Abstract:
A saw with a base assembly connected to a mounting portion; a motor unit which is pivotally mounted on the mounting portion to allow the motor unit to pivot towards or away from the base assembly to perform chop cuts, a table mounted on the motor unit to enable the saw to act as a table saw and a table fence capable of being releaseably attached to the table  114 . The table fence comprises a guide plate, a guide fence moveably connected to the guide plate, and a locking mechanism for releaseably locking the position of the guide fence to the guide plate.

Description:
FIELD  
       [0001]     The present invention relates to saws, and in particular, to powered saws which can perform miter cuts, chops cuts, sliding cuts or bevel cuts, or any combination of these functions.  
       BACKGROUND  
       [0002]     WO98/18588 discloses a sliding compound miter saw. Such a saw can perform bevel cuts, miter cuts, sliding cuts and chop cuts. The sliding compound miter saw disclosed comprises a base  12  (using the same reference numbers as those used in WO98/18588) having a rotatable table  14  mounted within it. The rotatable table  14 , in conjunction with a fence  26  fixed to the base  12 , enables the sliding compound miter saw to perform miter cuts. Connected to the rear of the table  14  is a bevel mount  16  which is able to pivot about a horizontal axis in relation to the table  14 . The pivotal movement of the bevel mount  16  in relation to the table  14  enables the sliding compound miter saw to perform bevel cuts. Slideably mounted onto the bevel mount  16  are two guide rods  34  which are capable of sliding horizontally, backwards and forwards. The rods  34  enable the sliding compound miter saw to perform sliding cuts. Pivotally mounted on the end of the guide rods  34  is a motor unit  36 , which comprises a motor  22  for rotationally driving a circular saw blade  18  mounted on a drive spindle on the motor unit  36 . The pivotal movement of the motor unit  36  in relation to the guide rods  34  enable the saw to perform chop cuts.  
         [0003]     Rigidly mounted to the motor unit  36  is a fixed guard  40  which surrounds the cutting edge of the top half of the cutting blade  18 . Pivotally mounted to the motor unit is a pivotal guard  42  which can pivot between a first position where it surrounds the cutting edge of the lower half of the cutting blade and a retracted position where the cutting edge of the lower half of the blade  18  is exposed for use in cutting.  
         [0004]     The pivotal guard is pivoted between its two positions using a mechanical linkage which comprises a series of mechanical arms  48 ,  50 , which are pivotally connected to each other and the saw, and cams  52 ,  54  which control the movement of the arms  48 ,  50 . As the motor unit is pivoted downwards, the mechanical linkage causes the lower cutting edge of the blade to become exposed due to the retraction of the pivotal guard by the mechanical linkage.  
         [0005]     JP2005-178281 describes a chop saw with a table mounted on top of the motor unit. The table enables the saw to be used as a table saw.  
         [0006]     Table saws typically comprise a table fence which help an operator to guide work pieces across the table in a linear direction.  
       SUMMARY  
       [0007]     There is provided a saw comprising a base assembly connected to a mounting portion, a motor unit which is pivotally mounted on the mounting portion to allow the motor unit to pivot towards or away from the base assembly to perform chop cuts; and/or slidingly connected to the mounting portion to allow the motor unit to slide across the base assembly to perform sliding cuts the motor unit having an output drive spindle upon which a circular saw blade can be rigidly mounted to be rotationally driven by the motor unit, a table mounted on the motor unit to enable the saw to act as a table saw and a table fence capable of being releaseably attached to the table, the table fence comprising a guide plate, a guide fence moveably connected to the guide plate, and a locking mechanism which can releaseably lock the position of the guide fence to the guide plate wherein, when the locking mechanism is activated, the guide fence is held rigidly relative to the guide plate and when it is released, it allows relative movement between the guide plate and the guide fence so that both the position and the orientation of the guide fence relative to the guide plate can be altered.  
         [0008]     Also provided is a table fence comprising a guide plate, a guide fence moveably connected to the guide plate, and a locking mechanism which can releaseably lock the position of the guide fence to the guide plate wherein, when the locking mechanism is activated, the guide fence is held rigidly relative to the guide plate and when it is released, it allows relative movement between the guide plate and the guide fence so that both the position and the orientation of the guide fence relative to the guide plate can be altered.  
         [0009]     In addition a saw may have a base assembly connected to a mounting portion, a motor unit which is pivotally mounted on the mounting portion to allow the motor unit to pivot towards or away from the base assembly to perform chop cuts; and/or slidingly connected to the mounting portion to allow the motor unit to slide across the base assembly to perform sliding cuts, the motor unit having an output drive spindle upon which a circular saw blade can be rigidly mounted to be rotationally driven by the motor unit, wherein there is further provided a table mounted on the motor unit to enable the saw to act as a table saw and a table fence capable of being releaseably attached to the table, characterised in that the table fence comprises a cam mechanism moveable between two positions, a first position where it frictionally holds onto a part of the table and a second position where it is disengaged from the table.  
         [0010]     Also described is a table fence for a saw comprising a base assembly connected to a mounting portion, a motor unit which is pivotally mounted on the mounting portion to allow the motor unit to pivot towards or away from the base assembly to perform chop cuts, and/or slidingly connected to the mounting portion to allow the motor unit to slide across the base assembly to perform sliding cuts the motor unit having an output drive spindle upon which a circular saw blade can be rigidly mounted to be rotationally driven by the motor unit, and a table mounted on the motor unit to enable the saw to act as a table saw, wherein the table fence is capable of being releaseably attached to the table of such a saw, characterised in that the table fence comprises a cam mechanism moveable between two positions, a first position where it is capable of frictionally holding onto a part of a table of such a saw and a second position where it is not capable of frictionally holding onto that part of a table of such a saw. 
     
    
     DESCRIPTION OF THE DRAWINGS  
       [0011]     An embodiment of the present invention will now be described with reference to the accompanying drawings of which:  
         [0012]      FIG. 1  shows a sliding compound miter saw with a table from a first perspective;  
         [0013]      FIG. 2  shows a sliding compound miter saw with a table from a second perspective;  
         [0014]      FIGS. 3A  to  3 I show the table fence of the first embodiment of the table fence of which.  
         [0015]      FIG. 3A  is a top downward looking view;  
         [0016]      FIG. 38  is a front view in the directions of Arrows Q in  FIG. 3A :  
         [0017]      FIG. 3C  is an end view in the direction of Arrows R in  FIG. 3B ;  
         [0018]      FIG. 3D  is a vertical cross sectional view along the line indicated by Arrows B in  FIG. 3A ;  
         [0019]      FIG. 3E  is a vertical cross section of the table fence in the direction of Arrows T in Figure A with the latch lever in a second position;  
         [0020]      FIGS. 3F and 3G  are front views with the latch lever in different positions; and  
         [0021]      FIG. 3H  is a vertical cross section of the table fence in the direction of Arrows T in Figure A with the latch lever in a first position;  
         [0022]      FIG. 4  shows a rear perspective view of the table fence  300  with the guide fence in a first position;  
         [0023]      FIG. 5  shows a rear perspective view of the table fence  300  with the guide fence in a second position;  
         [0024]      FIG. 6  shows the underside of the table fence, and  
         [0025]      FIG. 7  shows a perspective view of the table fence of the second embodiment of the table fence;  
         [0026]      FIG. 8  shows an underside view of the table fence of the second embodiment of the table fence;  
         [0027]      FIG. 9  shows a rear perspective view of part of the table fence of the second embodiment of the table fence; and  
         [0028]      FIG. 10  shows an underside view of the cast of the second embodiment of the second embodiment of the table fence. 
     
    
     DETAILED DESCRIPTION  
       [0029]     The embodiments described herein relate to a sliding compound miter saw, similar to that described in WO98/18588, which has a table mounted on top of the motor unit to enable the saw to act as a table saw.  
