Abstract:
Members formed from thermally conductive components which have a gap therebetween. The gap is bridged and the conductive components integrated into a composite member by a reinforced polymer. This provides a thermal break which inhibits the flow of heat between the conductive components of the member. This construction also blocks the transfer of sound and other vibrations between the conductive components of the member. The construction also mitigates the formation of condensation on an artifact fixed to one of the components.

Description:
TECHNICAL FIELD OF THE INVENTION  
         [0001]    The present invention relates to novel, improved members with features which inhibit the transfer of heat from one edge of the member to another. These features also inhibit the transmission of sound and other vibrations and mitigate the formation of condensate.  
           [0002]    One important application of the principles of the present invention is found in the provision of heat and vibration transfer resistant structural members for steel framed buildings, and what follows will be devoted primarily to that application of the invention. It is to be understood that this is being done for the sake of clarity and convenience and is not intended to limit the scope of the appended claims.  
         BACKGROUND OF THE INVENTION  
         [0003]    Buildings and other structures with exterior walls, ceilings, floors, and/or roofs framed from steel components are ubiquitous because of the superior physical properties of steel vis-a-vis wood, concrete, and other building materials and because steel components commonly prove more economical because less material is used. One particularly significant disadvantage of such structural members is that they transfer heat from the interior of the building in which they are found to its exterior and in the opposite direction. Sound and other vibrations are transferred with equal facility.  
           [0004]    This minimally inhibited transfer of heat is deleterious because it can result in the spreading of fire. And, in less severe instances, the transfer of heat through the steel members can result in an expensive loss of heat from the building in which they are found and/or can increase air conditioning costs by allowing the transfer of heat from the ambient surroundings to the interior of a building.  
           [0005]    Different approaches to the problems dealt with in the preceding paragraphs have been proposed if not actually used. One is to configure a building component, in this case a stud, such that stagnant air pockets are formed between the exterior/interior edges of the stud and inner/outer panels covering the pocket-defining surfaces of the component. The just-described solution to the thermal isolation problem is disclosed in U.S. Pat. No. 4,235,057 issued Nov. 25, 1980.  
           [0006]    The Executive Summary of the 1999 North American Steel Framing Alliance Business Plan (page 4A) suggests, in the abstract, the use of “greater thicknesses of cavity/wall insulation and/or exterior rigid board insulation to provide a thermal break.” On page 9A of the Executive Summary, the authors recognize that there is a need for improved thermal performance. This need persists to the present day.  
         SUMMARY OF THE PRESENT INVENTION  
         [0007]    A novel, cost effective solution to the heat transfer problem has now been discovered and is disclosed herein. Specifically, members embodying the principles of the present invention are composed of two (or more) components with a gap tberebetween. This gap is spanned, and the components of the member joined into a heat transfer resistant composite, with a thermally insulating, high strength, reinforced polymer. This inhibits the transfer of heat (or sound or other vibrations) from one component of the member to another. The result is a structural member which is strong and cost effective and which satisfactorily inhibits the transfer of heat and audible (and other) vibrations.  
           [0008]    The reinforced, polymeric material may be bonded to the metallic elements of the structural member in any desired manner. For example, there are a number of sheet type adhesives which can be used for that purpose.  
           [0009]    Other advantages of a member embodying the principles of the present invention are:  
           [0010]    The formation of condensate on artifacts attached to the members is inhibited.  
           [0011]    The members can be spaced further apart in a wall, ceiling, roof, etc. than comparably employed members fabricated from a material such as wood (typically 24 ins. on center versus 16 ins. on center for wall studs, and 48 ins. versus 24 ins. on center for roof trusses);  
           [0012]    Structural members as disclosed herein can be easily designed by conversion and extrapolation of the dimensions, shapes and other properties of structural members fabricated from materials such as wood;  
           [0013]    In many instances involving roof trusses, the commonly employed plywood underlayment is not required;  
           [0014]    The composite structural members are non-flammable when a fire retardant is employed, are in large part made of recyclable materials (such as steel), and do not give off toxic fumes when heated;  
           [0015]    All radiuses are easily formed;  
           [0016]    The herein disclosed members are lighter and stronger than many members of other materials and configurations; and they have superior resistance to seismic disturbances and to high winds, of which hurricanes are one example; Also, they are resistant to condensation.  
