Patent Publication Number: US-11396754-B2

Title: System for supporting non-structural building components

Description:
RELATED APPLICATION 
     This patent application claims priority to Australian Patent Application No. 2017904132, filed on Oct. 12, 2017, which has been incorporated herein in its entirety for all purposes. 
     FIELD OF THE INVENTION 
     The present invention relates to a system for supporting non-structural building components. 
     BACKGROUND 
     Non-structural building components are used in the functioning of many buildings to distribute building services, such as electrical power and data, water, gas, and ventilation and refrigeration. It is common for non-structural building components to be suspended beneath a soffit of the building. However, it will be appreciated that in some instances non-structural building components may additionally or alternatively need to be supported adjacent a vertical wall of the building. 
     It is known to support non-structural building components in an elevated position beneath a soffit using suspension hangers, each of which is a rigid threaded rod. The upper end of the suspension hanger is embedded in (or otherwise secured to) a soffit. The building service components are then secured to the lower end of the suspension hanger using internally threaded nuts, and other fastening components. 
     In some instances, it is important that buildings and the components are properly protected and will continue to operate after an event in which the building is subject to substantial shock and/or vibration. Such events include earthquakes and other seismic events, and commercial blasts. In these instances, the non-structural components need to be braced and/or isolated so as to receive minimal damage. In order to withstand such events, it is known to provide bracing to the non-structural building components, however the bracing puts compressive and bending loads on the suspension hanger. To prevent the suspension hangers collapsing, the threaded rods are then reinforced, which adds weight and complexity to the system. Further, installation of the system is more complicated and time consuming. 
     There is a need to address the above, and/or at least provide a useful alternative. 
     SUMMARY 
     There is provided a system for supporting a non-structural building component beneath a soffit of a building, the system having a plurality of suspension assemblies that each comprise: 
     a first elongate non-rigid member that is secured at an upper end to a structural portion of the building at a first location, and at a lower end to one of: the non-structural building component, or a support member to which the non-structural building component is secured; and 
     at least one second elongate non-rigid member that is secured at a lower end to one of: the non-structural building component, or the support member to which the non-structural building component is secured, and at an upper end to a structural portion of the building at a second location, 
     wherein: 
     the first elongate non-rigid member is oriented substantially vertically, 
     the second location is horizontally spaced from the first location, such that the second elongate non-rigid member is inclined to vertical, and 
     when the building is in a stable condition, the tensile force in the first elongate non-rigid member is greater than the vertical component of the tensile force in the second elongate non-rigid member. 
     Preferably, when the building is in a stable condition, substantially all of the vertical load of the non-structural building component is supported by the first elongate non-rigid members. 
     In some embodiments, each suspension assembly has two second elongate non-rigid members, and the upper ends of the two second elongate non-rigid members are secured to structural portion of the building at spaced apart second locations. 
     Preferably, each of the second elongate non-rigid members is provided with an adjuster that facilitates adjustment of the length of the respective second elongate non-rigid member between upper and lower ends. In some embodiments, the second elongate non-rigid members are flexible. In such embodiments, the adjuster can comprise a cleat. 
     Preferably, the system has pairs of the suspension assemblies that are arranged so that, within each pair, one of the second elongate non-rigid members of a first suspension assembly lies in vertical plane that is parallel to a vertical plane in which one of the second elongate non-rigid members of a second suspension assembly lies. 
     In embodiments in which each suspension assembly has a single second elongate non-rigid member, the pairs of suspension assemblies are preferably arranged so that tensile forces in the first elongate members, and the vertical components of the tensile forces in the second elongate non-rigid members are substantially coplanar. 
     In certain embodiments, each of the assemblies includes one or more dampers that are each configured to inhibit transmission of vibration to the building. 
     In some embodiments, the system can further comprise one or more support members to which the non-structural building component is secured, and wherein the lower ends of the first and second elongate non-rigid members in the suspension assemblies are secured to the support members. In one form, each support member can include a strut that extends transversely across each the non-structural building component, and opposing ends of the strut are each supported by a pair of the suspension assemblies. The struts can be positioned beneath the non-structural building component. 
