Abstract:
A miter saw has a base assembly, a table assembly assembly rotatably attached to the base assembly, and a drive assembly pivotally attached to the table assembly. The drive assembly has a motor and a blade driven by the motor. The table assembly has at least one elastic bumper thereon.

Description:
FIELD 
       [0001]    This specification relates to miter saws and more specifically to fine-adjust miter mechanisms for such miter saws. 
       BACKGROUND 
       [0002]    A miter saw typically has the capacity to crosscut work pieces placed against its horizontal table and vertical fence. This saw can be rotated to make vertical cuts through a work piece at various angles relative to the fence. A vertical cut is known as a “miter cut.” 
         [0003]    A compound miter saw has the capability to tilt the blade (counterclockwise) to an angle relative to the table, generally from 0 degrees to 45 degrees left of vertical. A cut made with the blade tilted at an angle (and perpendicular to the fence) is known as a “bevel cut.” A cut made with the blade set to both an angle relative to the fence (miter angle) and an angle relative to the base (bevel angle) is known as a “compound cut.” 
         [0004]    A dual bevel compound miter saw has the added capacity to tilt the blade to an angle relative to the table generally from 45 degrees left of vertical to 45 degrees right of vertical. This arrangement allows for more “compound cut” variations. 
         [0005]    A slide miter saw has the saw component mounted to a rail system allowing it to slide backward and forward thereby increasing the saw&#39;s cutting capacities. The slide mechanisms are typically added to a compound saw. 
         [0006]    Miter saws typically include a detent system that allows the table and the attached cutting tool to be preset to specific angles relative to the fixed fence. A detent system provides an accurate means to preset and reset the saw to make the most popular cuts. A miter saw typically provides 10 to 12 preset detent positions or recesses. 
         [0007]    The typical miter saw table includes a rotating disc-like work surface that is supported by the tools&#39; base. The table includes a support member for a lock handle in the front and a saw mounting area to the rear, behind the fence. In addition, a spring-loaded retractable detent pin or wedge is mounted in the handle area. The base typically has a rounded front shape that is concentric with its table and includes detent holes or slots positioned to accept the above-mentioned pin or wedge. The locking handle moves to create pressure against the rounded front of the base outside of the detent slot or hole locations. The lock handle may be of a rotating screw-type or lever cam-type design. In order to indicate the saw&#39;s preset cutting position, the rotating table supports a pointer that relates to an angle scale on the fixed base. 
         [0008]    In using a detent system to preset the miter cut angle, the user would first loosen the lock handle, and retract the detent pin or insert. This would be followed by rotating the table, releasing the detent pin or insert into a desired slot or recess, and relocking the handle. 
         [0009]    If a user wants to preset the miter saw for an angle cut not provided by the detent system, he would allow the spring-loaded pin or insert to rest against the front surface of the base outside of the detent slots and tighten the locking handle. For these cuts, the user must use the locking handle to hold the saw&#39;s position. Due to the interaction between the lever and the detent, however, the prior art arrangements do not allow for a fine adjustment that is near one of the predetermined detent positions. 
         [0010]    It is thus desirable to provide a miter saw with a fine-adjustment mechanism whereby the user can quickly and easily make slight adjustments to the angle of cut. Several solutions have been attempted, as shown in US Patent Published Application Nos. 20040154448 and 20050262984. However, such solutions require many parts, which add cost to the miter saw, as well as increase the assembly time. 
       SUMMARY 
       [0011]    A miter saw including a base assembly, a table assembly rotatably attached to the base assembly, a drive assembly pivotally attached to the table assembly, the drive assembly including a motor and a blade driven by the motor, where the table assembly has at least one elastic bumper thereon. 
         [0012]    Additional features and benefits of the present invention are described, and will be apparent from, the accompanying drawings and the detailed description below. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0013]    The accompanying drawings illustrate preferred embodiments according to the practical application of the principles thereof, and in which: 
           [0014]      FIG. 1  is an exemplary sliding miter saw incorporating the invention. 
           [0015]      FIG. 2  is a partial cross-section of the miter detent override mechanism. 
           [0016]      FIG. 3  is a partial top plan view of a first embodiment of a miter fine-adjust mechanism according to the invention. 
           [0017]      FIG. 4  is a partial cross-sectional view of a second embodiment of a miter fine-adjust mechanism according to the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    The present invention will now be described more fully hereinafter. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. 
         [0019]    In  FIGS. 1 through 4 , an exemplary sliding compound miter saw according to the present invention is designated generally by the reference numeral  10 . The sliding compound miter saw  10  preferably includes a base assembly  12 , an angularly movable turntable or table assembly  14 , an angularly movable housing assembly  16 , a saw blade  18 , a blade guard mechanism or assembly  20 , a motor  22  drivingly connected to the saw blade  18  by way of a drive assembly  36 , a handle arrangement  24 , and a workpiece-supporting fence assembly  26 . 
