Abstract:
A saw includes a base, a table supported above the base and configured to support a workpiece, an arm coupled to and extending above the base, and a saw unit supported by the arm so that the saw unit is disposed above the table. A first rail is fixedly coupled to the base and extends in a longitudinal direction, and a first bearing member is coupled to the table. The first bearing member moves along the first rail so that the table is moveable relative to the base in the longitudinal direction between a cantilevered position and an uncantilevered position, without any movement of the table relative to the first bearing member. The first bearing member is directly in contact with the first rail in both the cantilevered and uncantilevered positions.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. Patent Application No. 11/017,992, filed Dec. 21, 2004, titled “Tile Saw,” now pending, which is a continuation of U.S. Patent Application No. 10/140,668, filed May 8, 2002, titled “Tile Saw, now U.S. Pat. No. 6,845,768, which is a continuation of U.S. Patent Application No. 09/413,769, filed Oct. 7, 1999, titled “Tile Saw,” now U.S. Pat. No. 6,427,677, which claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 60/106,568, filed Nov. 2, 1998, titled “Tile Saw,” each of which is incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    This application relates generally to tile or masonry saws and, more particularly, to tile saws with expanded capacity. 
       BACKGROUND 
       [0003]    A typical tile saw includes a base which supports a generally flat table top. A saw unit may be disposed on the base or table for cutting a workpiece, such as a tile or masonry brick, disposed on the table. However, the maximum cutting capacity of such tile saws is limited by the size of the machine, i.e., the envelope. 
         [0004]    Accordingly, persons skilled in the art have devised a tile saw where the base has two tracks and the table has bearings or wheels riding on the tracks, so that the table can be slid relative to the saw unit for increased capacity. Such tile saws, however, are usually susceptible to dust collecting between the tracks and wheels, which creates binding between the base and the table. Ultimately, the binding may cause uneven, inaccurate cuts, which may translate into loss of time, materials and/or profit for the user. 
         [0005]    Further, the capacity of such tile saws is usually limited to the length of the tracks. In other words, if a user wants increased capacity, he may have to lengthen the tracks. However, longer tracks may result in less portability of the tile saw. 
         [0006]    It is an object of this invention to provide a saw with increased cutting capacity without sacrificing portability. 
       SUMMARY 
       [0007]    In an aspect, a tile saw comprises a base, a table disposed on the base, a saw unit disposed on the base, a first stationary rail having a first length extending generally along a first direction, the first stationary rail being connected to one of the table and saw unit, and a first movable rail engaging the first stationary rail and extending generally parallel to the first stationary rail, the first movable rail being connected to the other of the table and saw unit, wherein the first movable rail is movable with respect to the first stationary rail such that the other of the table and saw unit is movable generally along the first direction over a range which exceeds the first length. The first movable rail may be slidingly received over the first stationary rail. 
         [0008]    Additional features and benefits of the present invention will be apparent from the accompanying drawings, the detailed description below, and the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a perspective side view of a first embodiment of a tile saw according to the present invention; 
           [0010]      FIG. 2  is a plan view, partially in cross section, of the tile saw illustrated in  FIG. 1 ; 
           [0011]      FIG. 3  is a perspective view showing an embodiment of a telescoping rack and pinion assembly according to the present invention; 
           [0012]      FIG. 4  is a side elevation view, partially in cross-section, along plane IV-IV of  FIG. 1 ; 
           [0013]      FIGS. 5A and 5B  are schematic illustrations of the telescoping fence assembly according to the present invention; 
           [0014]      FIGS. 6A and 6B  are enlarged perspective views illustrating the bumps schematically shown in  FIGS. 5A and 5B ; 
           [0015]      FIG. 7  is a perspective side view of a second embodiment of a tile saw according to the present invention; 
           [0016]      FIG. 8  is a side elevation view of the knob drive assembly of the second embodiment; 
           [0017]      FIG. 9  is a perspective side view of a third embodiment of a tile saw according to the present invention; 
           [0018]      FIG. 10  is a perspective side view of a fourth embodiment of a tile saw according to the present invention; and 
           [0019]      FIG. 11  is a perspective side view of a fifth embodiment of a tile saw according to the present invention 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    The invention is now described with reference to the accompanying figures, wherein like numerals designate like parts.  FIG. 1  illustrates a first embodiment of the present invention, where tile saw  10  comprises a base  11  which supports a generally rectangular work table  12 . Slidable relative to table  12  is saw unit  13 , which comprises a blade  14  and a motor  15  driving the blade  14 . The saw unit  13  is slidably disposed on guide rods  16 , so that the saw unit  13  can be positioned at any position along rods  16 . Persons skilled in the art will recognize that one guide rod  16  may be used, but it is possible to use at least two rods  16  in order to increase stability. 
         [0021]    Further, saw unit  13  can be adapted to bevel, i.e., change the angle of blade  14  relative to the table  12 , as is known in the art. 
         [0022]    Saw unit  13  also has a water conduit  8  for lubricating and cooling the blade  14 , as is known in the art. Water sent through conduit  8  will drain into base  11  through table  12  and may be re-pumped through conduit  8  as is known in the art. 
         [0023]    The saw unit  13  is adapted so that a drill press  30  can be attached thereto. By changing the relative position of saw unit  13  and/or table  12 , the drill press  30  can be positioned over a tile workpiece for making round or arcuate cuts. Accordingly, the drill press  30  may be provided with an annular or circular cutting tool, e.g., made of diamond. 
         [0024]    Rail assemblies  100  are used to provide slidable movement between the saw unit  13  and table  12 . Persons skilled in the art are directed to U.S. Pat. No. 5,722,308, assigned to the present assignee, for further information on the rail assemblies  100  and their operation. Further, U.S. Pat. No. 5,722,308 is hereby incorporated by reference into the present specification. 
         [0025]    Rail assemblies  100  are each comprised of an inner rail  18  and an outer rail  19 . Inner rails  18  are disposed on the front and rear of table  12 . In one implementation, the inner rails  18  have a generally C-shaped cross-section and a length generally equal to the width of table  12 . Inner rails  18  are fixedly secured to table  12  using a plurality of fasteners  101  which are spaced along the entire length of inner rail  18 . As shown in  FIG. 4 , fasteners  101  include a bolt  102 , a nut  103  and a bushing  122 . Bolt  102  extends through inner rail  110  and through a bracket  124  which is secured to or is an integral part of table  12 . Bushing  122  is made from UHMW-PE or low friction polymeric material and is located between inner rail  18  and bracket  124  with the assembly being secured by nut  103 . Bushing  122  may extend over the entire length of inner rail  18 . 
         [0026]    A glide strip  18 C may be disposed on or wrapped around inner rail  18  to facilitate the movement of outer rail  19  with respect to inner rail  18 . In an embodiment, glide strip  18 C is made of UHMW polyethylene or a nylon based material injection molded over inner rail  18 . Glide strip  18 C extends over the entire length of inner rail  18 . 
         [0027]    Outer rails  19  are generally C-shaped members slidingly received over the inner rails  18 . Outer rails  19  are made of steel and roll-formed into the desired shape. A rail mechanism  200  allows a user to move the outer rails  19  relative to the inner rails  18 , as explained below. 
         [0028]    Carriages  17  supporting guide rods  16  and saw unit  13  are fixedly disposed on the outer rails  19 . Persons skilled in the art will recognize that the tile saw  10  may be designed so that only one carriage supports the guide rods  16  and saw unit  13 . 
         [0029]    By providing outer rails  19  which telescope with inner rails  18 , the saw unit  13  is deployable beyond the envelope of work table  12  in order to provide additional cutting capacity, as shown in  FIG. 1 , yet maintaining a compact envelope for simplifying transportation of tile saw  10 . The compact envelope of tile saw  10  facilitates both storage of tile saw  10  and the movement of tile saw  10  from one job site to the another. 
         [0030]    Persons skilled in the art will recognize that, to perform the cut, the operator need only push saw unit  13  towards the workpiece. The rigid connection between the outer rails  19 , the carriages  17  and the rails  16  will maintain the outer rails  19  moving together the same distance. Persons skilled in the art will recognize that other means to obtain the same result exist. 
         [0031]    For example, outer rails  19  may comprise a rack  376  which can be integral with outer rail  19  or it can be a separate component attached to a lower extending flange of outer rail  19  by a plurality of screws. Rack  376  extends over the entire length of outer rail  19 . Rack  376  includes a plurality of rack teeth  378  which may extend over the entire surface of the rack. An enlarged tooth may be provided at the end of each rack  376  to limit the travel of outer rail  19  with respect to inner rail  18  in either direction, as disclosed in U.S. Pat. No. 5,722,308, which is again hereby incorporated by reference. 