           [0017]    Such members don&#39;t shrink, rot, warp, creep, split, bow, buckle, twist, or creak under load; and they are immune to attacks by ants and other insects and vermin.  
           [0018]    Because of the just-described properties, buildings employing these structural members typically may not require servicing to correct structural defects, and the cost of insurance may be lower.  
           [0019]    Members embodying the principles of the present invention have a high degree of integrity, and construction of structures such as buildings is facilitated by such members;  
           [0020]    Yet another advantage of the present invention is that its principles may easily be employed in products other than building components—for example, in turbine engine inlet filters.  
           [0021]    Another advantage of the present invention is that batts and other preformed units of insulation can be used instead of the ubiquitous foamed and blown insulation although a foam or blown insulation can be employed if one so desires.  
           [0022]    The objects, features, and advantages of the present invention will be apparent to the reader from the foregoing and the appended claims and from the accompanying drawings taken in conjunction with the accompanying description. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]    [0023]FIG. 1 is a partial perspective of a building framework; the framework has steel sills, studs, stud cap, ceiling joists, and rafters, all embodying the principles of the present invention;  
         [0024]    [0024]FIG. 2 is a perspective view of a structural member which embodies the principles of the present invention and which can be employed in the framework of FIG. 1;  
         [0025]    [0025]FIG. 3 is a cross sectional view of the structural member shown in FIG. 2.  
         [0026]    [0026]FIG. 4 is an exploded view of the FIGS. 2 and 3 structural member;  
         [0027]    FIGS.  5 - 8  (and FIG. 4) illustrate different configurations of holes that may be provided in the member&#39;s components to reduce the weight of the member, to provide a way in which thermal insulation elements or opposite sides of the webs may be brought into contact to bond the two components together, to impede the transfer of heat and vibrations from one member component to another; and to impede the condensation of moisture;  
         [0028]    [0028]FIG. 9 is an exploded view of a second embodiment of the invention in which a thermal plug is employed to provide a thermal break between two components of a member;  
         [0029]    [0029]FIG. 10 is a section through the member depicted in FIG. 9;  
         [0030]    [0030]FIG. 11 is a perspective view of yet another embodiment of the present invention; in this embodiment a fiber-reinforced thermal break with reinforcing strands oriented at right angles to the flow of thermal energy is employed to provide a thermal break between two elements of a structural member in accord with the principles of the present invention; this figure also shows an asymmetric, often preferred location of the thermal break between inner and outer edges of the member;  
         [0031]    [0031]FIG. 12 is a section through the member of FIG. 11; this figure shows more clearly a preferred orientation of the reinforcing strands (or rovings) in a plug located in the gap between first and second components of the member;  
         [0032]    [0032]FIG. 13 is a plan view of a structural member embodying the principles of the invention which is aperatured to accommodate pipes, electrical conduits, and the like;  
         [0033]    [0033]FIG. 14 is a perspective view of the FIG. 13 component;  
         [0034]    [0034]FIG. 15 is a schematic view of a line for manufacturing a perform of a structural member embodying the principles of the present invention; and  
         [0035]    [0035]FIG. 16 is a schematic view of a line for converting a perform such as the one outputted by the FIG. 15 manufacturing line to a structural member of specific configuration, the structural members outputted from the FIG. 16 manufacturing line embody the principles of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0036]    The discussion which follows deals with multiple embodiments of the invention. To the extent that components of these embodiments are alike, they will be identified by the same reference characters.  
         [0037]    Referring now to the drawings, FIG. 1 depicts a steel building framework  20 . This framework is made up of a sill  22 , vertical studs  24 , and a top plate  26 , or cap, supporting ceiling joists  28  and rafters  30 . Framework components  22 ,  24 ,  26 , and  30  embody, and are constructed in accord with, the principles of the present invention; and rafters  28  may be so constructed as to embody those principles.  
         [0038]    A representative one of the structural components depicted in FIG. 1 is illustrated in FIGS. 2 and 3 and identified by reference character  32 . Structural member  32  has two, substantially identical, mirror image-related, thermally conductive, vibration transmitting (typically steel) components  34  and  36  with a gap  38  therebetween. A third, insulating component  39  spans this gap, integrating the components  34  and  36  into an integral structure and providing a thermal break between components  34  and  36 . This break minimizes the flow of heat between components  34  and  36 . It also attenuates sound and other vibrations and makes panels or other artifacts attached to structural number  32  less susceptible to condensation.  
         [0039]    As indicated above, the configuration and other characteristics of the two structural number components  34  and  36  are essentially identical. Therefore, in the ensuing description of those components, common features will be for the most part identified by the same reference characters with the suffixes L and capitol R being employed to identify the left-hand and right-hand components  34  and  36  of structural member  32  with that member oriented as shown in FIGS. 2 and 3.  
         [0040]    As shown in FIGS. 2 and 3, each of the components  34  and  36  has a flat, web forming segment  40 , an integral flange segment  42  oriented at right angles to element  40 , and an also integral, inturned lip  44  extending at right angles from the exposed edge  46  of flange  42 .  
         [0041]    The insulating component  39  of structural member  32  is fabricated from two separate layers (or pads)  48  and  50  of an insulating material. In the manufacture of a representative structural member  32 , these elements are fused together into a single entity (component  39 ) which is located in the gap  38  between the web-forming segments  40 L and  40 R of components  34  and  36  and laps onto the web-forming elements  40 L and  40 R of components  34  and  36 .  
         [0042]    At the present time, the preferred insulating material is TWINTEX, a material woven from multistrand rovings of a polypropylene and glass fibers. TWINTEX is available from Vetrotex America, Maumee, Ohio.  
         [0043]    TWINTEX is an effective thermal insulator. It also has the advantage of being stronger than steel. Therefore, the strength of a structural member is not reduced by using that material to bridge the gap between adjacent components of that member. The TWINTEX material is 30 to 40 percent polypropylene and 70 to 60 percent fiberglass reinforcement.  
         [0044]    The reinforcing glass fibers of the composite materials described above conduct heat to some extent. Consequently, it may be advantageous to fill the gap between the two components of a structural member as disclosed herein with a material which des not contain glass or other thermally conductive components. Urethane foams useful for this purpose are available from a variety of manufacturers. Such a strip is employed in structural member  32 . This strip is shown in FIG. 4 and identified by reference character  52 .  
         [0045]    As shown in FIG. 4, holes (identified by reference character  56 ) maybe be punched or otherwise formed in the apposite segments  40 L and  40 R of the two components  34  and  36  of structural member  32 . In the manufacture of the structural member, components  34  and  36  and the thermal insulation component  39  are heated to a temperature at which the polymeric constituent of the break-providing, thermal barrier material  39  flows in a manner akin to that of a high viscosity fluid into the aperture  56  along with the fibers embedded in that constituent of the insulating material. This creates multiple bonds between the two layers  48  and  50  of the fiber reinforced, thermoplastic material shown in FIG. 4, anchoring the two layers to each other and to the component segments  40 L and  40 R. These holes may be round (FIG. 4), elliptical (reference character  62  in FIG. 5) or, in many instances, may more effectively be of a polygonal configuration such as those square holes identified by reference character  64  in FIG. 6 and the triangular holes identified by reference  66  in FIG. 7. Another effective hole shape is the raceway configuration identified by reference character  68  in FIG. 8. Other configurations may of course be employed.  
         [0046]    Continuing with the drawings, FIGS. 9 and 10 depict, in fragmentary form, an installation  73  in which exterior and interior panels  74  and  75  are attached to opposite edges of a structural member  77  embodying the principles of the present invention. The arrangement shown in FIGS. 9 and 10 has the advantage that the spaces such as  78 L and  78 R between exterior and interior panels  74  and  75  can be filled with batts and other modules of insulation identified by reference characters  79 - 1  and  79 - 2  in FIG. 10. Of course, these spaces can instead be filled by blowing the insulation into spaces such as  78  and  79  or by foaming the insulation in those spaces, etc.  
         [0047]    Referring still to FIG. 10, another advantage of the structural members disclosed herein is that, when temperatures fall, the transfer of heat from interior panel  74  to exterior panel  75  is significantly impeded. The result is that, under many, if not all conditions, the condensation of moisture (or sweating) on interior panel  74  is significantly reduced if not entirely eliminated.  
