Abstract:
Method of forming members 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. After the gap is bridged with the reinforced polymer, the member may be punched with holes and roll formed.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation-in-part of U.S. application Ser. No. 10/165,093 filed on Jun. 6, 2002 and presently allowed but not issued. 
     
    
     TECHNICAL FIELD OF THE INVENTION  
       [0002]     The present invention relates to a method of making 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.  
         [0003]     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  
       [0004]     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-à-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.  
         [0005]     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.  
         [0006]     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 25 Nov. 1980.  
         [0007]     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 INVENTION  
       [0008]     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 therebetween. This gap is spanned, and the components of the member joined in to 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.  
         [0009]     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. The disclosed method provides an efficient and economical way to produce the member.  
         [0010]     Other advantages of a member made using the principles of the present invention are:  
         [0011]     The formation of condensate on artifacts attached to the members is inhibited; 
        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);     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;     In many instances involving roof trusses, the commonly employed plywood underlayment is not required;     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;     All radiuses are easily formed;     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;     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.        
 
         [0019]     Because of the just-described properties, buildings employing these structural members typically may not require servicing to correct structural defects, and the costs of insurance may be lower; 
        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;     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.        
 
         [0022]     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.  
         [0023]     Also significant is the advantage of the method of the present invention which provides an economical and effective approach to manufacture of the members with a thermal break discussed in detail above.  
         [0024]     The object, 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  
       [0025]      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;  
         [0026]      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 ;  
         [0027]      FIG. 3  is a cross-sectional view of the structural member shown in  FIG. 2 ;  
         [0028]      FIG. 4  is an exploded view of the  FIGS. 2 and 3  structural member;  
         [0029]      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 of 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;  
         [0030]      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;  
         [0031]      FIG. 10  is a section through the member depicted in  FIG. 9 ;  
         [0032]      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;  
         [0033]      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;  
         [0034]      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;  
         [0035]      FIG. 14  is a perspective view of the  FIG. 13  component; and  
         [0036]      FIG. 15  is a schematic view of a line for manufacturing a preform of a structural member embodying the principles of the present invention.  
         [0037]      FIG. 16  is a schematic view of a line for manufacturing a preform of a structural member embodying the principles of the present invention having the cutting step after the roll-forming step.  
         [0038]      FIG. 17  is a schematic view similar to  FIGS. 15 and 16  but additionally showing a rotary punching system.  
         [0039]      FIG. 18  is a partial schematic view similar to  FIG. 17  and showing view lines A-A, and sectional lines B-B and C-C.  
         [0040]      FIG. 19  shows sectional views through lines B-B and C-C of  FIG. 18 .  
         [0041]      FIG. 20  shows a top view from lines A-A of  FIG. 18 .  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0042]     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.  
         [0043]     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.  
         [0044]     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.  
         [0045]     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 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 .  
         [0046]     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 .  
         [0047]     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 .  
         [0048]     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.  
         [0049]     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.  
         [0050]     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 does 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 .  
         [0051]     As shown in  FIG. 4 , holes (identified by reference character  56 ) may 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  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.  
         [0052]     Continuing with these 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 filed 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.  
         [0053]     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.  
         [0054]     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.  
         [0055]      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.  
         [0056]     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 is used when the polymeric material of the insulation material is not flame proof.  
         [0057]     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 if  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 .  
         [0058]     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.  
         [0059]     Referring to the  FIG. 15 , the method of manufacturing a structural member with a thermal break in accordance with the present invention can be described.  FIG. 15  shows a manufacturing line  100  moving in the direction shown by arrow  123 .  FIG. 15  shows a master coil  105  which dispenses a strip of metal, preferably steel, therefrom. The strip  104  is fed to a pair of slitters or knives  180  and  182  which slit the steel from master coil  105  into two portions lengthwise, while driving those portions forward in the manufacturing line  100 . Guides  302 A and guides  302  (farther downstream) are used to set and maintain a predetermined gap between the two portions. Before the slitted strip  104  enters the guides  302 , thermal insulation (such as TWINTEX)  108  from unwind roll  112  is placed on the top surface of the two portions of the strip  104  covering the gap between the two portions. In a similar manner, thermal insulation  110  from unwind roll  114  is fed to the bottom surface of the two portions of strip  104  covering the gap being set by guides  302 . Idler rolls  116  and  118  facilitate the placement of insulation  108  and  110 , respectively, on strip  104 . Immediately prior to the thermal insulation  108  and  110  being applied to the top and bottom of strip  104 , an adhesive film is applied to the top and bottom sides of strip  104 . This adhesive film is sandwiched between the strip  104  and thermal insulation  108  and  110  on the top and bottom sides of strip  104  and serves to ultimately bond the insulation  108  and  110  to the strip  104 .  