         [0020]    The table assembly  14  is preferably secured to the base assembly  12  such that it can be rotated in order to provide adjustment for miter cutting of a workpiece. The rotation of the table assembly  14  changes the angle of saw blade  18  relative to the fence assembly  26  but maintains the perpendicularity of the plane of the saw blade  18  with the table assembly  14 . A locking mechanism  28  can be activated in order to lock the table assembly  14  to the base assembly  12  at a desired miter-cutting position. 
         [0021]    The housing assembly  16  may be secured to the table assembly  14  such that it can be pivoted with respect to the table assembly in order to provide adjustment for bevel cutting of the workpiece  13 . The bevel pivoting of the housing assembly  16  changes the angle of the saw blade  18  relative to the table assembly  14  but maintains the perpendicularity of the saw blade  18  with respect to the fence assembly  26 . A locking mechanism  30  can be activated in order to lock the housing assembly  16  to table assembly  14  at a desired bevel-cutting position. As can be appreciated by one skilled in the art, the adjustments for mitering and beveling can be performed separately or simultaneously in order to perform a compound miter and bevel cut. 
         [0022]    The housing assembly  16  may also include a support housing or assembly  32 , which mounts a pair of support arms  34  for sliding movement with respect to the remainder of the housing assembly  16 . The saw blade  18 , the blade guard  20 , the motor  22  and the handle  24  are all preferably mounted to a drive assembly  36 , which is pivotally interconnected with the support arms  34  and thus the support assembly  32 . The pivoting of the drive assembly  36  downwardly towards the table assembly  14  operates to bring the saw blade  18  into a workpiece-engaging position and simultaneously open the blade guard  20  in order to cut a workpiece which is supported by the table assembly and the fence assembly  26 . The sliding movement of the support arms  34  relative to the housing  16  permits the drive assembly  36  and thus the saw blade  18  to be pulled or pushed through the workpiece. 
         [0023]    The blade guard assembly  20  preferably includes a fixed upper blade guard  40  and a movable lower blade guard  42 . The movable guard  42  is interconnected for pivotal movement between a “closed” position, wherein the movable guard  42  covers a maximum portion of the cutting periphery of the blade  18 , and an “open” position covering a minimum portion of the cutting periphery of the blade  18  in order to allow the blade  18  to perform cutting operations on the workpiece  13  and to allow for blade removal or replacement. Persons skilled in the art are referred to U.S. Pat. No. 6,182,548, which is hereby fully incorporated by reference, for more information on an exemplary blade guard assembly  20 . 
         [0024]    Referring to  FIGS. 1-3 , locking mechanism  28  preferably comprises a miter locking mechanism  66  and a miter detent override mechanism  68 . Persons skilled in the art are referred to U.S. Pat. No. 6,810,780, which is hereby fully incorporated herein by reference, for further information on an exemplary miter locking mechanism  66 . Preferably, miter locking mechanism  66  has a handle  72  which may be activated by the user to lock the table assembly  14  in the desired miter angle. 
         [0025]    Miter detent override mechanism  68  preferably comprises a detent spring  92  and a detent override lever  94 . Persons skilled in the art are referred to U.S. Pat. No. 6,810,780, which is hereby fully incorporated herein by reference, for further information on an exemplary miter detent override mechanism  68 . 
         [0026]    Detent spring  92  may be secured to table assembly  14  using a pair of bolts that extend through apertures formed in detent spring  92 . Detent spring  92  may be a generally U-shaped spring which includes a formed detent  98  on the connecting leg of the U. Detent spring  92  is preferably normally positioned as shown in  FIG. 2  with the shape of detent spring  92  being designed such that detent  98  biased into one of the detent slots  54  disposed on table assembly  14  or on a detent plate  53  attached to table assembly  14  to releasably position support table assembly  14  with respect to base assembly  12  at one of the more common miter angles defined by detent slots  54 . 
         [0027]    Detent override lever  94  is preferably pivotably secured to table  14 . Lever  94  preferably has two outer ends extending towards handle  72 . Preferably, handle  72  is positioned between the two ends of lever  94  as shown in  FIGS. 1-3 . The opposite of inner end of lever  94  preferably extends toward detent spring  92 . The inner end of lever  94  is positioned under the outer end of detent spring  92  to enable lever  94  to move detent  98  out of engagement with the respective slot  54 . 
         [0028]    Detent spring  92  may include a pair of contoured tabs  104  which are cradled by the inner end of detent override lever  94 . A biasing spring  106  preferably biases lever  94  in a clockwise direction, as shown in  FIG. 2 , such that the inner end of lever  94  maintains engagement with contoured tabs  104 . 
         [0029]    With such arrangement, when it is desired to reset support table assembly  14  to a new miter angle, handle  72  of miter locking mechanism  66  is first moved to its released position and one of the outer ends of lever  94  is pushed downward to pivot lever  94  in a clockwise direction. Table assembly  14  can now be rotated until the desired miter angle is reached. At this point, detent override lever  94  can be released causing detent  98  to engage another detent slot  54  if it is desired to select one of the more popular miter angles defined by detent slots  54 . Handle  72  of miter locking mechanism  66  can then moved to its locked position to secure table assembly  14  with respect to base assembly  12 . 
