Abstract:
A table saw including a base, a work table on the base, a slot defined through the work table, a saw blade extending through the slot, and an optic indicating device located beneath the work table including at least one light emitter. The light beam of the light emitter parallels to the plane of the saw blade. The cutting position and the obliquity of the saw blade indicated by the optic indicating device.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a table saw, particularly relates to a table saw with an optical indicating device. 
       BACKGROUND OF THE INVENTION 
       [0002]    A conventional table saw can cut a wood piece in a line by using a blade driven by a motor. The table saw includes a base, a work table disposed on the base, and a blade extending through the work table. The blade is driven by a motor. A riving knife is disposed under the work table and mounted on an adjusting mechanism, and the blade can tilt by operating the adjusting mechanism. A miter gauge is disposed on the work table, and the operator can use the miter gauge to guide the workpiece at a pre-defined angle. A guard is mounted above the blade, and can prevent the operator from being hurt and dust from spraying. 
         [0003]    U.S. Publication No. 20040261592 A1 (Chen) discloses a table saw, which has a riving on which knife is mounted a laser device, and the light emitted by the laser device is located in front of the blade to indicate the position of the cut. The operator can cut the workpiece by using the light for guiding the workpiece. 
         [0004]    The laser device is mounted on the riving knife, but the riving knife will be shaken during cutting of the workpiece, and then the light may wander, which may lead to a low quality workpiece. Furthermore, if the operator puts up the guard by mistake, the laser device may irradiate the eyes of the operator directly, which may hurt the operator. 
         [0005]    Further, during cutting of the workpiece, the operator cannot guide the workpiece without the miter gauge, for to do so would be very dangerous. So it is useless to fix the laser device on the riving knife without changing the operating method of the fence or the miter gauge. 
         [0006]    U.S. Pat. No. 6,263,584 (Owens) discloses a table saw with a detachable laser device. The light of the laser device can work with a protractor to set the bevel angle of the blade. Then, before startup of the table saw, the laser device is removed, and the blade can cut the workpiece at the pre-defined angle. 
         [0007]    But with this table saw, it is necessary to mount and remove the laser device to cut workpieces with a different angle, and requires working with a protractor, which is inconvenient. 
       SUMMARY OF THE INVENTION 
       [0008]    One object of the present invention is to provide a table saw with an optical indicating device which can be more stable and convenient. 
         [0009]    Another object of the present invention is to provide a table saw with an optical indicating device which can precisely indicate the blade&#39;s cutting position and bevel angle. 
         [0010]    According to the objects aforementioned, the present invention provides a table saw including a base, a work table disposed on the base, a slot defined on the work table, a blade extending through the slot, wherein an optical indicating device is disposed below the work table, the optical indicating device including at least one light generator, the light generator emitting a light beam parallel with the plane of the blade. 
         [0011]    The present invention further provides that the light generator may be a light-emitting diode (LED). 
         [0012]    The present invention further provides that the light generator may be a laser diode. 
         [0013]    The present invention further provides that the optical indicating device may include a mounting base, with the light generator disposed on the mounting base, the light generator electrically connected with a power supply. 
         [0014]    The present invention further provides that the power supply may be a cell. 
         [0015]    The present invention further provides that the optical indicating device may be moved with the blade. 
         [0016]    The present invention further provides that the work table may include an indicating section, the light beam projected onto the indicating section forming a line indicating the cut position of the blade. 
         [0017]    The present invention further provides that the indicating section may be made of translucent material. 
         [0018]    The present invention further provides that the blade has a width, and that the light beam may be located within interior of the width of the blade. 
         [0019]    The present invention further provides that the blade has a width, and that the light beam may be located on the outside of the width of the blade, the width having a left side edge and a right side edge, with the light beam aligned with the left side edge or the right side edge. 
         [0020]    The present invention further provides a scale may be mounted on the base, the light beam projected onto the scale forming a line indicating the bevel angle of the blade. 
         [0021]    The present invention further provides that the scale may be made of translucent material. 
         [0022]    The present invention further provides that the scale may be curve shaped. 
