Abstract:
Systems and methods are disclosed to enhance functionality of a power drill, comprising: providing a shaft having one or more threaded sections with different diameters, wherein a pilot bit is inserted into one threaded section; and selectably converting the power drill into either: an adjustable hole cutter by inserting a bar through the shaft, wherein the bar comprises one or more holders to receive cutting blades; or a fixed size hole cutter or hole saw by converting the adjustable hole cutter for use as a hole saw or a hole cutter arbor.

Description:
BACKGROUND 
       [0001]    The present invention relates to a combination hole saw arbor and adjustable hole cutter shaft. 
         [0002]    Cutters and hole saws are tools used to make cut-outs in a material, such as, for example, wood, steel, fiberglass, and plastic. The hole saw is commonly adaptable to be attached to a hand drill, either power driven or manually operated, in a manner and fashion similar to conventional drill bits and the like. Different styles or sizes of hole saws vary in their mounting configurations, such as the size of the threaded apertures used in coupling the hole saw to the hand drill. For this reason, the tool user often requires an arbor that is specific for each type and/or size of hole saw. 
         [0003]    Hole cutters fall into different categories which include hole saws with a saw like edge consisting of multiple teeth, a grit hole saw with a edge that has a hard grit fused to the metal band of the hole cutter, large toothed hole cutters with side slots (gullets) in the barrel. A hole saw is a tool used to make cut-outs in a material, such as, for example, wood, steel, fiberglass, and plastic. The hole saw is commonly adaptable to be attached to a hand drill, either power driven or manually operated, in a manner and fashion similar to conventional drill bits and the like. Different styles or sizes of hole saws vary in their mounting configurations, such as the size of the threaded apertures used in coupling the hole saw to the hand drill. For this reason, the tool user often requires an arbor that is specific for each type and/or size of hole saw. 
         [0004]    Adjustable hole cutters are of two types with either one or two cutting blades. With a single blade hole cutter the cutting blade is attached to one end of a bar that can be adjusted for a range of radii (and hole sizes) and it usually requires the use of counterweights to offset the mass of the blade holder and blade. With a twin blade hole cutter there is no need for the counterweights and this results in a simpler and more durable tool. Both types can be used in a pillar or drill press with or without the shield or used with a shield in a hand held electric drill. 
         [0005]    U.S. Pat. No. 3,999,869 discloses an arbor for use with different size power tool chuck jaws and has a main body section of enlarged cross section relative to a shank of the arbor. The shank and main body section have a plurality of grooves therein with each groove longitudinally extending the length of the shank and into the adjoining main body section to define a continuous chuck jaw engaging surface which in the main body section of the arbor is of enlarged circumferential dimension relative to that of the shank drive surface for engaging different size chuck jaws in non-slipping positive driving relation. 
         [0006]    U.S. Pat. No. 7,104,738 discloses an arbor with a shaft and a locking mechanism operatively coupled to the shaft. The arbor also includes an adapter removably coupled to the shaft by the locking mechanism, the adapter being selectively configurable within the shaft between at least a first operating position, where the adapter is configured to secure a first tool accessory to the arbor, and a second operating position, where the adapter is configured to secure a second tool accessory different at least in part from the first tool accessory. 
       SUMMARY 
       [0007]    In one aspect, systems and methods are disclosed to enhance functionality of a power drill, comprising: providing a shaft having one or more threaded sections with different diameters, wherein a pilot bit is inserted into one threaded section; and selectably converting the power drill into either: an adjustable hole cutter by inserting a bar through the shaft, wherein the bar comprises one or more holders to receive cutting blades; or a fixed size hole cutter or hole saw by converting the adjustable hole cutter for use as a hole saw or a hole cutter arbor. 
         [0008]    In another aspect, a cutting tool to enhance functionality of a power drill includes a shaft having one or more threaded sections with different diameters, wherein a pilot bit is inserted the shaft; wherein the shaft converts the power drill into either an adjustable hole cutter including a bar coupled to the shaft, wherein the bar comprises one or more holders to receive cutting blades or a fixed size hole cutter or hole saw secured to the shaft to convert the adjustable hole cutter for use as a hole saw or a hole cutter arbor. 
         [0009]    In another aspect, a cutting tool to enhance functionality of a power drill includes a shaft having one or more threaded sections with different diameters, wherein a pilot bit is inserted the shaft; where the cutting tool converts the power drill into either an adjustable hole cutter including a bar coupled to the shaft, wherein the bar comprises one or more holders to receive cutting blades, or the cutting tool converts the power drill into a fixed size hole cutter or hole saw secured to the shaft that converts the adjustable hole cutter for use as a hole saw or a hole cutter arbor, and all cutting can be done with a protective shield in place mounted using a ball bearing assembly in the center of the shield. 
         [0010]    Advantages of the preferred embodiments may include one or more of the following. Single and multiple blade adjustable hole cutters are supported. The system enables the dual use of the shaft for use with an adjustable hole cutter and for use with a hole cutter or hole saw. The system can work with both single blade and two blade adjustable hole cutting tools and tools with and without a shield. The adjustable hole cutter works in conjunction with a shield to contain the cutting debris from the cutting operation of the adjustable hole cutter blade or blades it can also be used to contain the debris and shavings from a cutting operation using a hole cutter or hole saw. Further, the cutting depth of the hole cutting device is regulated by the use of a shield and an adjustment knob on the threaded section of the shaft which limits the penetration of the shaft through the shield and in this manner limits the penetration of the hole saw or hole cutter into the material being cut. In one embodiment, the hole saw can have a steel band with a cutting edge which may consist of many small teeth or may consist of a bonded coating of abrasive grit material, and a hole cutter, which has a steel band that has separate gullets and individually mounted cutting teeth. The new and improved combination arbor which is particularly designed to be used with different size chuck jaws of power tools such as conventional electric drills. The system is capable of withstanding high torque demands without slippage in a compact rugged construction suited to provide reliable service over an extended period of time and which is quickly and easily manufactured at significant cost savings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  shows an exemplary combination hole saw arbor and adjustable hole cutter shaft. 
           [0012]      FIG. 2  shows an exemplary hole saw mounted to the shaft and without bar and blade holders. 
           [0013]      FIG. 3  shows a standard adjustable hole cutter assembly with the shaft of  FIG. 1 . 
           [0014]      FIG. 4  shows an exemplary fully assembled adjustable hole cutter and shield. 
           [0015]      FIG. 5  shows in more details the end of shaft that is designed to provide for attachment of pilot bit, bar, and two different thread mount sizes of hole cutters. 
           [0016]      FIG. 6  shows exemplary blade holders with the blades removed to allow for unimpeded full cutting depth of the hole cutter. 
           [0017]      FIG. 7  shows an exemplary single blade cutter. 
       
    
    
     DESCRIPTION 
       [0018]      FIG. 1  shows an exemplary combination hole saw arbor and adjustable hole cutter shaft, while  FIG. 2  shows an exemplary hole saw mounted to the shaft and without bar and blade holders.  FIG. 2  shows that the cutting tool can selectably convert the power drill from the adjustable hole cutter mode into a fixed size hole cutter or hole saw by converting the adjustable hole cutter for use as a hole saw or a hole cutter arbor. 
         [0019]    In  FIG. 1 , a protection cowl  15  includes a shield top  152  and a shield side  153  with a shield height  151  that determines the maximum cutting depth possible while using the shield. An optional rubber pad support can be mounted on the protection cowl  15  to prevent scratching or damaging the surface being cut. A shaft body  10  includes a shaft shank  12 . The shaft  10  is used to hold a tangential bar with one or more holders for cutting blades with the bar adjustable to enable cutting of holes of varying diameters by adjusting the position of the blade holder for the cutting blades relative to the center axis of the shaft. Preferably, the shaft  10  is machined so that its outside diameter will fit inside the ball bearing insert of the shield. The shaft  10  has a center bore for inserting a pilot bit to restrict horizontal movement of the hole cutting blades. This bore has a perpendicular threaded hole to permit the use of a screw to prevent movement of the pilot bit independent of the shaft. The shaft&#39;s shank  12  supports for gripping by a drill chuck, among others. The protective cowl  15  is secured to the shaft shank  12  using a suitable gearing screw and a compression spring. The shaft body  10  is adapted to be inserted into the protective cowl  15  through a ball bearing insert  154  that permits the shaft  10  to rotate while the shield remains stationary. The shaft body includes an aperture  13  for inserting and mounting a measurement bar  30  there through. The measurement bar  30  includes a bar member  31  that supports blade holders  32  at each end of the bar member  31 . The positions of blade holders  32  determine the size of hole that will be cut. A cutting blade  33  projects from each blade holder  32  to cut the hole. The blade holders  32  can be loosened and moved to any location along the bar and which supports the cutting blade  33 . 
         [0020]    The system of  FIG. 1  also includes a hole cutter  20  with a band steel side  21  and cutting teeth  211  of the hole saw in the hole cutter. Teeth  211  could be tooth or carbide or diamond grit. The shaft  10  can be connected to a hole cutter  20  through a threaded section  22  of the shaft  10  to which hole cutter  20  is mounted. A pilot bit  14  is provided to laterally stabilize the hole cutter of  FIG. 1  while it is rotating and cutting. The pilot bit  14  mounts into aperture  11  bored into the shaft  10 . In one embodiment, the mounting is achieved through a pilot bit  14  that is secured to an aperture  11  in the shaft  10  to receive the pilot bit  14 . An aperture  210  is positioned on the hole cutter  20  for mounting hole cutter  20  to the threaded section  22  of the arbor adapter. The added threaded section at the end of the shaft where the pilot bit is inserted can be used to secure a fixed size hole cutter or hole saw at its base. This enables the same shaft to be used for an adjustable hole cutter and for use as a hole saw or hole cutter arbor for use with any power drill. 
         [0021]    The system of  FIG. 1  applies to single as well as twin blade hole cutters, each of which employs a central shaft and a bar that provides for adjusting the radius of the hole cutter&#39;s blade or blades. The hole cutter shaft supports the bar and the pilot bit and with the system of  FIG. 1 , supports a fixed size hole cutter. The standard practice has been to use a hole saw arbor adapter with a ½″-20 thread for hole cutters smaller than 1⅛ inch diameter and a separate arbor adapter with a ⅝″-18 thread for larger sizes of hole cutters. The system of  FIG. 1  includes the use of a dual threaded section that provides for attaching either a ½″-20 or a ⅝″-18 threaded hole saw to the single shaft which then serves as an arbor adapter for use by a drill. 
         [0022]      FIG. 2  shows the shaft being used to convert the power drill into a fixed sized hole cutter. In this mode, the blades of the adjustable hole cutter are removed and only the hole cutter  20  remains. In this manner, the shaft adapts the power drill into a fixed size hole cutter or hole saw by converting the adjustable hole cutter for use as a hole saw or a hole cutter arbor. 
         [0023]      FIG. 3  shows a standard adjustable hole cutter assembly with the shaft of  FIG. 1 , while 
         [0024]      FIG. 4  shows an exemplary fully assembled adjustable hole cutter and shield. The embodiment of  FIG. 4  shows that adjustment can be made to the blade holders  32  to change cutting radius of the tool&#39;s blades (twin blade model). The system enables the dual use of the shaft for use with an adjustable hole cutter and for use with a hole cutter or hole saw. The system can work with both single blade and two blade adjustable hole cutting tools and tools with and without a shield. The adjustable hole cutter works in conjunction with a shield to contain the cutting debris from the cutting operation of the adjustable hole cutter blade or blades it can also be used to contain the debris and shavings from a cutting operation using a hole cutter or hole saw. Further, the cutting depth of the hole cutting device is regulated by the use of a shield and an adjustment knob on the threaded section of the shaft which limits the penetration of the shaft through the shield and in this manner limits the penetration of the hole saw or hole cutter into the material being cut. 
         [0025]      FIG. 5  shows in more details the end of shaft that is designed to provide for attachment of pilot bit, bar, and two different thread mount sizes of hole cutters. Dual threads  22  are used which to avoid the need to use two different arbors for the different mount sizes. In  FIG. 5 , threaded section  220  can include (½″-20) threads for small hole saws. A second threaded section  221  can be used and may be (⅝″-18) for hole saws 1⅛″ diameter and larger. This embodiment with two threaded sections of different diameters allows the user to use a small hole cutter with a ½″ thread mounting and a large hole cutter with a ⅝″ thread mounting, for example, on a single shaft with no additional parts or adapters needed. In contrast, prior work has entailed adapters to convert the end of an arbor for a different size mountings. 
         [0026]      FIG. 6  shows exemplary blade holders with the blades removed. The 2 blades attached to the moveable blade holders would each be removed prior to cutting with the hole saw or hole cutter. The system of  FIG. 6  allows the full cutting depth of the hole cutter without being impeded. With a single blade adjustable hole cutter, the blade would also be removed to maximize the height of the hole cutter and the maximum cutting depth possible. The maximum cutting depth would be limited only by the hole saw or hole cutter or the depth of the shield, depending on which one is used. 
         [0027]      FIG. 6  shows that the cutting tool can selectably convert the power drill from the adjustable hole cutter mode into a fixed size hole cutter or hole saw by converting the adjustable hole cutter for use as a hole saw or a hole cutter arbor. 
         [0028]      FIG. 7  shows an exemplary single blade cutter. In this embodiment, a protection cowl or shield CL-220-3 is provided with an rubber pad support CL-220-4 at the bottom of the cowl or shield. A gearing screw CL-220-1 secures a compression spring CL-220-2 to the cowl CL-220-3 and the shaft with an axle CL-220-5. A measurement bar CL-220-8 is secured to the axle CL-220-5 by a suitable attachment CL-220-9 such as a screw, among others. A balance bar CL-220-14 can be attached to one end of the measurement bar CL-220-8. A blade BH-003T such as a tungsten carbide blade is connected to the measurement bar CL-220-8. Additionally, another attachment CL-220-14 secures a drill bit CL-220-15 to the axle CL-220-5. The measurement bar CL-220-8 can be mounted directly to the cowl CL-220-3 or alternatively can be mounted through a fixed disk CL-220-7 and a fixed adjusting disk CL-220-6. 
         [0029]    A reference list of the elements used in the above embodiments is as follows: 
         [0000]    
       
         
               
               
             
               
               
             
           
               
                   
               
               
                 Number 
                 Description 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 211 
                 Cutting teeth of hole saw—could be tooth or carbide or diamond 
               
               
                   
                 grit 
               
               
                 21 
                 Band steel side of the hole cutter 
               
               
                 210 
                 Aperture for mounting hole cutter—threaded for arbor adapter 
               
               
                 22 
                 Threaded section of the shaft to which hole cutter is mounted 
               
               
                 11 
                 Pilot Bit mounts into aperture bored into the shaft 
               
               
                 13 
                 Aperture for mounting a bar (No. 31) that supports blade holder 
               
               
                   
                 (No. 32) 
               
               
                 10 
                 Shaft body 
               
               
                 12 
                 Shaft&#39;s shank for gripping by a drill chuck 
               
               
                 31 
                 Bar that supports blade holders—position of blade holder 
               
               
                   
                 determines size of hole that will be cut 
               
               
                 32 
                 Blade holder which can be loosened and moved to any location 
               
               
                   
                 along the bar and which supports the cutting blade (No. 33) 
               
               
                 33 
                 Cutting blade for adjustable hole cutter 
               
               
                 153 
                 Side of shield—height determines maximum cutting depth 
               
               
                   
                 possible while using the shield 
               
               
                 151 
                 Shield 
               
               
                 152 
                 Top of shield 
               
               
                 154 
                 Ball Bearing Insert which permits shaft to rotate while the shield 
               
               
                   
                 remains stationary 
               
               
                 14 
                 Pilot Bit 
               
               
                 220 
                 Threaded section (½″-20) for small hole saws 
               
               
                 221 
                 Threaded section (⅝″-18) for hole saws 1⅛″ diameter and 
               
               
                   
                 larger 
               
               
                   
               
             
          
         
       
     
         [0030]    The hole cutter is well suited to cutting very hard materials such as ceramic tiles. With these materials a tungsten carbide grit or a diamond grit hole cutter is used. The edge may have a saw type edge or a blunt square tooth edge or a continuous rim of grit bonded to it depending upon the application requirements. The arbor adapter converts the cowls or shields for use with hole cutters. This embodiment permits users to make use of their adjustable hole cutter shaft and shield without need for the XL Arbor Adapter when cutting holes of less depth. 
         [0031]    It will be seen that the above embodiments can be used in electric drills with ¼ inch, ⅜ inch and ½ inch or larger capacity chucks, e.g., and will be used for driving a variety of different size hole saws, such as 9/16 inch to, say, 8 inch hole saws for different cutting applications in various materials such as plastic, wood and metal. Moreover, the system is quick to assemble and easy to manufacture and assemble to achieve the desired cost savings. 
         [0032]    While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.