Abstract:
A fence assembly for miter saw includes a mounting base defining a first abutting surface, and a fence unit mounted at the mounting base in one of first, second and third positions in such a manner that the second abutting surface of the fence unit is disposed co-planar with the first abutting surface of the mounting base when the fence unit is set in the first position; the third abutting surface of the fence unit is disposed in a non-coplanar relationship with the first abutting surface of the mounting base to face toward the same direction when the fence unit is set in the second position; the fourth abutting surface of the fence unit is disposed in a non-coplanar relationship with the first abutting surface of the mounting base to face toward the same direction when the fence unit is set in the third position.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to miter saw technology and more particularly, to a fence assembly for use in a miter saw. 
         [0003]    2. Description of the Related Art 
         [0004]    When using a miter saw to cut a workpiece, the user will place the workpiece on the worktable to abut the workpiece against a fence, enabling the workpiece to be supported in position by the fence and avoiding displacement of the workpiece during the cutting operation. 
         [0005]    In a conventional miter saw, the fence is affixed to the supporting base and not adjustable to change the position according to actual cutting requirements. Subject to the limitation of the position of the fence, the saw arm can simply be moved within a predetermined stroke, resulting in a limitation on the cutting stroke. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention has been developed in view of the prior art limitations. It is one of the main objects of the present invention to provide a fence assembly for a miter saw, which allows adjustment of the position of the fence according to actual cutting requirements of the workpiece, which solves the problem of a limited cutting stroke. 
         [0007]    To achieve this and other objects of the present invention, a fence assembly comprises a mounting base and a fence unit. The mounting base mounted at a supporting base, comprising a first abutting surface that extends perpendicular to the first work surface of the supporting base. The fence unit is able to be detachably mounted at the mounting base and turnable relative to the mounting base between a first position, a second position and a third position. The fence unit comprises a second abutting surface, a third abutting surface that extends perpendicular to the second abutting surface, and a fourth abutting surface located on a back side of the second abutting surface. The second abutting surface is disposed perpendicular to the first work surface of the supporting base and coplanar with the first abutting surface of the mounting base when the fence unit is set in the first position. At this time, the first abutting surface of the mounting base and the second abutting surface of the fence unit provide support to the workpiece to be cut. The third abutting surface of the fence unit is disposed perpendicular to the first work surface of the supporting base and in a non-coplanar relationship with the first abutting surface of the mounting base when the respective said fence unit is set in the second position. At this time, simply the third abutting surface of the fence unit provides support to the workpiece to be cut. The fourth abutting surface is disposed non-coplanar with the first abutting surface of the mounting base to face toward the same direction when the fence unit is set in the third position. At this time, simply the fourth abutting surface of the fence unit provides support to the workpiece to be cut. 
         [0008]    Thus, the position of the fence unit of the fence assembly can be adjusted according to actual cutting requirements of the workpiece. When the fence unit is set in the first position, a saw arm of the miter saw can maintain its original cutting stroke. When the fence unit is set in the second position, the gap between the third abutting surface of the fence unit and the first abutting surface of the mounting base is used to increase the cutting stroke of the saw arm of the miter saw, making the miter saw practical for cutting a relatively thinner workpiece. When the fence unit is set in the third position, the gap between the fourth abutting surface of the fence unit and the first abutting surface of the mounting base is used to increase the cutting stroke of the saw arm of the miter saw, making the miter saw practical for cutting a relatively thicker workpiece. 
         [0009]    Other and further advantages and features of the present invention will be understood by reference to the following specification in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a perspective view, illustrating a fence assembly installed in a miter saw worktable in accordance with the present invention. 
           [0011]      FIG. 2  is an exploded view of the fence assembly in accordance with the present invention. 
           [0012]      FIG. 3  is an exploded view of a part of the present invention, illustrating the fence unit in the second position. 
           [0013]      FIG. 4  is similar to  FIG. 3 , illustrating the fence unit in the third position. 
           [0014]      FIG. 5  is a side view of the present invention, illustrating the fence unit in the first position. 
           [0015]      FIG. 6  is similar to  FIG. 5 , illustrating the fence unit in the second position. 
           [0016]      FIG. 7  is similar to  FIG. 5 , illustrating the fence unit in the third position. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]    Referring to  FIG. 1 , a fence assembly  10  in accordance with the present invention is shown used in a miter saw that comprises a supporting base  16 , and a worktable  12  rotatably supported on the supporting base  16 . The supporting base  16  comprises a first work surface  18 . The worktable  12  comprises a second work surface  14  coplanar with the first work surface  18 . The first work surface  18  and the second work surface  14  are adapted for supporting a workpiece (not shown). Because the miter saw (not shown) is of the known machine tool and not within the scope of the present invention and in order to save space, the structural details and operating principle of the miter saw will not be discussed here. 
         [0018]    Referring to  FIGS. 2-6 , the fence assembly  10  comprises a mounting base  20  and two fence units  30 . 
         [0019]    The mounting base  20  is affixed, e.g., attached by bolting, screwing, welding, gluing, or other means known in the art, to the supporting base  16  and bridging over the second work surface  14  of the worktable  12 , comprising two mounting parts  21  and an arched connection part  22  connected between the two mounting parts  21 . Each mounting part  21  defines a bottom wall  23 , a first upright wall  24  and a second upright wall  256 . The first upright wall  24  and the second upright wall  26  are respectively connected to the bottom wall  23 , for example, to the top surface or the side surface of the bottom wall in a known manner. Thus, the bottom wall  23 , the first upright wall  24  and the second upright wall  26  defines a retaining groove  27 . Further, the first upright wall  24  defines a first abutting surface  29  that extends perpendicular to the first work surface  18 . The second upright wall  26  defines therein a locating hole  261  in communication with the retaining groove  27 . 
         [0020]    Each fence unit  30  comprises an abutment portion  31 . The abutment portion  31  defines a second abutting surface  32  on a front side thereof, a third abutting surface  33  on a bottom side thereof, and a fourth abutting surface  34  on a back side thereof. Thus, the third abutting surface  33  extends perpendicular to the second abutting surface  32 ; the fourth abutting surface  34  is located on a back side of the second abutting surface  32 . Each fence unit  30  further comprises a first engaging portion  35  and a second engaging portion  36 . The first engaging portion  35  is connected to the bottom side of the abutment portion  31 , defining a first bearing surface  37  on a front side thereof. The first bearing surface  37  extends perpendicular to the third abutting surface  33  of the abutment portion  31 . The second engaging portion  36  is connected to the back side of the abutment portion  31 , defining a second bearing surface  38  on a top side thereof. The second bearing surface  38  extends perpendicular to the fourth abutting surface  34  of the abutment portion  31 . 
         [0021]    When the fence unit  30  is in a first position P 1 , as shown in  FIG. 5 , the first engaging portion  35  of the fence unit  30  is engaged into the retaining groove  27  of the mounting part  21 . At this time, the second abutting surface  32  of the fence unit  30  is disposed perpendicular to the first work surface  18  of the supporting base  16  and maintained coplanar with the first abutting surface  29  of the mounting base  20 . When the fence unit  30  is in a second position P 2 , as shown in  FIG. 3  and  FIG. 6 , the second engaging portion  36  of the fence unit  30  is engaged into the retaining groove  27  of the mounting part  21 . At this time, the third abutting surface  33  of the fence unit  30  extends perpendicular to the first work surface  18  of the supporting base  16  in a non-coplanar relationship with the first abutting surface  29  of the mounting base  20 . When the fence unit  30  is in a third position P 3 , as shown in  FIG. 4  and  FIG. 7 , the first engaging portion  35  of the fence unit  30  is engaged into the retaining groove  27  of the mounting part  21 . At this time, the fourth abutting surface  34  of the fence unit  30  is disposed in a non-coplanar relationship with the first abutting surface  29  of the mounting base  20  to face toward the direction toward which the first abutting surface  29  of the mounting base  20  faces. When the fence unit  30  is in a third position P 3 , the fourth abutting surface  34  and the first abutting surface  29  are substantially kept in parallel. 
         [0022]    As illustrated in  FIGS. 2-4 , when the fence unit  30  is set in the first position P 1 , a locking member  40  (for example, lock screw bolt) is installed to lock the fence unit  30  in the first position P 1 . At this time, the locking member  40  is threaded into the locating hole  261  with the distal end thereof stopped against the back side of the first engaging portion  35  of the fence unit  30 , forcing the engaging portion  35  of the fence unit  30  to abut against the first upright wall  24  of the mounting base  20  firmly. When the fence unit  30  is set in the second position P 2 , the locking member  40  is threaded into the locating hole  261  with the distal end thereof stopped against the second bearing surface  38  of the second engaging portion  36  of the fence unit  30 , forcing the second engaging portion  36  of the fence unit  30  to abut against the first upright wall  24  of the mounting base  20  firmly. When the fence unit  30  is set in the third position P 3 , the locking member  40  is threaded into the locating hole  261  with the distal end thereof stopped against the first bearing surface  37  of the first engaging portion  35  of the fence unit  30 , forcing the first engaging portion  35  of the fence unit  30  to abut against the first upright wall  24  of the mounting base  20  firmly. 
         [0023]    Thus, when the user sets the fence unit  30  in the first position P 1 , as illustrated in  FIG. 5 , the first abutting surface  29  of the mounting base  20  and the second abutting surface  32  of the fence unit  30  provide positive support to the workpiece. At this time, the saw arm maintains its original cutting stroke S 1 . 
         [0024]    When the user turns the fence unit  30  through an angle of 90 degrees from the first position P 1  to the second position P 2  and locks the fence unit  30  in position, as shown in  FIG. 6 , a gap is left between the third abutting surface  33  of the fence unit  30  and the first abutting surface  29  of the mounting base  20 . The presence of this gap causes the cutting stroke of the saw arm to be changed from S 1  to S 2  (see  FIG. 6 ). Further, after the fence unit  30  is turned through an angle of 90 degrees, an elevational, e.g., height, difference is produced between the third abutting surface  33  of the fence unit  30  and the first abutting surface  29  of the mounting base  20  due to the positioning of the first engaging portion  35  of the fence unit  30 . In order to maintain cutting stability, the user can place a raiser block  50  on the first work surface  18  of the supporting base  16  to abut the raiser block  50  against the first engaging portion  35  of the fence unit  30  and to keep a top surface of the raiser block  50  flush with the first bearing surface  37  of the first engaging portion  35  of the fence unit  30 , and then place the workpiece on the top surface of the raiser block  50 , enabling the workpiece to be supported by or against the third abutting surface  33  of the fence unit  30  in position. This arrangement is practical for cutting a relatively thinner workpiece. 
         [0025]    When the user turns the fence unit  30  through an angle of 180 degrees from the first position P 1  to the third position P 3  and locks the fence unit  30  in position, as shown in  FIG. 4  and  FIG. 7 , a gap is left between the fourth abutting surface  34  of the fence unit  30  and the first abutting surface  29  of the mounting base  20  due to the non-coplanar relationship. The presence of this gap causes the cutting stroke of the saw arm to be changed from S 1  to S 3 . Further, after the fence unit  30  is turned through an angle of 180 degrees, an elevational, or height, difference is produced between the fourth abutting surface  34  of the fence unit  30  and the first abutting surface  29  of the mounting base  20  due to the positioning of the second engaging portion  36  of the fence unit  30 . In order to maintain cutting stability, the user can place another raiser block  52  on the first work surface  18  of the supporting base  16  to abut the raiser block  52  against the second engaging portion  36  of the fence unit  30  and to keep a top surface of the raiser block  52  in flush with the second bearing surface  38  of the second engaging portion  36  of the fence unit  30 , and then place the workpiece on the top surface of the raiser block  52 , enabling the workpiece to be supported by or against the fourth abutting surface  34  of the fence unit  30  in position. This arrangement is practical for cutting a relatively thicker workpiece. 
         [0026]    In conclusion, the fence assembly  10  of the present invention allows adjustment of each position of the fence unit  30  according to the actual cutting requirements for the workpiece so that the cutting stroke of the saw arm can be relatively adjusted, and thus, the design of the present invention solves of the problem of limited cutting stroke of the prior art designs.