Patent Publication Number: US-11027452-B2

Title: Blade guard for a table saw

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional continuation of U.S. patent application Ser. No. 13/385,415, filed Feb. 17, 2012, which in turn claims the benefit of and priority from U.S. Provisional Patent Application Ser. No. 61/463,557, filed Feb. 17, 2011, the disclosures of which are both herein incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to table saw attachments designed to improve safety and performance. More specifically, this disclosure relates to blade guards with hold-down capability, splitters, and anti-kickback devices. 
     BACKGROUND 
     A table saw is a power tool used to cut a workpiece to a desired size or shape. A table saw includes a work surface or table and a circular blade extending up through the table. A person uses a table saw by holding a piece of wood or other workpiece on the table and feeding it past the spinning blade to make a cut. Sometimes the workpiece will climb or rise up on the blade, creating a safety hazard that can result in the workpiece shifting unexpectedly or being kicked back or propelled by the blade toward the user. A user may inadvertently contact the spinning blade while trying to reposition the workpiece or as a result of the workpiece shifting or kicking back. The blade guard disclosed in this document provides a configuration that holds the workpiece down as the workpiece approaches the blade and as it is being cut to minimize the workpiece from climbing on the blade. 
     The disclosed blade guard also includes structure to substantially enclose the blade and protect against contact with the blade, a splitter or spreader to keep a workpiece from shifting sideways and catching on the rear edge of the blade, and an anti-kickback device such as a set of anti-kickback pawls configured to oppose a workpiece being thrown back toward a user. In one configuration, the blade guard also provides a block to prevent workpieces from contacting the blade if the workpieces are too high or thick to freely pass under the anti-kickback pawls or under any other structure associated with the blade guard and/or splitter. 
    
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
         FIG. 1  shows a table saw. 
         FIG. 2  shows the table saw of  FIG. 1  equipped with a blade guard. 
         FIG. 3  shows a side view of the blade guard of  FIG. 2  installed in the table saw of  FIG. 1  with the blade elevated. 
         FIG. 4  shows a perspective view of the blade guard in  FIG. 2 . 
         FIG. 5  shows a left side view of the blade guard in  FIG. 2 . 
         FIG. 6  shows a bottom view of the blade guard in  FIG. 2 . 
         FIG. 7  shows a top view of the blade guard in  FIG. 2 . 
         FIG. 8  shows a rear view of the blade guard in  FIG. 2 . 
         FIG. 9  shows a front view the blade guard in  FIG. 2 . 
         FIG. 10  shows an exploded view of the blade guard in  FIG. 2 . 
         FIG. 11  shows a perspective view of the top guard of the blade guard in  FIG. 2 . 
         FIG. 12  shows a left side view of the top guard of the blade guard in  FIG. 2 . 
         FIG. 13  shows a right side view of the top guard of the blade guard in  FIG. 2 . 
         FIG. 14  shows a front view of the top guard of the blade guard in  FIG. 2 . 
         FIG. 15  shows a top view of the top guard of the blade guard in  FIG. 2 . 
         FIG. 16  shows a bottom view of the top guard of the blade guard in  FIG. 2 . 
         FIG. 17  shows a side view of the blade guard of  FIG. 2  installed in the table saw of  FIG. 1  with a piece of wood being cut. 
         FIG. 18  shows a side view of the left front side guard of the blade guard in  FIG. 2 . 
         FIG. 19  shows a side view of the left middle side guard of the blade guard in  FIG. 2 . 
         FIG. 20  shows a side view of the left rear side guard of the blade guard in  FIG. 2 . 
         FIG. 21  shows a side view of the splitter of the blade guard in  FIG. 2 . 
         FIG. 22  shows a side view of the splitter of the blade guard of  FIG. 2  installed in the table saw of  FIG. 1  with the top guard lifted out of the splitter. 
         FIG. 23  shows a side view of the blade guard of  FIG. 2  installed in the table saw of  FIG. 1  in a hold-down position with the blade elevated. 
         FIG. 24  shows a side view of the blade guard of  FIG. 2  installed in the table saw of  FIG. 1  in a hold-down position and a piece of wood being cut. 
         FIG. 25  shows a perspective view of the pawl assembly of the blade guard in  FIG. 2 . 
         FIG. 26  shows a side view of the pawl assembly of the blade guard in  FIG. 2 . 
         FIG. 27  shows a rear view of the pawl assembly of the blade guard in  FIG. 2 . 
         FIG. 28  shows a perspective view of the bushing of the pawl assembly in  FIG. 25 . 