         [0060]     For the sake of clarity, only one of the adhesive film supply arrangements is shown. This supply arrangement comprises unwind roll  119  and idler roll  120 . The adhesive film is identified by reference character  121 .  
         [0061]     It should be noted that as an alternative to slitting a single roll of metal strip  104  into two portions, two separate rolls (not shown) of metal strip could be used. The gap between the two separate strips from the two rolls would be set by guides  302 A and guides  302 . This arrangement is not shown but can be readily appreciated. The method previously and subsequently described would be directly applicable under this configuration.  
         [0062]     At this point, a sandwich  122  of two thermal insulation strips  108  and  110 , two adhesive films  121 , and steel strip  104  is created. This sandwich is then fed to a belt type heating unit  124 . In heating unit  124 , the adhesive films (only one of which, numeral  121 , 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 .  
         [0063]     As an alternative to applying adhesive films  121  from unwind roll  119  to the strip  104 , adhesive could be sprayed from a sprayer  121 A upstream of the application of the thermal insulation  108  and  110 . The sprayer  121 A could spray either or both sides of the strip  104 .  
         [0064]     In this newly formed sandwich  122 , the polymeric matrix of the thermal insulation strips softens and is displaced along with its component 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 an 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  39  between the two structural component elements  40 L and  40 R (see  FIG. 3 ).  
         [0065]     Referring back to  FIG. 15 , the sandwich  122  of bonded together insulating and steel members  104 ,  108 , and  110  and adhesive  121  (or sprayed-on adhesive from sprayer  121 A) then passes to cooling unit or chiller  126  downstream of heating unit  124 . 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. The sandwich  122  is pinched between laminator rolls  300  and  301  as it exits the heater  124  to further assist in bonding.  
         [0066]     At this point, it should be mentioned that the length of the unwound strip  104  (now a component in sandwich  122  described above) is monitored with respect to length in a well known manner by a computer control system and encoder. This monitoring of length is important as sandwich  122  is now fed to punch press  93  which punches holes  94  into the strip  104  at predetermined locations, depending on the application. These holes  94  are also shown in  FIGS. 13 and 14 . Punching of holes  94  is done by punch press  93  and can be done with a stoppage of the processing line in a stationary manner or “on the fly”, meaning that the processing line can continually run as the holes  94  are punched. The sandwich  122  with a punched hole therein is now fed to a cutting station  190  having a cutting blade  188  which cuts the sandwich  122  having the thermal insulation bonded thereto and a hole therein into predetermined lengths. At this point in the process, the sandwich  122  is substantially flat and delivered to a roll former  186  where flanges and return lips are produced with the exiting product from the roll former  186  similar to structural member  32  as depicted in  FIG. 3 . As the now formed member  32  exits the roll former  186 , fire retardant can be applied to the upper and lower surfaces of the member  32  from nozzles  148  and  150 . The fire retardant can be, for example, antimony trioxide.  
         [0067]     As an alternative to cutting the sandwich  122  into predetermined lengths at cutting station  190  and subsequently roll forming it in roll former  186 , the sandwich can be roll formed and then cut.  FIG. 16  shows this alternative arrangement. The cutting station  190 A ( FIG. 16 ) is placed after the roller former  186 . In this application, the cutting blade  188 A would be profiled.  
         [0068]     Another alternative in the manufacture of the thermal structural member is to punch holes or apertures in the opposite marginal edges of strip  104  as it is fed to the processing line.  FIG. 17  shows a rotary punching system  305  which can be used for this purpose. Rotary hole punches  306 A and  306 B punch holes or apertures (which can be seen in  FIGS. 4 through 8 ) in the opposite marginal edges of the strip  104 . A variety of patterns can be used as discussed previously and shown in these figures. The main purpose is to allow the insulation material after application and heating to flow in a manner similar to a high viscosity fluid into the holes along with the fibers embedded in a component of the insulating material. The net effect, as discussed previously, is a superior bonding of the insulating material  108  and  110  to the strip  104 . After punching the holes, the strip  104  itself can be pre-heated in a conventional way by a pre-heater  125  to facilitate further the superior bonding.  
         [0069]     For some applications, the application of the thermal insulation to only one side of the structural member components may be sufficient. Such a finished member can be manufactured on a line as illustrated in  FIGS. 15-17  with the bottom side thermal insulation unwind roll  114  inactivated or deleted.  
         [0070]     Referring now to  FIGS. 18-20 , a guide system  302  for maintaining the gap between the first and second component of the strip  104  can be described. The guide system  302  is incorporated to the entry side of the laminating system of the present invention as best shown in  FIG. 18 . Now referring specifically to  FIGS. 19 and 20 , guide system  302  has an overhead cam support plate  400  which carries offset cam rolls  403  and  404 . Referring to  FIG. 20 , it can be seen that cam roll  403  abuts the inside edge of one portion of the strip  104 B. Cam roll  404  abuts the inside edge of the other portion of the strip  104 A. The gap between the two strips is shown as reference numeral  406 . The number of cam rolls  403  and  404  can vary, depending on the application. At least two abutting each side of the strip portions  104 A and  104 B is preferred, and as many as eight could be provided. Guide side blocks  401  and  402  work in cooperation with the cam rolls  403  and  404 . The support blocks  401  and  402  assure that the outside width of the strip portions  104 A and  104 B is maintained as best shown in the views of  FIG. 19 , both during and after the laminating process. Section CC of  FIG. 19  shows cam  404  rollingly engaging the inside edge of strip  104 B while block  402  controls the outside edge of the strip  104 B, thereby maintaining width, accuracy, and parallelism. An exit guide (not shown) could also guide the sandwich  122  as it exits the laminating process. Edge blocks similar to those shown in the views of  FIG. 19  could be used with adjustments to and away from the outside edges of the sandwich  122  allowing for various widths of sandwich  122  to be produced.  
         [0071]     The reader will be aware that there are many applications in which the principles of the present invention 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 described 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.