Abstract:
A miter angle indicating tool includes three members that are pivotally attached. The miter angle indicating member is adapted to display the miter angle in or around a corner requiring a miter joint, or to display the bisecting angle of an object. Once the required angle is displayed, the indicating tool can be used to either transcribe the angle onto the material that will form the miter joint or as a jig to set the cutting apparatus to the proper cutting position. In the preferred form of the tool, one member forms a case for storage of the other two members when not in use.

Description:
[0001]    This application claims priority from provisional U.S. Pat. application Ser. No. 60/408,036, filed Sep. 4, 2002, which is incorporated herein in its entirety. 
     
    
     
       BACKGROUND AND TECHNICAL FIELD OF THE INVENTION  
         [0002]    The present invention is directed towards a tool for use with construction projects. Although the invention may be used in many fields, such as plumbing, roofing, and drafting, it has particular relevance to the field of finish carpentry and will be discussed with respect thereto.  
           [0003]    Carpenters must frequently join materials at an angle in a manner commonly known as a miter joint. A miter joint typically consists of two pieces of material that are joined at a corner, where each of the pieces is cut at a bisecting angle of the corner angle requiring the miter joint. Miter joints are used on molding surrounding doors, windows, and floor bases as well as in the risers and runs on staircase stringers. As doors, windows, walls, and staircases are frequently not perfectly square due to natural imperfections, the actual angle required for the miter joint must first be determined and then the materials cut to this angle.  
           [0004]    Devices are known for measuring the required miter angle of a particular joint. These measuring devices typically consist of two members or legs that are joined at a pivot point. The measuring device is positioned within a corner requiring a miter joint and the members of the device are then pivoted such that they contact the surfaces of the corner that create the angle. A scale is provided on the device that, when the members are pivoted to the correct angle, enable the user to read the required miter angle for the corner. See, for example, U.S. Pat. No. 6,237,238 B1 issued to Shapiro. The required miter angle may then be set on the apparatus that will be used to cut the material to be joined. Alternatively, another device may be set to the required angle and used to scribe this angle onto the material to be joined. In this method the cutting apparatus is aligned to the mark on the material by sight.  
           [0005]    However, problems exist with these methods with regards to translating the measured miter angle into a finish cut on the material to be joined. Imprecision between the gage scales of the device used for measuring the required miter angle and of the cutting apparatus can result in inaccurate miter cuts, resulting in miter joints that are not properly flush. Also, human imprecision is added when the operator must read one scale and transfer the value to another scale. Additionally, it is inefficient to set the angle on another device and use it to scribe the required angle onto the material to be joined.  
           [0006]    The present invention overcomes such difficulties and enables the operator to accurately and efficiently determine a required miter angle for a given joint and directly transcribe that angle onto the material to be cut. By directly transcribing the angle onto the material to be cut, the cutting apparatus can be accurately adjusted by sight by aligning the cutting blade over the transcribed mark prior to cutting and any imprecision associated with the cutting apparatus&#39; gage scale is avoided. Alternatively, the present invention can be used as a jig to set the cutting apparatus to the proper cutting position. Further, the tool is constructed such that miter angles for both internal corners and edge corners can be determined.  
         SUMMARY OF THE INVENTION  
         [0007]    The present invention discloses a miter angle indicating tool which has an angle indicating blade, a bevel blade, and a case; all of which are pivotally attached to each other at their respective ends. The indicating blade is constructed with an indicating edge that aligns through the center point of the pivot point formed by the pivotal attachment of the indicating blade, the bevel blade, and the case.  
           [0008]    In use, the tool is placed into or around a corner, and edges of the bevel blade and case are made to contact the surfaces comprising the corner. To obtain the miter or bisecting angle, the indicating blade is then positioned such that the indicating edge intersects a point established by the intersection of the interior edges of the bevel blade and case. When the tool is secured in this position, it can then be used to transcribe the miter angle onto a work surface or as a jig to set the cutting position of a cutting apparatus.  
           [0009]    It is an object of this invention to provide an accurate indicator of the miter angle required for a work surface. It is a further object of this invention to avoid the inaccuracies and time delays associated with the reading of a gage scale on known miter angle measurement devices. It is still a further object of this invention to enable a miter angle to be transcribed onto a work surface or to provide a jig with which to set a miter angle cutting apparatus. These and other objects, features, and advantages of the invention will be made apparent from the following description and attached drawings.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 is a plan view of one embodiment of the miter angle measuring and transcribing device in an open position;  
         [0011]    [0011]FIGS. 2A, 2B, and  2 C show three orientations of the device in a closed position;  
         [0012]    [0012]FIG. 3A is a plan view of the miter angle blade member from the embodiment of FIG. 1;  
         [0013]    [0013]FIG. 3B is a plan view of the bevel blade of member from the embodiment of FIG. 1;  
         [0014]    [0014]FIG. 3C is a plan view of the case member from the embodiment of FIG. 1;  
         [0015]    [0015]FIG. 4 is a plan view of another embodiment of the present invention shown in an open position;  
         [0016]    [0016]FIG. 5A is a plan view of the miter angle blade member of the embodiment of FIG. 4; and  
         [0017]    [0017]FIGS. 5B and 5C show the middle and bottom blade members of the embodiment of FIG. 4. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0018]    As can be seen in FIGS. 1, 2A,  2 B,  2 C,  3 A,  3 B, and  3 C, the preferred embodiment of the miter angle indicating tool  10  includes a first or miter angle indicator blade  12 , a second or bevel blade  13 , and a case  14 . Indicator blade  12 , bevel blade  13 , and case  14  are pivotally connected at joint  15  by fastener assembly  16 , which allows the indicator blade  12 , bevel blade  13 , and case  14  to be fixedly secured in a desired position, but also permits blades  12  and  13  to be pivoted to a closed position inside case  14 . In the illustrated embodiment, indicator blade  12  is mounted on top of bevel blade  13  for ease of alignment as will be more fully described below.  
         [0019]    As best seen in FIGS.  2 A- 2 C, fastener assembly  16  includes a bolt  17 , a washer  18 , and a wing-nut  19 , with the bolt extending through openings provided in the proximal ends of case  14  and blades  12  and  13 . Blades  12  and  13  are preferably elongated plate members and are preferably formed from a metal material, such as stainless steel, including high tempered steel, or aluminum. However, it should be understood that blades  12  and  13  may be formed from wood, plastic or a composite material or the like. Case  14  preferably comprises a plastic case and may be formed such as by molding or may be assembled from two or more plastic members. Similarly, case  14  may be formed from other materials, including metal, wood, or a composite material. Bevel blade  13  and case  14  are constructed to have commensurate widths W1, W2, and also have rounded ends  13   a  and  14   a  at joint  15 . Indicator blade  12  also has a rounded end  12   a  (FIG. 3A) at joint  15  and includes measuring scale  22 , which can be used as a depth measurement tool or just as a scale. Further, indicator blade  12  is constructed such that its edge  23  provides an indicating edge, which aligns with the center point of joint  15 . In this manner, as will be more fully described below, indicator blade  12  may be used to determine the miter angle on a corner or edge.  
         [0020]    Referring to FIGS. 2B and 2C, case  14  includes slot  24  into which indicator blade  12  and bevel blade  13  can be pivoted and housed when not in use. Additionally, case  14  has notch  25  on its outer edge that is in communication with slot  24  and exposes indicator blade  12  and bevel blade  13  when they are housed within slot  24 , and in turn aids in the removal of indicator blade  12  and bevel blade  13  from slot  24  when they are needed. In the illustrated embodiment, slot  24  may comprise a through-slot or may comprise a slotted recess, as will be noted below. In addition, to ease handling of tool  10 , tool  10  may be provided with one or more grips  26 , such as indentations, located on either side of case  14 . Grips  26  especially facilitate handling of tool  10  when in operation.  
         [0021]    Optionally, case  14  also includes a stop to limit the position of blades  12  and  13  in case  14 . For example, in the illustrated embodiment the stop comprises an angled support area  27  formed within slot  24  that contacts the distal ends of blades  12  and  13 . Optionally, the distal ends of blades  12  and  13  are pointed, such as defined by pointed edge  28  of indicator blade  12  and pointed edge  29  of, bevel blade  13 . Thus, when blades  12  and  13  are housed within slot  24 , edges  28  and  29  are retained in slot  24  by support area  27 . In this manner, blades  12  and  13  cannot pass through case  14  and, instead, are retained in slot  24  by the stop formed by support area  27 . Alternately, the stop may be formed by a closed side of case  14 , such as when slot  24  comprises a slotted recess and does not extend through case  14 —in which case distal ends of blades  12  and  13  may be flat or “squared-off”.  
         [0022]    Referring to FIG. 3B, bevel blade  13  includes an elongate opening  30  that enables tool  10  to be used as a bevel by allowing bevel blade  13  to slide and rotate relative to joint  15 . As bolt  17  passes through opening  30 , bevel blade  13  is constrained and only free to slide a distance defined by the length of opening  30 . Bevel blade  13  also includes indicating line  31  that can be aligned with edge  32  of case  14  such that a 90° angle is established between bevel blade  13  and case  14  when indicating line  31  is aligned with edge  32 .  
