Abstract:
A conduit reamer for a cutting tool includes a generally cylindrical body having a longitudinal axis and a blade coupled to the generally cylindrical body. The blade includes a first blade portion defining a first height of the conduit reamer with respect to the longitudinal axis and a second blade portion defining a second height of the conduit reamer with respect to the longitudinal axis, wherein the first height is different than the second height. The conduit reamer further includes a shank end having a shank configured to be received and driven by the cutting tool, a bit end opposite the shank end and having a cavity configured to receive a tool bit, and a locking mechanism positioned proximate the bit end and configured to secure the tool bit within the cavity.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   The present patent application claims priority to U.S. Provisional Patent Application Ser. No. 60/893,302, titled “CONDUIT REAMER TOOL ELEMENT,” filed on Mar. 6, 2007, the entire contents of which is hereby incorporated by reference. 

   BACKGROUND 
   The present invention relates to an accessory bit for a power tool, and, more particularly, to a conduit reamer tool element or bit for a power tool. 
   SUMMARY 
   In one embodiment, the invention provides a conduit reamer for a cutting tool. The conduit reamer includes a generally cylindrical body having a longitudinal axis and a blade coupled to the generally cylindrical body. The blade includes a first blade portion defining a first height of the conduit reamer with respect to the longitudinal axis and a second blade portion defining a second height of the conduit reamer with respect to the longitudinal axis, wherein the first height is different than the second height. The conduit reamer further includes a shank end having a shank configured to be received and driven by the cutting tool, a bit end opposite the shank end and having a cavity configured to receive a tool bit, and a locking mechanism positioned proximate the bit end and configured to secure the tool bit within the cavity. 
   In another embodiment, the invention provides a conduit reamer for a cutting tool. The conduit reamer includes a generally cylindrical body that includes a first cylindrical portion having a first diameter and a second cylindrical portion having a second diameter. The second diameter is different than the first diameter. The conduit reamer further includes a blade having a first blade portion and a second blade portion. The first blade portion is positioned adjacent the first cylindrical portion and the second blade portion is positioned adjacent the second cylindrical portion. The conduit reamer further includes a shank end having a shank configured to be received and driven by the cutting tool, a bit end opposite the shank end and having a cavity configured to receive a tool bit, and a locking mechanism positioned proximate the bit end and configured to secure the tool bit within the cavity. 
   In another embodiment, the invention provides a conduit reamer for a power tool. The conduit reamer includes a generally cylindrical body that includes a first end portion, a second end portion, a first cylindrical portion having a first diameter, and a second cylindrical portion having a second diameter. The second diameter is different than the first diameter. The conduit reamer further includes a shank end having a shank and configured to couple the conduit reamer to the power tool and a bit end opposite the shank end and configured to receive a tool bit. 
   Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a conduit reamer bit for a power tool according to an embodiment of the present invention. 
       FIG. 1A  is a cross-sectional view of a portion of the conduit reamer bit of  FIG. 1  illustrating a bore for receiving a tool bit. 
       FIG. 2  is a conduit reamer bit for a power tool according to another embodiment of the present invention. 
       FIG. 3  is a conduit reamer bit for a power tool according to yet another embodiment of the present invention. 
       FIG. 4  is a cross-sectional view of a portion of a locking mechanism of the present invention. 
       FIG. 5  is a cross-sectional view of another embodiment of a locking mechanism the present invention. 
       FIG. 6  is a side view of a portion of the conduit reamer bit of  FIG. 1  showing the conduit reamer bit in operation and reaming a pipe. 
   

   Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. 
   DETAILED DESCRIPTION 
   An accessory bit, such as a conduit reamer tool element or bit  50 , is shown in  FIGS. 1-3 . The conduit reamer bit  50  is configured to engage with the chuck of a power tool, such as, for example, a drill, a driver drill, a screwdriver (all not shown) and the like. 
   In the constructions shown, the conduit reamer bit  50  includes a generally cylindrical body  55 , a first end portion  60  and a second end portion  65 . The first end portion  60  includes a shank  70 . The shank  70  allows the conduit reamer bit  50  to connect to a power tool. The shank  70  may have one of several different configurations, such as, for example, a generally circular cross-sectional shape, a hexagonal cross-sectional shape, a D-shaped cross-sectional shape, a hexagonal cross-sectional shape with a groove  75  (as shown in  FIGS. 1-3 ), a three flat sided cross-sectional shape, and the like. 
   In some constructions, the second end portion  60  includes a longitudinal bore or cavity  79  for receiving and/or retaining a second tool element or bit  80  to be driven by a power tool (not shown), such as a drill, when the conduit reamer  50  is connected to the tool. In some constructions, the bit  80  can be a flat head screw bit, a Phillips head screw bit, a slotted screw bit, a torque-style screw bit, a Robertson screw bit or another bit for engaging with a workpiece. For example, bit  80  may be a Phillips screw bit used for driving screws into a workpiece. The conduit reamer  50  and tool bit  80  combination provides a multi-function tool accessory for an operator that can perform a plurality of tasks, including, but not limited to, reaming a conduit or pipe by smoothing burrs on both the interior and exterior surfaces of the conduit and engaging the tool bit with a workpiece to perform drilling functions. 
   As shown in  FIGS. 1-3 , the generally cylindrical body  55  of the conduit reamer bit  50  includes three stepped cylindrical portions  100 ,  105  and  110 . A hook-shaped member or blade  120 ,  125  and  130  is coupled to the cylindrical portions  100 ,  105  and  110 , respectively. In some constructions, such as the constructions shown in  FIGS. 1-2 , the hook-shaped members  120 ,  125  and  130  are formed from an integral piece of material, such as steel or another metallic material. In other constructions, the hook-shaped members  120 ,  125  and  130  are integral with the cylindrical portions  100 ,  105  and  110 , respectively. In other constructions, such as the construction shown in  FIG. 3 , the hook-shaped members  120 ,  125  and  130  are separate members and are individually coupled to the body  55 . The hook-shaped members may be selectively removable, either individually or collectively, with a hex key, such as an Allen wrench or other type of tool, operable at hex screw  86 . 
   In the illustrated embodiments, the first cylindrical portion  100  and associated blade  120  are configured for reaming and smoothing a pipe  12  having a 1-inch diameter (see  FIG. 6 ).  FIG. 6  shows the conduit reamer bit  50  positioned to ream a pipe  12 , such that blade  120  on first cylindrical portion  100  contacts the exterior portion of pipe  12  during reaming and smoothing operation. The second cylindrical portion  105  and associated blade  125  are configured for reaming and smoothing a pipe having a ¾-inch diameter. The third cylindrical portion  110  and associated blade  130  are configured for reaming and smoothing a pipe having a ½-inch diameter. In other constructions, the cylindrical portions and associated blades may be configured to ream and smooth pipe having other diameter dimensions than shown and described. In further constructions, the conduit reamer bit  50  includes fewer or more cylindrical portions and associated blades than shown and described. 
   As shown in  FIG. 1A , in one embodiment of the invention, the cavity  79  may include a magnet  81  positioned within the cavity  79 . The magnet  81  helps retain bit  80  within the cavity  79 . In other constructions, the cavity  79  may include a plurality of magnets to retain bit  80  within the cavity. 
   In some constructions, such as the construction shown in  FIG. 1 , the second end portion  65  includes a sleeve  85  wrapped substantially around a portion of the bit  80 . The sleeve  85  helps retain the bit  80  within the cavity  79 . In some constructions, such as the construction shown in  FIG. 3 , the bit  80  is removable by operation of a hex key, such as an Allen wrench or other type of tool, operable at hex screw  86 . 
   In other constructions, such as the construction shown in  FIG. 2 , the second end portion  65  includes a locking mechanism  90  for securing the second bit  80  within the cavity. For example, the locking mechanism  90  may be the locking mechanism shown and described in U.S. patent application Ser. No. 11/681,546, filed Mar. 2, 2007, or U.S. application Ser. No. 11/681,553, filed Mar. 2, 2007, the entire contents of all of which are hereby incorporated by reference. In some embodiments, the locking mechanism can be substantially similar to the quick-change chuck assembly described in U.S. Pat. Nos. 6,457,916 and 5,417,527, the tool bit holder described in U.S. Pat. No. 6,561,523, the chuck assembly described in U.S. Pat. Nos. 5,013,194 and 4,900,202, and/or the multiple mode chuck described in U.S. Pat. No. 6,966,562, the entire contents of each of which is hereby incorporated by reference. 
     FIG. 4  illustrates one embodiment of a locking mechanism  90  for the conduit reamer  50   a  in a locked position. In  FIG. 4 , the locking mechanism  90  includes an actuator  140  supported on an exterior surface  145  of the shank  70 . The actuator  140  is configured to move the locking member  152  between a locked position and an unlocked position. Channels  148  extend radially through the shank  70 , and locking members  152  are supported in the channels  148  for movement between the locked position (shown in  FIG. 4 ), in which the locking members  152  extend radially inwardly into the recess cavity bore  156  to secure the bit (not shown) within the bore  156 , and the unlocked position, in which the locking members  152  are movable along the channels  148  and out of the bore  156 . Locking members  152  are shown as balls, although in other embodiments, the locking members may be another known locking member, such as a roller or the like. 