         [0048]    Irrespective of the shape of the openings, they are preferably arranged in two staggered rows to reduce the transfer of thermal energy from one structural member component to another. This lengthens the paths along which thermal energy and vibrations are conducted, decreasing the ability of the structural member components in which the anchoring holes are formed to transfer thermal energy and vibrations.  
         [0049]    [0049]FIGS. 11 and 12 depict a structural member  80  which embodies the principles of the present invention and in which the transfer of heat from one to the other of the two structural member components  34  and  36  is inhibited by orienting the parallel strands  81  of insulating material  82  in the gap  38  between the apposite edges  39 L and  39 R of structural component segments  40 L and  40 R at right angles to the longitudinal axis  83  of structural member  80 . As discussed above, the transfer of thermal energy from one to the other of the structural member components  34  and  36  spanwise of the element  81  is significantly slower than the transfer of heat lengthwise of those elements. Therefore, the FIGS. 11 and 12 strand orientation is preferred for insulating materials which have only (or a considerable portion) parallel strands.  
         [0050]    Structural member  80  also has layers (or on coatings)  87  and  88  of fire retardant on the exposed faces  89  and  90  of thermal barrier component  82 . A fire retardant used when the polymeric material of the insulation material is not flame proof.  
         [0051]    As discussed above, superior performance can often be obtained by locating the thermal break-providing gap and insulation closer to an exterior wall end of the structural member than the inner wall. A structural member of the character just described is the structural member  80  illustrated in FIGS. 11 and 12. The thermal break gap  84  of structural member  80  is much nearer to the exterior wall supporting face  85  of structural member component  34  than it is to interior wall supporting face  86  of structural member  36 .  
         [0052]    As discussed above, it is conventional for pipes, electrical conduits, pipes, and the like to be routed through the structural members of a building&#39;s framework. A structural member with an opening provided for this purpose is depicted in FIGS. 13 and 14 and identified by reference character  92 . As is best shown in FIG. 14, the hole  94  provided for the purposes just described is formed in any convenient fashion through the structural member components  34  and  36  and the third, thermal break-providing component  39  of structural member  32  of FIG. 10. As best shown in FIG. 14 a bushing  95  having a cylindrical barrel  96  and an integral, radially extending lip or flange  97  may optionally be installed in the opening  94  with the flange  97  of the bushing locating the bushing in the arrow  98  direction relative to the thermal break-providing component  39  of the structural member. This bushing adds to the structural member strength that may be lost by forming the necessarily fairly large hole in the structural member. Also, the insert isolates elements threaded through and in the hole from the usually rough edges of the hole, thereby protecting such elements from damage.  
         [0053]    Referring still to the drawings, FIGS. 15 and 16 depict two manufacturing lines which may be employed in conjunction to fabricate structural members of the character described above. These manufacturing lines are respectively identified by reference character  100  (FIG. 15) and reference character  102  (FIG. 16)  
         [0054]    In manufacturing line  100  a strip of metal  104  (steel in the above-discussed exemplary application of the invention) is fed from an unwind roll  105  to a work station identified generally by reference character  106 . Strips  108  and  110  of TWINTEX or other selected insulating material are fed from unwind rolls  112  and  114  past idler rolls  116  and  118  to work station  106  on opposite sides of steel strip  104 . At the same time, an adhesive film is fed through the work station  106  on both the top and bottom sides of strip  104  and between that strip and thermal insulation strip  108  and between steel strip  104  and thermal insulation strip  110 .  
         [0055]    For the sake of clarity, only one of the adhesive film supply arrangements is shown. This supply arrangement comprises unwind roll  119  and idle-roll  120 ; and the strip of adhesive is identified by reference character  121 .  
         [0056]    At the upstream end of work station  106 , a sandwich  122  of two thermal insulation strips  108  and  110 , two adhesive films, and steel strip  104  is created, This sandwich is fed in the arrow  123  direction first to a belt type heating unit  124  and then to a chilling unit  126  of similar construction. In heating unit  124 , the adhesive films (only one of which is depicted) are heated to a temperature high enough for the adhesive to bond the strips of thermal insulation  108  and  110  to the opposite sides of steel strip  104 .  
         [0057]    At the same time, the polymeric matrix of the thermal insulation strips softens and is displaced along with its complement of reinforcing fibers into the gap between the two components  34  and  36  of the structural element  32  as shown in FIG. 3. The result is a H-section, thermal break-providing body of insulation. The edge segment of structural member element  40 L is captured (or encapsulated) by two legs  130  and  132  of the insulating material. The other two legs  134  and  136  of the insulating material encapsulate complementary structural component element  40 R, and the insulation material in the bar  134  of the H fills the gap  38  between the two structural component elements  40 L and  40 R (See FIG. 3).  
         [0058]    The sandwich  122  of bonded together insulating and steel members  104 ,  108 , and  110  (See FIG. 15) then passes to cooling unit  126 . Here, the polymeric matrix of the fused together layers of steel and thermal insulating material is cooled to solidify and permanently bond the insulating layers to the metallic substrate. From the cooling unit the sandwich  122  of now bonded together layers is fed in the direction indicated by arrow  123  to a rewind roll  143  where the sandwich is wound on a mandrel  144 .  
         [0059]    Optionally as shown in FIG. 15, the sandwich  122  of fused together layers may be fed to a work station  146  before sandwich is wound on rewind roll  144 . At station  146 , nozzles  148  and  150  spray a fire retardant such as antimony trioxide on the two, exposed surfaces of the sandwich.  
         [0060]    Alternatively, the fire retardant can be in strip form as indicated by reference character  151  and  152  in FIG. 15. Strips  151  and  152  are supplied from unwind rolls  153  and  154  in a work station  155 . Press rolls  156  and  157  securely bond the fire retardant strips to sandwich  122 .  
         [0061]    An alternative to the above-discussed fire retardant coating is to employ an insulation tape or the like in which the fire retardant is incorporated in the insulating material. Indeed, there may be applications in which a combination of incorporated fire retardant and a fire retardant coating can be employed to advantage.  
         [0062]    For some applications, the application of the thermal insulation to only one side of the structural member components may be sufficient. Preforms for such members can be manufactured on a line as illustrated in FIG. 15 with the bottom side thermal insulation unwind roll  114  and the companion adhesive unwind roll (not shown) inactivated or deleted.  
         [0063]    As discussed above in conjunction with FIGS. 11 and 12, it is generally preferred that the thermal break between components making up a structural member embodying the principles of the present invention be nearer an exterior wall segment of the structural member than it is to the interior wall defining segment of the structural member. The FIG. 15 manufacturing line can be used where the thermal break gap (for example, gap  38  in FIG. 3) is symmetrically located with respect to the span of the structural component  32 . However, if the gap  38  is asymmetrically located (FIGS. 11 and 12) the location of the thermal insulation layers (reference character  156  in FIG. 3) will cause the sandwich of thermal insulation layers and steel substrate to run off of the mandrel of rewind roll  144  when the sandwich is rewound.  
         [0064]    Next, sandwich  162  is split into structural member blanks or performs  172 ,  174 , and  176  by the knives  178  and  180  of work station  182 . The performs are each wound on a roll such as  184 , unwound from that roll, formed to shape in work station  186  and cut to length by the knife  188  of work station  190 .  
         [0065]    In this circumstance, the manufacturing line  102  shown in FIG. 16 may advantageously be used to avoid the runoff problem. In this instance, an unwind roll  160  corresponding to the rewind roll  144  of manufacturing line  100  is employed. The thermal insulation/steel substrate sandwich  162  wound on roll  160  is fabricated in essentially the same manner as sandwich  122  (FIG. 15) except that the insulating material is so laid down as to span gaps (not shown) between substrate strips  164  and  166 , substrate strips  166 , and  168 , and substrate strips  168  and  170 , of the sandwich or perform  162 . This balances the sandwich  162 , keeping it from running off of unwind roll  160  as might happen in the case of a single, sandwich  122  with an asymmetrically located gap.  
         [0066]    The reader will be aware that there are many applications in which the principles of the present may be employed to advantage in addition to those named above. For example, the material from which the structural member core is formed need not be steel, but may instead be brass, copper, or another alloy or metal or a non-metallic material, and the thermal barrier may be formed from a material other than the fiber reinforced polymeric material and polyurethane foam identified above. Therefore, the presented embodiments of the invention are to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description; and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.