         FIG. 29  shows a front view of the bushing of the pawl assembly in  FIG. 25 . 
         FIG. 30  shows a perspective view of the pawl spring of the pawl assembly in  FIG. 25 . 
         FIG. 31  shows a side view of the pawl spring of the pawl assembly in  FIG. 25 . 
         FIG. 32  shows a front view of the pawl spring of the pawl assembly in  FIG. 25 . 
         FIG. 33  shows a side view of the blade guard of  FIG. 2  installed in the table saw of  FIG. 1  in a standard position with a piece of wood being cut and anti-kickback pawls removed. 
         FIG. 34  shows a side view of the blade guard of  FIG. 2  installed in the table saw of  FIG. 1  in a standard position with anti-kickback pawls in a position of unstable equilibrium. 
         FIG. 35  shows a side view of the blade guard of  FIG. 2  installed in the table saw of  FIG. 1  in a standard position with a piece of wood being cut and anti-kickback pawls disabled. 
         FIG. 36  shows a side view of the blade guard of  FIG. 2  raised. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a saw  10  including a table  12  and a circular blade  14 . The blade extends up through a slot  16  in a table insert  18 , and the insert  18  fits within an opening in the table. A piece of wood, or other material to be cut, is placed on the table and pushed into contact with the spinning blade to make a cut. 
       FIG. 2  shows the saw of  FIG. 1  with a blade guard  20 . The main purpose of blade guard  20  is to protect a user of the saw from accidentally contacting the spinning blade. The blade guard is shown in more detail in  FIGS. 3-10 . The blade guard includes a top guard  22  and side guards  24 . The top guard prevents a user from moving down into the teeth of the blade from a position above the saw, and the side guards  24 , which include front side guards  28 ,  34 , middle side guards  30 ,  36 , and rear side guards  32 ,  38 , stop a user from moving into the teeth of the blade from the side. The blade guard is mounted on a splitter  26 . The splitter is positioned behind and adjacent the back edge of the blade, thereby preventing a workpiece from shifting and catching the back edge of the blade which could result in kickback. The splitter also shields the back edge of the blade and helps prevent a user from accidentally contacting the back edge of the blade. 
     In the exemplary embodiment shown in  FIGS. 3-10 , top guard  22  is made from an elongate and rigid piece of transparent polycarbonate. The top guard attaches to the splitter and extends toward the front of the saw, as shown in  FIG. 3 . The top guard extends far enough to cover the top edge of the blade and to prevent a user from contacting the blade from above. The transparency of the top guard allows the user to see the blade and the workpiece as the workpiece is being cut. 
     The forward end of the top guard includes a nose or tip  27  that slopes down toward table  12 . When the top guard is mounted on the splitter in the configuration shown in  FIG. 3 , the tip is the lowest part of the top guard, or the part of the top guard closest to table  12 , and it extends below the top guard&#39;s lower surface. Tip  27  blocks a workpiece from moving into the blade if the workpiece is too thick to move past the splitter or past any devices attached to the splitter. Expressed differently, the height or thickness of a workpiece that can be successfully cut with the blade guard installed on the saw is limited by the presence of the top guard and other structures attached along the top of the splitter that would interfere with an over-thick workpiece. Accordingly, tip  27  functions to prevent over-thick workpieces from moving into the blade and possibly jamming against or bumping into the splitter or other structures, which could result in a dangerous condition for the user. 
     In the exemplary embodiment shown in  FIGS. 3 through 10 , top guard  22  is also relatively narrow from side-to-side. Making the top guard narrow allows a user to position a workpiece guide or fence as close as possible to the blade to make narrow cuts. Top guard  22  is most narrow at the back end (i.e., the end that attaches to the splitter) and the top guard gets wider moving towards the front to accommodate any sideways deflection. 
       FIGS. 11 through 16  show top guard  22  isolated from other structure. The top guard has a top surface  44  which runs from the tip  46  of the nose  27  to about the middle of the top guard, where it separates into two strips  47  with a gap  150  between the strips. Gap  150  allows the top guard to fit over the splitter and be mounted thereto, as will be explained. 
     To form nose  27 , the front of the top surface curves down and tapers inward along the sides. The taper on the left side allows the blade guard to tilt to forty-five degrees without interfering with the table and the taper is mirrored on the right side to be aesthetically pleasing. The sides taper moving down as if coming to a point but instead of forming a point the sides are clipped off near the bottom so that the tip  46  of the nose is flat or cut straight across. Side walls  50  of the top guard meet the edges of the top surface as it curves down to give support to the nose and follow the curved surface gradually tapering off a little over half way down the nose. The nose extends down about one-and-one-half inches from the top of the top guard, ending anywhere from zero to about three-eighths of an inch above the top of the blade when the guard is installed on the splitter. As stated, the nose acts like a stop to prevent workpieces that are too thick from moving in toward the blade and splitter. 
