Patent Publication Number: US-2004052599-A1

Title: Miter saw arrangement for increased cutting capacity

Description:
FIELD OF THE INVENTION  
       [0001] This invention relates generally to miter saws and specifically to arrangements for increasing cutting capacity in slide and/or non-sliding miter saws.  
       BACKGROUND OF THE INVENTION  
       [0002] Slide miter saws are well known in the art as they provide extended cutting range over non-sliding miter saws. Referring to FIG. 1, non-sliding and slide miter saws both have a base  11 , a rotatable table  12  attached to the base  11 , a saw assembly  20  including a motor  21 , a blade  22  rotatable about axis A and driven by the motor  21 , a cover housing  23  covering motor  21 , an upper blade guard  24  covering the upper part of blade  22 , and a lower guard  25  (shown in broken lines) pivotably attached to upper blade guard  24  for covering the lower part of blade  21 . Accordingly, the saw assembly  20  is pivoted downwardly for cutting a workpiece disposed on the base  11  and table  12 .  
       [0003] In addition, slide miter saws enable the user to move the saw assembly horizontally along the table. As shown in FIG. 2, most slide miter saws accomplish this by connecting the upper blade guard  24  (and thus the saw assembly  20 ) to a pivot arm, which in turn is connected to a trunnion  13 , which is fixedly connected to at least one rail  14 , which is slidably attached to a support housing  15  connected to the table  12  (see, e.g., U.S. Pat. No. 6,067,885). With such arrangement, the user would pull the saw assembly  20  forwardly, move the saw assembly  20  downwardly, then push the saw assembly  20  rearwardly for cutting the workpiece W.  
       [0004] This typical arrangement has been found to limit cutting capacity of the miter saw. This is because the cover housing  23  contacts the workpiece W, thus stopping the chopping movement. In particular, it has been found that the distance D1 between axis A and the bottom surface of cover housing  23  near upper blade guard  24  is equal to or larger than the distance D2 between axis A and the bottom surface of cover housing  23  at a point farther away from upper blade guard  24 .  
       SUMMARY OF THE INVENTION  
       [0005] In accordance with the present invention, an improved miter saw is employed. The miter saw includes a base, a table rotatably attached to the base, a saw assembly connected to the table, the saw assembly comprising a motor, a blade rotatable about an axis and driven by the motor, an upper blade guard for covering an upper part of the blade and having a bottom surface, and a housing connected to the upper blade guard, the housing having a bottom surface disposed below the axis, wherein a first distance between the axis and the bottom surface of at least one of the housing and the upper blade guard at a first point along the axis near the upper blade guard is smaller than a second distance between the axis and the bottom surface of at least one of the housing and the upper blade guard at a second point along the axis, the second point being farther away from the upper blade guard than the first point.  
       [0006] 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 DRAWINGS  
     [0007] The accompanying drawings illustrate preferred embodiments of the invention according to the practical application of the principles thereof, and in which:  
     [0008]FIG. 1 is a front view of a prior art slide miter saw;  
     [0009]FIG. 2 is a top view of the prior art slide miter saw of FIG. 1;  
     [0010]FIG. 3 is a front view of a slide miter saw according to the invention;  
     [0011]FIG. 4 is a top view of the slide miter saw of FIG. 1; and  
     [0012]FIG. 5 is a partial cross-sectional view along line V-V of FIG. 4. 
    
    
     DETAILED DESCRIPTION  
     [0013] The invention is now described with reference to the accompanying figures, wherein like numerals designate like parts. Persons skilled in the art should understand that, while the invention is being explained in terms of a slide miter saw, the invention is also applicable to non-sliding miter saws.  
     [0014] Referring to FIGS.  3 - 5 , a slide miter saw  10  preferably has a base  11 , a table  12  rotatably connected to the base  11 , a support housing  15  pivotally connected to table  12 , at least one (and preferably two) rail(s)  14  slidably connected to the support housing  15 , a trunnion  13  attached to one end of the rail(s)  15 , and a saw assembly  20  which comprises a pivot arm  26  pivotably attached to trunnion  13 , a motor  21 , a blade  22  rotatable about axis A and driven by the motor  21 , an upper blade guard  24  for covering an upper part of blade  22 , and a lower blade  25  pivotally attached to the upper blade guard  24  for covering a lower part of blade  22 . Preferably the motor  21  is attached to the upper blade guard  17 . These elements are well known in the art. Persons skilled in the art are referred to U.S. Pat. No. 6,067,885, which is wholly incorporated by reference herein.  
     [0015] The slide miter saw  10  may also have a movable fence assembly  40  attached to the base  11 . Movable fence assembly  40  preferably extends laterally across table  12 , against which a workpiece can be positioned and supported for performing a cutting operation thereon. Movable fence assembly  40  may include a fixed fence  41  attached to base  11 , and a movable fence  42  connected to the fixed fence  41 . Preferably, movable fence  42  is slidably attached to fixed fence  41 . Persons skilled in the art are referred to U.S. Pat. Nos. 5,297,463 and 5,943,931, which are wholly incorporated by reference herein.  
     [0016] Motor  21  may be covered by a cover housing  23  attached to the upper blade guard  24 . Cover housing  23  may cover motor  21  and/or any transmissions disposed between the motor  21  and blade  22 . Cover housing  23  may have a lower or bottom surface  23 S, which is preferably below the axis A. Similarly, upper blade guard  24  may have a lower or bottom surface  24 S, which may be below axis A.  
     [0017] Preferably, blade  22  is mounted on a spindle  16 , which extends into cover housing  23 , and is driven by motor  21 . Spindle  16  may be supported by bearings  17 ,  18 . Blade  22  may be clamped unto spindle  16  via claims 26, 27 disposed on both sides of blade  22 , and held in place by a bolt  28 , which is preferably threaded into spindle  16 .  
     [0018] It is desirable to shape the volume underneath spindle  16  to maximize cutting capacity. Accordingly, a pocket  30  may be created by manipulating the distances between axis A and bottom surfaces  23 S and/or  24 S. In particular, it is desirable to ensure that wherein the distance D1′ between axis A and the bottom surface  23 S and/or  24 S at point X along axis A near the upper blade guard  24  is smaller than the distance D2′ between axis A and the bottom surface  23 S and/or  24 S at point Y along axis A. Preferably, point Y is farther away from the upper blade guard  24  than point X. In addition, points X and Y are disposed along axis A on the same side of blade  22 .  
     [0019] By manipulating distances in such manner, pocket  30  is created. Preferably, the height and width of pocket  30  is about 3.33 inches and about 1.744 inches, respectively, for a miter saw that carries a blade with a diameter of about 8.5 inches. With such arrangement, a user could cut a 3¼″ base molding placed vertically against fence assembly  40  at a miter angle of about 42° to about 48°. Such cut is achieved when the saw assembly  20  is placed near the fence and moved downwardly in a chopping action, rather than sliding it across the workpiece.  
     [0020] Persons skilled in the art will recognize that the size and shape of pocket  30  can be modified according to design requirements and specifications, etc.  
     [0021] Persons skilled in the art may recognize other additions or alternatives to the means disclosed herein. However, all these additions and/or alterations are considered to be equivalents of the present invention.