   As shown in  FIG. 4 , the locking mechanism  90  includes the actuator  140  supported on the exterior surface  145  of the shank  70  for axial movement along the shank  70  between the locked position, which is a forward-most position (shown in  FIG. 4 ) and an unlocked position, which is a rearward-most position (not shown). The actuator  140  also includes a recess  159  extending circumferentially around an interior surface  160  of the actuator  140 . The recess  159  includes ramps  158  configured to prevent any jamming of the locking members  152  within the recess  159  during operation of the locking mechanism  90 . In still other embodiments, the actuator  140  may include a recess  159  extending in a serpentine path or threaded around the shank  70 . 
   In this manner, when the actuator  140  is moved toward the locked position, the interior surface  160  of the actuator  140  moves into camming engagement with each of the locking members  152  to move the locking members  152  radially inwardly along the channels  148  toward the bore  156  (as shown in  FIG. 4 ). When the actuator  140  is moved toward the unlocked position, the recess  159  is moved into radial alignment with the channels  148  so that the locking members  152  move radially outwardly along the channels  148  and away from the bore  156  to allow removal of the tool bit from the bore. 
   The locking mechanism  90  also includes a biasing member  164  for biasing the actuator  140  toward the locked position. As shown in  FIG. 4 , the biasing member  164  can be supported on the exterior surface  145  of the shank  70  between an outwardly-extending shoulder  166  of the shank  70  and an interior shoulder  170  of the actuator  140 . 
     FIG. 5  illustrates another embodiment of a locking mechanism  200  on a conduit reamer  50   a  including a shank  204 . In the illustrated embodiment of  FIG. 5 , the locking mechanism  200  includes a sleeve  208  supported on an exterior surface  212  of the shank  204  and an actuator  216 . Channels  220  extend radially through the shank  204  and a portion of the sleeve  208 . As shown in  FIG. 5 , a first end of each channel  220  opens into a bore  224  in the shank  204  and a second end of each channel  220  opens axially toward a rear end  228  of the sleeve  208 . 
     FIG. 5  shows the locked position, in which locking members  232  are supported in the channels  220  for movement wherein the locking members  232  extend radially inwardly from the second end of the channel  220  and into the bore  224  to secure the tool bit in the bore  224 . In an unlocked position, the locking members  232  are movable along the channels  220  and out of the bore  224 . 
   In the illustrated embodiment, the locking mechanism  200  includes two locking members  232  supported for movement along two channels  220 . In other embodiments, the locking mechanism can include one, three, or more locking members supported for movement along one, three, or more channels. 
   As shown in  FIG. 5 , the locking mechanism  200  includes actuator  216  supported on the exterior surface  212  of the shank  204  for axial movement along the shank  204  between the locked or forward-most position (shown in  FIG. 5 ) and the unlocked or rearward-most position. In the illustrated embodiment of  FIG. 5 , the actuator  216  also includes a forwardly-extending protrusion  236 . 
   In this manner, when the actuator  216  is moved toward the locked position, the protrusion  236  is moved into camming engagement with each of the locking members  232  to move the locking members  232  forwardly and radially inwardly along the channels  220  toward the locked positions in the bore  224 . When the actuator  216  is moved toward the unlocked position, the locking members  232  move radially outwardly along the channels  220  and away from the bore  224  to allow removal of the tool bit. 
   In the illustrated embodiment of  FIG. 5 , the locking mechanism  200  also includes a biasing member  240  for biasing the actuator  216  toward the locked position. As shown in  FIG. 5 , the biasing member  240  is supported on the exterior surface  212  of the shank  204  between a collar  244  and an interior shoulder  248  of the actuator  216 . 
   As also shown in  FIG. 5 , a rearward portion  252  of the actuator  216  extends rearwardly across the biasing member  240  to substantially enclose the biasing member  240  and to prevent debris from entering the locking mechanism  200 . 
   In some embodiments, the outer surface  256  of the actuator  216  is knurled and/or includes outwardly extending protrusions to provide a slip-resistant gripping surface. In these and other embodiments, the outer surface  256  of the actuator  216  or a portion of the outer surface  256  of the actuator  216  includes or may be formed from an elastic material to provide a cushion grip. 
   Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the invention as described. Various features and advantages of the invention are set forth in the following claims.