     Side walls  50  extend down from the top surface as shown and have three steps or indentations moving from the nose towards the rear. These indentations allow the side guards to run alongside the side walls and overlap each other, as shown in  FIG. 4 . The first indentation  52  is at the front of the top guard just behind the nose, as shown in  FIG. 15 . The side walls are inset a distance roughly equal to the thickness of the front side guards leaving a flat vertical surface  54  facing the rear and positioned just in front of each front side guard. Moving to the rear about two inches from the first vertical surface is a second vertical surface  54  formed by a second indentation  56  which provides a place for the middle side guard to fit between the inner side of the front side guard and the side wall of the top guard. Moving again to the rear about two inches from the second vertical surface is a third vertical surface  54  formed by a third indentation  58  which provides a place for the rear side guard to fit between the inner side of the middle side guard and the side wall of the top guard. At this point the side walls have reached the narrowest width, which is then maintained all the way to the end of the top guard moving to the rear. Another two inches back from the third vertical surface is a vertical wall  60  that runs between the two side walls for strength. Beyond this vertical wall  60  the two side walls of the top guard are separated by gap  150 . The inner surface of each side wall adjacent gap  150  includes projections  62  in the form of a set of vertical ridges  62 , spaced about one-half inch apart. These ridges contact the sides of the splitter to keep the top guard positioned correctly. 
     Side guards  24  hang down from top guard  22 , as shown in  FIG. 3 , and are free to pivot around their points of connection to the top guard. Because they are free to pivot, the side guards rotate back when contacted by a workpiece moving toward the blade and they rest upon the top surface of the workpiece as the workpiece moves past, as shown in  FIG. 17 . When the workpiece moves past the side guards, the side guards drop back down due to gravity. This configuration may be referred to as floating or free-floating side guards. 
     The side guards hang down from both the right and left sides of the top guard to shield each side of the blade. In the depicted embodiment, there are three side guards on each side, although there could be more. The side guards on the right side include front side guard  28 , middle side  30  and rear side guard  32 . The side guards on the left side are mirror images of those on the right side, and they include front side guard  34 , middle side guard  36  and rear side guard  38 . Each side guard is generally flat with a rim around the edge and has a somewhat triangular shape. In order to shield the teeth of the blade, the front side guards are larger than the middle side guards which are in turn larger than the rear side guards. The side guards are pivotally attached to the top guard by press-fit rivets  68  and, as stated, are free to pivot. The side guards are positioned so that they overlap slightly when they hang down. They are also positioned so that they do not catch on one another when they pivot. The rear side guard is seated farthest inward, next is the middle side guard, and finally, the front side guard which is seated farthest to the outside, as can be seen in  FIG. 4 . The side guards cover the teeth of the blade from the top of the blade to the front. They are sized to cover about a 1-inch thick strip along the outer perimeter of the blade. In the depicted embodiment, the side guards do not cover the rear of the blade; the splitter covers the teeth at the rear of the blade. 
     The side guards are generally triangularly shaped, as mentioned, with the smallest angle, roughly thirty degrees, formed at the top between two long straight sides—side  70  which faces the front of the side guard, and side  72  which faces the rear of the side guard, as shown in  FIGS. 18 through 20 . The two sides approach each other, without intersecting, near the top of the side guard close to the rivet. Each of the two long straight sides is joined to short straight segments  74  and  76 , one segment at the end of each long straight side at the end closest to the rivet. The short straight segments are joined by a short curved segment  78  which forms a rounded corner about the rivet. The two straight segments  74  and  76  are oriented such that lines perpendicular to each segment form an angle that ranges from roughly ninety degrees for the front side guard to sixty degrees for the rear side guard. 
     The bottom portions of the side guards are different for the front, middle and rear side guards in order to provide the desired blade coverage. The front side guard is like a triangle with each bottom corner clipped off, and with the corner that faces the rear clipped off more than the other bottom corner. The clipped corners are replaced by straight segments  80  and  82 , and a straight bottom segment  84  runs between them, as shown in  FIG. 18 . In all, the perimeter of the front side guard consists of long straight side  70  joined to a short straight segment  74  joined to a rounded corner  78  about the rivet, joined to another short straight segment  76  joined to another long straight side  72  joined to a shorter straight segment  80  which is joined to a slightly shorter straight bottom segment  84  that is joined to an even shorter straight segment  82  which joins the bottom end of the long straight side  70  to complete the perimeter. 
