Patent Publication Number: US-9849963-B2

Title: Beam flange clamp, structural beam joint with beam flange clamps and method for forming a structural beam joint

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This patent application claims priority to European Patent Application 14 185 311.9 filed Sep. 18, 2014, the entire disclosure of which is incorporated by reference herein. 
     TECHNICAL FIELD 
     The present disclosure relates to a beam flange clamp, a structural beam joint using such clamps and a method for forming structural beam joint using beam flange clamps, specifically in the aerospace industry for perpendicularly running structural beams of aircraft floors, aircraft fuselage or aircraft wing boxes. 
     BACKGROUND 
     Beams, joists and frames for construction work, for example in aeronautics, civil engineering or architecture, are designed to withstand bending forces acting perpendicularly to the direction of extension of the respective beams. Conventional beams may be implemented as integral parts with flanges at the edges and a web spanning between the flanges. 
     Such beams used for building of a structural framework, i.e. structural beams, need to be connected at joint locations where beams running at an angle with respect to each other intersect. The intersecting beams need to be kept in alignment with each other, especially at those intersections—therefore, connection techniques have been developed to force-fit or friction-lock the intersecting beams with each other. 
     For example, if the beams are placed on top of each other with a bottom flange portion of the upper beam lying flat on a top flange portion of the lower beam, congruent holes or cutouts may be provided in the respective flange portions which are brought into alignment in order to attach the bottom flange portion of the upper beam the top flange portion of the lower beam by riveting or bolting. Such a connection requires sufficient edge margins, pitches, material thicknesses and accessibility for riveting tools. Therefore, the connection of the beams is already planned at a design stage in order to provide for the necessary bores. Additional or late modifications after design stage often lead to considerable additional effort in re-planning and are difficult to apply in already manufactured beams. 
     Other approaches include providing standardized or custom-made interlocking means that have recesses to receive the respective parts of the beams to be interlocked. For example, document U.S. Pat. No. 4,379,651 A discloses a method for releasably rigidly fastening two intersected metal profiles by four L-shaped members enclosing respective side faces of the metal profiles. Document U.S. Pat. No. 729,445 A discloses means for clamping and securing cross metal beams together that include securing clips with edgewise fitting notched partitions for receiving flanges of crossed metal beams. 
     SUMMARY 
     It is a feature of the disclosure herein to provide solutions for connecting intersecting structural beams at the intersecting joint positions which allow for independence of the beam design. Moreover, it is an idea of the disclosure herein to provide for beam interconnection solutions that do not require one of the beams to have specific design features such as bores or recesses for receiving the joint interconnection. 
     A first aspect of the disclosure pertains to a beam flange clamp comprising a clamp body having a first vise jaw portion with a first gripping surface and a second vise jaw portion with a second gripping surface. The first gripping surface and the second gripping surface are oriented parallel to each other, are facing the same direction and are offset in height by a predetermined clamping distance. The at least one bolting hole is formed through the first vise jaw portion perpendicularly to the first gripping surface. 
     According to a second aspect of the disclosure, a structural beam joint comprises a first structural beam having a web portion and at least one first flange portion, a second structural beam having at least one second flange portion, the second structural beam having an axis of extension being angled with respect to the axis of extension of the first structural beam and intersecting with the first structural beam, at least one beam flange clamp according to the first aspect of the disclosure, and at least one fastening pin or bolt inserted in the at least one bolting hole of the at least one beam flange clamp. The at least one first flange portion of the first structural beam abuts the at least one second flange portion of the second structural beam. The at least one fastening pin or bolt tightens the clamp body of the at least one beam flange clamp to the first flange portion of the first structural beam so that the first gripping surface of the at least one beam flange clamp presses the at least one second flange portion of the second structural beam to the at least one first flange portion of the first structural beam. 
     According to a third aspect of the disclosure, a method for forming a structural beam joint comprises abutting a first flange portion of a first structural beam to a second flange portion of a second structural beam, the second structural beam having an axis of extension being angled with respect to the axis of extension of the first structural beam and intersecting with the first structural beam; pressing a first gripping surface of a beam flange clamp which comprises a clamp body having a first vise jaw portion with a first gripping surface and a second vise jaw portion with a second gripping surface, the first gripping surface and the second gripping surface being oriented parallel to each other, facing the same direction and being offset in height by a predetermined clamping distance, to the second flange portion of the second structural beam against the first flange portion of the first structural beam; introducing a fastening pin or bolt in a bolting hole being formed through the first vise jaw portion perpendicularly to the first gripping surface of the clamp body of the beam flange clamp; and tightening the clamp body of the beam flange clamp to the first flange portion of the first structural beam by the fastening pin or bolt. 