         [0023]    The present invention further provides that the work table may include an indicating section and a scale mounted on the base, the optical indicating device having a first light generator and a second light generator. The first light generator emits a light, and at least a portion of the light projects onto the indicating section and forms a first line, indicating the cut position of the blade, and at least a portion of the light projects onto the scale and forms a second line, indicating the bevel angle of the blade. 
         [0024]    The present invention further provides that a second light generator may emit a light projecting onto the indicating section and form a third line, indicating the cut position of the blade. 
         [0025]    The present invention further provides that the blade has a width, the width having a left side edge and a right side edge, the first line may be aligned with the right side edge of the width, and the third line may be aligned with the left side edge of the width. 
         [0026]    The present invention further provides that the table saw may include a rod connected to the lower surface of the work table, a bevel seat pivotally connected to the rod, and a bracket pivotally connected to the pivot seat. 
         [0027]    The present invention further provides that the optical indicating device may be disposed on the bevel seat. 
         [0028]    The present invention further provides that the optical indicating device may be disposed on the bracket. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0029]      FIG. 1  is a perspective view of the present invention, in which the bevel angle is 0°; 
           [0030]      FIG. 2  is a perspective view of the table saw shown in  FIG. 1 , in which the bevel angle is 20°; 
           [0031]      FIG. 3  is a cross sectional view of the table saw shown in  FIG. 1 ; 
           [0032]      FIG. 4  is a perspective view of part of the assembly of the table saw shown in  FIG. 1 ; 
           [0033]      FIG. 5  is a perspective view of part of the assembly of the table saw shown in  FIG. 1 ; 
           [0034]      FIG. 6  is a sketched view of the blade aligned with the indicating line, in which the indicating line is within the range of blade&#39;s width, and aligned with the left side edge of the width; 
           [0035]      FIG. 7  is a sketched view of the blade aligned with the indicating line, in which the indicating line is within the range of blade&#39;s width, and aligned with the right side edge of the width; 
           [0036]      FIG. 8  is a sketched view of the blade aligned with the indicating line, in which the indicating line is outside the range of blade&#39;s width, and aligned with the left side edge of the width; 
           [0037]      FIG. 9  is a sketched view of the blade aligned with the indicating line, in which the indicating line is outside the range of blade&#39;s width, and aligned with the right side edge of the width; 
           [0038]      FIG. 10  is a perspective view showing the indicating line of a workpiece aligned to the indicating line of the blade; 
           [0039]      FIG. 11  is a perspective view of part of the assembly of present invention, in which an optical indicating device has two light generators; 
           [0040]      FIG. 12  is a perspective view of part of the assembly of present invention, in which the blade has only one indicating line; 
           [0041]      FIG. 13  is a perspective view of part of the assembly of present invention, in which an alternative optical indicating device has two light generators; 
           [0042]      FIG. 14  is a perspective view of part of the assembly of present invention, in which the blade has two indicating lines. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0043]    A table saw is the preferred embodiment of the present invention. 
         [0044]    As shown in  FIGS. 1 to 5 , a table saw  1  includes a base  2 , a work table  3  connected to the base  2 , a cutter protection board  5  fixed to the work table  3 , and a slot  6  set on the cutter protection board  5 , wherein the circular saw blade  9  driven by a motor  7  passes through the slot  6 . 
         [0045]    A translucent indicating section  11  lying in front of the cutter protection board  5  is mounted on the work table  3 , wherein the indicating section  11  can be made of translucent plastics or any other translucent materials. A guide channel  13  for installing planar angle gauge  15  is configured in the upper surface of the work table  3 . 
         [0046]    A scale  17  is set on the base  2 , and the scale  17  is preferably curved. The scale  17  is made of translucent plastic or any other translucent materials. 
         [0047]    The scale  17  has a marking section  171  and a non-marking section  172 , wherein the back of the marking section  171  is printed with graduated line  18  and graduation values  19 . Except for the part printed with graduated line  18 , the other parts of the marking section  171  are all treated for opacity, so light beams can permeate through the graduated line  18  and the non-marking section  172  only, which clearly shows the indicating scale. 
         [0048]    An adjusting mechanism  14  is mounted below the work table  3 , wherein the adjusting mechanism  14  includes a bevel seat  22  and a bracket  24 . 
