Abstract:
The present invention relates to a miter saw, including a base, a work table, a saw unit pivotally mounted on the base, and fence assembly connected to the base. The fence assembly is directly removably mounted on the base so as not to cause space between the two fences, thus promoting cutting precision and making simple structures at a lower cost. The fences having different heights are interchangeably used, which increases inclined cutting angles.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a national phase entry under 35 U.S.C. §371 of International Patent Application PCT/CN2009/075657, filed Dec. 16, 2009, published in Chinese as International Patent Publication WO 2010/069257 A1 on Jun. 24, 2010, which claims the benefit under Article 8 of the Patent Cooperation Treaty to Chinese Patent Application Serial No. 200810184983.3 filed Dec. 18, 2008, and Chinese Patent Application Serial No. 200810188664.X, filed Dec. 19, 2008, the entire disclosure of each of which is hereby incorporated herein by this reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to a miter saw and, more specifically, to a miter saw having a fence assembly. 
       BACKGROUND 
       [0003]    Currently, the traditional miter saw, as a cutting tool, has been widely used in a variety of cutting applications. Miter saws usually include a base, a working table rotatably mounted on the base, and a saw unit pivotally mounted on the working table. The saw unit includes an angle support mounted on the working table, a motor and a saw blade driven by the motor. 
         [0004]    The miter saw includes a fence assembly connected with the base, usually for supporting the workpiece. The fence assembly extends upwardly along the traverse and across the working table. The fence assembly usually includes a fixed fence fixedly mounted on the working table and an auxiliary fence that is movable relative to the fixed fence. The auxiliary fence may be installed in a variety of forms, such as a slidable auxiliary fence that is movable relative to the fixed fence, a pivotal auxiliary fence that is pivotal relative to the fixed fence, and a pin auxiliary fence that can be inserted or pulled out relative to the fixed fence and so on. 
         [0005]    U.S. Pat. No. 6,899,005 discloses a miter saw, which includes a fixed fence fixedly interconnected with the base, and a movable fence movably interconnected to the fixed fence, wherein the fixed fence includes a fixed workpiece-supporting surface perpendicular to the working table and the movable fence includes a movable workpiece-supporting surface perpendicular to the working table. The fixed workpiece-supporting surface and the movable workpiece-supporting surface support the workpiece together while cutting. When there is a need to increase the cutting angle, the operator can move the movable fence to avoid other assemblies of the motor or the saw unit interfering with the movable fence for convenience while cutting. 
         [0006]    However, there are some defects in conventional fence assemblies. Because both the fixed workpiece-supporting surface and the movable workpiece-supporting surface support the workpiece together, while the movable workpiece-supporting surface needs to slide relative to the fixed workpiece-supporting surface, it is difficult to ensure the vertical alignment of the fixed fence and the movable fence, thus affecting the cutting precision. 
         [0007]    Although the workpiece-supporting surface is mainly used for supporting the workpiece to be cut, there is a need for finishing and arranging a fixed fence, thus demanding a bigger base and bigger area for finishing, which leads to higher costs. 
       DISCLOSURE 
       [0008]    The subject invention provides a miter saw having a fence assembly that can increase inclined cutting angles and provide a supporting surface that has more precision for the workpiece. 
         [0009]    The subject invention provides a miter saw having a small base and a low cost. 
         [0010]    In one embodiment of the invention, a miter saw for cutting a workpiece comprises a base having a supporting surface for supporting the workpiece; a turntable pivotally mounted on the base; a saw unit pivotally connected to the base, the saw unit comprising a motor and a saw blade rotary driven by the motor; a first fence having a first configuration, the first fence having a first stopping surface that is perpendicular to the supporting surface; a second fence having a second configuration, the second fence having a second stopping surface that is perpendicular to the supporting surface; wherein the first fence and the second fence are selectably and detachably mounted on the base, and the first configuration is different from the second configuration. 
         [0011]    In one embodiment, the first configuration has a first height that is the largest distance that the first stopping surface extends upwardly from the supporting surface, and the second configuration has a second height that is the largest distance that the second stopping surface extends upwardly from the supporting surface, and wherein the first height is not equal to the second height. 
         [0012]    In a further embodiment, the first fence and the second fence mounted on the base are interchangeable with each other. 
         [0013]    In another embodiment, the base has two opposite sides relative to the saw blade. 
         [0014]    In one embodiment, the first fence or second fence is mounted on one side of the base. 
         [0015]    In one embodiment, the second fence or first fence is mounted on the other side of the base. 
         [0016]    In one embodiment, the miter saw has two first fences, respectively mounted on the two opposite sides. 
         [0017]    In one embodiment, the miter saw has two second fences, respectively mounted on the two opposite sides. 
         [0018]    In one embodiment, a guiding device is disposed between the base and at least one of the first fence has and the second fence, and the guiding device comprises at least one guiding member mounted on the at least one of the first and second fences and a guiding groove mounted on the base, wherein the guiding members are slidably disposed in the guiding groove. 
         [0019]    In one embodiment, a locking device is disposed between the base and at least one of the first fence and the second fence. The locking device comprises a screw extending through the at least one guiding member and the at least one of the first and second fences to engage with a nut. 
         [0020]    In one embodiment, a positioning device is mounted on at least one of the first and second fences for supporting the workpiece. The positioning device comprises a body and a positioning plate attached on one end of the body. The body is movably mounted on at least one of the first fence and the second fence, and the positioning plate and the first fence assembly support the workpiece together. 
         [0021]    In one embodiment, the positioning device comprises a storage position and a work position. In the work position, the body is parallel with the supporting surface; and in the storage position, the body is perpendicular to the supporting surface. 
         [0022]    In one embodiment, an opening is displaced on at least one of the first and second stopping surfaces. 
         [0023]    In one embodiment, a miter saw for cutting the workpiece comprises a base having a supporting surface for supporting a workpiece; a turntable pivotally mounted on the base; a saw pivotally connected to the base, the saw unit comprising a motor and a saw blade rotary driven by the motor; a first fence assembly connected to the base, the first fence assembly comprising a first fence that has a first stopping surface that is perpendicular to the supporting surface, the first stopping surface having a first height that is the largest distance that the first stopping surface extends upwardly from the supporting surface; wherein the base comprises a mounting surface for engaging the first fence, the mounting surface and the stopping surface being angularly disposed. 
         [0024]    In a further embodiment, the angle of the first fence and the mounting surface is 90 degrees. 
         [0025]    In one embodiment, the miter saw further comprises a second fence that is interchangeable with the first fence. 
         [0026]    In one embodiment, the second fence has a second stopping surface that is perpendicular to the supporting surface. The second stopping surface may have a second height that is the largest distance that the second stopping surface extends upwardly from the supporting surface. The second height may not be equal to the first height. 
         [0027]    In one embodiment, a guiding device is disposed between the base and the first fence. The guiding device comprises a guiding member mounted on the first fence and a guiding groove mounted on the base, the guiding member being slidably disposed in the guiding groove. 
         [0028]    In one embodiment, a positioning device is mounted on the first fence for supporting the workpiece. The positioning device comprises a body and a positioning plate attached on one end of the body. The body is movably mounted on the first fence assembly, and the positioning plate and the first fence support the workpiece together. 
         [0029]    In one embodiment, an opening is displaced on at least one of the first and second stopping surfaces. 
         [0030]    In comparison with prior art, the advantages of the present invention are that the base has a mounting surface to cooperate with the fence, and the mounting surface and workpiece supporting surface are angularly disposed so that the fence does not need to be directly mounted on the workpiece supporting surface. This reduces the area of finish surface and the cost. The base can be small and fences having different heights can be disassembled from the base, thus avoiding the drawbacks of the difficult alignment of the fixed fence and movable fence and the misalignment in the upright direction. This promotes cutting precision and makes simpler structures and lower costs. Since the fences have different heights and are interchangeably used, the number of available inclined cutting angles is increased. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0031]    The present invention is further detailed in combination with the drawings attached and the embodiments described hereinafter, wherein: 
           [0032]      FIG. 1  depicts the miter saw having a first fence according to the present invention. 
           [0033]      FIG. 2  illustrates a disassembled view of the miter saw according to the present invention. 
           [0034]      FIG. 3  is the disassembled view of the miter saw according to the present invention. 
           [0035]      FIG. 4  is the disassembled view of the miter saw according to the present invention. 
           [0036]      FIG. 5  depicts the miter saw having a second fence according to the present invention. 
           [0037]      FIG. 6  is the disassembled view of the miter saw according to the present invention. 
           [0038]      FIG. 7  depicts the miter saw having a positioning device according to the present invention. 
           [0039]      FIG. 8  illustrates the miter saw having a positioning device according to the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0040]    The present invention will be described in more detail herein with reference to the figures and embodiments. 
         [0041]    Referring to  FIG. 1 , a miter saw includes a base  1 , a working table  2  rotatably mounted on the base  1 , a supporting frame  4  connected to the working table  2 , and a saw unit  3  connected to the supporting frame  4 . The saw unit  3  is pivotally connected to the supporting frame  4  by a pivotal axis  30  so that the saw unit  3  can be pivoted up and down relative to the base  1  to cut the workpiece. 
         [0042]    The working table  2  is movably mounted on the base  1 , and a locking mechanism  20  is arranged between the working table  2  and the base  1  for locking the working table  2  on the base  1 . The working table  2  includes the working surface  21  for supporting the workpiece. 
         [0043]    The saw unit  3  includes a saw blade  31 , a motor  36  for driving the saw blade  31  to rotate (the dotted line shows a part of the motor in the figures), a fixed protective cover  33  and a movable protective cover  34 , and a handle  35  for driving the saw unit  3  to pivotally rotate by the pivotal axis  30 , wherein the motor  36  is rotatably mounted in the motor casing  32 . The handle  35  is fixedly mounted on the fixed protective cover  33 , and is used by the operator to cut the workpiece by holding the saw unit  3 , and a switch is mounted on the handle  35  to start and close the motor  36 . The fixed protective cover  33  is generally fixed to the motor casing  32  for covering a part of the saw blade  31 . The movable protective cover  34  is pivotally mounted on the fixed protective cover  33  for covering a part of the saw blade  31  in a non-cutting position. A movable cover driven mechanism (not shown in the Figures) is connected to the movable protective cover  34  for opening and closing the movable cover  34  quickly. The fixed protective cover  33  is connected to the support  4  via a pivot  30 . The handle  35  can be operated to make the saw unit  3  perform cutting operations. 
         [0044]    The base  1  includes a workpiece-supporting surface  11  for supporting the workpiece, and a right and a left side relative to the saw blade  31 , the front side being close to the operator and a corresponding back side. The workpiece-supporting surface  11  and the working surface  21  are generally in the same plane and support the workpiece to be cut together. 
         [0045]    The support  4  is pivotally connected to the working table  2  via a longitudinal axis  41  (as shown in  FIG. 3 ), thus the support  4  and the saw unit  3  are pivotable clockwise and counterclockwise with the longitudinal axis  41  inclining to a determined angle relative to the working table  2  to cut the workpiece, that is, the support  4  and the saw unit  3  incline to the right and left for double-swing cutting. A lock mechanism  40  disposed between the support  4  and the work table  2  locks the support  4  on the work table  2 . 
         [0046]    The miter saw  100  further includes a first fence assembly  5  that includes a pair of first fences  51  mounted on the right and left sides of the base  1 . The two first fences  51  in the same plane are respectively across the work table  2 , and support the workpiece together. The first fences  51  may be connected together or be set independently. In this embodiment, a pair of the first fences is set independently and relatively independent of the individual. The specific structure of the first fences  51  and its connection with the base  1  will be described by illustrating one of the first fences  51 . 
         [0047]    The first fence  51  comprises a first stopping surface  511  that is perpendicular to the workpiece-supporting surface  11  for supporting the workpiece to be cut. The first stopping surface  511  has a first height E, which is the largest distance, where the first stopping surface extends upwardly from the workpiece-supporting surface  11 . The first height E equals the distance between the highest point of the first fence  51  and the workpiece-supporting surface  11 . 
         [0048]    The first fence  51  has a first configuration that may include construction, shape, and size and so on, wherein the size means the length, height and width of the first fence  51  or the area of the first stopping surface  511 , and the shape means the first fence  51  may be rectangular, oval, trapezoidal and so on, then the construction means the first fence  51  has openings or protrusions and so on. 
         [0049]    In this embodiment, the first fence  51  is roughly rectangular and has at least one opening  513  and step  514 . As the first stopping surface  511  is the finish surface, it can reduce the area of the finish surface by arranging opening  513  on the surface, thereby reducing costs, and the structure is easier to make. 
         [0050]    When cutting the anomalous workpiece, the workpiece can get through the opening  513 , thereby giving the workpiece to be cut a better stopping surface. 
         [0051]    The first fence  51  is releasably mounted on the base  1 . Referring to  FIG. 2 , the base  1  has a first mounting surface  12  (only shows the side of the mounting surface) that cooperates with the first fence  51 . The first mounting surface  12  is disposed parallel to the first stopping surface  511  and at the back side of the workpiece-supporting surface  11  to a determined angle relative to the workpiece-supporting surface  11  on the base  1 . 
         [0052]    In this embodiment, the first mounting surface  12  is disposed at an angle of 90° to the workpiece-supporting surface  11 . The first mounting surface  12  and the first stopping surface  511  are fit completely (as shown in  FIG. 1 ), while the first fence  51  is mounted on the base  1 . 