     Each support member can include a strap member having two ends that are attached to the respective strut, and extends about the non-structural building component so as to secure the non-structural building component to the strut. Each support can further include one or more dampers that are each configured to inhibit transmission of vibration to the building. 
     In at least some alternative embodiments, the system includes tether members that are secured to the non-structural building component, and the lower ends of at least one of the first and second elongate non-rigid members in a respective one of the suspension assemblies is secured to each tether member. In some further alternative embodiments, the non-structural building component has integrally formed tether members, and the lower ends of at least one of the first and second elongate non-rigid members in a respective one of the suspension assemblies is secured to each tether member. 
     The present invention also provides a method for installing a system for supporting a non-structural building component beneath a soffit of a building, the method involving: 
     providing a plurality of suspension assemblies as previously described; 
     securing the upper end of a first elongate non-rigid building component to a structural portion of the building at a first location, the first location being selected such that, in the installed system, the first elongate non-rigid building component is oriented substantially vertically; 
     securing the upper end of at least one second elongate non-rigid building component to a structural portion of the building at a second location that is spaced horizontally spaced from first location; 
     securing the lower end of first elongate non-rigid building component to one of: the non-structural building component, or a support member to which the non-structural building component is secured; 
     securing the lower end of second elongate non-rigid building component to one of: the non-structural building component, or a support member to which the non-structural building component is secured, whereby in the installed system, the second elongate non-rigid member is inclined to vertical; and 
     setting the tension in the second elongate non-rigid member such that the tensile force in the first elongate non-rigid member is greater than the vertical component of the tensile force in the second elongate non-rigid member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the invention may be more easily understood, an embodiment will now be described, by way of example only, with reference to the accompanying drawings, in which: 
         FIG. 1 : is a perspective schematic view of a system for supporting non-structural building components according to a first embodiment of the present invention; 
         FIG. 2 : is a bottom view of the system of  FIG. 1 ; 
         FIG. 3 : is a vertical cross section of the system as viewed along the line X-X in  FIG. 2 ; 
         FIG. 4 : is a bottom view of a system for supporting non-structural building components according to a second embodiment of the present invention; 
         FIG. 5 : is a bottom view a system for supporting non-structural building components according to a third embodiment of the present invention; 
         FIG. 6 : is a vertical cross section of the system, as viewed along the line Y-Y in  FIG. 5 ; 
         FIG. 7 : is a bottom view of a system for supporting non-structural building components according to a fourth embodiment of the present invention; and 
         FIGS. 8 to 13 : show steps in the installation of the system of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 to 3  show a system  10  for supporting a non-structural building component beneath a soffit S of a building, the system  10  being in accordance with a first embodiment. For clarity, the soffit S is not shown in  FIGS. 1 and 2 . In these Figures, the component is a section of duct D of a heating, ventilation and air conditioning (HVAC) system. 
     It will be appreciated that the invention is not limited to the forms of non-structural building component that are illustrated in the drawings. The system  10  can be used for any non-structural building component (or components) that are to be suspended within a building. By way of example only, the non-structural building components that system  10  can be used to support include ductwork, data and/or electrical cable tray, variable air volume (VAV) boxes, sprinkler pipe, junction boxes, lighting, plumbing, fan coil units, and pump units. 
     The system  10  has a plurality of suspension assemblies  12 ; in the example illustrated in  FIG. 1 , the system  10  has four suspension assemblies  12 . Each of the suspension assemblies  12  has a first elongate non-rigid member  14 , and a second elongate non-rigid member  16 . In this example, the first and second elongate non-rigid members each include a cable. However, it will be understood that some alternative embodiments of the system could use elongate non-rigid members in the form of wire rope, plain wire, chain, non-metallic fibre(s), and the like. In some of these alternatives, the elongate non-rigid members can include a shroud portion that extends around one or more longitudinal tensile elements. 
     For simplicity of the following description the cable of the first elongate non-rigid member is hereinafter referred to as “first cable  14 ”. Similarly, the cable of the second elongate non-rigid member is hereinafter referred to as “second cable  16 ”. 