         [0049]    A rod  20  is fixed on the lower surface of the work table  3  along the longitudinal direction of the work table  3 . The bevel seat  22  is pivotally connected on the rod  20 . The bracket  24  is rotatably connected onto the bevel seat  22 . 
         [0050]    The motor  7  is fixed on the bracket  24 . The blade  9  is fastened on the output shaft  8  of the motor. A shaft sleeve is set near the blade  9  on the motor  7 . The first connecting piece  25  is pivotally connected onto the shaft sleeve. 
         [0051]    The first connecting piece  25  can also be pivotally connected onto the output shaft  8  of the motor. 
         [0052]    The second connecting piece  26  is a long rectangular board body whose one end is pivotally connected with the first connecting piece  25  through pins and the other end is pivotally connected with the bevel seat  22  via pins. 
         [0053]    One end of the first connecting piece  25  is bent to form a side plate  251  on which a riving knife  27  is fixedly linked. The riving knife  27  is a sheet with a cutting part  271  which keeps certain clearance away from the edge of the blade  9 . A pawl  30  and hood supporting arm  32  are pivotally coupled on the riving knife  27 . The riving knife  27 , pawl  30  and hood supporting arm  32  can go up and down together with the blade  9  through the first connecting piece  25  and the second connecting piece  26 . 
         [0054]    The base  2  has a panel  4  on which a curved slot  12  is set. The exterior part of the handwheel shaft  34  rotatably mounted on the bevel seat  22  passes through the slot  12 , wherein a handwheel  36  is detachably installed on the exterior part of the handwheel shaft  34  and the handwheel  36  is exposed outside the panel  4  for convenient operation. 
         [0055]    An optical indicating device  10  is fixedly configured on the bevel seat  22 . It is known to those skilled in this art that the optical indicating device  10  could alternatively be fixed to the bracket  24 . 
         [0056]    The optical indicating device  10  includes a mounting base  101  fixedly mounted on the bevel seat  22 , a light generator  102  set on the mounting base  101 , wherein the light generator  102  is electrically connected with a power supply  103 . A switch  104  which is used to connect or disconnect the power supply  103  is set on the power supply  103 . Preferably, the power supply  103  is a cell. As known to those skilled in this art, the power supply  103  may be a permanent magnet generator or a transformer. It is known to those skilled in this art that the optical indicating device  10  may further include an adjusting piece used to adjust the light generator  102 , the angle of light beam emitted by the light generator  102  and the parallelism of the light beam with the plane of the blade  9 , and no further details are given herein. 
         [0057]    The light generator  102  can select either an LED or a laser diode as the light source. The light generator  102  taking laser diode as light source has better concentrated energy and clearer light beam emitted. 
         [0058]    The LED can be one of single-color, dual-color and RGB full-color LEDs, wherein the dual-color and RGB full-color LEDs together with the control circuit form the light generator. To make the light beam emitted clearer, the colors with higher contrast between the indicating section  11  and scale  17  such as white, blue or red can be chosen, namely, the light generator  102  can select the LED with corresponding color to give off corresponding single color. With dual-color LED, different single colors can be emitted according to actual need through the control circuit. If RGB full-color LED is selected, not only different single colors of R, G and B can be given off as desired, but also the light beam of any color can be emitted under the control of the three primary colors of R, G and B. LED is non-irritant to people&#39;s eyes, safer in use and lower in cost. 
         [0059]    The light generator  102  can also select LED as light source, which generate planar light beam through the conversion of the combination of lenses. This structure can realize more concentrated LED light and clearer light beam. 
         [0060]    The light beam emitted by the light generator  102  is parallel to the plane of the blade  9 . The optical indicating device  10  is moved together with the blade  9 , namely the optical indicating device  10  and blade  9  make simultaneous deflection movement. 
         [0061]    The switch  104  is turned on to connect the power supply  103 , then the light generator  102  will emit a light beam. One part of the light beam is projected onto the indicating section  11  of the work table  3  to form an indicating line  105   a  which is used to indicate the cutting location of the blade  9 . One part of the light beam is projected onto the scale  17  to form an indicating line  105   b  which is used to indicate the bevel angle of the blade  9 . 
         [0062]    The indicating section  11  and the scale  17  are both made of translucent materials, and the light beam can be projected onto the indicating section  11  and the scale  17  to form very clear indicating lines  105   a ,  105   b  without any disclosure. Therefore, the light beam will not be directed into the operator&#39;s eyes and present any harm to the operator. 
         [0063]    The blade  9  has a width W which is provided with a left side edge and a right side edge. 
         [0064]    As shown in  FIG. 6 , the indicating line  105   a  is located within the range of the width W of the blade  9  and aligned with the left side edge of the width W. As shown in  FIG. 7 , the indicating line  105   a  is located within the range of the width W of the blade  9  and aligned with the right side edge of the width W. 
         [0065]    As shown in  FIG. 8 , the indicating line  105   a  is located outside the range of the width W of the blade  9  and aligned with the left side edge of the width W. As shown in  FIG. 9 , the indicating line  105   a  is located outside the range of the width W of the blade  9  and aligned with the right side edge of the width W. 
         [0066]    It is known to those skilled in this art that the indicating line  105   a  can be either aligned with the central plane of the blade  9  or aligned with any location within the range of the width W of the blade  9 . 
         [0067]    Since the part of light beam emitted by the light generator  102  is projected to the scale  17  to form an indicating line  105   b , the width of the indicating lines  105   a ,  105   b  are preferably the same as that of the graduated line  18 . 
         [0068]    For different alignment locations of indicating line  105   a  with blade  9 , the installation location of the scale  17  can be adjusted. Therefore, the scale  17  can be set to slide along the panel  4 . Moreover, according to different alignment locations of indicating line  105   a  with blade  9 , different indicating structures for installation locations are set. For example, the concave part is set on panel  4  for different installation locations, convex part engaged with the concave part is set on the scale  17 , or other fitting modes known in this field may be adopted. Further details are not given herein. 
         [0069]    Preferably, the scale  17  is fixed onto the panel  4 , and the indicating line  105   a  is aligned with the blade  9  in one of the ways shown in  FIGS. 6 to 7  so that is the operator can easily operate the saw. 
         [0070]    It is known to those skilled in this art that the light generator  102  can generate two light beams in parallel through the conversion of the combination of lenses, wherein the two light beams are parallel to the plane of the blade  9 , part of one light beam is projected onto the indicating section  11  to form the first indicating line which is aligned with the right side edge of the width W of the blade  9  and indicates the cutting location of the blade  9 , part is projected onto the scale  17  to form the second indicating line which indicates the bevel angle of the blade  9 ; the other light beam is projected onto the indicating section  11  to form the third indicating line which is aligned with the left side edge of the width W of the blade  9  and indicates the cutting location of the blade  9 . 
         [0071]    As shown in  FIGS. 11 to 14 , the optical indicating device  10  of the present invention can also include two light generators  102 A,  102 B, wherein the light beams emitted by the two light generators  102 A,  102 B are parallel to the plane of the blade  9 . 
         [0072]    As shown in  FIGS. 11 and 12 , when the light beams emitted by the two light generators  102 A,  102 B are on the same plane, the light beam given off by the first light generator  102 A is projected onto the indicating section  11  to form the first indicating line  1051  which indicates the cutting location of the blade  9 , the light beam given off by the second light generator  102 B is projected onto the scale  17  to form the second indicating line  1052  which indicates the bevel angle of the blade  9 . The light beams emitted by the two light generators  102 A,  102 B can be partly projected onto the indicating section  11  and partly projected onto the scale  17 . 
         [0073]    As shown in the  FIGS. 13 and 14 , when the light beams emitted by the two light generators  102 A,  102 B are not on the same plane, part of the light beam given off by the first light generator  102 A is projected onto the indicating section  11  to form the first indicating line  1051  which is aligned with the right side edge of the width W of blade  9 , part of the light beam given off by the first light generator  102 A is projected onto scale  17  to form the second indicating line  1052  which indicates the bevel angle of the blade  9 ; the light beam emitted by the second light generator  102 B is projected onto the indicating section  11  to form the third indicating line  1053  which is aligned with the left side edge of the width W of the blade  9 . 
         [0074]    The optical indicating device  10  can also include more light generators. More details are not given herein. 
         [0075]    As shown in  FIGS. 1 to 9 , in transverse workpiece sawing state, turn on the switch  104  to connect the power supply  103 , the light generator  102  then gives off light beam, push the handwheel  36  forward to drive the adjusting mechanism  14  to swing around the rod  20 , the swinging of the adjusting mechanism  14  drives the motor  7 , blade  9 , riving knife  27 , pawl  30  and hood supporting arm  32  to swing in the same direction simultaneously, namely, the optical indicating device  10  is moved together with the blade  9 , until the indicating line  105   b  aims at the graduated line of 0 degree on the scale  17 , as shown in  FIG. 1 , at this time, the bevel angle of the blade  9  is 0 degree, namely, the included angle between the plane of the blade  9  and that of the work table  3  is 90 degrees and the indicating line  105   a  is in the first location. 
         [0076]    A locking wrench  40  is used to lock the adjusting mechanism relative to the work table  3 . When sawing a workpiece, the operator puts the workpiece to be processed on the work table  3  and guides orientation by means of a planar angle gauge  15 , further details are as shown in  FIG. 10 . Mark an indicating line L 1  on the workpiece to be pressed with a pencil, confirm the location for sawing, push the planar angle gauge  15  so that the indicating line L 1  is aligned with the indicating line  105   a , at this time the blade  9  is also aligned with the indicating line L 1 . Start the table saw  1 , push the planar angle gauge  15  so as to drive the workpiece to be processed to move along the direction aiming at the blade  9 , saw the workpiece to be processed to the scheduled bevel angle, afterwards, start the switch  104  to disconnect the power supply  103 . 
         [0077]    When it is required to saw the work piece to be processed into an inclination angle of 20 degrees, the operator shall push the handwheel  36  along the direction indicated by B as shown in  FIG. 1  to drive the adjusting mechanism  14  to swing around the rod  20  until the indicating line  105   b  aims at the graduated line of 20 degrees on the scale  17 , as shown in  FIG. 2 , the indicating line  105   a  is deflected to the second location. At this time, the bevel angle of the blade  9  bevel angle is 20 degrees, namely, the included angle between the plane of the blade  9  and that of the work table  3  is 70 degrees. 
         [0078]    A locking wrench  40  is used to lock the adjusting mechanism  14  relative to the work table  3 . When sawing a workpiece, the operator puts the workpiece to be processed on the work table  3  and guides orientation by means of a planar angle gauge  15 . Mark an indicating line L 1  on the workpiece to be pressed with a pencil, confirm the location for sawing, push the planar angle gauge  15  so that the indicating line is aligned with the indicating line  105   a , at this time the blade  9  is also aligned with the indicating line. Start the table saw  1 , push the planar angle gauge  15  so as to drive the workpiece to be processed to move along the direction of the bevel angle of the blade  9 , saw the workpiece to be processed to the scheduled inclination angle, afterwards, start the switch  104  to disconnect the power supply  103 . 
         [0079]    By means of the planar angle gauge  15  and optical indicating device  10 , the operator can saw the workpiece to be processed into the scheduled inclination angle or bevel angle for convenient operation. 
         [0080]    Since the optical indicating device  10  is fixedly installed onto the bevel seat  22  and can swing with the swinging of the adjusting mechanism  14 , motor  7  and bevel angle of the blade  9 , the light beam emitted by the optical indicating device  10  keeps parallel to the plane of the blade  9  and accurately indicates the sawing direction and the bevel angle of the blade. Moreover, with the beam, the graduation value can be easily observed unlike regular graduation indication which is prone to generate visual error, thus improving the processing quality of workpiece and avoiding waste. 
         [0081]    When keeping changing the workpiece sawing angle, the optical indicating device  10  does not need to be detached repeatedly, so the operator can conveniently use the tool and can greatly improve working efficiency. 
         [0082]    For longitudinal sawing requirement, the operator can also easily saw the workpiece to be process into the scheduled inclination angle by means of the guardrail and the optical indicating device  10 .