         [0032]    Rail mechanism  200  comprises a pinion shaft  150 , a pair of pinion gears  340  and an adjustment wheel  154 . Pinion gears  340  and adjustment wheel  154  are fixedly secured to pinion shaft  150  for rotation therewith. Pinion shaft  150  is rotatably secured to base  11  (e.g., by bearing mounts  346 ) such that pinion gears  340  are engaged with rack teeth  378  on each outer rail  19  with adjustment wheel  154  extending beyond the front outer rail  19  for accessibility by an individual. Thus, rotation of adjustment wheel  154  cause rotation of pinion shaft  150  and pinion gears  340  which, due to their engagement with rack teeth  378  of rack  376 , cause longitudinal movement of each outer rail  19  with respect to each inner rail  18  and the movement of saw unit  13  relative to saw table  12 . 
         [0033]    Due to the fact that both front and rear pinion gears  340  rotate simultaneously and by the same amount due to their rotation with pinion shaft  150 , both outer rails  19  will move together and the same distance due to the engagement of rack teeth  378  of each rack  376  with a respective pinion gear  340 . This simultaneous and equal movement of each outer rail  19  will thus ensure that the relationship between saw unit  13  and table  12  will be maintained during the movement of the saw unit  13 . 
         [0034]    Accordingly, the present invention allows the saw unit  13  to be moved over a range of lengths which exceeds the length of the stationary inner rails  18 . The saw unit  13  can be moved beyond the width of the work table  12 , outwardly of either side edge, without requiring that the stationary rails have a length which is greater than the width of the table to provide for such movement. 
         [0035]    The telescoping rails of the present invention have sufficient clearance between each inner rail and outer rail disposed thereon to accommodate the non-straightness of the rails. This clearance can cause excessive end play of the outer rail as it moves toward its totally extended position. Thus, it may be desirable, in the present invention, to provide a system for stabilizing the outer rail as it moves to it fully extended position. 
         [0036]    Accordingly,  FIGS. 5A and 5B  schematically represent an inner rail.  18  and an outer rail  19 . As before, inner rail  18  is adapted to be secured to work table  12 . Outer rail  19  telescopically engages inner rail  18  as shown previously with sufficient clearance maintained between the inner and outer rails to accommodate any non-straightness. Each end of inner rail  18  would include an outwardly extending bump  504  and each end of outer rail  19  would include an inwardly extending bump  506 . Bumps  504  contact the inner surface of outer rail  19  while bumps  506  contact the outer surface of inner rail  18 . These contact points help stabilize the movable rail against vertical movement in any extended position of the movable rails. However, bumps  504  and  506  must be provided in a manner which allows for outer rail  19  to move from the position shown in  FIG. 5A  to that shown in  5 B. That is, it is necessary for inwardly extending bumps  506  to pass through outwardly extending bumps  504 . 
         [0037]      FIG. 6A  illustrates a construction of inner rail  18  and outer rail  19  which provides bumps  504  and  506  which pass through each other. As explained above, guide strip  18 C may be injection molded over inner rail  18  as shown. Glide strip  18 C may be molded so as define a pair of pads  508  on the upper and lower surfaces of inner rail  18  at each end. Each pair of pads  508  defines a channel  510  extending longitudinally along the length of inner rail  18  for a short distance. The pair of pads  508  are designed such that they slidingly engage the interior surfaces of outer rail  19  to reduce or eliminate the clearances between the two rails. Pads  508  also could be a separate component assembled to inner rail  18 . 
         [0038]      FIG. 6B  illustrates outer rail  19  incorporating inwardly extending pads  512  integrally formed as a part of outer rail  19  at each end. One pad  512  is formed into an upper wall of outer rail  19  while the second pad  512  is formed into the lower wall of outer rail  19 . Pads  512  may be formed by stamping the rails inwardly in the roll forming process of the rails. Pads  512  are positioned to align with channels  510  defined by pads  508  such that outer rail  19  is allowed to move outwardly beyond inner rail  18  in both directions as is schematically illustrated in  FIGS. 5A and 5B . Pads  508  function as bumps  504  and pads  512  function as bumps  506  as described with reference to  FIGS. 5A and 5B . Thus, the contact of pads  508  and  512  with outer rail  19  and inner rail  18 , respectively, stabilizes the outer rails in the extended position. Persons skilled in the art are directed to U.S. Pat. No. 5,722,308, for other means for providing bumps  504  and  506 . 
         [0039]    Furthermore, persons skilled in the art are directed to U.S. Pat. No. 5,722,308, for further means for moving the outer rails  19  in relation to the inner rails  18 . 
         [0040]      FIG. 7  illustrates a second embodiment of the tile saw according to the present invention, where like numerals refer to like parts. This embodiment operates in a similar manner to the first embodiment. The main differences between this embodiment and the previous one is that: (1) inner rails  18  may be attached on the same side of base  11 ; (2) carriage  17  may be connected to both outer rails  19 ; and/or (3) rods  16  may be cantilevered. A first inner rail  18  is disposed above a second inner rail  18  in a parallel manner. Also at least one of rods  16  may have a stop  16 S to prevent saw unit  13  from being removed off rods  16 . Having such construction allows the user to cut a workpiece W having a width greater than the width of table  12  and/or base  11 . 
         [0041]    In order to move the outer rails  19 , the operator need only push on saw unit  13 . Alternatively, a knob assembly  400  may be provided in base  11 . Knob  154  is connected to a pinion  410 , which meshes with two pinions  411 . Pinions  411  have the same diameter and/or distance between teeth. Pinions  411  then mesh with the corresponding outer rails  19 . Accordingly, when user rotates knob  154 , pinions  410  and  411  rotate, moving outer rails  19  in the same direction and speed. 
         [0042]      FIG. 9  illustrates a third embodiment of the tile saw according to the present invention, where like numerals refer to like parts. This embodiment operates in a similar manner to the previous embodiments. The main difference between this embodiment with the first embodiment is that the table  12  is fixedly attached to the outer rails  19 , so that the table  12  can be moved relative to saw unit  13  and base  11 . Accordingly, carriages  17  are fixedly connected to base  11 . In addition, a sheet may be attached to table  12 , so that water from table  12  is collected on the sheet and drained into base  11 . The sheet may be pliable so that it can follow table  12  through the entire range of motion. As mentioned above, the user need only push the table  12   13  to cut the workpiece. Alternatively, the user may turn knob  154 , thus rotating pinion shaft  150  and forcing outer rails  19  (and thus table  12 ) to move. 
         [0043]      FIG. 10  illustrates a fourth embodiment of the tile saw according to the present invention, where like numerals refer to like parts. This embodiment operates in a similar manner to the previous embodiments. The main differences between this embodiment and the third embodiment is that: (1) inner rails  18  may be attached on the same side of base  11 ; and/or (2) rods  16  may be cantilevered. A first inner rail  18  is disposed above a second inner rail  18  in a parallel manner. Also at least one of rods  16  may have a stop  16 S to prevent saw unit  13  from being removed off rods  16 . Having such construction allows the user to cut a workpiece W having a width greater than the width of table  12  and/or base  11 . 
         [0044]    In an example, the lower outer rail  19  supports the table  12  via a beam  19 B. 
         [0045]    In order to move the outer rails  19 , the user need only push table  12 . Alternative, a knob assembly similar to knob assembly  400  may be provided in base  11 . Accordingly, when user rotates knob  154 , pinions  410  and  411  rotate, moving outer rails  19  in the same direction and speed. 
         [0046]      FIG. 11  illustrates a fifth embodiment of the tile saw according to the present invention, where like numerals refer to like parts. This embodiment operates in a similar manner to the first and third embodiments. The main differences between this embodiment and the third embodiment is that: (1) saw unit  13  is disposed below table  12 ; and/or (2) table  12  is split in order to allow blade  14  to extend therethrough throughout the range of movement of table  12 . 
         [0047]    Saw unit  13  may have a riving knife  13 K connected thereto so that the cut pieces of workpiece W do not contact each other. The use and installation of riving knife  13 K is well known in the art. 
         [0048]    Water conduit  8  (not shown) may be disposed below table  12  for lubricating and cooling the blade  13 , as is known in the art. 
         [0049]    Numerous modifications may be made to the exemplary implementations described above. These and other implementations are within the scope of the following claims.