         [0053]    A guiding device  7  and a locking device  9  are located between the first fence  51  and the base  1 . In this embodiment, the guiding device  7  comprises a guiding member  71  mounted on the first fence  51 , a guiding groove  72  mounted on the base  1 , and the guiding members  71  are slidably received into the guiding groove  72 . 
         [0054]    The guiding member  71  and the first fence  51  are assembled together by a locking unit (not shown). Of course, the guiding member  71  and the first fence  51  can be integrated. 
         [0055]    The guiding member  71  is a T-shaped member having an upper surface  712  and a stopping surface  711 , which the guiding groove  72  is leaned on. The guiding groove  72  is a T-shaped groove having a blocking surface  721  contacted with the stopping surface  711 , and the guiding members  71  are slidably received into the guiding groove  72 . Of course, as is well-known by the person skilled in the art, the guiding groove  72  and guiding member may be other shapes like swallow-tailed groove, V-groove, etc. 
         [0056]    Referring to  FIG. 3 , a blocking surface  14  is disposed on the base  1  for supporting the first fence  51 . The blocking surface  14  is disposed parallel to the workpiece-supporting surface  11  and perpendicular to the first mounting surface  12 . First fence  51  has a down surface  512  cooperating with the blocking surface  14 , and the down surface  512  is disposed perpendicular to the first stopping surface  511 . 
         [0057]    The locking device  9  has a screw  91  and an engaged nut  92 , the screw  91  extending through the holes of guiding member  71  and the first fence  51 , then engages with the nut  92 , thus locking the first fence  51  on the base  1 . 
         [0058]    Referring to  FIG. 4 , when the first fence  51  needs to be assembled, simply insert the guiding member  71  into the guiding groove  72 , then slide down until the down surface  512  of the first fence  51  is blocked by the blocking surface  14  of the base  1 , and then tighten the nut  92  so that the stopping surface  711  of the guiding member  71  contacts the blocking surface  721  of the guiding groove  72 . In this way, the first fence  51  is fixed at one side of the base  1  for locating the workpiece to be cut, while the upper surface  712  of the guiding member  71  is approximately parallel to the workpiece-supporting surface  11  (as shown in  FIG. 1 ). First fence  51  can be directly mounted on the base  1 , and since there is only one fence position, it will not cause space as fixed or movable fences, and affect the cutting precision. 
         [0059]    When removal of the first fence  51  is desired, just loosen the nut  92 , making space between the supporting surface  711  of the guide member and the blocking surface  721  of the guiding groove  72 , and then easily remove the first fence  51  by sliding it up. 
         [0060]    Referring to  FIG. 5 , the miter saw  100  further includes a second fence assembly  6  having a pair of second fences  61  mounted on the right and left sides of the base  1 , and the two second fences  61  in the same plane are respectively across the work table  2  and support the workpiece together. The second fences  61  may be connected together or be set independently. In this embodiment, a pair of the second fences  61  is set independently and relatively independent of the individual as the first fence  51 . 
         [0061]    The second fence  61  comprises a second stopping surface  611  that is perpendicular to the supporting surface  11  for supporting the workpiece to be cut. The second stopping surface  611  has a second height F, which is largest distance, where the second stopping surface  611  extends upwardly from the supporting surface  11 . The second height F equals the distance between the highest point of the second fence  61  and the supporting surface  11 . Second height F is less than the first height E, that is, the height of the second fence  61  is less than the height of the first fence  51 . In this way, the second fence assembly  6  is suitable for supporting the lower workpiece or the workpiece that needs a larger angle, and the first fence assembly  5  is suitable for supporting the higher workpiece or the workpiece that needs a smaller angle. 
         [0062]    The second fence  61  has a second configuration that may include construction, shape, and size and so on, wherein the “size” means the length, height and width of the second fence  61  or the area of the second stopping surface  611 , the “shape” means the second fence  61  may be rectangular, oval, trapezoidal and so on, the “construction” means the second fence  61  has openings or protrusions and so on. The first configuration is different from the second configuration. In this embodiment, the two configurations mainly have differences in height. 
         [0063]    Of course, as is well-known by the person skilled in the art, they may have the same height, different lengths or widths, or different shapes such as rectangle or trapezoid, or with or without openings and so on. 
         [0064]    We can arrange some openings on the second supporting surface  611  of the second fence  61  to reduce the area of the finish surface or make the workpiece to get through. In this embodiment, there is no opening on the second fence  61 . 
         [0065]    When the second fence  61  is mounted on the base  1 , the second stopping surface  611  and the mounting surface  12  of the base  1  are fit completely. 
         [0066]    Referring to  FIG. 6 , a guiding device  7  and a locking device  9 , which have the same structure as the devices between the first fence assembly  5  and the base  1  (not shown in the figures), are located between the second fence assembly  6  and the base  1 . The second fence assembly  6  is also removably mounted at two sides of the base  1  for locating the workpiece to be cut. 
         [0067]    As the first fence assembly  5  and the second fence assembly  6  can be mounted on or dismounted from the base  1 , the first fence assembly  5  and the second fence assembly  6  can be selected to be mounted on the base  1  according to the practical situation for supporting the workpiece. 
         [0068]    Referring to  FIG. 5 , when the operator needs to cut the lower workpiece or a larger angle workpiece, they can mount the second fence assembly  6  on the base  1  according to the above-mentioned method. Referring to  FIG. 1 , when cutting the higher workpiece or a smaller angle workpiece, the operator can dismount the second fence assembly  6  from the base  1  according to the above-mentioned method, then mount the first fence assembly  5 . In this way, the operator can choose the suitable fence assembly according to the practical situation for supporting the workpiece, thereby increasing the cutting angle and providing a more precise supporting surface. 
         [0069]    Of course, if the operator does not need to incline to the right to cut the workpiece but instead needs to incline to the left to cut the workpiece, he can mount the first fence  51 , for example, the higher fence on the right side of the base  1  during use. As needed, the operator can choose one of the second fence  62  and the first fence  51  to mount on the left side of the base  1 . Similarly, the operator can mount the first fence  51 , i.e., the higher fence, on the left side of the base  1  and, as needed, the operator can choose one of the second fence  62  and the first fence  51  to mount on the right side of the base  1 . 
         [0070]    Of course, as the second fence  61  and the first fence  51  are relatively independent, the first fence  51  and the second fence  61 , having two different heights, can be constituted into one new fence assembly. When it is desired to incline to the right to cut the larger angle workpiece, the lower second fence  62  can be mounted at the right side while the higher first fence  51  is mounted at the left side, and vice versa. 
         [0071]    As shown in  FIGS. 2 ,  3 ,  7 , and  8 , a positioning device  8  is located on the first fence  51  for the operator to cut the crown molding  200 . Of course, the positioning device  8  also applies to the second fence assembly  6 . 
         [0072]    It sets one of the positioning devices  8  on the first fence  51  as an example. As shown in  FIG. 2 , the positioning devices  8  include a body  81  of a long groove  82 , a connecting plate  84  disposed at one side of the body  81 , and a positioning plate  83  connected to the connecting plate  84 , which is perpendicular to the body  81 , and the positioning plate  83  is perpendicular to connecting plate  84 . The positioning plate  83  and the first fence  51  are used for positioning the crown molding  200  together. 
         [0073]    A fixing device  85  is disposed between the positioning device  8  and the first fence  51 , the fixing device  85  being mounted at the other side of the body  81  for fixing the body on the first fence  51 , and the fixing device  85  may slide relative to the long groove  82 . 
         [0074]    The fixing device  85  includes a screw  86  and a threaded hole  87  engaged with the screw  86 , the hole  87  being disposed on the first fence  51 , and the screw  86  can slide relative to the long groove  82 , which includes a knob  88 . 
         [0075]    The positioning device  8  has a storage position and work position. As shown in  FIG. 8 , at its work position, the body  81  of the positioning devices  8  is parallel to the supporting surface  11 . The positioning devices  8  and the first fence  51  support the crown molding  200  together. As shown in  FIG. 3 , at its storage position, i.e., when using the positioning devices  8  is not needed, the body  81  is perpendicular to the supporting surface  11 , thus, not affecting the first fence  51  for supporting the workpiece, which is not a crown molding. 
         [0076]    As shown in  FIG. 7 , when crown molding  200  needs to be cut, first loosen the knob  88  so that it can make the body  81  of the positioning devices  8  pivot around the screw  86  until the down surface of the connecting plate  84  and the supporting surface  11  fit together. As shown in  FIG. 8 , tightening the knob  88  so that the positioning device  8  is fixed on the first fence  51 , and together with the first fence assembly  5 , support the crown molding  200 . 
         [0077]    Of course, the crown molding  200  has different sizes, as shown in  FIG. 8 , and in order to facilitate position, loosen the knob  88  and adjust the body  81 . Then the body  81  slides in the long groove  82  along the direction of H as shown in  FIG. 8  until it arrives at the desired position, then tightening the knob  88 .