely within the scope of the teachings hereof. However, horizontal orientations serve the dual purpose of supporting the facade and permitting translational movement without the necessity of further load bearing supports. To facilitate relative translational movement between the track elements 74 and guide 82 or double guide 84, a friction-resistant strip 98 of polytetrafluoroethylene, commonly sold under the trademark TEFLON, or other suitable synthetic resin material may be employed. 
     Angle irons 28 or other suitable mounting brackets are secured to the building 18 or 20 so as to present an upright, preferably planar, fixed mounting surface 100 for receiving the track element 74 thereon. Track elements 74 are fixed to the surface by a mounting pin 102 which is preferably threaded into surface 100, or alternatively may be welded thereto or embedded in the building structure. Pin 102 preferably passes through a central bore 104 in the bight 80 and the head of the pin 102 and a suitable washer restrain the track elements 74 against outward movement relative to the building. The track elements 74 preferably are slightly spaced away from the surface 100 and leveled so that the rails 76 and 78 lay in an upright plane by leveling bolts 106 and 108 which are threadably held in respective apertures 110 and 112 extending through the vertically disposed rails and bight 80. The leveling bolts 106 and 108 are screwed into apertures 110 and 112 until they engage surface 100 and the track elements 74 are properly aligned and oriented. In the case of track 14a, the guide 82 is preferably secured to the facade 16 by machine screws 114 and 116, while in the embodiment shown herein, double guide 84 of track 14b is welded to mounting bracket 38 as shown in FIG. 3. 
     The hinge 12 and the track 14 are preferably covered at the ends of the facade 16 by seal cap 24 and end cap 26. Seal cap 24 includes a bracket 118 which is preferably threadably mounted to the building 18 by bolt 120. The bracket 118 includes fingers 122 defining slots therebetween for carrying resilient and yieldable vinyl seal strips 124 or alternatively a seal with integrally formed strips 124 may be substituted. Seal strips 124 extend between bracket 118 to engage receiver 40 but are sufficiently flexible to yield responsive to movement of the receiver 40 and facade 16. In this connection, the ends of the strips 124 engaging the receiver 40 may be bent to more readily yield to movement of the facade 16. A corner flashing 126 is fastened to bracket 118 for purposes of appearance but does not engage receiver 40 and thus does not interfere with translational or other movement of the facade 16. 
     End cap 26 is positioned opposite seal cap 24 to enclose the remote end of the facade 16. The end cap 26 includes a resilient vinyl panel 128 and a cover flashing 130. The vinyl panel 128 extends between the building 20 and the facade 16 to engage both and partially enclose the area between the facade 16 and the building and preferably is oriented vertically as shown in FIGS. 3 and 6. The cover flashing 130 is fastened to the facade 16 by screws 132 or other suitable fasteners and is provided with notches 134 as shown in FIG. 6 in alignment with the tracks 14a, and more particularly the track elements 74. In the event of a seismic event, the panel 128 is sufficiently yieldable and resilient so as to permit the facade 16 to move along the tracks 14 and the track elements to distend or enlarge the panel 128 without permanent damage unless the seismic event is particularly violent. Thus, the panel 128 is permitted to yield and deform rather than forcing the corner flashing 130 to absorb the forces resulting from movement of facade 16 along track 14a relative to building 20. 
     It is to be understood that the facade 16 may be of any conventional construction, so that metal, masonry, wood or other building materials may be used in its construction without substantial effect on the operability of the present invention. Similarly, buildings 18 and 20, while preferably of modern, earthquake-resistant design and materials, may be of any suitable construction for supporting the weight load of the facade. Buildings 18 and 20 each have respective front walls 136 and 138 which are preferably though not necessarily in substantial alignment, and further present side walls 140 and 142 which are preferably upright, opposed and substantially parallel. However, it may be understood that the invention hereof is uniquely adaptable to accommodate mounting of the facade to walls which are not so configured. In order to accommodate movement of the buildings 18 and 20 during seismic events, the gap 22 therebetween is preferably at least 48 inches, although smaller dimensions of gap 22 can readily be accommodated by the support hereof. 
     In use, the tracks 14a and 14b are attached to angle irons 28 by the threaded pins 102 as shown in FIGS. 4 and 5. As may be seen in FIG. 4, when the facade 16 is provided in multiple sections 16a and 16b, a lip 144 may be fastened by screws 114 to one of the adjacent facades, in this case 16b, and then extend across the lower margin of the upper facade 16a to serve as a weather strip and provide a somewhat continuous appearance. After the tracks 14 are in place, leveling bolts 106 are adjusted to properly orient the track elements 74 relative to the respective building 18 or 20. Hinge bracket 46, which may have been pre-attached to double guide 84 by welding or other fastening means, is coupled to hinge plate 30 by link 48. 
     Thereafter, the respective guides 82 are attached to the facade by machine screws 114 and 116 as shown in FIG. 4, and double guide 84, carrying hinge bracket 46 is slidably coupled to track element 74 of track 14b. The facade 16, now carrying the guide 82, is mounted to the track element 74 of track 14a by sliding the guides 82 onto track element 74 until the facade is properly positioned relative to walls 136 and 138. Mounting bracket 38 is then coupled to hinge plate 30 by aligning the slot 42 with hinge pin 32 until vertically aligned with the hole 64 of mounting bracket 38 aligned with corresponding holes in the facade 16. Link 66 is then inserted through the hole 64 and the corresponding holes in the facade 16 for coupling the facade 16 to the hinge plate 30 and therefore the track 14b. Thereafter, seal cap 24 and end cap 26 are fastened to the building 18 and facade 16 respectively and as described above. 
     It may be appreciated that so mounted, in the event of an earthquake or other seismic event, the facade is permitted limited movement relative to buildings 18 and 20. In this connection, the configuration hereof permits limited translational movement of the facade 16 along track 14a along a first translational axis A as shown in FIG. 3. At the same time, track 14b permits limited translational movement of the facade 16 normal to its plane along axis B. Finally, as may be evident from viewing FIG. 7, the receiver 40 is permitted to move a limited distance along hinge pin 32 and thus along a third translational movement axis C. It may be appreciated that axes A, B and C lie along three orthogonal axes. 
     Further, the relative separation between shoulders 44 and junction 36 of the hinge plate permits the receiver 40 and thus the facade 16 coupled thereto to pivot about an axis parallel to axis C through a preferable range of at least about 6°. Link 48 pivotally couples hinge plate 30 to hinge bracket 46 for limited pivotal movement of the hinge plate 30 and thus the facade 16 relative to the hinge bracket 46 and thus the building 18 to which it is attached. Link 48 thus defines a pivot axis which is substantially parallel, though not necessarily so to axis A. The limitation on pivoting is provided by the limited space between end wall 58 and the hinge bracket 46, so that excessive pivoting is inhibited upon engagement of the end wall 58 and the hinge bracket 46. Link 66 similarly pivotally couples facade 16 to hinge plate 30 and thus building 18. Link 66 defines a pivot axis which is preferably, though not necessarily, substantially parallel to translational axis B. Again, the amount of pivoting about link 66 is limited by the relatively small clearance 68 between the end of facade 16 and the receiver 40 of mounting bracket 38, so that only limited pivoting is permitted in the manner previously described between the hinge plate 30 and the hinge bracket 46. From the foregoing, it may be appreciated that hinge pin 32, link 48 and link 66 define three respective orthogonal pivot axes preferably substantially parallel to translational axes A, B and C. 
     In the event of a seismic disturbance such as an earthquake causing relative movement between buildings 18 and 20, facade 16 is permitted limited independent shifting, thereby restricting stress on the threaded pins 102 holding the track elements 74 to the respective buildings. For example, if building 18 oscillates along axis B while building 20 moves back and forth along axis A, the facade 16 is permitted limited movement along tracks 14a and 14b to accommodate relative movement. This is further enhanced by the ability of the facade 16 to pivot about hinge pin 32, so that stresses do not build up internally within the facade 16. The use of friction resistant strips 98 serves to further lessen the build-up of stress within facade 16 and to lessen the likelihood that the guides 82 and the double guides 84 will seize relative to track elements 74 during periods of seismic activity. By permitting limited movement about three orthogonal pivot axes and limited translational movement along three axes, the facade support 10 hereof is able to accommodate independent movement between two adjacent buildings 18 and 20, even when the movement of the buildings is independent, including relative vertical movement between the buildings. By employing seal cap 24 and end cap 26 as described herein many routine seismic events may be accommodated without structural or aesthetic damage either to the facade 16 or to the support 10. 
     Although preferred forms of the invention have been described above, it is to be recognized that such disclosure is by way of illustration only, and should not be utilized in a limiting sense in interpreting the scope of the present invention. Obvious modifications to the exemplary embodiments, as hereinabove set forth, could be readily made by those skilled in the art without departing from the spirit of the present invention. 
     The inventors hereby state their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of their invention as pertains to any apparatus not materially departing from but outside the liberal scope of the invention as set out in the following claims.