     The middle side guard  36 , shown in  FIG. 19 , is shaped like a triangle with two bottom rounded corners  86  and  88  on either side of a straight bottom segment  90 , and two long straight sides  70  and  72  which join short segments  74  and  76  and rounded corner  78  at the top. The length of bottom segment  90  of the middle side guard is about the same as length of the long straight side  72  of the front guard. The lengths of the long straight sides of the middle side guard are approximately the same and these are about the same as the length of the long straight sides of the front side guard. 
     The rear side guard  38 , shown in  FIG. 20 , is shaped like a triangle with both bottom corners clipped off and replaced by segments  102  and  104  which join at a rounded corner  106 . 
     Segment  102  is forward of segment  104  and slightly longer than segment  104 . Segment  104  joins with side  72  at rounded corner  138 . Side  102  is joined to side  70  at corner  130 . Segments  74  and  76 , and rounded corner  78 , join sides  70  and  72 , as with the other side guards. Of course, the side guards could take many other shapes. 
     As mentioned, the side guards are pivotally attached to the top guard by press-fit rivets  68 . Each rivet is pressed into a hole  108  in a boss  110  on the outside of each side guard near the top of each side guard under rounded corner  78  (the holes and bosses are labeled in  FIGS. 18 through 20 ). The rivets are press-fit into the holes in the side guards so that they rotate along with the side guards to reduce play in the assembly. Each boss  110  is flush with a raised rim  112  around the perimeter of each side guard. The raised rim minimizes the contact area between the side guards to reduce friction between the side guards as they pass by each other when pivoting. Each rivet then passes through a hole  114  in a raised boss  116  along side wall  50  of top guard  22 . Bosses  116  are raised to create a little gap between the side guards and the side wall. An E-clip  118  (shown in  FIG. 10 ) fits around a groove at the end of each rivet to secure each rivet in place. The top guard is designed to be as narrow as possible and the E-clips provide a way to secure the rivets with minimal extension towards the interior of the guard. 
     Surfaces  122  on the outer edge of segments  74  of each side guard face the front of the top guard and act, in conjunction with vertical surfaces  54  on the top guard, as stops. When the side guards hang down without contacting a workpiece or the saw table, surfaces  122  contact vertical surfaces  54  and keep the side guards in a position where sides  70  slope back, as shown in  FIG. 3 , so that when the blade guard is installed in the saw, the side guards will pivot back as the blade is lowered or when a workpiece is fed into the blade guard. 
     In order for the side guards to pivot back smoothly and reliably, the side guards are designed so that the point of contact between the bottom of each side guard and the surface of the table is positioned to the rear of the rivet attaching the side guard to the top guard. The farther back the contact point is from the pivot point the more easily the side guard pivots back. However, if the front edge of the front side guards (i.e., sides  70 ) in the depicted embodiment were to run from near the rivet to the point of contact with the table, in some positions the front side guard would not adequately cover the teeth of the blade from the sides. Accordingly, front side  70  of the front side guards runs from near the rivet down to a first corner point  126  that is forward of a second corner point  128  between segments  82  and  84 , as shown in  FIG. 3 . When in the position shown in  FIG. 3 , second corner point  128  is the point of contact with the table. As the front side guards pivot back, second corner point  128  rises up and first corner point  126  becomes the point of contact with the table or workpiece. For the middle side guards, the bottom corner  86  contacts the table or workpiece. The front side guards continue to contact the table at contact point  126  as the middle side guards pivot back so that the front teeth of the blade continue to be adequately covered, as shown in  FIG. 17 . For the rear side guards, bottom corner  130 , between side  70  and segment  102 , contacts the table or workpiece. As with the front and middle side guards, corner  130  on the rear guard is positioned far enough back from the rivet to allow the rear side guard to pivot back smoothly while providing coverage for the teeth of the blade. Side  102  at the bottom of the rear side guard extends to the rear to further cover the blade. 
     Top Guard  22  is mounted on splitter  26 , as shown in  FIG. 3 . The splitter is a flat piece of metal with a front edge  140  shaped to follow the perimeter of the blade, as shown in  FIG. 21 . The splitter is securely mounted in the saw to move with the blade as the blade changes elevation and/or tilts. As stated previously, the splitter functions to prevent the workpiece from shifting and to shield the back of the blade. 
     Top guard  22  attaches to splitter  26  in such a way that it is held securely in place when in its operable position, but is also quickly and easily installed or removed by hand without the need of tools and without the need of moving a bail or lever. A user might remove the top guard for some cutting operations, and therefore, being able to install and remove the top guard quickly and easily facilitates guard usage and makes it more likely that a user will re-install the top guard after removing it. 
     In the depicted embodiment, a user removes the top guard from the splitter by first pulling the top guard forward or toward the front of the saw, and then rotating the top guard upward to a substantially vertical position. Once the top guard is in a substantially vertical position it can be lifted up and away from the splitter, as shown in  FIG. 22 . These steps are repeated in reverse to install the top guard; the top guard is first oriented substantially vertically then set into the splitter and rotated downwards until it snaps into place. 
     A latch mechanism by which the top guard is held on the splitter consists of a bolt  142 , two pins  144  and  146 , and two coil springs  148 , one spring on each side of the top guard. Bolt  142  is located toward the rear and along the bottom of the top guard, as shown in  FIG. 10 . As mentioned, the right and left sides of the top guard are set apart with a gap  150  between them, as shown in  FIG. 16 . The top guard is configured to fit over the splitter with the splitter filling gap  150 . To keep the top guard rigid, bolt  142  passes through a hole  152  in the left side of the top guard and then through a spacer  154  situated between the left and right sides of the top guard and then through a hole  156  in the right side of the top guard. A hexagonal cavity  158  on the outside wall of the right side of the top guard holds a nut  160  that is threaded on the end of bolt  142 . Pin  144  passes through two aligned oval holes  162 , one hole in each side of the top guard. Pin  144  is free to move in the oval holes and is held in place by the two springs  148 . The springs lie lengthwise within recessed areas  164  on the right and left sides of the top guard. One end of each spring fits within a groove  166  on each end of pin  144 . The other end of each spring attaches to the top guard by hooking into a small hole located in a support  168  positioned within and towards the front of each recessed area  164 . The springs are sized to bias or pull pin  144  toward the forward end of oval holes  162 , but the pin can move to the rear of the oval holes by stretching the springs. Second pin  146  is press-fit into a hole  170  on the side of the top guard forward from pin  144 . The top guard attaches to the splitter at pins  144  and  146  and so those pins are spaced apart far enough to create a sturdy structure that has minimal lateral movement. 
     To install the top guard on the splitter, the top guard is first oriented substantially vertically with spacer  154  positioned above a cutout  172  in the splitter. Cutout  172  is shaped somewhat like the letter “J”, as shown in  FIG. 21 . Cutout  172  includes a first notch  174  in the forward edge of the cutout, and a second notch  176  in the rear section of the cutout. The top guard is lowered into cutout  172  until the spacer  154  and pin  144  hit the bottom of the cutout, and the top guard is then tilted forward. As the top guard tilts forward, spacer  154  rides up a curved section  177  along the bottom of the cutout and the spacer moves into second notch  176 . At this point, spacer  154  and pin  144  are trapped in second notch  176  and cannot move further up. As the top guard moves further down, it pivots about spacer  154  and eventually pin  146  hits a curved edge  178  at the entry of another cutout  180  located towards the front of the splitter. Curved edge  178  guides pin  146  into cutout  180  while stretching springs  148 . Cutout  180  includes a notch  181  shaped so that when pin  146  moves past curved edge  178 , springs  148  pull pin  146  toward the back of the splitter and into notch  181 , thereby holding pin  146  in place. At the same time, springs  148  pull pin  144  into notch  174  in cutout  172 . The tension in springs  148  keeps pins  144  and  146  pulled tightly together against the splitter thus securing the top guard in place on the splitter. 
     Positioning cutouts  172  and  180  a relatively large distance apart, having splitter  26  extend into gap  150  in the top guard, and sizing gap  150  so that projections  62  contact the sides of the splitter, allows the top guard to be attached or mounted securely to the splitter without any significant side-to-side play in the top guard. Also with this configuration, a user can release or remove the top guard from the splitter by pulling the top guard forward to stretch springs  148  until pin  146  clears notch  181 . The user can then pivot the top guard upward until pin  144  clears notch  174 , and then the user can lift the top guard up and away from the splitter, as described. This can all be done without using any tool and without having to move a locking bail or lever. 
     Additionally, the user can pivot the top guard up to a generally vertical position while pin  166  remains in cutout  172 , as shown in  FIG. 36 . Cutout  172  in the splitter includes a surface  234 , shown in  FIG. 21 , which provides a stop against which the top guard can rest when the top guard is pivoted up. With the top guard in this position, a user can perform tasks, such as changing the blade, without having to completely remove the top guard from the splitter. 
     The configuration of the top guard described thus far allows a workpiece to pass under the top guard with only the bottom edges of the side guards contacting the workpiece. With this configuration the top guard is above the blade and there is a gap between the top of the blade and the bottom of the top guard. This configuration provides the maximum possible depth of cut while using the top guard. However, with this configuration a workpiece may also shift or climb the blade unexpectedly, which can result in a dangerous condition such as kickback. To address this issue, top guard  22  can be flipped over to hold down the workpiece. 
       FIG. 23  shows top guard  22  mounted on splitter  26  in a hold-down position. In this position the front of the top guard is closer to the table than the rest of the top guard, and also closer to the table than any other items attached to the splitter, such as anti-kickback pawls. In the depicted embodiment, this is accomplished by the top guard slanting down at a slight angle from the splitter towards the front of the saw. When in a hold-down position, the top of the blade protrudes up into the top guard so that the bottom of the top guard is slightly below the top of the blade. For example, the bottom of the top guard may be around ¼ inch below the top of the blade. With the top guard in this configuration, a user can adjust the elevation of the blade and top guard so that the top guard contacts the top surface of the workpiece as the workpiece is moved into the blade, thereby holding the workpiece down against the table, while the top of the blade still extends above the workpiece to cut through the workpiece, as shown in  FIG. 24 . The top guard can be constructed to have some limited or inherent flexibility so that when the top guard is lowered onto the workpiece, a downward force is created on the workpiece by the top guard in the area of contact to help hold the workpiece on the table. 
     In the hold-down position a workpiece can be guided into the blade with more control since the top guard helps hold the workpiece down. This is particularly helpful when cutting sheet goods such as 4′×8′ plywood sheets which can flex and climb the blade, and which can be difficult for a person to handle and feed into the saw without shifting. 
     The top guard includes a hollow area  64 , shown in  FIG. 4  on what is the upper surface of the top guard in that figure. However, when the top guard is in the hold-down position shown in  FIGS. 23 and 24 , hollow area  64  is on the underside of the top guard and the hollow area fits over and around the top of the blade. The hollow area is shaped to follow the contour of the blade so that the blade can extend up into the interior of the top guard. 
     When the top guard is turned over for the hold-down configuration, side guards  24  pivot around so that they continue to hang down from the top guard and shield the teeth of the blade. The side guards function as in the non-hold-down configuration discussed above, although side edges  72  face forward instead of sides  70 . Additionally, surfaces  124  on the side guards abut surfaces  54  on the top guard to hold the side guards at an angle, instead of surfaces  122 . As stated, in the depicted embodiment the top guard is designed to slope down when in the hold-down position so that the lowest point on the top guard is at the bottom of the nose, thus reducing the chance of binding occurring between the workpiece and the top guard as the workpiece moves past the blade. The shapes of the side guards are determined experimentally to achieve the desired blade coverage whether the guard is in a hold-down or non-hold-down position. The guard may quickly and easily be removed or installed from a hold-down position in the same way as it can be removed or installed from the non-hold-down position described earlier. The ability of the blade guard described herein to be quickly and easily changed from a non-hold-down position to a hold-down position without the use of tools and without having to move a bail or lever is a significant advantage over other blade guards. 
     Blade guard  20  also includes a pair of anti-kickback pawls  182 , as shown in  FIGS. 4 through 10 . The anti-kickback pawls are designed to rotate back and ride gently on the surface of a workpiece as the workpiece moves past the blade without impeding the movement of the workpiece. However, if the workpiece kicks back toward the user, the anti-kickback pawls dig into the workpiece to stop the kickback. 
     Sometimes a workpiece may be soft or have a surface prone to scratching, or the anti-kickback pawls may be biased down with enough force to scratch or leave visible impressions on the surface of the workpiece. If the anti-kickback pawls cannot be easily removed or disabled, the user might remove the entire blade guard or permanently remove the anti-kickback pawls to avoid scratching the workpieces. To address this situation, anti-kickback pawls  182  are designed in such a way that they can either be rotated up into a position that holds them out of the way or they can be easily removed and re-installed without the use of tools. 