     According to a fourth aspect of the disclosure, an aircraft includes a floor framework a floor framework with interconnected structural beams, wherein the structural beams are interconnected with structural beam joints according to the second aspect of the disclosure. 
     An idea on which the present disclosure is based is to use one or more vise type components that are securely fastened to only one of the intersecting beams by riveting or bolting and that are able to clamp abutting flange portions of the intersecting beams to each other. The use of vise type components does not require the other one of the intersecting beams to be specifically prepared with bores, bolting holes or other fastening measures, therefore simplifying the mounting procedure for the beam joint as well as enhancing the flexibility in clamping together beams of different designs. 
     Particularly advantageous may additionally be the reduction of costs, weight, lead time, part count and manufacturing complexity coming along with being independent of beam design when designing the structural beams to be interconnected. Beam-to-beam connections may be changed in a very late stage of the framework manufacturing processes with little to no additional effort. Retrofitting and cabin customization is advantageously applicable when employing the solution of the disclosure herein, specifically due to the flexibility to adapt the interconnection mechanisms of the disclosure herein to existing or legacy structural beams. 
     According to an embodiment of the beam flange clamp or the method, the clamp body may be substantially L-shaped, the first vise jaw portion and the second vise jaw portion forming the legs of the L-shaped clamp body. 
     According to a further embodiment of the beam flange clamp or the method, the clamp body may be chamfered at the vertex of the L-shape and/or the distal end of the first vise jaw portion. This may facilitate mounting access to the beam flange clamp at the structural beam joint. 
     According to a further embodiment of the beam flange clamp or the method, the at least one bolting hole may be located between the first gripping surface and the second gripping surface. The bolting connection is therefore stable and the torsional moments on the first and second gripping surface may at least partially cancel each other out, thus relieving part of the mechanical stress on the beam flange clamp. 
     According to a further embodiment of the beam flange clamp, the clamp body may be integrally formed from one of a metal, a metal alloy and plastics. Such integrally formed clamps are easy and inexpensively to manufacture in conventional manufacturing processes. 
     According to an embodiment of the structural beam joint, the first structural beam may have an H-shaped cross-section. According to a further embodiment of the structural beam joint, the second structural beam may have an H-shaped or T-shaped cross-section. Such beams are often used as supporting beams for framework structure, such as a floor framework for an aircraft. 
     According to a further embodiment of the structural beam joint, the structural beam joint may specifically comprise four beam flange clamps according to the first aspect of the disclosure with two of the four beam flange clamps clamping opposite sides of the second flange portion of the second structural beam to respectively opposite sides of the at least one first flange portion of the first structural beam. The four beam flange clamps may be positioned in each corner of the intersection between the two structural beams, thus reliably and firmly fixing the structural beam joint. 
     According to a further embodiment of the method, the method may comprise repeating the steps of pressing, introducing and tightening for four beam flange clamps with two of the four beam flange clamps clamping opposite sides of the second flange portion of the second structural beam to respectively opposite sides of the at least one first flange portion of the first structural beam. Therefore, the four beam flange clamps may be positioned in each corner of the intersection between the two structural beams, thus reliably and firmly fixing the structural beam joint. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure herein will be explained in greater detail with reference to exemplary embodiments depicted in the drawings as appended. 
       The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate the embodiments of the present disclosure and together with the description serve to explain the principles of the disclosure herein. Other embodiments of the present disclosure and many of the intended advantages of the present disclosure will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts. 
         FIG. 1  schematically illustrates a perspective view of a beam flange clamp according to an embodiment of the disclosure herein. 
         FIG. 2  schematically illustrates a perspective view of a structural beam joint according to another embodiment of the disclosure herein. 
         FIG. 3  schematically illustrates a block diagram of a method for forming a structural beam joint according to another embodiment of the disclosure herein. 
     
    
    
     In the figures, like reference numerals denote like or functionally like components, unless indicated otherwise. Any directional terminology like “top”, “bottom”, “left”, “right”, “above”, “below”, “horizontal”, “vertical”, “back”, “front”, and similar terms are merely used for explanatory purposes and are not intended to delimit the embodiments to the specific arrangements as shown in the drawings. 
     Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present disclosure. Generally, this application is intended to cover any adaptations or variations of the specific embodiments discussed herein. 
     Structural beams within the meaning of this disclosure comprise any longitudinally extended, rigid member or structure that is loaded transversely, such as oblong bars of metal, metal alloys, plastics or other rigid or semi-rigid materials. Structural beams within the meaning of the disclosure herein may comprise crossbeams, longerons, stringers, frames, struts, ribs, spars, stabilizers, formers and similar structural members. 
     The methods and mechanisms for joining structural beams as disclosed hereinforth may be used in a lot of applications, including—but not limited to—constructions of frames, stringers and crossbeams in aircraft, interior design, bridge building, vehicle carriages, civil engineering, applications for children&#39;s toys and similar. 
     DETAILED DESCRIPTION 
       FIG. 1  shows a schematic illustration of a beam flange clamp  10 . The beam flange clamp  10  has a clamp body  1  that may for example be formed from metal, metal alloy or plastics, in particular as an integral clamp body. The clamp body  1  is generally L-shaped a first vise jaw portion  3  extending horizontally and a second vise jaw portion  2  extending perpendicular thereto vertically. In other words, the vise jaw portions  2  and  3  form legs of the L-shape of the clamp body  1 . At the vertex of the L-shape, the clamp body  1  may comprise a chamfered edge  8 . Similarly, the distal end of the first vise jaw portion  3  may be chamfered as well. When seen in the direction of the axes of extension of any of the vise jaw portions  2  and  3 , the clamp body  1  may have a rectangular cross section. Thus, on top of each of the vise jaw portions  2  and  3 , gripping surfaces  4  and  5  are formed. The first gripping surface  5  on top of the first vise jaw portion  3  is oriented parallel to the second gripping surface  4  on top of the first vise jaw portion  2 . Both gripping surfaces  4  and  5  are facing generally in the same direction, i.e. upwards in the illustration of  FIG. 1 . 
     By virtue of the protrusion of the second vise jaw portion  2  with respect to the first vise jaw portion  3 , the gripping surfaces  4  and  5  are offset in height by a predetermined clamping distance d with respect to each other. Thus, if the second gripping surface  5  is brought in planar contact with a first flat component to be gripped, the non-zero clamping distance d allows for insertion of second flat component to be gripped between the first gripping surface  5  and the first flat component. 
     In a manner similar to a vise, the beam flange clamp  10  may be tightened to the first flat component by a bolt or pin  7  that is pushed through a bolting hole  6  which is formed through the first vise jaw portion  3  perpendicularly to the first gripping surface  5  and a corresponding bolting hole  25  in the first flat component. The bolt or pin  7  may for example be threaded so that respective screwing nuts may be tightened on both sides of the bolt or pin  7 , thereby forming a force-fit between the first flat component and the first vise jaw portion  2  and consequently interlocking the second flat component in between. 
     By forming the bolting hole  6  between the first gripping surface  5  and the second gripping surface  4  along the axis of extension of the first vise jaw portion  3 , the torsional forces around the bolt axis of the bolt  7  due to the gripping forces acting on the gripping surfaces  5  and  6  may be partially cancelled out. Of course, it may be possible to provide for more than one bolting hole  6  in the clamp body  1 , as exemplarily illustrated in  FIG. 1 . 
       FIG. 2  schematically illustrates a structural beam joint  100  of two structural beams  20  and  30 , which are shown only partially here for reasons of lucidity in the drawing. The structural beam joint  100  is an intersection of a first structural beam  20  having a web portion  22 , a top flange portion  21  and at least one bottom flange portion. The structural beam  20  may for example be an H-shaped crossbeam. The bottom flange portion is in the case of the structural beam  20  made up from a flange portion  23  outside the joint area and a flange portion  24  at the joint area with the structural beam  30 . The flange portion  24  is recessed within the web portion  22  with respect to the flange portion  23 , i.e. the height of the web portion  22  (distance between the top flange portion  21  and the respective bottom flange portion) is lower in the region of the flange portion  24  than in the region of the flange portion  23 . This recess aids in placing the beam  20  on top of the beam  30  at the intersection in order to keep the overall height of the intersection area as low as possible. However, it should be noted that the division of flange portions  23  and  24  is only exemplary in  FIG. 2 , and a flange portion  23  of continuous extension throughout the joint area with the structural beam  30  may equally be possible as well. In particular, the interconnection mechanism for the two structural beams  20  and  30  with beam flange clamps  10  as illustrated in  FIG. 1  is not dependent on the form or shape of the flange portions  23 ,  24 . 
     The second structural beam  30  which may be an H-shaped or T-shaped crossbeam has at least one second flange portion  31 . The second structural beam  30  is arranged along an axis of extension which is angled with respect to the axis of extension of the first structural beam  20  so that the structural beams  20  and  30  intersect each other at an intersecting region. In the exemplary illustration of  FIG. 2  the intersection angle may be 90°, however, any other angle may be equally possible as well. 
     Two beam flange clamps  10  are shown in  FIG. 2  on one side face of the web portion  22  of the first structural beam  20 . It should be noted that the back side face of the web portion  22  may be provided with two similar beam flange clamps  10  as well. One front side and back side pair of beam flange clamps  10  may be provided at each side of the web portion  32  of the structural beam  30 , so that an overall number of four beam flange clamps  10  may be provided in each inner corner of the structural beam joint  100 . 
     Fastening pins or bolts  7  are inserted in the bolting holes  6  of the beam flange clamps  10 . In congruence with the clamp bolting holes  6 , flange bolting holes  25  may be cut, milled or otherwise introduced in the flange portion  24  of the first structural beam  20 . The clamp bolting holes  6  are then brought into alignment with the flange bolting holes  25  so that the fastening pins or bolts  7  may reach from the bottom side of the beam flange clamps  10  to the top surface of the flange portion  24 . 
     The structural beams  20  and  30  are arranged in such a manner that bottom flange portion  24  of the first structural beam  20  abuts the top flange portion  31  of the second structural beam  30 . By tightening the fastening pins or bolts  7  the clamp body  1  of the beam flange clamps  10  sandwiches the top flange portion  31  of the second structural beam  30  between the top flange portion  24  of the first structural beam  20  and the first gripping surface  5  of the beam flange clamps  10 . In other words, the beam flange clamps  10  presses the top flange portion  31  of the second structural beam  30  to the bottom flange portion  24  of the first structural beam  20 , thereby interlocking the two structural beams  20  and  30  in firm force-fit arrangement. By using four of such beam flange clamps  10  in the different inner corners of the structural beam joint  100 , i.e. two of the four beam flange clamps  10  clamping opposite sides of the top flange portion  31  of the second structural beam  30  to respectively opposite sides of the bottom flange portion  24  of the first structural beam  20 , the relative angular position of the structural beams  20  and  30  towards each other may remain fixed. 
       FIG. 3  schematically illustrates a method M for forming a structural beam joint, such as a structural beam joint  100  as shown and explained in conjunction with  FIG. 2 . The method M may for example advantageously employ beam flange clamps such as the beam flange clamp  10  as illustrated and explained in conjunction with  FIG. 2 . 
     The method M for forming a structural beam joint comprises at S 1  abutting a first flange portion  24  of a first structural beam  20  to a second flange portion  31  of a second structural beam  30 . The second structural beam  30  may have its axis of extension being angled with respect to the axis of extension of the first structural beam  20  such that an intersection of the two structural beams  20  and  30  is formed. At S 2 , a first gripping surface  5  of a beam flange clamp  10  is pressed to the second flange portion  31  of the second structural beam  30  against the first flange portion  24  of the first structural beam  20 . The beam flange clamp  10  being used may in particular be a beam flange clamp  10  as shown and explained in conjunction with  FIG. 1 . 
     Then, at S 3 , a fastening pin or bolt  7  is introduced in a bolting hole  6  being formed through the first vise jaw portion  3  perpendicularly to the first gripping surface  5  of the clamp body  1  of the beam flange clamp  10 , such that at S 4 , the clamp body  1  of the beam flange clamp  10  may be tightened to the first flange portion  24  of the first structural beam  20  by the fastening pin or bolt  7 . 
     As schematically illustrated as S 5 , the steps S 2 , S 3  and S 4  may be repeated for four beam flange clamps  10  with two of the four beam flange clamps  10  clamping opposite sides of the second flange portion  31  of the second structural beam  30  to respectively opposite sides of the at least one first flange portion  24  of the first structural beam  20 . 
     The method M as well as the resulting structural beam joints  100  may be advantageously used for forming a structural framework such as a floor framework of an aircraft. Such a floor framework with interconnected structural beams  20 ,  30  at structural beam joints  100  aids in easier cabin customization and facilitates re-design of floor frameworks even after the design of the structural beams  20  and particularly  30  has already been finished. 
     In the foregoing detailed description, various features are grouped together in one or more examples or examples with the purpose of streamlining the disclosure. It is to be understood that the above description is intended to be illustrative, and not restrictive. It is intended to cover all alternatives, modifications and equivalents. Many other examples will be apparent to one skilled in the art upon reviewing the above specification. 
     The embodiments were chosen and described in order to best explain the principles of the disclosure herein and its practical applications, to thereby enable others skilled in the art to best utilize the disclosure herein and various embodiments with various modifications as are suited to the particular use contemplated. While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. In the appended claims and throughout the specification, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein,” respectively. Furthermore, “a” or “one” does not exclude a plurality in the present case. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.