         [0023]    In operation, tool  10  can be used, amongst other ways, to create a miter joint at a corner. Ends  12   a ,  13   a ,  14   a  of the indicator blade  12 , bevel blade  13 , and case  14  are positioned in or along a corner to where the surfaces comprising the corner meet. Edge  33  of bevel blade  13  and edge  34  of case  14  are then made to contact the surfaces comprising the corner. When bevel blade  13  and case  14  are positioned in this manner, it can be seen that inner edge  35  of bevel blade  13  and inner edge  32  of case  14  intersect at point  36 . Indicator blade  12  can then pivotally positioned such that indicator edge  23  also intersects the intersection of inner edge  35  of blade  13  and inner edge  32  of case  14  at point  36 . Once edge  23  is set to intersect point  36 , wing-nut  19  is preferably tightened such that the relative positions of indicator blade  12 , bevel blade  13 , and case  14  are fixed.  
         [0024]    When tool  10  is fixed in this manner, the angle defined by edges  23  and  35  or  13  and  32  is the miter or bisecting angle of the corner. Tool  10  can then be used to scribe the miter angle onto the material that will form the miter joint such that two pieces of the material cut at the miter angle will create an accurate miter joint for the corner. Alternatively, tool  10  can be used as a jig to set the position of the cutting apparatus that will put the miter angle on the material to be joined in or around the corner.  
         [0025]    The thickness T1 (FIG. 2B) of case  14  also provides support for tool  10  during operation. When positioning case  14  in or around a corner, edge  32  or edge  34  will prevent wobbling by providing sufficient surface area to contact one of the surfaces comprising the corner. It should be understood that case  14  may be formed from a single member or a plurality of members, which are interconnected using conventionally fasteners, welds, or the like.  
         [0026]    [0026]FIGS. 4 and 5 show an alternative embodiment of the miter angle indicating tool  110 . Tool  110  includes a miter angle indicator blade  112 , a first bevel or middle blade  113 , and a second bevel or bottom blade  114 , which are pivotally connected at the proximal ends  112   a ,  113   a , and  114   a  at joint  115 . In this embodiment, as shown in FIG. 5D, indicator blade  112 , first bevel blade  113 , and second bevel blade  114  have substantially commensurate thicknesses T2, T3, and T4. In addition, the width of blades  113  and  114  are also approximately equal. However, it should be understood that the thickness of the respective blades and widths o the blades may vary. In addition, similar to the previous embodiment, the proximal ends of blades  112 ,  113 , and  114  may be rounded so that the tool may used to fit for an inside angle measurement. Also, preferably to ease insert of tool  10  into a pocket of a user of tool  10 , distal ends  112   b ,  113   b , and  114   b  of blades  112 ,  113 , and  114  are flat or squared off. Operation of the tool in this embodiment is substantially equivalent to the operation described above in connection with the tool illustrated in FIG. 1.  
         [0027]    Indicator blade  112  has a round through-hole  150  at its proximal end  112   a . First bevel blade  113  similarly has a round through hole  152  at proximal end  113   a . Bottom blade  114 , however, has square hole  154  at its proximal end  114   a  to permit blades  112  and  113  to be moved relative to blade  114 , as will be more fully described below. Blades  112 ,  113 , and  114  are secured together at joint  115  by a bolt (not shown) with a square shoulder, which is inserted through square hole  154  such that the square shoulder of the bolt prevents relative movement of second bevel blade  114  with respect to the bolt. First bevel blade  113  and indicator blade  112  are then placed over the bolt such that blade  113  is positioned between blade  114  and indicator blade  112 . Further, blade  113  and indicator blade  112  are able to pivot relative to the bolt and blade  114 . A washer and wing-nut (not shown) are then placed over the bolt and are tightened to secure the three blades  112 ,  113 , and  114  such that relative motion of all three blades is limited when the tool  110  is not in use, or when the tool position is set, for example, when the miter angle of a given corner has been determined. It should be understood that the previous embodiment may also incorporate a square hole and corresponding fastener with a square shoulder to better enable the bevel blade and indicator blade to pivot with respect to the case.  
         [0028]    Optionally, indicator blade  112 , middle blade  113 , and bottom blade  114  are constructed with indicating lines  156   a ,  156   b ,  156   c ,  158 , and  159 . Indicating lines  156   a ,  156   b ,  156   c ,  158  and  159  enable tool  110  to be adjusted to commonly used angles in the construction fields. For example, when indicating line  159  of bottom blade  114  is aligned with edge  135  of middle blade  113 , a 90° angle is formed between blade  113  and middle blade  114 . When indicating line  156   a  of indicator blade  112  is then aligned with indicating line  160  of bottom blade  114  a 45° angle will be formed between edge  123  of indicator blade  112  and edge  132  of blade  114 . When indicating line  156   c  of blade  112  is aligned with indicating line  160 , a 60° angle is formed between edge  123  of blade  112  and inner edge  135  of blade  113  and a 30° angle is formed between edge  123  of blade  112  and inner edge  132  of blade  114 . It should be understood that blade  112  may include other indicator lines  152 , for example at 0°, 90°, 180°, 270° with respect to edge  123 .