Patent Publication Number: US-6668817-B2

Title: Chuckable natural stone tile edge chipping tool

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to tools used for shaping and cutting tile and, more particularly, to tools used to chipping natural stone tile. 
     2. Description of Related Art 
     Natural stone tile is widely used for decorative floors. Natural stone tile may be manufactured from a variety of naturally-occurring materials, such as marble, granite, slate, flagstone, onyx, and sandstone. As is the case with denim jeans, it has become fashionable to use natural stone tile which has a used, or rustic appearance. Natural stone tile is often given a rustic appearance by placing the tile in a large drum filled with small stones. When the drum is rotated, the stones abrade the edges of the tile, giving the edges a rounded and worn appearance. This is obviously an expensive, labor-intensive process, which can result in a near doubling of the price of the tile. The increase in cost is related not only to the additional labor required to treat the tile, but is also related to the cost of the equipment required by the rustication process. Because natural stone tile is of generally uniform composition throughout its entire thickness, the rustication process does not remove or damage a protective coating, such as the glass layer that is present on fired ceramic tile. 
     What is needed is a relatively inexpensive, portable, simple-to-use tool which can be employed by an installer of tile to abrade the edges of each piece of tile prior to the installation thereof. It would be desirable that such a tool would provide an appearance similar to that achieved by the more costly rotating drum process. Such a tool would also have a flexibility advantage over use of the rotating drum process, as small quantities of tile could be treated in a cost-effective manner. 
     SUMMARY OF THE INVENTION 
     The present invention provides both a method and an apparatus, or tool, for chipping the edges of natural stone tile in order to give the tile a used or rustic appearance. The tool comprises an axially-rotatable, cylindrical member having an array of studs affixed or embedded in the cylindrical surface. A drive shaft, affixed to one end of the cylindrical member, may be inserted within the chuck of a powered drill motor or other similar powered device. A handle is rotatably coupled to the opposite end of the cylindrical member. For a preferred embodiment of the invention, the handle consists of a tubular sleeve which is rotatably mounted on bearing races over a support shaft that is rigidly and coaxially affixed to the cylindrical member. Alternatively, the cylindrical member may have a hollow cylindrical recess at the handle end thereof, and a handle may be rotatably mounted within the recess in bearing races. 
     The studs may be affixed to the cylindrical member in various ways. For one embodiment of the invention, the studs are domed globs of welded material. For another embodiment, the studs are tungsten carbide inserts, each of which is mounted within a recess formed within the cylindrical member. The inserts may be affixed within the recesses with brazing compound or with an epoxy adhesive. For yet another embodiment of the invention, the studs are integral with the cylindrical member, being, for example, investment cast, sand cast, or forged as a unit. 
     In order to use the tool, the drive shaft is secured within the chuck of a drill motor or other similar device designed to provide powered rotary motion to a shaft. With the operator holding both the drill motor and the handle of the chipping tool, the rotating studded cylindrical member is moved along and against the edge of a piece of natural stone tile. The edge of the tile is thereby chipped or abraded. The amount of material removed from the edge may be controlled by varying the amount of time and pressure. The angle can be varied over several strokes, thereby imparting a roughly curved edge to the tile. Using the tool and method, up to three 12-inch-square tile may be treated per minute. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view of the chipping tool body; 
     FIG. 2 is an exploded view of view of the chipping tool body fitted with ball bearing races, a sleeve, and a padded grip; 
     FIG. 3 is a cross sectional view of the assembled chipping tool, taken through a plane which passes through the longitudinal axis of the tool body; 
     FIG. 4 is a side elevational view of the assembled chipping tool; 
     FIG. 5 is a cross sectional view of the cylindrical member of the tool body, taken through section line  5 — 5  of FIG. 4; 
     FIG. 6 is a handle-end view of the assembled tool, taken perpendicular to the longitudinal axis of the tool body; 
     FIG. 7 is a cross sectional view of the drive shaft portion and integral cylindrical member portion of an alternative embodiment of the tool having embedded studs; 
     FIG. 8 is a side view of the tool coupled to a drill motor and positioned to abrade the edge of a piece of natural stone tile; and 
     FIG. 9 is a piece of stone tile, the edge of which has been chipped using the tool. 
     FIG. 10 shows a piece of tile  904 , an edge of which has been abraded to form a generally chamferred profile  1001  using the tool  300 . 
     FIG. 11 shows a piece of tile  904 , an edge of which has been abraded to form a generally rounded profile  1101  using the tool  300 . 
    
    
     PREFERRED EMBODIMENT OF THE INVENTION 
     The present invention provides both a method and an apparatus, or tool, for chipping the edges of natural stone tile in order to give the tile a used or rustic appearance. The tool will now be described with reference to the attached drawing figures. 
     Referring now to FIG. 1, the tool comprises a tool body  100 , which includes an axially-rotatable, cylindrical chipping member  101  having an array of studs  102 , arranged in rows, which are either integral with, affixed or embedded in the cylindrical surface  103 . A drive shaft portion  104 , affixed to one end of the cylindrical chipping member  101 , may be inserted within the chuck of a powered drill motor or other similar powered device. A handle shaft portion  105 , on which a handle may be axially rotatably mounted, is affixed to the opposite end of the cylindrical chipping member  101 . It will be noted that the handle shaft  105  has three snap-ring grooves  106 A,  106 B and  106 C machined or ground therein. For a preferred embodiment of the invention, the tool body is made of steel, which may be heat treated for durability and strength. The studs may be affixed to the cylindrical member in various ways. For one embodiment of the invention, the studs are domed globs of welded material. For another, the tool body and studs are investment cast, sand-cast, or forged as a unit. For another, the tool body  100  and studs  102  are also unitary, having been machined or ground from a steel billet. 
     Referring now to FIG. 2, an exploded view of the tool shows the tool body  100  of FIG. 1 fitted with a pair of ball-bearing assemblies  201 A and  201 B. External snap rings  202 , which fit into are employed to retain the ball-bearing assemblies  201 A and  201 B at the appropriate locations on the handle shaft  105 . A handle sleeve  203  slides over the ball-bearing assemblies  201 A and  201 B. The handle sleeve is preferably made from steel tubing. A handle grip  204 , which for a preferred embodiment of the invention is made of polymeric foam material, slips over the handle sleeve  203 . 
     Referring now to FIG. 3, the cross-sectional view of the assembled tool  300  shows the shape of the studs  102  on the cylindrical chipping member  101 , as well as the details of the ball-bearing assemblies  201 A and  201 B. Each ball-bearing assembly  201 A and  201 B has both an inner race  301  and an outer race  302 , between which a plurality of ball-bearings  303  are positioned. As the tool will be used for a job which necessarily will generate dust and grit, the ball-bearing assemblies  201 A and  201 B are of the sealed type. Each ball-bearing assembly  201 A and  201 B has a dust seal  304  on each side of the ball bearings  303 . As is typical for such an application, the dust seals  304  are affixed to the outer ball-bearing race  302 . Each dust seal  304  is washer shaped, having a central aperture, and each end of the inner ball-bearing race  301  spins within the central aperture of a dust seal  304 . Also shown in this cross-sectional view is the handle sleeve  203 , which has been slipped over the outer bearing races  302  of each ball-bearing assembly  201 A and  201 B. Internal snap rings  305 , which fit into grooves  306  machined in the inner circumferential surface  307  of the handle sleeve  203 , maintain proper positioning of the handle sleeve  203 . The handle grip  204  is shown installed over the upper surface of the handle sleeve  203 . The handle grip  204  is preferably sized so that its internal diameter is less than the external diameter of the handle sleeve  203 . As the handle grip  204  is preferably made of an expandable material, it may be slipped over the handle sleeve  203  using a mixture of water and liquid detergent. After the water evaporates, the grip  204  is firmly affixed to the handle sleeve  203 . 
     Referring now to FIG. 4, the chipping tool  300  is shown completely assembled. The handle shaft portion  105  of the tool body  100  is covered by the handle sleeve  203  and the handle grip  204 . 
     Referring now to FIG. 5, a cross-sectional view through the cylindrical chipping member  101  shows the staggered arrangement of the various rows of studs  102 , which combine to make the array. 
     Referring now to FIG. 6, the handle end of the tool is shown with the outer dust seal  304  removed from the ball-bearing assemblies  201 A and  201 B to show the structure thereof. Also not shown are the ball-bearing retainers which maintain the ball bearings  303  radially spaced about the axis of the ball-bearing assembly  201 A. As the structure of ball-bearing assemblies is well known in the art and is not the focus of this invention, these details have been eliminated from the drawings. It will be noted that the internal snap ring  305  is equipped with installation/removal holes  601  for compressive snap ring pliers (not shown), while the external snap ring  202  is equipped with installation/removal recesses  602  for extensive snap ring pliers (also not shown). 
     Referring now to FIG. 7, an alternative embodiment  101 -A of the cylindrical chipping member of the tool body  100  is shown. Each stud  701  is embedded within an the internal snap ring  305  is equipped with installation/removal holes  601  for compressive snap ring pliers (not shown), while the external snap ring  202  is equipped with installation/removal recesses  602  for extensive snap ring pliers (also not shown). 
     Referring now to FIG. 7, an alternative embodiment  101 -A of the cylindrical chipping member of the tool body  100  is shown. Each stud  701  is embedded within an aperture  702  within the cylindrical chipping member  101 -A. The studs are preferably made of a wear-resistant material, such as tool steel or tungsten carbide. Each of the studs  701  may be affixed within its associated aperture  702  by one several well-known techniques, such as brazing, epoxy bonding, or crimping of the rim of the aperture  702  against the stud  701 . 
     FIG. 8 shows a cross-sectional view of the alternative embodiment cylindrical chipping member  101 -A. 
     Though not presently considered to be the preferred embodiment of the invention, the cylindrical member may have a hollow cylindrical recess at the handle end thereof, and a handle may be rotatably mounted within the recess in bearing races. 
     Referring now to FIG. 9, the tile chipping tool  300  is coupled to the chuck  901  of a drill motor  902  or other similar powered drive, and positioned to abrade the edge  903  of a piece of natural stone tile  904 . The operator secures the tile in a vice or other clamp, holds the drill motor  902  in one hand, and the grip-covered rotatable handle sleeve  203  in the other hand. With the drill motor operating and rotating the tool, the cylindrical chipping member  101  is held against the edge  903  of the tile  904  and moved back and forth against the edge  903 . The edge  903  of the tile  904  is chipped or abraded through contact with the studs  102 . Particles of the tile  904  may be removed from each of the four edges  903  thereof, thereby providing a rustic appearance for the tile  904 . The amount of material removed from the edge  903  may be controlled by varying the amount of time and pressure with which the cylindrical chipping member  101  is held against the edge as it rotates. The angle can be varied over several strokes, thereby imparting a roughly curved edge to the tile. Using the tool and method, up to three 12-inch-square tile may be treated per minute. 
     FIG. 10 shows a piece of tile  904 , an edge of which has been abraded to form a generally chamferred profile  1001  using the tool  300 . 
     FIG. 11 shows a piece of tile  904 , an edge of which has been abraded to form a generally rounded profile  1101  using the tool  300 . 
     Although only a single embodiment of the chuckable, natural stone tile edge chipping tool has been disclosed herein, it will be obvious to those having ordinary skill in the art that changes and modifications may be made thereto without departing from the scope and the spirit of the invention as hereinafter claimed.