       FIG. 10  shows an exploded view of anti-kickback pawl assembly  200 , and  FIGS. 25  though  27  show anti-kickback pawl assembly  200  isolated from other structure. Anti-kickback pawls  182  are held together in the anti-kickback pawl assembly by a spring  184  and bolt  186 . Bolt  186  passes through a flat washer  188  then through a specially designed bushing  190  which also serves as a standoff. As shown in  FIGS. 28 and 29 , bushing  190  is cylindrical with three thin sections  192  of an equal smaller diameter and two wider sections  194  of an equal larger diameter. The sections are arranged so that one thin section with a smaller diameter is between the two wider sections with a larger diameter, and one thin section with a smaller diameter is on the outside of each wider section. On the other side of the bushing, bolt  186  passes through another flat washer  188  and then threads into a nut  196 . The two, thin outside sections of bushing  190  have a diameter that is slightly smaller than the diameter of a hole  198  in each anti-kickback pawl near the top of the pawl (the hole is labeled in  FIG. 10 ), and a width that is slightly larger than the thickness of an anti-kickback pawl. As shown in  FIGS. 8 and 10 , each anti-kickback pawl sits on one of the outside thin sections of bushing  190 . The middle thin section of bushing  190  provides a groove for the splitter to fit into when the anti-kickback pawl assembly  200  is installed on the splitter. 
       FIGS. 30 through 32  show various views of a spring  184 . As shown in  FIG. 31 , spring  184  has a generally triangular shape when viewed from the side with a coil at the top corner and straight segments emerging downward from the front and the back sides of the coil.  FIG. 30  shows a perspective view of spring  184 . Spring  184  is formed out of a wire that is bent in the middle as if bent around the shaft of a small cylindrical rod to form an open loop  202 . The two ends of the wire then approach each other so that the loop has an almost tear-drop shape after which the wires bend outward from each other slightly. The wires continue straight and more or less parallel to each other for about an inch leaving a gap between them which is a little wider than the thickness of the splitter. Each wire is then wound in such a way as to create a coil  204  on each side of the loop and the two coils are generally coaxial. Viewing the spring from the right side, the right coil is wound clockwise moving outward. Viewing the spring from the left side, the left coil is wound counter-clockwise moving outward. Each end of the wire exits its respective coil on the outward facing side of the coil, to the rear of the coil on the opposite side of the coil from which the loop extends. The ends of the wires continue straight and generally coplanar for about an inch. The plane formed by the straight wire segments  206  near the loop is at an angle, roughly thirty degrees, to the plane formed by the straight segments  208  that exit the coils. Each of the wires then bends roughly ninety degrees outward and continues about an eighth of an inch along a line that is roughly parallel to the axis through the coils. The wires then bend ninety degrees again forming a corner  209  and continue for about one quarter of an inch in a direction that forms an angle roughly 120 degrees with straight segments  208 . Each wire then bends ninety degrees inward for another eighth of an inch parallel to the other eighth-inch segment. Finally, each wire bends ninety degrees and continues for about one-sixteenth of an inch in a direction roughly parallel to the quarter inch segments to from one-sixteenth of an inch spring end segments  210 . A small hole  212  is located in each anti-kickback pawl, to the front of and below hole  198 , and each spring end segment  210  passes through a hole  212  and lies roughly against the inner surface of each pawl to connect the spring to each pawl. 
     Spring  184  stretches over bushing  190  so that straight segments  206  lie against the front of the wider sections  194  of bushing  190  and straight segments  208  lie against the back side of sections  194 . Corners  209  catch the back sides of each anti-kickback pawl and, as stated, each end  210  is inserted into a hole  212  in each anti-kickback pawl. Each hole  212  is positioned on an anti-kickback pawl so that the triangle formed by hole  212  and the point of contact between straight segment  206  and bushing  190  and the point of contact between straight segment  208  and bushing  190  keeps spring  184  in tension stretched over bushing  190  and holds the anti-kickback pawl assembly together as a unit. 
     As shown in  FIGS. 4 and 10 , anti-kickback pawls  182  are attached at the top, rear of the splitter by spring  184  and bolt  186 . Splitter  26  includes an extension  214  with a notch  216  (labeled in  FIG. 21 ). Loop  202  of spring  184  hooks around and over extension  214  so that the loop fits in notch  216 , as shown in  FIG. 5 . Splitter  26  also includes a cutout  222  immediately rearward of extension  214 , and the cutout includes a notch  220 . Bushing  190  in pawl assembly  200  fits into notch  220  so that groove  218 , formed by the center thin section  192  in the center of bushing  190 , fits over the edge of the splitter along notch  220 . The distance between notches  216  and  220  causes spring  184  to stretch, and the tension in the spring holds the pawl assembly on the splitter. 
       FIG. 33  shows the blade guard with the anti-kickback pawls removed. To remove the anti-kickback pawl assembly, the user holds both sides of bolt  186  and pulls the bolt back stretching spring  184  until the bolt clears notch  220 . Cutout  222  includes an opening  224  large enough for bolt  186  to pass through, so when bolt  186  clears notch  220 , the user can lift the bolt up and out of opening  224 . Splitter  26  includes an extension  226  defining a rearward edge of cutout  222 . Extension  226  helps direct the movement of the anti-kickback assembly as it is being removed or installed. 
     To re-install the anti-kickback pawl assembly, loop  202  is fitted over extension and center groove  218  of bushing  190  is positioned over the top edge of the splitter. Bolt  186  is then pulled back, stretching spring  184 , and moved into cutout  222  through opening  224 . The top and bottom edges of extension  214  and cutout  222  are rounded to facilitate movement of the bushing into the cutout. The bolt is then released and spring  184  pulls the bolt into notch  220  and the remaining tension in the spring holds the anti-kickback assembly in place. 
     In normal operation, spring  184  pulls the anti-kickback pawls down and forward until the front edge of each anti-kickback pawl contacts a pawl stop  228  on the splitter. Pawl stop  228  consists of a small metal cylinder press-fit into the splitter. When a piece of wood, or other workpiece, passes through the blade guard, the anti-kickback pawls rotate back so that the bottom of the pawls ride gently on the surface of the workpiece. As the anti-kickback pawls rotate back, the distance between notch  216  at the top of splitter  26  around which the loop  202  of spring  184  is anchored, and holes  212  through which the ends  210  of spring  184  pass in the anti-kickback pawls, increases and spring  184  is stretched. The resulting tension in the spring creates the restoring force that causes the anti-kickback pawls to rotate forward again after the workpiece leaves the blade guard. However, because coils  204  are not fixed, the top of spring  184  is able to pivot upwards about notch  216  and towards the front of the blade guard as spring  184  is stretched thus reducing the tension in the spring from what it would have been if coils  204  were fixed. That is, because of the geometry of the spring, the distance between notch  216  (which may also be referred to as an anchor point) and holes  212  is less as the anti-kickback pawls rotate back than it would have been if coils  204  were held at a fixed position and holes  212  were at a set distance from the fixed position of the coil. This results in a reduced restoring force by the spring. Not only is the restoring force reduced for this configuration but the difference is greater the more the anti-kickback pawls rotate back. A reduced restoring force helps to minimize marks or visible impressions that the tips of the anti-kickback pawls might otherwise leave on workpieces. 
     The geometry of spring  184  also allows the anti-kickback pawls to be easily disabled simply by rotating the pawls upward to a stable position. When the anti-kickback pawls are rotated back, the tension in the spring increases as the distance between anchor point  216  and each hole  212  increases, and reaches its maximum when anchor point  216  and hole  212  are in line with pivot axis  230  at the center of bolt  186  when viewed from the side, as shown in  FIG. 34 , which is a point of unstable equilibrium. When the anti-kickback pawls, and thus holes  212 , are rotated down below this centerline going through anchor point  216  and pivot axis  230 , spring  184  pulls the anti-kickback pawls downward until they contact the surface of the workpiece or stops  228 . However, if the anti-kickback pawls are rotated upward beyond this centerline, that is, when it is “overcenter”, spring  184  pulls the anti-kickback pawls upward until stops  232 , which are extensions at the top of each anti-kickback pawl, abuts stops  228 . The spring then holds the pawls up in a disabled position above the workpiece.  FIG. 35  shows the anti-kickback pawls rotated up to a stable and disabled position. 
     INDUSTRIAL APPLICABILITY 
     The blade guards with hold-down capability, splitters, and anti-kickback devices disclosed herein are applicable to woodworking power tool equipment, and particularly to table saws. 
     It is believed that the disclosure set forth above encompasses multiple distinct inventions with independent utility. While each of these inventions has been disclosed in its preferred form, the specific embodiments thereof as disclosed and illustrated herein are not to be considered in a limiting sense as numerous variations are possible. The subject matter of the inventions includes all novel and non-obvious combinations and sub-combinations of the various elements, features, functions and/or properties disclosed herein. No single feature, function, element or property of the disclosed embodiments is essential to all of the disclosed inventions. Similarly, the recitation of “a” or “a first” element, or the equivalent thereof, should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. 
     It is believed that the following claims particularly point out certain combinations and sub-combinations that are directed to disclosed inventions and are novel and non-obvious. Inventions embodied in other combinations and sub-combinations of features, functions, elements and/or properties may be claimed through amendment of the present claims or presentation of new claims in this or a related application. Such amended or new claims, whether they are directed to a different invention or directed to the same invention, whether different, broader, narrower or equal in scope to the original claims, are also regarded as included within the subject matter of the inventions of the present disclosure.