         [0030]     A first embodiment of the table fence will now be described with reference to FIGS.  1  to  6 . Referring to  FIGS. 1 and 2 , there is provided a sliding compound miter saw with a table  114  which can perform bevel cuts, miter cuts, sliding cuts and chop cuts. The saw comprises a base having a rotatable table  104  mounted within it. An extension arm  106  is preferably attached to the periphery of the rotatable table  104  and extends forward in well known manner. The rotatable table  104 , in conjunction with a fence  108  fixed to the base  102 , enables the saw to perform miter cuts. A bevel mount  110  is preferably connected to the rear of the rotatable table  104 , and is able to pivot about a horizontal axis in relation to the rotatable table  104 . The pivotal movement of the bevel mount  110  in relation to the rotatable table  14  enables the saw to perform bevel cuts. Two guide rods  112 ,  116  may be slideably mounted onto the bevel mount  110 , and are capable of sliding horizontally, backwards and forwards. The rods  112 ,  116  enable the saw to perform sliding cuts. A motor unit  118 , may be pivotally mounted on the end of the guide rods  112 ,  116 . Motor unit  118  may comprise a motor (not shown) for rotationally driving a circular saw blade  120  mounted on a drive spindle on the motor unit  118 . The pivotal movement of the motor unit  118  in relation to the guide rods  112 ,  116  enable the saw to perform chop cuts. The motor unit  118  is preferably biased to an upward position by a spring (not shown). A slot  122  may extend across the rotatable table  104  and along the extension arm  106 .  
         [0031]     Mounted on the top of the saw is a table  114  which enables the saw to be also used as a table saw. The table  114  is preferably attached to the top side of the motor unit  118 . A slot  124  may be formed through the table  114  through which the top section of the circular saw blade  120  projects. The motor unit  118  can be locked in a downward position such that the table  114  is horizontal. A work piece, such as a piece of wood, can then be slid across the top of the table  114  to engage with the top section of the saw blade  120  thus enabling the saw to be used as a saw table. A riving knife  126  may be located towards the rear of the saw blade  120  and a guard  128  can surround the top of the saw blade  120  when the saw is not being used as a table saw, which includes a shoot  130  for the extraction of wood chips.  
         [0032]     The saw preferably comprises a plurality of guards located below the table  114  which are capable of enclosing the lower section of the saw blade for safety purposes when the saw is not being used for performing chop, miter, bevel or sliding cuts, for example, when the saw is being used as a table saw, with the motor unit  118  locked downwardly.  
         [0033]     A handle  132  may be attached to the motor unit  118  by which a user can grip and pivot the motor unit  118  and the circular saw blade  120  downwards towards the rotatable table  104 . An electric switch  134  is preferably mounted on the handle  132  for activating the motor.  
         [0034]     The motor unit  118  can be locked in its lowest pivotal position against the biasing force of the spring. When the motor unit  118  is in this position, the table  114  is horizontal. In this position the table  114  can be used as a table saw, the work piece  216  being cut by the part of the saw blade  120  which passes through the slot  124 .  
         [0035]     When the motor unit  118  is free to pivot, the saw can be used as a sliding compound miter saw.  
         [0036]     The height of the table  114 , and hence the amount of saw blade  120  passing through it, can be adjusted vertically.  
         [0037]     Referring to  FIGS. 3A  to  3 G,  4 ,  5  and  6  there is provided a table fence  300  for use with the table  114 .  
         [0038]     The table fence is used by an operator to guide work pieces across the table  114  when the saw is being used as a table saw. It is important that the movement of a work piece, when it is being cut, is linear and that its direction is parallel to the plane of the blade. This to ensure a smooth cuffing action. A table fence is therefore provided. The operator slides the work piece along a straight side of the table fence  300 , the straight side being aligned with the plane of the blade  120 .  
         [0039]     The table fence  300  preferably comprise a guide fence  302 . The guide fence  302  may have an elongate tubular structure having a substantially uniform cross-section along its length. A flat vertical face  304  may be formed on one side along the length of the fence guide  302 . In use, a work piece is slid along this surface  304 .  
