Abstract:
A sawing machine includes a base, a saw arm assembly pivotally connected to the base and having a L-shaped groove defined therein, a saw blade pivotally mounted to the saw arm assembly, a handle pivotally mounted to the L-shaped groove of the saw arm assembly for rotatable movement relative to the saw arm assembly, and a locking mechanism mounted to the handle for locking the handle to the saw arm assembly. Before operation, the handle is adjusted to the best angle that the user can conveniently apply the force, so that the user can operate the sawing machine easily and conveniently.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a sawing machine and more particularly, to a sawing machine, which allows the operator to easily apply the force to operate the sawing machine conveniently and easily. 
         [0003]    2. Description of the Related Art 
         [0004]    U.S. Pat. No. 6,658,976, entitled “Ergonomic miter saw handle”, disclosed an ergonomic miter saw having a base and a saw arm assembly pivotally mounted to the base, and a cutting disk pivotally mounted to the saw arm assembly. The saw arm assembly is connected with a handle through a rotatable joint for rotation of the handle. 
         [0005]    Before cutting the workpiece that has been placed on the base, the operator must adjust the tilting angle of the cutting disk. At this time, the user can rotate the rotatable joint to the desired angle and then use a locking mechanism to lock the handle. After the handle is locked, the user can hold the grip of the handle and then force the cutting disk downward to move and to cut the workpiece. 
         [0006]    According to the aforesaid design, the handle and the rotatable joint have a common pivot axis therethrough so that the handle is pivotable together with the saw arm assembly and adjustable to the desired angle by means of the rotatable joint. However, when moving the handle downwards to lower the cutting disk during a cutting operation of the miter saw, the operator cannot easily force the handle downward to drive movement of the cutting disk. Therefore, this design of miter saw is still not convenient in operation. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a sawing machine, which facilitates force exertion and enhances the operational convenience. 
         [0008]    To achieve the foregoing object of the present invention, the sawing machine is composed of a base, a saw arm assembly pivotally connected to the base and having a L-shaped groove defined therein, a saw blade pivotally supported on the saw arm assembly, a handle pivotally coupled to the L-shaped groove of the saw arm assembly and rotatable relative to the saw arm assembly, and a locking mechanism installed in the handle and connected to the saw arm assembly for locking the handle to a predetermined angle of the saw arm assembly. The L-shaped groove has a first groove portion and a second groove portion both of which are connected at the right angle. 
         [0009]    Further, the saw arm assembly includes a sliding block movable along the first groove portion of the L-shaped groove. The handle is movable along the second groove portion of the L-shaped groove and connected with the sliding block. Thus, the handle is rotatable relative to the saw arm assembly. 
         [0010]    Before operating the sawing machine, the user can adjust the handle to the best angle convenient for applying the force, so that the user can operate the sawing machine conveniently and easily. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a perspective view of a sawing machine according to the present invention. 
           [0012]      FIG. 2  is an exploded view of the sawing machine according to the present invention. 
           [0013]      FIG. 3  is a sectional view of a part of the present invention, showing the structure of the locking mechanism. 
           [0014]      FIG. 4  is a schematic drawing showing the status of the two stop plates and the sliding block before rotation of the handle 
           [0015]      FIG. 5  is another schematic drawing showing the status of the two stop plates and the sliding block after a 45° rotation of the handle 
           [0016]      FIG. 6  is another schematic drawing showing the status of the two stop plates and the sliding block after a 90° rotation of the handle 
           [0017]      FIG. 7  is similar to  FIG. 1  but showing the handle rotated for 90°. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    Referring to  FIG. 13 , a sawing machine  10  in accordance with a preferred embodiment of the present invention is composed of a base  20 , a saw arm assembly  30 , a saw blade  40 , a motor  50 , a handle  60 , and a locking mechanism  70 . 
         [0019]    The base  20  is a flat circular block member for placing a workpiece thereon for being cut. 
         [0020]    The saw arm assembly  30  includes a body  32  formed of two half shells  33  and  34 . The two half shells  33  and  34  abut together. One half shell, namely, the first half shell  33  has one end pivotally connected to the base  20 , and the other end provided with a coupling portion  332 . The first half shell  33  further has a first groove  334  formed in the coupling portion  332  and extending in a direction perpendicular to the base  20 . The second half shell  34  has one end pivotally connected to the base  20 , and the other end provided with a coupling portion  342 . The second half shell  34  further has a second groove  344  formed in the coupling portion  342  and extending in a parallel manner relative to the base  20 . The two half shells  33  and  34  abut each other to enable interconnection of the first groove  334  and the second groove  344  to form a L-shaped groove  35 . Referring to  FIG. 4 , the saw arm assembly  30  further includes a mount  36  installed in the coupling portions  332  and  342 . The mount  36  has a L-shaped hole  362  corresponding to the L-shaped groove  35 . Further, a first stop plate  37  and a second stop plate  38  are respectively mounted in the L-shaped hole  362  of the mount  36 . The L-shaped hole  362  has a vertical section  364 , and a horizontal section  366 . The first stop plate  37  is mounted in the vertical section  364  of the L-shaped hole  362 , and movable vertically along the vertical section  364 . Further, the first stop plate  37  has a circular through hole  372  at the bottom side. The second stop plate  38  is mounted in the horizontal section  366  of the L-shaped hole  362 , and movable horizontally along the horizontal section  366 . Further, the second stop plate  38  has an elongated slot  382  on its left half part. Further, the mount  36  has three position points  368   a - 368   c  in the vertical section  364 . According to the present preferred embodiment, these three position points  368   a - 368   c  correspond to 0° position, 45° position, and 90° position respectively. The first stop plate  37  is marked with an index  374 . When moving the first stop plate  37  vertically along the vertical section  364 , the index  374  can be aligned at one of the three position points  368   a - 368   c . The saw arm assembly  30  further includes a sliding block  39 . The sliding block  39  is mounted in the second groove  344  of the second half shell  34 , and movable horizontally along the second groove  344 . The sliding block  39  has a through hole  392 , and a flange  394  annularly protruding from one side thereof around the through hole  392  toward the mount  36 . The flange  394  extends through the horizontal section  366  of the L-shaped hole  362  and into the elongated slot  382  of the second stop plate  38 . When the sliding block  39  is horizontally moved along the second groove  344 , the second stop plate  38  is carried by the flange  394  of the sliding block  39  to move along the horizontal section  366  of the L-shaped hole  362 . 
         [0021]    The saw blade  40  is rotatably mounted on the body  32  of the saw arm assembly  30  for cutting the workpiece placed on the base  20 . 
         [0022]    The motor  50  is mounted to the body  32  of the saw arm assembly  30  for rotating the saw blade  40 . 
         [0023]    The handle  60  has a grip  62  for holding by the user, an oval protrusion  64  provided at one end of the grip  62 , and a round rod  66  extending outward from the oval protrusion  64 . The round rod  66  extends through the through hole  372  of the first stop plate  37  into the first groove  334  of the first half shell  33 . By means of the round rod  66 , the handle  60  can drive the first stop plate  37  to move vertically along the vertical section  364 . Further, the oval protrusion  64  has a hole  642 . 
         [0024]    Referring to  FIG. 3 , the locking mechanism  70  includes a pin  72 , a locating member  74 , a lever  76 , and a stop rod  78 . The pin  72  is peripherally threaded. The locating member  74  is a hexagonal nut having a relatively smaller outer diameter portion at a midsection thereof and a relatively greater outer diameter portion on each of the front and rear ends thereof. The pin  72  is inserted in proper order through the through hole  392  of the sliding block  39 , the elongated slot  382  of the second stop plate  38  and the hole  642  of the oval protrusion  64 , and then screwedly connected with the locating member  74 . The lever  76  is sleeved onto the locating member  74  and stopped against the oval protrusion  64  of the handle  60 . The stop rod  78  is inserted through the lever  76  and stopped against the midsection of the locating member  74  to prevent the lever  76  from rotation relative to the locating member  74 , thereby locking the handle  60  at a predetermined angle. 
         [0025]    When the handle  60  is located at the zero angle position as shown in  FIGS. 1 and 4 , the first stop plate  37  is located below the vertical section  364  of the L-shaped hole  362 , and the index  374  of the first stop plate  37  is aligned with the position point  368   a  corresponding to the zero angle; the second stop plate  38  is located at the right side of the horizontal section  366  of the L-shaped hole  362 , and the flange  394  of the sliding block  39  is located at the right end of the elongated slot  382 . At this time, the operator can conveniently operate the handle  60  to cut the workpiece in vertical direction. When intending to adjust the handle  60  to 45° angle, it is necessary to loosen the locating member  76  to the unlocking position, and then to rotate the handle  60  clockwise. When the handle  60  is rotated clockwise, as shown in  FIG. 5 , the round rod  66  of the handle  60  is moved upwards along the first groove  334  of the L-shaped groove  35  to carry the first stop plate  37  upwards along the vertical section  364  of the L-shaped hole  362  to enable the index  374  to be aligned with the position point  368   b  corresponding to 45° angle, and at the same time, the handle  60  moves the sliding block  39  leftwards along the second groove  344  of the L-shaped groove  35  to enable the flange  394  of the sliding block  39  to be moved from the right end of the elongated slot  382  of the second stop plate  38  to the left end of the elongated slot  382 . Thereafter, the lever  76  is turned to the locking position to lock the handle  60  to the 45° angle position. If the operator keeps rotating the handle  60  clockwise, as shown in  FIG. 6 , the handle  60  moves the first stop plate  37  to the top side of the vertical section  364  of the L-shaped hole  362  to enable the index  374  of the first stop plate  37  to be aligned with the position point  368   c  corresponding to 90° angle. When the first stop plate  37  is moved to the top side of the vertical section  364  of the L-shaped hole  362 , the handle  60  simultaneously carries the sliding block  39  leftwards. At this time, the flange  394  of the sliding block  39  moves the second stop plate  38  leftwards along the horizontal section  366  of the L-shaped hole  362  to enable the second stop plate  38  to be positioned in the intersection between the vertical section  364  and horizontal section  366  of the L-shaped hole  362 , and the handle  60  is now located at the 90° angle position as shown in  FIG. 7 . Further, the first stop plate  37  and the second stop plate  38  each provide a function of preventing the chippings from going through the L-shaped hole  362  into the L-shaped groove  35  and from hindering movement of the sliding block  39 . 
         [0026]    By means of the aforesaid design and subject to different cutting requirements, the operator can conveniently unlock the locking mechanism and adjust the angle of the handle between 0° and 90°, and then lock the locking mechanism again after the handle has been adjusted to the desired angle. Because the handle can be conveniently adjusted to the desired angle within 0°-90°, the user can apply force to the handle to move the saw blade in cutting the workpiece efficiently. 
         [0027]    Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims