Abstract:
An insert for I-joist web holes provides support and separation for piping, tubing and/or cabling guided through the installed I-joist&#39;s web. At the same time, the insert protects the web hole against destructive forces commonly related to the installation process and/or gravitational loads of piping, tubing and/or cabling.

Description:
PRIORITY CLAIM  
       [0001]     The present invention claims priority to U.S. Provisional Application of the same title and inventor, Application No. 60/552,326, filed Mar. 10, 2004, which is hereby incorporated by reference.  
       CROSS REFERENCES  
       [0002]     The present invention cross references and incorporates by reference U.S. Pat. No. 6,857,831, filed Feb. 27, 2004, titled “I-joist Hole Cutting Apparatus” and U.S. application Ser. No. 10/410,505, filed Apr. 8, 2003, titled “Buckling Opposing Support for I-joist”, both of the same inventor as in the present application. 
     
    
     FIELD OF INVENTION  
       [0003]     The present invention relates to web inserts for I-joists. More particularly, the present invention relates to web inserts for supporting tubing, piping, cables and the like commonly installed across web holes of wooden I-joists in architectural constructions.  
       BACKGROUND OF INVENTION  
       [0004]     I-joists referred in the following and in the context with the present invention are made from wood and wood like materials. I-joists become increasingly popular in architectural construction due to their high load carrying capability and their low weight, as well as their inexpensive fabrication and their good workability. I-joist&#39;s high gravitational load carrying capability is provided by a large height to width ratio with a thinned central web portion connecting the top and bottom chord. Top and bottom chords are mainly exposed to tensile or compressive loads in grain direction of naturally grown wood, whereas the web has to withstand tensile, compressive and shear loads in varying combination. Because of the webs&#39; diverse load exposure and its relatively large height, webs are commonly fabricated from omni directionally laminated veneers or wood fiber patches. The I-joist is a multi material structural element with two sets of materials of quite diverse composition and physical properties bonded together along the interfaces between top and bottom chords and their respective central webs.  
         [0005]     Maintaining the structural integrity of the bonding interface between web and chords is crucial for the I-joist&#39;s load carrying capability. I-joist manufacturers provide therefore standards for maximum web hole sizes and minimum remaining intact web structure height along the bonding interface. A practicable fabrication of web holes in accordance with such web hole standards is provided by a web hole cutting apparatus, the patent for which is incorporated by reference. Irrespective a proper cutting, the web hole may still suffer damage during the consecutive installation of pipes, tubes, and cabling at the construction site. Particularly sensitive is the bottom portion of the web hole due to its exposure to the gravitational loads of the through guided elements. Therefore, there exists a need for a structural element protecting the web hole against damage during installation and/or gravitational loads of piping, tubing, cabling and the like guided through that web hole. The present invention addresses this need.  
         [0006]     In an installed I-joist, web area is limited for cutting web holes. As a common result, a multitude of pipes, tubes and/or cables tend to be cramped through a single web hole. The resulting friction between the individual through guided elements may cause excessive lateral loads on the web, which in turn may increase the I-joist&#39;s buckling risk at the already weakened web hole location. Therefore, there exists a need for a structural element that keeps individual through guided elements separated and spaced within a single web hole. The present invention addresses also this need.  
       SUMMARY  
       [0007]     An I-joist having a standardized hole cut in the vertical web portion between its top and bottom chord may be combined with an insert correspondingly shaped to the dimensional standards of the I-joist and the cut hole. The insert provides clustered cutout contours for positioning and holding various through guided elements such as tubing, piping, cables and the like commonly installed across I-joists in architectural constructions. The insert may be snapped on the I-joist, screwed on, nailed on, attached with a countering thread ring and/or in combination with an I-joist support. The insert may be preferably fabricated from plastic  
         [0008]     The insert is an easy to handle and easy installable element that in combination with standardized cut web holes provides guiding and support across I-joists in accordance with specialized needs of plumbers, electricians and the like.  
     
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0009]      FIG. 1  shows a first perspective view onto the front of a first exemplary insert assembled on an I-joist portion.  
         [0010]      FIG. 2  shows a second perspective view onto the back of an exemplary insert and I-joist portion of  FIG. 1 .  
         [0011]      FIG. 3  shows the second perspective view onto the back of a second exemplary insert assembled on an I-joist portion.  
         [0012]      FIG. 4  shows the second perspective view onto the back of a third exemplary insert assembled on an I-joist portion.  
         [0013]      FIG. 5  shows the second perspective view onto the back of a fourth exemplary insert assembled in combination with a first exemplary thread flange on an I-joist portion.  
         [0014]      FIG. 6  depicts the first perspective view of the first exemplary thread flange of  FIG. 5 .  
         [0015]      FIG. 7  depicts the first perspective view of a second exemplary thread flange.  
         [0016]      FIG. 8  depicts the second perspective view of the fourth exemplary insert of  FIG. 5 .  
         [0017]      FIG. 9  depicts the second perspective view of a fifth exemplary insert.  
         [0018]      FIG. 10  shows the second perspective view onto the back of a sixth exemplary insert assembled in combination with an exemplary I-joist support on an I-joist portion. 
     
    
     DETAILED DESCRIPTION  
       [0019]     An I-joist  10 , a portion of which is depicted in the Figures, may be combined with an insert  20 A- 20 F in various configurations and eventual combination with other structures, such as attachment pins  30  as in  FIG. 1 , thread flange  40 A,  40 B as in  FIGS. 5-7  and/or an I-joist support  50  as in  FIG. 10 . Attachment pins  30  may be nails, screws and the like well known in the field of architectural construction. The insert  20 A- 20 F provides at least one cutout contour  25  for guiding at least one of a pipe, a tube, and a cable through the web hole  13  without direct contact between the web hole  13  and said at least one of a pipe, a tube and a cable, such that the web hole  13  edges are protected against inadvertent damaging.  
         [0020]     According to  FIG. 1 , a first exemplary embodiment of an insert  20 A may have a flange  21  for snuggly contacting the web portion  13  of I-joist  10 . The flange  21  may have a circumferential contour that at least partially complies with at least one of the bottom chord  11  and the top chord  12  in assembled position such that a distinct orientation of the insert  20 A with respect to the I-joist  10  may be warranted. The flange  21  contour may also substantially comply with the web height WH and may have a primary chord rest  211  at least partially corresponding to an inside contour of at least one the two chords  11 ,  12 . The flange  21  may also feature attachment holes  22  positioned on the flange  21  in a radially outward distance to the fit ring  28  providing sufficient spacing to the edge of the web hole  14  to prevent splitting of the web due to an eventual wedging effect of attachment pins  30  driven into the solid web  13 . The insert  20 A may be attached at the web  13  via attachment pins  30  shown in  FIG. 1  in assembly approach.  
         [0021]     Inserts  20 A- 20 F may feature cutout contours  25  in varying configurations and spacing as may best accommodate the particular needs for installing tubes, pipes, wiring and the like through guided elements commonly employed in architectural constructions. The cutout contours  25  are densely arrayed to provide support and positioning for such through guided elements in tight clusters. At the same time, the cutout contours  25  provide spacing preferably in compliance with well known building codes and the like.  
         [0022]     In the example of insert  20 A, the cutout contours  25  are substantially square except peripheral cutout contours  25  limited by the surrounding fit ring  28  as shown in  FIG. 2 . Also, for the insert  20 A, the cutout contours  25  extend all the way up to the ribs  26 . The ribs  26  enforce the cutout contours  25  by providing structural support of and load transfer from the cutout contours  25  towards attachment features and interface features of the inserts  20 A- 20 F such as the flange  21 , fit ring  28  and load rest  27 . The ribs  26  support against gravitational loads of the guided through elements as well as against eventual other loads commonly associated with imperfect assembly conditions of the through guided elements. The cutout contours  25  may be concentrically arrayed with respect to the fit ring  28  as shown in  FIGS. 3-5  and  8 - 10 . Alternately, the cutout contours  25  may be linearly arrayed as illustrated in  FIGS. 1, 2 .  
         [0023]     The fit ring  28  is adjacent the flange  21  and may comply with its outside contour to the hole diameter HD of the standardized web hole  14  for positioning the insert  20 A- 20 F within the web hole  14 . Such web hole  14  may be cut into the web  13  via a specialized tool that cuts the hole with diameter HD and with a predetermined chord offset OF from at least one but preferably both of top chord  12  and bottom chord  11 . Such specialized tool may one as described in the cross referenced patent titled “I-joist Hole Cutting Apparatus”. Hole diameter HD and chord offset OF are preferably predetermined in accordance with well known static and other safety criteria well known for I-joists employed in architectural constructions.  
         [0024]     The inserts  20 A- 20 F are preferably dimensioned in accordance with standardized hole diameter HD and chord offset OF for an I-joist  10  of a dimensional standard characterized also by web height WH. For example, at the time of the present invention was made, there exist dimensional standards in the United States for web heights WH of at least between 4.5″ and 13.0″ with 0.5″ increment. Corresponding hole diameters HD may be about 0.5″ or 0.75″ in diameter smaller than the web heights WH making the standardized offsets OF about 0.25″ and 0.375″.  
         [0025]     Referring to  FIG. 3 , an exemplary insert  20 B may have cutout contours  25  that recess from the ribs  26  and/or are shaped independently from the ribs  26 . In the exemplary embodiment represented by insert  20 B, the cutout contours  25  may be of substantially circular shape and concentrically arrayed within the boundaries of the fit ring  28 . The ribs  26  may be arranged correspondingly in star like fashion with an optional central ring like rib portion around a central cutout.  
         [0026]     Referring to  FIG. 4 , an exemplary insert  20 C may have a number of well known snap fingers  29  resiliently attached or being a resilient portion of insert  20 C. The snap fingers  29  may be dimensioned and positioned in a well known fashion such that a full insertion of the insert  20 C in the standardized web hole  14  results in an interlocking engagement between the snap fingers&#39;  29  hook tips and the side of the web  13  that is opposite to the insertion side. The snap fingers  29  are preferably recessed into the fit ring  28  such that they fit together with the fit ring  28  within the web hole  14 .  
         [0027]     The present invention includes embodiments, in which the fit ring  28  is other than circular. Referring to  FIG. 5  and in the preferred case of a circular fit ring  28  corresponding to a circular web hole  14  as described above, an exemplary insert  20 D may be attached to the I-joist  10  at a web hole  14  via a thread flange  40 A or  40 B as shown in  FIG. 7 . In such embodiment and as is illustrated in  FIG. 8 , the insert  20 D may feature a thread ring  23  extending next to the fit ring  28 . The thread ring  23  has an outside thread corresponding to an internal thread of the thread flange  40 A. In that way, the web  13  is sandwiched between the flange  21  and the thread flange  40 A,  40 B once the insert  20 D is assembled with the I-joist  10 . The thread flange  40 A may feature a secondary cord rest  41  that may at least partially conform to an inside contour of at least one of top chord  12  and bottom chord  11 . The primary and secondary cord rests  211 ,  41  may alternately serve to oppose the rotational movement and torque between thread flange  40 A,  40 B and the insert  20 D during tightening and to eventually transfer gravitational loads from through guided elements onto the bottom chord  11 . A thread flange  40 B may feature puncture features  42  that may puncture the web  14  during tightening of the insert  20 D and prevent thereby inadvertent rotation of the thread ring  40 B. Features of thread rings  40 A,  40 B may be combined as may be well appreciated by anyone skilled in the art.  
         [0028]     Referring to  FIG. 9 , an exemplary insert  20 E may feature a cut thread  24  on the circumference of the fit ring  28 . The cut thread  24  may be configured in a well known fashion such that a rotational movement of the insert  20 E at a cut web hole  14  causes the insert  20 E to cut into the web hole  14  in a spiraling movement until the flange  21  is fully threaded into the web  13 . Friction of the cut thread  24  within the web hole  14  may assure a reliable interconnection of the insert  20 E with the I-joist  10 .  
         [0029]     Referring to  FIG. 10 , an exemplary insert  20 F may be combined with an I-joist support  50  as described in the cross referenced application titled “Buckling Opposing Support for I-joist”. I-joist support  50  may be additionally employed in cases where either the web hole  14  is inadvertently fabricated with dimensions exceeding the corresponding safety standard and/or in cases where gravitational loads received by the insert  20 F may require an intermediate load transfer and broader load distribution onto the  1 joist  10  via the I-joist support  50 .  
         [0030]     The I-joist support  50  may feature attachment holes and a chord rest  54  for a rigid interconnection between I-joist support  50  and I-joist  10  such that load carrying capacity and/or buckling resistance of the I-joist  10  is improved.  
         [0031]     Gravitational load transfer may be provided from a load rest  27  of the insert  20 F onto a correspondingly shaped central contour  51  of the I-joist support  50 . In case of a U-shaped support  50 , the load rest  27  may correspond to a central arc of the central contour  51  as illustrated in  FIG. 10 . Gravitational load transfer may also be provided via attachment pins simultaneously engaging in attachment holes  22  and correspondingly positioned insert alignment holes  53 . Regardless the exemplary illustration of  FIG. 10  and as may be well appreciated by anyone skilled in the art, the insert  20 F may feature any other elements described in the embodiments above for attachment to the web  13  and optionally in addition to the I-joist support  50 .  
         [0032]     For example, a thread ring  40 A may be shaped in correspondence to the central contour  51  and/or to the cord rest  54  such that gravitational load may be transmitted from the insert  20 D via the thread ring  40 A onto the I-joist support  50 . In that case, merely the ring  40 A may be provided in different configuration to provide combined and exclusive utilization of insert  20 D and I-joist support  50 .  
         [0033]     Inserts  20 A- 20 F are preferably monolithically fabricated from plastic. Thread flange  40 A,  40 B may be fabricated from plastic or sheet metal. I-joist support  50  may be fabricated preferably from sheet metal.  
         [0034]     Accordingly, the invention described in the specification above is set forth by the following claims and their legal equivalent: