Abstract:
An extension assembly configured to permit a user to drill a hole through inaccessible areas in a wall is disclosed. The extension assembly includes a flexible, solid core rod having first and second ends and a holding means. The rod is configured to extend through a hole in a wall cavity and flex therein to position a tool bit at an inaccessible location in the wall cavity and permit a user to drill a hole through a substrate at the inaccessible location. The holding means is secured to the second end of the rod for releasably holding a tool bit for rotation with the rod and includes a sleeve adapted to slide axially along a body of the holding means between a secured position where a tool bit is securely held within the holding means and a release position where the tool bit is released from the holding means.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to the field of flexible drill bits used to create extended length holes and holes through inaccessible areas in walls and framing. More particularly, the invention relates to a flexible, extendable drill bit assembly that allows the use of a variety of drilling heads and accessories. 
     Flexible, extended drill bits are widely employed to create a system of holes within residential and commercial building construction for the purpose of running extended wiring and cabling throughout the building. The extended length drill bits presently available are of a unitary construction, requiring a user to purchase a drill bit having a specified diameter for each individually sized hole desired. The drill bits come in various lengths which require a user to purchase a separate drill bit for each specified length of a hole. Moreover, when the cutting edge is damaged, the entire drill bit must be replaced, incurring additional expense. 
     Accordingly, there is a need for a flexible, extendable drill bit assembly that allows the use of drill bits and other accessories of various sizes. 
     BRIEF SUMMARY OF THE INVENTION 
     This need is addressed by providing an extension assembly configured to permit a user to drill a hole through inaccessible areas in a wall. The extension assembly includes a flexible, solid core rod having first and second ends. The rod being configured to extend through a hole in a wall cavity and flex therein to position a tool bit at an inaccessible location in the wall cavity and permit a user to drill a hole through a substrate at the inaccessible location. The extension assembly further including a holding means secured to the second end of the rod for releasably holding a tool bit for rotation with the rod. The holding means including a sleeve adapted to slide axially along a body of the holding means between a secured position where a tool bit is securely held within the holding means and a release position where the tool bit is released from the holding means. 
     This need may also be addressed by providing a drill bit assembly configured to permit a user to drill a hole through inaccessible substrates in a wall includes a flexible, solid core rod having first and second ends; and a quick-release head secured to the second end of the rod for receiving and securing a drill bit therein. The head including a sleeve adapted to slide axially along a body of the head between a secured position where a drill bit is securely held within the head and a release position where the drill bit is released from the head. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The subject matter that is regarded as the invention may be best understood by reference to the following description taken in conjunction with the accompanying drawing figures in which: 
         FIG. 1  shows a user drilling an extended length hole through a wall; 
         FIG. 2  is an exploded view of a drill bit assembly; 
         FIG. 3  is a side view of the quick-release head of the drill bit assembly of  FIG. 2 ; 
         FIG. 4  is a cross-section of the quick-release head of  FIG. 3 ; 
         FIG. 5  shows two drill bit assemblies of  FIG. 2  connected together; 
         FIG. 6  is an exploded view of a drill bit assembly; 
         FIG. 7  is a cross-section of a quick-release head of the drill bit assembly of  FIG. 6  in a secure, closed position; 
         FIG. 8  is a cross-section of the quick-release head of  FIG. 7  in an open, receiving position. 
         FIG. 9  shows the quick-release head of  FIG. 7  in the secure, closed position; 
         FIG. 10  shows the quick-release head of  FIG. 7  in the open, receiving position; 
         FIG. 11  shows a drill bit assembly; 
         FIG. 12  shows the drill bit assembly of  FIG. 11  in a secured position; 
         FIG. 13  is a cross-section of a quick-release head of the drill bit assembly of  FIG. 11 ; 
         FIG. 14  is a drill bit assembly; 
         FIG. 15  shows the drill bit assembly of  FIG. 14  in a secured position; 
         FIG. 16  is a cross-section of a quick-release head of the drill bit assembly of  FIG. 14 ; 
         FIG. 17  is an exploded view of a drill bit assembly; 
         FIG. 18  shows a drill bit of the drill bit assembly of  FIG. 17 ; 
         FIG. 19  shows an exploded view of the drill bit assembly of  FIG. 18 ; and 
         FIG. 20  shows a drill bit assembly. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now specifically to the drawings, a flexible, extendable drill bit assembly is illustrated in  FIG. 1  and shown generally at reference numeral  10 . As shown, the drill bit assembly  10  allows a user to drill a hole through a wall to allow the user to run wiring and cabling. 
     As shown in  FIG. 2 , the drill bit assembly  10  includes a flexible, solid-core extension rod  11  to withstand the forces of drilling, a tailpiece  12  secured to a first end  13  of the rod  11  and adapted to be received by a drill  15 , and a quick-release head  14  secured to an opposing second end  16  of the rod  11 . The tailpiece  12  includes a shank  25  with a hexagonal profile to prevent slipping within the drill  15 . As illustrated, the first and second ends  13  and  16  are received by the tailpiece  12  and head  14 , respectively, and secured by set screws  17 . It should be appreciated that the rod  11  may be secured to the tailpiece  12  and head  14  by any suitable fastening means, such as adhesives or welding. Furthermore, the first end of the rod could have a hexagonal shape for being received by a chuck of a drill. A drill bit  18  is received by the head  14  and may be removed and replaced by another drill bit when the cutting edge is damaged. 
     Referring to  FIGS. 3 and 4 , the head  14  includes a body  20  having a first bore  21  positioned in a first end  22  for receiving the rod  11  and a second bore  23  positioned in an opposing second end  24  for receiving the drill bit  18 . As illustrated, the second bore  23  has a hexagonal profile; however, any suitable profile may be used. A spun-over sleeve  26  is positioned over the second end  24  for releasing and securing the drill bit  18  within the second bore  23 . The sleeve  24  includes a chamfered section  27  that abuts against the body  14  to retain the sleeve on the body  14  during use. 
     A spring  28  is contained between the sleeve  26  and the second end  24  to bias the sleeve  26  towards a securing position. A locking ball  30  is positioned in a recess  31  of the second end  24  for locking the drill bit  18  in the second bore  23 . When in the securing position, the sleeve  26  presses the ball  30  inwardly into the second bore  23  to hold the drill bit  18  in position. To release the drill bit  18 , the sleeve  26  is pulled back towards the first end  22 , thereby compressing the spring  27  and allowing the ball  30  to move outwardly from the bore  23  and into a recess  32  defined by the sleeve  26 . 
     As illustrated in  FIG. 5 , the drill bit assembly  10  may be connected to another drill bit assembly  10 ′. As illustrated, the shank  25  of the assembly  10  is inserted into a quick-release head  14 ′ of the drill bit assembly  10 ′. By connecting multiple drill bit assemblies together, a user can extend the length of the drill bit for longer runs. 
     Referring to  FIG. 6 , a drill bit assembly is shown generally at reference numeral  100 . Like drill bit assembly  10 , drill bit assembly  100  includes a flexible, solid-core extension rod  111 , a tailpiece  112 , and a quick-release head  114 . 
     As shown in  FIGS. 7 and 8 , like head  14 , head  114  includes a spun-over sleeve  126  having a chamfer and a body  120  having a first bore  121  and a second bore  123 . The head  114  also includes a spring  128  and a locking ball  130 . Unlike the head  14 , head  114  includes a shield  140  and a magnet  141 . The shield  140  is attached to a second end  124  of the body  120  independent of the sleeve  126 ,  FIGS. 8 and 10 , and is adapted to prevent the sleeve  126  from being inadvertently pushed back towards a first end  122  of the body  120  by a stationary object, which would release a drill bit  118  secured in the second bore  123 . As illustrated in  FIG. 9 , the shield  140  has a diameter slightly larger than a diameter of the sleeve  126 . The shield  140  may be integrally formed with the body  120 , secured by press-fitting the shield  140  onto the body  120 , or any other means for securing the shield  140  to the body  120 . 
     As can be seen in  FIGS. 9 and 10 , the head  114  operates in substantially the same manner as the head  14 . 
     Referring to  FIGS. 11 and 12 , a drill bit assembly is shown generally at reference numeral  200 . Like drill bit assembly  10 , drill bit assembly  200  includes a flexible, solid-core extension rod  211 , a tailpiece  212  (not shown), and a quick-release head  214 . 
     As shown in  FIG. 13 , like head  14 , head  214  includes a sleeve  226  having a chamfer  227  and a body  220  having a first bore  221  and a second bore  223 . The head  214  also includes a spring  228  and a locking ball  230 . The head may also include a magnet like magnet  141  in  FIGS. 7 and 8 . 
     Referring again to  FIGS. 11 and 12 , unlike the head  14 , head  214  includes a threaded nut/collar  250  in threaded engagement with threads  251  positioned along the body  220 . The collar  250  is positioned behind the sleeve  226  to prevent the sleeve  226  from being inadvertently pushed back towards a first end  222  of the body  220  by a stationary object, which would release a drill bit secured in the second bore  223 . As illustrated in  FIG. 11 , when the collar  250  is rotated into a release position, the sleeve  226  may be pushed back to allow a drill bit to be released. As shown in  FIG. 12 , when the collar  250  is in the secured position, the collar  250  is positioned tightly against the chamfer  227  of the sleeve  226 , thereby preventing the release of a drill bit. 
     Referring to  FIGS. 14 and 15 , a drill bit assembly is shown generally at reference numeral  300 . Like drill bit assembly  10 , drill bit assembly  300  includes a flexible, solid-core extension rod  311 , a tailpiece  312  (not shown), and a quick-release head  314 . As shown in  FIG. 16 , head  314  includes a sleeve  326  having a chamfer  327  and a body  320  having a first bore  321  and a second bore  323 . The head  314  also includes a spring  328  and a locking ball  330 . Head  314  may also include a magnet like magnet  141  shown in  FIGS. 7 and 8 . 
     Unlike the head  14 , head  314  includes a push button detent  352  positioned on sleeve  326  for interaction with nut/collar  350 . The push button detent  352  may also be used to lock sleeve  326  in a secured position directly. The collar  350  is positioned behind the sleeve  326  and slidable along the body  320  from a released position,  FIG. 14 , to a secured position,  FIG. 15 , where a portion of the collar  350  is slid over the sleeve  326  such that the push button detent  352  engages a receiver  353  on the collar  352 . When in the secured position, the collar  350  and detent  352  prevent the sleeve  326  from being inadvertently pushed back towards a first end  322  of the body  320  by a stationary object, which would release a drill bit secured in the second bore  323 . 
     Referring to  FIG. 17 , a drill bit assembly is shown generally at reference numeral  400 . Like drill bit assembly  10 , drill bit assembly  400  includes a flexible, solid-core extension rod  411 , a tailpiece  412  secured to a first end  413  of the rod  411  and adapted to be received by a drill  415 , and a quick-release head  414  secured to an opposing second end  416  of the rod  411 . The quick-release head  414  has the same characteristics as the head  14 . The tailpiece  412  includes a shank  425  with a hexagonal profile to prevent slipping within the drill  415 . As illustrated, the first and second ends  413  and  416  are received by the tailpiece  412  and head  414 , respectively, and secured by set screws  417 . It should be appreciated that the rod  411  may be secured to the tailpiece  412  and head  414  by any suitable fastening means, such as adhesives or welding. Furthermore, the first end of the rod  411  could have a hexagonal shape for being received by a chuck of a drill. As shown, a drill bit  418  is received by the head  414  and includes a shaft  419  having a hexagonal profile, a spring  437  positioned on the shaft  419 , and a shield  431  biased towards the head  414  by the spring  437 . 
     As illustrated in  FIGS. 18 and 19 , the spring  437  is positioned on the shaft such that the spring  437  rests between a cutting edge of the bit  418  and the shield  431  to allow the spring  437  to bias the shield  431  away from the cutting edge and towards the head  414 . The shield  431  is positioned over the shaft  419  and has a first end  432  for engagement with the spring  437  and a second end  433  for covering the sleeve  426  of the head  414 . 
     A pair of grooves or holes  434  and  435  are formed in the shaft  419  to allow a retainer  436 , such as a pin or clip or any other suitable retainer, to provide a stop for the shield  431 . Groove  434  is positioned along the shaft  419  such that the retainer  436  may be used to prevent the shield  431  from being pushed off of the shaft  419  by the spring  437 . This would be the configuration used in  FIG. 18 . Groove  435  would be used in the case where the spring  437  is eliminated and only the shield is used on the shaft  419 . In this configuration, the retainer  434  would be installed in the groove  435  such that the retainer  436  prevents the shield  431  from moving along the shaft  419  towards the cutting edge of the bit  418 , thereby preventing the shield  431  from disengaging the head  414  when the bit  418  is connected to the head  414 . 
     Referring to  FIG. 20 , a drill bit assembly is shown generally at reference numeral  500 . Like drill bit assembly  10 , drill bit assembly  500  includes a flexible, solid-core extension rod  511  and a tailpiece  512  secured to a first end  513  of the rod  511  (not shown). Unlike drill bit assembly  10 , drill bit assembly  500  includes a second tailpiece  537  positioned on the second end  516  of the rod  511  for connection to drill bit  518 . 
     As shown, drill bit  518  includes a quick-release head  514  having the same characteristics as head  14  positioned on a shaft  519  of the drill bit  518 . By placing the quick-release head  514  on the shaft  519  of the drill bit  518 , the sleeve  526  of the head  514  cannot be disengaged when drilling a hole, thereby preventing the drill bit  518  from disengaging the tailpiece  537 . 
     A flexible and extendible drill bit assembly is described above. Various details of the invention may be changed without departing from its scope. Furthermore, the foregoing description of the preferred embodiments of the invention and best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation.