Abstract:
A hanger device and method for connecting together I-beams which have first and second flanges connected by a web. The hanger is constructed from a first bracket ( 20 ) having first and second side members ( 22, 24 ) and an intermediate member ( 26 ) connected between the side members which is capable of supporting a second flange of a first I-Beam. At least one second bracket ( 30 ) is provided, having first and second side members ( 32, 34 ) and an intermediate member ( 36 ) connected between the side members. The first and second side members are provided with fixing apertures ( 40   a, b   ; 60   a, b ) arranged thereon to facilitate connection of the first and/or second side members to the first and/or second flanges of a second I-beam. The first and second side members of the first bracket are connected to each of the at least one second bracket(s) at the first side member thereof and at a pre-determined angle with respect to the first side member of the second bracket.

Description:
[0001]    The present invention relates to a hanger device used to connect two members such as I-beams and having a particular application in the construction industry.  
           [0002]    It is well known within the construction industry that wooden I-beams are used as a replacement for traditional solid timber beams, and their usage is made all the more popular due to their dimensional stability (no shrinkage, cupping or distortion) and superior load-carrying capacity (spanning capability). The wooden I-beam typically consists of upper and lower flange members made of either solid or laminated wood, and a central wood-based web member (typically plywood or oriented strand board) glued centrally between these upper and lower flanges into pre-cut grooves. Examples of I-beams are shown in FIG. 1. Typically, such beams are around 25 cm from flange to flange, the flanges being around 4 cm to 6 cm wide.  
           [0003]    The wooden I-beam is an extremely efficient structural shape but the gap that exists between the central web member and the upper and lower flanges makes it difficult to connect components to them at 90 degrees. Unfortunately, the need to connect components at 90 degrees is commonplace in domestic house construction, where for example, floor or roof members need to be trimmed around stair or chimney openings as shown in FIG. 2. Indeed, almost every example of domestic house construction will require beam connections at 90 degrees to each other.  
           [0004]    To form a 90 degree connection to an I-beam requires the gap between the web and both flanges to be packed or filled with a solid material, wood for example, such that a flush surface is created of sufficient area to receive an incoming beam or other structural member. These wood-based packing pieces, provided to facilitate such a 90-degree connection, are called “backer-blocks”.  
           [0005]    Where a number of beams need to be connected to a cross-member, known as a “header”, at 90 degrees, e.g. where floor beams are trimmed around a stair opening, then multiple backer blocks or a continuous backer block will be required. Metal hangers are then used to connect the incoming beam(s) to the supporting header beam at 90 degrees. These can either be face-fixed directly to the backer block material or top-fixed to the upper flange of the I-beam where less nails are required in the backer block.  
           [0006]    Top-fix hangers are generally used for light/medium duty applications as they have limited load-transferring ability but are relatively quick and easy to install. Face-fix hangers are typically used for higher load applications, but are generally more time consuming and expensive to fit.  
           [0007]    In the case of conventional face-fix connections, multiple nails are provided through the face of the hanger into the backer block. The backer block then transfers the loads imparted by the hanger (from the incoming beam) into the central web of the I-beam and thereby into the flanges of the I-beam header.  
           [0008]    In the case of the top-fix connection, the hanger has a top flange, which sits on the upper edge of the header upper flange, in addition to side flanges. In this case nails are passed through the top and side flanges of the hanger into the upper flange of the header, as well as additional nails being provided through the side flanges into the backer block. As a significant amount of the load from the hanger is being imposed eccentrically onto one side of the header upper flange, the backer block this time helps to prevent the upper flange from rotating as well as transmitting load from the face of the backer block into the central web.  
           [0009]    However, backer blocks are rather difficult, time-consuming and costly to install in practice. Typical fixing specifications require backer blocks to be provided on both sides of an I-beam web, with 6 long nails being installed from each side with their protruding points folded (clenched) over. Experience has shown that this is one of the most common sources of on-site errors when constructing I-beam floors, due to either incorrect types or numbers of nails being used to fix backer blocks in position.  
           [0010]    A number of hangers are disclosed in the prior art. It has been found that these hangers do not address the specific problems associated with I-beams discussed above and if used to connect I-beams in the manner discussed above would require backer blocks to be used to assist in load transfer and to provide a 90 degree intersection between I-beams. Hangers of this type are more suitable for use with solid timber beams. Much of the prior art is concerned with general purpose hangers suitable for use as masonary hangers. Such hangers are not designed to be used to support I-beams and are not designed to transfer the load experienced by I-beams.  
           [0011]    It is therefore an object of the present invention to address the problems outlined above as well as being able to connect two I-beams without the need for a backer block whilst maintaining the structural properties of a beam connection.  
           [0012]    It is a further object of the present invention to provide a pre-formed unitary hanger device to any given size for use with an I-beam connection which does not require on-site forming to secure both I-beams.  
           [0013]    It is independently an object of the invention to improve upon existing hanger devices in terms of the number and arrangement of fixing apertures used for the device and the associated reduction in cost, construction time and waste materials which occurs as a result of the use of this device.  
           [0014]    In accordance with a first aspect of the invention there is provided a hanger device for connecting together I-beams having first and second flanges connected by a web, the hanger comprising a first bracket having first and second side members and an intermediate member connected between the side members, the intermediate member being capable of supporting a second flange of a first I-Beam, at least one second bracket having first and second side members and an intermediate member connected between the side members, the first and second side members being provided with fixing apertures arranged thereon to facilitate connection of the first and/or second side members to the first and/or second flanges of a second I-beam,  
           [0015]    wherein the first or second side member of the first bracket is connected to the second bracket at the first side member thereof and at a pre-determined angle with respect to the first side member of the second bracket.  
           [0016]    Preferably, at least one of the first and second side members of the first bracket are provided with fixing apertures arranged to facilitate connection of said first and/or second side member to the first and/or second flange of a first I-beam.  
           [0017]    Preferably, the fixing apertures arranged on the first and second side members of the first bracket are positioned to provide a connection to the first and/or second flange substantially in the centre of the flange, the fixing apertures located on the first side member being offset with respect to the fixing apertures on the second side member.  
           [0018]    Preferably, the intermediate member is provided with a fixing aperture located substantially in the centre thereof.  
           [0019]    Preferably, the fixing apertures of the second bracket is provided with a pair of diagonally arranged fixing apertures located on the first side member being offset with respect to a pair of diagonally arranged fixing apertures on the second side member, for connection to the first flange of a second I-beam at substantially in the centre of the flange  
           [0020]    Preferably, the fixing apertures are arranged on the first and second side members for connection to the second flange of a second I-beam, substantially in the centre of the flange, with three triangularly arranged fixing apertures located on the first side member being offset with respect to a pair of diagonally arranged fixing apertures on the second side member.  
           [0021]    Optionally, the second bracket is substantially inverted j-shaped when in use.  
           [0022]    Optionally, the second bracket is substantially inverted U-shaped when in use.  
           [0023]    Preferably, the device is formed from a single piece of material.  
           [0024]    Preferably, the hanger is constructed from metal.  
           [0025]    Preferably, the predetermined angle is substantially 90°.  
           [0026]    Preferably, the first bracket is contiguous with the second bracket.  
           [0027]    Preferably, the first bracket is integrally formed with said second bracket.  
           [0028]    Preferably, at least a part of said second bracket is pre-formed to suit the thickness of an I-beam.  
           [0029]    In accordance with a second aspect of the present invention there is provided a method of connecting I-beams each having first and second flanges connected by a web, the method comprising the steps of:  
           [0030]    providing a hanger having first and second brackets arranged at a predetermined angle with respect to one another;  
           [0031]    supporting the second flange of the first I-beam on an intermediate member connected between first and second side members of a first bracket and;  
           [0032]    connecting the first and second side members of a second bracket to the first and/or second flanges of a second I-beam, through fixing apparatus arranged thereon.  
           [0033]    Preferably, the step of connecting the first and/or second flange of the first I-beam to the first and/or second side members of the first bracket through fixing apertures arranged thereon.  
           [0034]    In accordance with a third aspect of the invention there is provided a pre-formed hanger device for distributing a load between load carrying members, said device provided with means for connecting said members, said means comprising a first bracket and a second bracket adjacent thereto, said first bracket connecting to a first member and said second bracket connecting to a second member, wherein said second bracket is contiguous with at least a front and back surface of said second member. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0035]    Embodiments of the invention will now be described, by way of example only, by reference to the accompanying drawings, in which:  
         [0036]    [0036]FIGS. 1 a ,  1   b  and  1   c  are side views of typical I-beams;  
         [0037]    [0037]FIG. 2 is a perspective view of an example of the use of I-beams in building construction.  
         [0038]    [0038]FIGS. 3 a  to  3   h  show a number of view of a first embodiment of the present invention, FIGS. 3 a  and  3   b  are perspective views of the hanger device, FIG. 3 c  is a plan view, FIG. 3 d  is a right hand side elevation, FIG. 3 e  is a left hand side elevation and FIG. 3 h  is a back elevation;  
         [0039]    [0039]FIGS. 4 a  and  4   h  show a number of views of a second embodiment of the present invention, FIGS. 3 a  and  3   b  are perspective views of the hanger device, FIG. 3 c  is a plan view, FIG. 3 d  is a right hand side elevation, FIG. 3 e  is a front elevation, FIG. 3 f  is a left hand side elevation and FIG. 3 h  is a back elevation;  
         [0040]    [0040]FIG. 5 shows a perspective view of the hanger device of FIG. 3 b  with first and second I-beams attached thereto; and  
         [0041]    [0041]FIG. 6 shows a perspective view of the hanger device of FIG. 4 b  with first and second I-beams attached thereto. 
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0042]    Referring to FIGS. 3 a  and  3   b  of the drawings there is shown the general arrangement of a first embodiment of the hanger device  10  provided in accordance with the present invention. It can be clearly seen that the hanger  10  comprises two main brackets  20 ,  30 , which are contiguously formed from a unitary sheet of material. The first bracket  20  has first and second side members  22 ,  24  and an intermediate member  26  connecting the first and second side members  22 ,  24 . In this example, the first bracket  20  is pre-fabricated to form a generally U-shaped bracket in which a first I-beam can be fitted. As can be seen in FIG. 5, the I-beam is supported by intermediate member  26  and can be further secured in the first bracket  20  by a pre-determined number of nails or other suitable fixing means through fixing apertures  40  located in the first and second side members  22 ,  24  and in the intermediate member  26 .  
         [0043]    The fixing apertures  40   a ,  40   b  and  40   c  have been provided at positions in the first bracket  20 , which have been found to provide structurally secure attachment to the I-beam  80  without causing splitting of the flanges  90 ,  92  (FIG. 5). Unlike existing hanger devices, which have a series of fixing apertures provided over the entire surface of the hanger to allow nails or other fixing means to be driven into the I-beam at just about any position felt necessary, the points selected on the first bracket for providing these fixing apertures has been found to have a highly efficient load distribution. In the example of the present shown in FIGS. 3 a  and  3   b , the fixing aperture  40   c  is provided substantially in the centre of the intermediate member  26 . Additional fixing apertures  40   a  and  40   b  are located in the upper portions of side members  22 ,  24 . In addition, the fixing apertures  40   a  and  40   b  located in side members  22 ,  24  are off-set with respect to one another, this reduces the risk that holes in the second flange  92  will cause the second flange  92  to split.  
         [0044]    These hangers are designed to distribute loads in such a way as to avoid the need for backer blocks on 90 degree connections to wood I-beams, and thereby to eliminate the associated fixing costs and sources of site error involved.  
         [0045]    The hanger  10  has an inverted j-shaped second bracket  30 , having first and second side members  32  and  34  and an intermediate member  36  as shown which can wrap around the top flange of the I-beam and fit snugly to 3 faces of it. As with the first bracket  20 , fixing apertures  60   a  and  60   b  are provided into the first side member  32 , fixing aperture  60   c  is provided in the second side member  34 . The fixing apertures are designed to receive nails or other fixing means. The position of the fixing apertures  60   a ,  60   b  and  60   c  has been set to ensure that the bracket  30  is connected to the centre of each of the I-beam flanges. In addition, the apertures  60   a  and  60   b  located on the first and second side members  32 ,  34  are off-set with respect to one another. In this example, the fixing apertures are arranged in a diagonal pattern at the top end  38  of the second bracket  30 . A single fixing aperture  60   c  being arranged at the bottom end  39  of the second flange  30 .  
         [0046]    [0046]FIGS. 3 c  to  3   h  provide details of the positioning of 4 mm fixing apertures on the hanger  10 . In this example, fixing aperture  40   c  is provided in the centre of the intermediate member  26 , 23 mm from the first side member  22 . FIG. 3 d  shows fixing aperture  40   a  positioned 20 mm from the top edge and side edge of the first side member  22  and the position of fixing aperture  40   b  on the second side member positioned 10 mm from the top edge and side edge of the second side member  24 . The position of these fixing apertures  40   a  and  40   b  is also shown in FIG. 3 f.    
         [0047]    [0047]FIG. 3 e  is a front elevation showing diagonally arranged fixing apertures  60   a , the lower apertures  60   a  being positioned 30.5 mm below the intermediate member  36  and 9 mm from the outer edge of the side member  30 , the upper aperture being positioned 14 mm below the intermediate member  36  and 25.2 mm from the outer edge of the side member  30 . The position of fixing aperture  60   b  in side member  34  is shown relative to that of fixing aperture  60   a . This fixing aperture is positioned 25 mm from the outer sides of side member  34  and 23.3 mm from the intermediate member thereof. The back elevation FIG. 3 h  also shows the fixing apertures  60   a ,  60   b  and  60   c  from the opposite side to that shown in FIG. 3 e . Fixing aperture  60   c  is 21 mm from the outer edge  52  of the side member  32  and 20 mm from the bottom edge  54  thereof.  
         [0048]    In general, the position of the fixing apertures has been selected to minimise the number of nails required as the use of nails or other similar fixing means weakens the flanges.  
         [0049]    This arrangement enables a substantial amount of load to be transferred to both the front and back faces of the I-beam top flange  192 , and the resultant even distribution of load thereby serves to delay the onset of top flange rotation without the need for a backer-block to serve the same purpose. The hanger device of the present invention is therefore capable of transmitting equal or higher loads onto supporting beams than can be transmitted by conventional top-fix I-beam hangers, without the need for backer blocks to be provided to delay the onset of top-flange header beam rotation. The associated savings in site labour time by removing the need to fix backer blocks are considerable. In addition the hanger  10  has equal or less nail fixings than a conventional top-fix I-beam hanger, and is therefore just as easy and quick to install.  
         [0050]    [0050]FIGS. 4 a  and  4   b  show a second embodiment of the present invention. Here, similar reference numerals have been used to describe previously described features. This hanger  100  uses a similar load distribution principle as the hanger  10  of the first embodiment, but the second bracket  130  is extended to be substantially an inverted U-shape. This allows connection to both flanges  194 ,  196  of a second I-beam (as can be seen in FIG. 6).  
         [0051]    The bracket  130  wraps around the top flange of the second I-beam and extends downwardly to be fixed to the lower flange of the I-beam. By nailing the hanger to both the front and reverse side of the lower flange  194  of the I-beam, the load is transferred substantially uniformly (concentrically) into the centre of the top flange  196  of the I-beam and thereby directly into its central vertical plane. The majority of the load is supported at the bottom end  139  of the second bracket. Consequently, a greater number of fixing apertures  60  are provided on the first and second sides of the bracket  132 ,  134  at this point. In this embodiment, three triangularly arranged fixing apertures  60  are located on the first side member  134  and are offset with respect to a pair of diagonally arranged fixing apertures  60  on the second side member  132 .  
         [0052]    The tendency for top flange rotation is thereby almost removed, and this phenomenon is instead transferred to a much lesser degree to the bottom flange. The rotation of the bottom flange  194  in turn is counter-acted by nailing on opposing sides of the lower flange to restrain this tendency. The resulting connection is capable of transferring loads equal or exceeding those of conventional face-fix I-beam hangers, but without the need for backer-blocks to transfer the loads from the outer face into the central web of the header. In addition, as with the previous embodiment, the hanger of FIG. 4 has less nail fixings than a conventional face fix I-beam hanger and is therefore quicker and easier to install.  
         [0053]    [0053]FIGS. 4 c  to  4   f  provide details of the positioning of 4 mm fixing apertures on the hanger  100 .  
         [0054]    In this example, the fixing aperture  40   c  is provided in the centre of the intermediate member  126 , 19.5 mm from the front thereof. FIG. 4 d  shows fixing aperture  40   a  positioned 10 mm from the top and the side edges of side member  122 . Fixing aperture  40   b  being 20 mm from the top and side edges of side member  124 . The position of fixing aperture  40   b  is shown to illustrate the relative position of these fixing apertures.  
         [0055]    These fixing apertures are also shown in FIG. 4 f.    
         [0056]    [0056]FIGS. 4 e  and  4   g  show the position of the fixing apertures on the side member  132 ,  134  of the second bracket  130 . Apertures  60   f  are arranged in a triangular formation, 16.2 mm, 30.2 mm and 33.2 mm from the outer edges  150  of side members and 25 mm, 13 mm and 33 mm, respectively, from the bottom edges. The diagonally arranged fixing apertures  60   g  are arranged 13.2 mm and 30.7 mm from the outer edges  150  of the side members and 9 mm and 18 mm,respectively, from the bottom edges  152 . The position of fixing aperture  60   g  is shown to illustrate the relative position of fixing apertures  60   g  and  60   f.    
         [0057]    While certain modifications and variations have been described above, the invention is not restricted thereto and other modifications and variations can be adopted without departing from the scope of the invention.