     The upper ends of the first and second cables  14 ,  16  are secured to structural portions of the building. As shown in  FIG. 3 , in this example the upper end of the first cable  14  is secured at an upper end to the soffit S at a first location. To this end, the first elongate non-rigid member includes a stud-type anchor  18  that is embedded in the soffit S, and the anchor  18  is swaged onto the end of first cable  14 . The upper end of the second cable  16  is secured to the soffit S at a second location that is horizontally spaced from the first location. In this embodiment, the system  10  includes a threaded masonry bolt  20  that is embedded in the soffit S. The second elongate non-rigid member includes an eyelet  22  that is swaged onto the end of cable  16 . The eyelet  22  is located on the shank of the masonry bolt  20 , and retained by a  24 . 
     In the embodiment illustrated in  FIGS. 1 to 3 , the system  10  includes support members that each include a strut  26  on which the duct D is supported. In each suspension assembly  12 , the lower ends of the first and second cables  14 ,  16  are secured to one end of one of the struts  26 . Further, the four suspension assemblies  12  are arranged in pairs, with each pair of suspension assemblies  12  being connected to a respective strut  26 . 
     The first cables  14  are secured to the struts  26  by clamps  28 . To this end, each of the first cables  14  passes through a hole in the strut  26 , and one of the clamps  28  binds onto the cable  14  underneath the strut  26 . 
     Each of the support members also includes a strap member with two ends that are attached to the respective strut  26 . In this particular embodiment, each strap member is a flexible tie  30 . The tie  30  extends around the duct D so as to restrain the duct D to the strut  26 . In one example, the tie  30  can be a cable. As shown particularly in  FIG. 3 , each tie  30  is attached to the respective strut  26  by clamps  32  at each end. Each end of the tie  30  passes through a hole in the strut  26 , and one of the clamps  32  binds onto the tie  30  underneath the strut  26 . 
     In this particular embodiment, each of the clamps  28  includes a damper, so as to absorb shock loads in the respective first cable  14 . Similarly, each of the clamps  32  includes a damper that absorbs shock loads in the respective tie  30 . The inclusion of dampers aids in minimizing transfer of in-service vibration from the duct D to the structural components of the building. 
     Two eyelets  34  are attached to the ends of each strut  26 . A cleat  36  is installed on each second cable  16  between the masonry bolt  20  and the respective eyelet  34 . The free end of the second cable  16  extends through the eyelets  34 , and then back through the cleat  36 . In this way, the length of the portion of second cable  16  that is between the masonry bolt  20  and the respective eyelet  34  is adjustable. 
     As will be particularly evident from  FIG. 3 , the first cables  14  are oriented substantially vertically, and the second cables  16  are inclined to vertical. In the embodiment of  FIGS. 1 to 3 , the second cables  16  are inclined at approximately 45° to vertical. The system  10  is to be configured such that, when the building is in a stable condition, in each of the suspension assemblies  12 , the tensile force in the first cable  14  is greater than the vertical component of the tensile force in the second cable  16 . In this way, most, if not all, the weight of the duct D is carried by the first cables  14 . In other words, when the building is in a stable condition, substantially all of the vertical load of the duct D is supported by the first cables  14 . 
     For the purposes of this specification, it is to be understood that the expression “the building is in a stable condition” means that the building is substantially static and is not being subjected to vibration or shock loads. When an earthquake, seismic event, or similar event occurs, energy is transferred to the building through ground movement or pressure waves. This energy causes discernible movement and/or distortion (in other words, movement/distortion that can normally be felt by a person) of the structural part of the building can place the building in an “unstable” condition. 
       FIG. 2  shows a bottom view of the system  10 . As will be appreciated, in this view the first cables  14  are obscured by the struts  26 . In each of the two paired of suspension assemblies  12 , the second cables  16  of the suspension assemblies  12  are parallel to a vertical plane in which the first cables  14  lie. Consequently, when the building is in a stable condition, the horizontal components of forces applied to the duct D by the two suspension assemblies  12  in each pair (which are the horizontal components of the tensile forces in the second cables  16 ) can be approximately equal and act in opposite directions. In this way, the sum of all horizontal components of forces applied to the duct D by the system  10  can be greatly reduced. 
     It will be appreciated that in some alternative embodiments, the strap member may be a substantially rigid component. In some further alternative embodiments, the entire support member may be made of a flexible material. 
       FIG. 4  is a bottom view of a system  110  for supporting a non-structural building component beneath a soffit of a building, the system  110  being in accordance with a second embodiment. In  FIG. 4 , the component is a section of duct D of a HVAC system. The system  110  is substantially is substantially similar to the system  10  of  FIGS. 1 to 3 , and like components of the system  110  have the same reference numeral with the prefix “1”. 
     In a similar manner to the system  10 , the system  110  has the suspension assemblies  112  are arranged in pairs. As is evident from  FIG. 4 , each pair of suspension assemblies  112  is connected to a respective strut  126 . 
     The system  110  differs from system  10  in that each suspension assembly  112  has two second cables  116 . Within each suspension assembly  112 , the upper ends of the second cables  116  are secured to structural portion of the building at spaced apart second locations. Further, in this embodiment, the lower ends of the two second cables  116  are secured to one another by a common fastener such as bolt  138 . To this end, the system  110  has four eyelets  134  attached to the ends of each strut  126 , with one of the second cables  116  passing through a respective eyelet  134 . Thus, there are two eyelets  134  at secured to each end of the strut  126 . 
       FIG. 4  includes a dashed line P that indicates the location of a vertical plane that is coincident with the first cables (which are not visible in  FIG. 4 ). The vertical plane P is parallel to the viewing direction of  FIG. 4 , and thus only an edge of the plane P is visible. The attachment points of eyelets  134  to the strut  126  also lie in the vertical plane P. 
     In the system  110 , the second locations, at which the upper ends (not shown) of the second cables  116  are secured to the structural component of the building, are selected such that the each second cable  116  has a complementary second cable  116  in the other suspension assembly  112  of the pair. Each second cable  116  and its complementary second cable  116  have an equal horizontal angular separation a from the vertical plane P, but extending in the opposite direction. In this way, it is likely that the horizontal components of tensile forces applied through the second cables  116  to the duct D are substantially equal and opposite. 
     In this particular embodiment, the horizontal angular separation a of each of the four second cables  116  from the vertical plane P is equal. In this embodiment, this angular separation is approximately 45°. This has the benefit of facilitating installing the system  10  such that the tensile loads in the second cables  116  is substantially equal when the building is in a stable condition. 
       FIGS. 5 and 6  show a system  210  for supporting a non-structural building component beneath a soffit S of a building, the system  210  being in accordance with a third embodiment. In  FIGS. 5 and 6 , the component is a section of cable tray T in which data and/or electrical cables can be laid. The system  210  is substantially similar to the system  10  of  FIGS. 1 to 3 , and like components of the system  210  have the same reference numeral with the prefix “2”. 
     The system  210  differs from system  10  in that it includes two first tether members  240  (shown in  FIG. 6 ) to which the lower ends of the first cables  114  are secured. There is one first tether member  240  on each side of the cable tray T. The system  210  also has two second tether members  240  to which the lower ends of the second cables  216  are secured. 
     In this particular example, the two first tether members  240  are integral with the cable tray T, and the two second tether members  242  are separate components that are secured by fasteners to the tray T. Also in this particular example, the tether members  240 ,  242  are eyelets through which the respective first or second cable  214 ,  216  passes. 
     In this embodiment, in each suspension assembly  212 , the free end of the first cable  214  is secured to the portion of the first cable  214  that extends between the respective anchor  218  and eyelet  240 . To this end, a swagable clamp  244  can be used. 
       FIG. 7  shows a system  310  for supporting a non-structural building component D beneath a soffit of a building, the system  310  being in accordance with a third embodiment. The system  310  is substantially is substantially similar to the system  10  of  FIGS. 1 to 3 , and like components of the system  310  have the same reference numeral with the prefix “3”. 
     The system  310  is similar to the system  110  in that each suspension assembly  312  has two second cables  316 . 
     The system  310  is also similar to the system  210  in that each suspension assembly  312  has two tether members  342  to which the lower ends of the respective two second cables  316  are secured. In each suspension member  312  the point at which the two tether members  342  are attached to the building component D at a common location. In some alternative embodiments, the second cables in each suspension assembly may be secured to a common tether member. However, it will be appreciated that some further alternative embodiments, each suspension assembly may be arranged with tether members that are spaced apart. 
     In  FIG. 7 , the location of a vertical plane that is coincident with the first cables (which are not visible in  FIG. 7 ) is indicated by dashed line P. As will be appreciated, in this particular embodiment, the horizontal angular separation a of each of the four second cables  116  from the vertical plane P is equal. In this embodiment, this angular separation is approximately 45°. 
       FIGS. 8 to 13  illustrate steps in a method according to an embodiment of the invention, the method being for installing a system for supporting a non-structural building component (not shown in  FIGS. 8 to 13 ) beneath a soffit of a building. This example method is described in reference to an embodiment that is substantially similar to the system of  FIG. 1 , with reference to the components of one of the two suspension assemblies  12 , the strut  26 , and the tie  30  and clamp  32 . Accordingly, the reference numerals of  FIGS. 1 to 3  have been adopted for like components of the system. In this example, the method includes the steps of securing a plurality of suspension assemblies to structural portions of the building, and securing the non-structural building component to the suspension assemblies. 
     More particularly, securing each suspension assembly to structural portions of the building can involve:
         Step 1: securing the upper end of a first elongate non-rigid member to a structural portion of the building at a first location, the first location being selected such that, in the installed system, the first elongate non-rigid member is oriented substantially vertically;   Step 2: securing the upper end of at least one second elongate non-rigid member to a structural portion of the building at a second location that is spaced horizontally spaced from first location;   Step 3: securing the lower end of first elongate non-rigid member to one of: the non-structural building component, or a support member to which the non-structural building component is secured;   Step 4: securing the lower end of second elongate non-rigid member to one of: the non-structural building component, or a support member to which the non-structural building component is secured, whereby in the installed system, the second elongate non-rigid member is inclined to vertical; and   Step 5: setting the tension in the second elongate non-rigid member such that the tensile force in the first elongate non-rigid member is greater than the vertical component of the tensile force in the second elongate non-rigid member.       

       FIG. 8  illustrates Step 1, which in this embodiment more particularly involves embedding a stud-type anchor  18  in the soffit S, the anchor  18  is swaged onto the end of a first cable  14 . 
       FIG. 9  illustrates Step 2, which in this embodiment more particularly involves embedding a masonry bolt  20  in the soffit S, securing eyelet  22  to the bolt  20 , and—in this example—passing the second cable  16  through a second hole in the eyelet and swaging the nearest free end to the cable  16  to form a loop. 
       FIG. 10  illustrates a step of securing the building component to a strut  26 , which involves passing the tie  30  over the building component and attaching the ends of the tie  30  to the strut  26  using one or more clamps  32 . 
       FIG. 11  illustrates Step 3, which in this embodiment more particularly involves securing the lower end of the first cable  14  to the strut  26  using a clamp  28 . In this particular example, this process also involves securing eyelet  34  to the end of the strut  26 . 
       FIGS. 12 and 13  illustrate Step 4, which in this embodiment more particularly involves passing the second cable  16  through a first passage in cleat  36 , through a hole in eyelet  34 , and through a second passage in cleat  36 , thereby forming a loop in the second cable  16 . 
     Step 5 can involve pulling the free end of the second cable  16  shown in  FIG. 13  to set the tension in the second cable  16 . In at least some embodiments, this step may involve pulling on the free end of the second cable  16  to take up slack in the second cable  16 . Alternatively or additionally, this step may involve pulling on the free end of the second cable  16  to “hand tight”. 
     In this particular embodiment, the cleat  36  includes screws that can be tightened to lock the position of the second cable  16  in position within the passages of the cleat  36 . 
     It will be appreciated that the above described steps are to be repeated for all like suspension assemblies. Adjustment and/or modification to these steps will be identifiable for alternative embodiments. 
     In the embodiments described in reference to the Figures, the upper ends of the first and second elongate non-rigid members are secured to a soffit of a building using anchors or fasteners that are embedded in the material of the soffit. It will be appreciated that other securing methods may be adopted. By way of non-limiting example, in some non-illustrated embodiments, the first and/or second elongate non-rigid members may be cable (or the like) that is looped or otherwise secured to a structural component (such as a joist, beam, or truss) of the building. 
     It will be appreciated that embodiments of the system may include suspension assemblies of different form that support a common non-structural building component. 
     Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. 
     The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.