         [0040]     A guide plate  306  is preferably attached to the guide fence  302 , at one end of the guide fence  302 , via two bolts  322 ,  323 . Details of the connection between the guide fence  302  and the guide plate  306  is provided below.  
         [0041]     A latch lever  308  may be pivotally mounted on the guide plate  306 . The latch lever  308  can pivot from a first position  312  where it is horizontal (see  FIG. 3H ), extending in the same direction as the guide fence  302  to a second downward position  314  (see  FIG. 3E ). The latch lever  308  may be pivotally mounted on a pin  316  mounted on the underside of the guide plate  306  (see  FIG. 6 ), A lip  318  is preferably formed along the length of the guide plate. The end of the lever  308  adjacent the pin  316  faces the lip  318 . This results in a channel  320  being formed between the two.  
         [0042]     The end of the latch lever  308  adjacent the pin  316 , may be shaped so that it forms a cam  330 . The cam  330  is preferably shaped so that, when the latch lever  308  is in its first position  312  ( FIG. 3H ), the cam  330  reduces the width of the channel  320 , but when the latch lever  308  is in its second position  314  ( FIG. 3E ), the width of the channel  320  is increased.  
         [0043]     A groove  332  may be formed across the front of the table  114  (see  FIGS. 1 and 2 ). The groove  332  results in a ridge  334  of approximately square cross section being formed along the front edge of the table  114 . When the table fence  330  is located on the table  114 , the ridge  334  of the table  114  preferably locates within the channel  320  of the table fence  300 . (In  FIG. 3A  to  3 H, for simplicity of the drawings, the ridge  334  is simply shown as a square block. However, it is preferably integrally formed with the table  114  as shown in  FIGS. 1 and 2 .) The guide fence  302  may extend generally in a forward/rearward direction, parallel to the plane of the blade  120 . However, its precise alignment relative to the blade  120  can be altered, as described below.  
         [0044]     In order to mount the table fence  300  onto the table  114 , the latch lever  308  is preferably moved to its second position  314  so that the cam  330  is located outside of the channel  320 . The table fence  300  is placed on the table  114  so that the ridge  334  locates within the channel  320 . The latch lever  308  preferably extends forward beyond the front edge of the table  114 . This ensures that the table  114  does not interfere with the pivotal movement of the latch lever  308 . The latch lever  308  is then pivoted to its first position  312  so that the width of the channel  320  is reduced causing the cam  330  to frictionally engage with the side of the ridge  334 , sandwiching it between the cam  330  and the lip  318 . The shape of the cam  330  is such that it locks the table fence  300  to the ridge  334 . An operator can then use the vertical surface  304  of the guide fence  302  to guide a work piece in a straight direction into the cutting blade, the work piece sliding along the vertical surface  304  in a direction parallel to the plane of the blade  120 .  
         [0045]     In order to release the guide fence  302  from the table  114 , the operator pivots the latch lever  308  from its first position  312  to its second position  314 , moving the cam  330 , increasing the width of the channel  320 , disengaging it from the ridge  334 . The table fence  300  can then be removed from the table  114 .  
         [0046]     The position of the guide fence  302  from the cutting blade  120  can be adjusted. The latch lever  308  is pivoted to its second position, disengaging the cam  330  from the ridge  334 . The guide fence  302  is then slid towards or away from the cutting blade  120 . This results in the ridge  334  sliding within the channel  320 , until the desired position is reached. The latch lever  308  is then pivoted to its first position  312 , engaging with the ridge  334  and sandwiching it between the cam  330  and the lip  318  to lock the position of the guide fence  302  relative to the table  114 .  
         [0047]     The shape of the cam  330  is such that when the latch lever  308  is in its first position  312 , it is held there by the frictional engagement of the cam  330  with the ridge  334 .  
         [0048]     The position of the guide fence  302  can be adjusted relative to the guide plate  306 . The connection between the two will now be described in more detail.  
         [0049]     The guide fence  302  may comprise a tubular aperture  386  which runs through the full length of the guide fence. A slot  382  is preferably formed along the length of the lower surface  380  of the guide fence  302  which faces the guide plate  306 . The slot  382  provides a passageway into the tubular aperture  386 . A metal cast  388  may be located within the tubular aperture  386 , the dimensions of which are too large to permit it from passing through the slot  382 . Two threaded holes are preferably formed in the cast  388 .  
         [0050]     Two holes are preferably formed through the guide plate  306 . The shafts of the two bolts  323 ,  322  pass through the holes in the guide plate  306  and threadingly engage with the two threaded holes in the cast  388 . The head of the bolts  322 ,  323 , as seen in  FIG. 6 , are too large to pass through the holes in the guide plate  306 . When the bolts are tightened, they move the cast  388  towards the guide plate  306 , sandwiching the edges  390  of the guide fence  302  which form the edges of the slot  382  between guide plate  306  and the cast  388 . Once the bolts are tightened, the guide fence  302  is rigidly attached to the guide plate  306 . If the bolts are slackened, the position of the guide fence  302  can be moved relative to the guide plate  306 . The guide fence  302  can slide along its longitudinal axis, as the shafts of the bolts slide along the slot  382 .  FIG. 4  shows the guide fence  302  in a first position,  FIG. 5  shows it in a second position.  
         [0051]     The width of the slot  382  is preferably greater than the width of the shaft of the bolts  322 ,  323 . Therefore, when the bolts  322 ,  323  are slackened, the guide fence can also be moved angularly relative to the guide plate  306  to adjust the orientation of the guide fence  302  relative to the guide plate  306 . This allows the guide fence to be accurately aligned relative to the plane of the cutting blade  120 .  
         [0052]     Once the orientation has been adjusted so that accurate alignment has been made and the correct relative position selected, the bolts  322 ,  323  can be tightened to hold the position of the guide fence  302  relative to the guide plate  306 .  
         [0053]     A second embodiment of the table fence will now be described with reference to FIGS.  7  to  10 . The second embodiment is the same as the first embodiment except for the design of the bolts  322 ,  323  and the cast  388 . Where the same features occur in the second embodiment, the same reference numbers have been used.  
         [0054]     The first embodiment of the table fence used two bolts  322 ,  323  which clamped the guide fence  302  to the guide plate  306 . In the second embodiment, the two bolts  322 ,  323  have been replaced with one regular bolt  700  and a bolt  702  having a wing grip  704 . The regular bolt  700  is used for stability; during normal use it doesn&#39;t get tightened completely. The amount by which the bolt  700  is screwed into the cast  388  is set so that the guide fence  302  beam can slide freely and can be angled relative to the guide plate  306  without being too loose to set its alignment and position relative to the blade  120 . Then when the second bolt  702  is tightened using the wing grip  704  to lock the guide fence  302  securely. Such a design enables the position of the guide fence to be set manually as the regular bolt  700  does not have to be adjusted during normal use of the table fence, only the bolt  702  with the wing grip  704 .  
         [0055]     Two protrusions  706  are formed on the underside of the cast  388  near aperture  712  through which the regular bolt  700  passes. These protrusions  706  engage with the sides  710  of the edges  390  of the guide fence  302 . This prevents sideways movement of the guide fence  302  on the cast  388  at the position of the aperture  712  through which the regular bolt  700  passes. As such, the cast guide fence  302  is prevented sliding side ways relative to the cast  388  at the position of the aperture  712  along the length of the cast  388 . As such, the pivotal movement of the guide fence  302  on the cast  388  is about the aperture  712  for the regular bolt, the side to side slop of the guide fence  302  being restricted by the bolt  702  with the wing grip  704 .  
         [0056]     As such, when the bolt  702  with the wing grip  704  is unscrewed to loosen the guide fence  302 , the guide fence  302  can either pivot around these protrusions  706 , or slide along them, and can then be locked securely by the bolt  702  with the wing grip  704  being tightened.