         [0030]    When the desired miter angle is not one of the pre-selected miter angles defined by slots  54 , the adjustment of table assembly  14  is similar but different to that described above. When it is desired to reset table assembly  14  to a new miter angle, handle  72  of miter locking mechanism  66  is first moved to its released position and one of the outer ends of lever  94  is pushed downward to pivot lever  94  in a clockwise direction. This clockwise rotation of lever  94  causes the inner end of lever  94  to lift detent spring  92  causing the disengagement of detent  98  with its respective slot. When the desired miter angle is reached, handle  72  of miter locking mechanism  66  is moved to its locked position to secure table assembly  14  with respect to base assembly  12 . Once handle  72  has been locked, lever  94  can be released. The release of lever  94  allows detent spring  92  to engage the upper surface of detent plate  53  because detent  98  is not aligned with one of slots  54 . By keeping pressure on miter detent override lever  94  while engaging handle  72 , detent  98  is kept away from detent plate  53  and slots  54 . This allows the setting of a miter angle near one of the slots  54  (i.e., 44.degree. instead of 45.degree.) without having the biasing load of detent spring  92  reacting against detent plate  53  to urge table assembly  14  to the desired angle. 
         [0031]    Table assembly  14  may have a fine adjust mechanism for slightly changing the miter angle, i.e., the rotational position of table assembly  14  relative to base assembly  12 . Such fine adjust mechanism preferably includes an elastic bumper  73  affixed to table assembly  14 . Preferably bumper  73  is made of a relative soft elastic bumper mounted to table assembly  14 . Bumper  73  may be attached, glued on, molded unto, overmolded on, inserted through table assembly  14 . 
         [0032]    Bumper  73  may also provide aesthetic variations to table assembly  14 , such color breaks, shapes, etc. To these ends, bumper  73  may be shaped or colored in order to meet aesthetic requirements. 
         [0033]    The bumper  73  is preferably disposed on the sides of table assembly  14  so that it can cushion an impact provided by the user to urge table assembly  14  to the desired angle. Persons skilled in the art will recognize that, providing an elastic bumper, may allow the user to hit the table assembly  14  with a substantial force, yet only move table assembly  14 , because of the force being absorbed by bumper  73 . 
         [0034]    Any durometer of bumper  73  is contemplated. For example, the durometer may be between about 20 Shore O and about 80 Shore A. However, it is desired to provide the bumper  70  with characteristics that absorb and dampen some of the impact load and therefore a durometer of about 20 Shore A to about 75 Shore A is preferred. The durometer will be preferably dictated by the bumper thickness, the weight of table assembly  14 , and the bumper contact area at the shock point. 
         [0035]    Further information on bumper  73  and its characteristics may be found in US Published Application No. 20050058890, which is fully incorporated herein by reference. 
         [0036]    Preferably, a motor  75  is disposed in base assembly  12  or table assembly  14 . Motor  75  preferably carries an eccentric mass on its shaft can be turned on when finely adjusting the miter angle. Such motor  75  would create vibration, and separate base assembly  12  from table assembly  14 , allowing for easier adjustment. 
         [0037]    The user may also use another fine-adjust mechanism  80  provided on table assembly  14 . Fine-adjust mechanism  80  preferably includes a knob  81 , a shaft  82  attached to knob  81  for rotation therewith, and a pinion  84  fixedly attached to shaft  82  for rotation therewith. Accordingly, when knob  81  is rotated, pinion  84  rotates therewith. 
         [0038]    Pinion  84  preferably meshes with an arcuate rack  15  disposed on base assembly  12 . Accordingly, when knob  81  is rotated, the table assembly  14  rotates relative to base assembly  12 . Persons skilled in the art will recognize that a number of intervening gears may be disposed between knob  81  and pinion  84  to increase the mechanical advantage, to decrease the rotational motion of pinion  84  relative to knob  81 , to transmit motion around elements disposed on table assembly  14  and/or base assembly  12 . Persons skilled in the art are referred to US Published Application No. 20050262984, which is fully incorporated herein by reference, for further information on such mechanism. 
         [0039]      FIGS. 1 and 4  illustrate another miter angle fine-adjust mechanism. Support assembly  32  preferably has a trunnion  33  for pivotally supporting drive assembly  36 . Drive assembly  36  is preferably disposed on pivot pin  38 . One end of pivot pin  38  is preferably supported by trunnion  33 . The other end is preferably supported by support  37 , which is in turn supported by trunnion  33 . 
         [0040]    A screw  37 S may threadingly engage and extend through trunnion  33  while being captured by support  37 . Alternatively, screw  37 S may extend through trunnion  33  without threadingly engaging trunnion  33 , and threadingly engage support  37 . With such arrangement, a user can rotate screw  37 S, changing the angular relationship between the drive assembly  36  (and thus blade  18 ) and trunnion  33  (and thus table assembly  14 ). 
         [0041]    Persons skilled in the art will recognize that pivot pin  38  is preferably supported by bearings  39 , which may be disposed on trunnion  33 , support  37  and/or drive assembly  36 . 
         [0042]    While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.