Abstract:
A framing tool, namely framing square, is provided with an offset at the proximal ends of the two blades, so that the blades lie in parallel planes. This tool facilitates measuring and marking tubular beams, i.e., beams of generally square or rectangular cross section, but which may have rounded or radiused edges.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to hand tools that can be used in fabrication of structures from metal tubes and beams, and is more particularly directed to a framing tool, namely a squaring tool, that can be easily used for measuring and marking tubular beams, i.e., beams of generally square or rectangular cross section, but which may have rounded or radiused edges. 
     BACKGROUND OF THE INVENTION 
     Steel beams are widely employed in the construction of many types of structures, and in particular tube beams, i.e., rectangular section pipes, are employed in many situations. These tube beams need to be cut and welded in the construction process. 
     Steel beams, including tube beams, need to be measured and scored or marked for cutting and welding. A problem arises from the presence of the radiused corners or edges of the pipe. Typically, the welder working with this type of pipe has to use a squaring tool to measure the places along the pipe where a cut or weld is to be positioned. However, a standard, i.e., flat framing square, is difficult to use at the front or open edge of the tube beam, partly owing to the curved corners of the beam. It is difficult or impossible to place the second arm or blade of a flat framing square against a flat side of the tube beam when measuring and marking the front edge of another flat side of the tube beam, and typically the welder will have to tilt the tool to attempt to position the second blade against the side of the tube beam. However, this can lead to inaccuracies in marking the beam. 
     It is this difficulty to which the present invention is addressed. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     Accordingly, is an object of the present invention to provide a framing tool that can be used with tubular beams and which overcomes the drawbacks of the prior art. 
     It is a further object of the present invention to provide a framing tool of a straightforward design which is simple for the welder or other workman to use. 
     It is another object to provide a tool which can be employed in a number of different applications for speedy and accurate framing and marking of workpieces. 
     In accordance with an aspect of this invention a squaring tool is provided in which there are two blades directed at ninety degrees from one another, but there is an offset at the proximal ends where the blades are connected. This permits one blade to be positioned at the front edge of a top side or flange of the tube beam, with the other blade placed directly against a web or side wall of the beam but at a position a short distance away from the edge. The framing square is thus positioned square to the beam, and can be used for quickly and accurately marking a position on the top flange (or any other side of the beam), both at the edge and at other positions along the beam. 
     More specifically, a squaring tool is adapted for measuring exterior planar surfaces of a workpiece wherein said exterior planar surfaces are at substantially a right angle to one another and meet at a rounded or radiused edge. A first planar blade of the tool extends in a first direction in a first plane from a proximal end to a distal end of the blade, and has inside and outside parallel edges extend in that first direction. A second planar blade extends in a second direction, perpendicular to said first direction. The second blade is located in a second plane that is parallel to the first plane (the plane of the first blade) but offset from it by a predetermined offset distance. The second blade also has inside and outside parallel edges that extend in the second direction. An offset member joins the proximal end of the first blade with the proximal end of the second blade. This framing tool is constructed with inside edges of the first and second blades being free of any protuberance or obstruction. Consequently, each of said inside edges can lie flat against a respective exterior planar surface of the workpiece, and the blades themselves can also lay flat against a flat surface of the workpiece. 
     In preferred embodiments, the offset member extends at a first predetermined angle from the proximal end of the first blade and is joined to the proximal end of said second blade at a second angle complementary to said first angle, such that the two blades lie in parallel planes. The first and second angles may both be substantially 90 degrees, or the first and second angles may be substantially 45 and 135 degrees, respectively. each of said blades has gradations at predetermined intervals along the inside edges thereof. 
     Favorably, the offset member connects to the inside edge of said first blade at the proximal end thereof, and to a proximal edge of the second blade. 
     Each of the blades may have gradations at predetermined intervals along the inside edges thereof, or preferably on both the inside and outside edges. These may be in inch-based intervals or centimeter based intervals, or both. 
     The framing tool may be formed unitarily of steel, although an aluminum alloy, a tough plastic, or another sturdy material may be used for it, as appropriate. 
     The above and many other objects, features, and advantages of the invention will become apparent from the accompanying Drawing figures, which are to be considered in connection with the following description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  is a perspective view of a framing square according to an embodiment of this invention. 
         FIG. 2  is another perspective view illustrating an alternative embodiment of the present invention. 
         FIG. 3  is perspective view illustrating the use of the tool of the present invention with a tubular beam. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to  FIGS. 1 to 3  of the Drawing, and initially to  FIG. 1 , there is shown a framing square  10  there formed of a first blade  12  and a second blade  14  that extend at right angles from one another. Each of the blades  12  and  14  has two parallel edges, and has a proximal end ( 12 - 1  and  14 - 1 , respectively) at the corner formed by the two blades, and each has a proximal or free end ( 12 - 2  and  14 - 2 , respectively). The two blades  14  and  16  lie in parallel planes that are spaced apart from one another. An offset  16  joins the proximal ends of the two blades, and here the offset  16  meets the side of the first blade proximal end  12 - 1  at ninety degrees and also joins the end of the second blade proximal end  14 - 1  at ninety degrees. The offset  16  extends about one to two inches, although the exact length of the offset is not critical. 
       FIG. 2  shows a second embodiment in which the framing square  110  has a first blade  112  and a second blade  114  that extend out in directions that are at right angles to one another, and the blades  112  and  114  lie in parallel planes that spaced an offset amount from one another. Here an offset  116  joins the proximal ends of the two blades, but at angles of forty-five degrees and one-hundred thirty-five degrees, i.e., bent down 45 degrees and then bent up 45 degrees. In other embodiments, the offset can be angled at any two angles that are complementary to one another, and will result in the two blades lying parallel to one another. 
     In each embodiment, the blades have markings or gradations spaced along at least the inside edge, and favorably on both edges and both sides of the blades. These can be in intervals of inches and fractions of an inch, or in International units (centimeters and millimeters). Most favorably, the framing square  10  or  110  is formed of a single piece of steel sheet, but can be formed of another suitable material, e.g., a sturdy aluminum alloy or any of a variety of modern synthetic plastic resins. 
     The method of employing the squaring tool of this invention is illustrated in  FIG. 3 . In this application, the framing tool  10  is used for measuring and marking a steel tubular beam  20 , in which adjacent web or flange surfaces  22  and  24  are flat and at right angles to one another, but are joined at a rounded or radiused edge  26 . In this application, the first blade  12  can be laid along the beam  20  on web surface  22 , and the second blade  14  is a short distance below that with its edge along flange surface  24 . The flat of the blade  12  and the edge of the blade  14  are placed flush against the respective surfaces  22  and  24 , and with the blade  12  square to the beam axis. This allows the beam to be marked accurately, using the blade or blades as a guide, to mark the workpiece for cutting or welding at specific locations along the web surface from the front edge to similar locations along the beam and spaced back from the front edge, along the web surface  22 . The tool  10  can be held square to the beam because the end  12 - 1  of the first blade and the offset  12  joining to the proximal end  14 - 1  of second blade  14  bridge around the curved or radiused edge  26 , by virtue of the offset  16 . This is not possible with a standard, single-plane framing square. The offset  16  or  116  avoids having to lie the tool onto the rounded or radiused edge  26 . The second blade  14  or  114  is placed axially along the beam  20 , i.e., parallel the web surface  22  and also parallel to the edge  26 , and does not have to be angled back on the tubular beam. 
     Also the inside edges of the two blades are flat and straight, and free of any protuberances or obstructions, so that they can both contact the flat surfaces of the tubular beam  20  flush against the respective surface of the beam. 
     In the illustrated embodiments, the shorter, second blade  14  or  114  is shown offset from the right-hand side of the first blade  12  or  112 , but the tool could be fabricated with the second blade offset from the left-hand side of the first blade. 
     This framing tool may also be employed favorably when working with other beam types that have a flange and web joined at a rounded edge, e.g., an L-profile beam or a C-profile channel beam. 
     Many modifications and variations are possible, in addition to the above-described preferred embodiments of the invention, without departing from the scope and spirit of the present invention, as defined in the appended claims.