Hole saw slug removal device

Abstract

The hole saw slug removal device is constructed to fit within a hole saw and provides for automatic ejection of waste slugs from within the hole saw. The hole saw slug removal device has two discs affixed on either end of a compression spring. The device is inserted into the hole saw, and one disc retains the compression spring within the hole saw by locking onto the drill bit or against the inner surface of the hole saw. Upon operation of the hole saw, the spring compresses and the other disc is pushed down by the force of the sawing, the spring expanding to automatically eject the slug from within the hole saw when the saw is withdrawn from the workpiece. The hole saw pilot bit may have an annular groove on the shank between the flat(s) and fluted cutting edges that is engaged by one of the discs.

1 . A hole saw slug removal device for automatic slug ejection, comprising: 
 a hole saw pilot drill bit having an upper shank portion defining at least one flat, a lower portion having fluted cutting edges, and an annular groove disposed between the upper and lower portions;    a helical compression spring having opposed first and second ends;    a first annular disc attached to the compression spring at the first end of the spring, the first disc being slidable over the fluted cutting edges; and    a second disc attached to the second end of the compression spring, the second disc being annular and defining an inner circumference, the second disc releasably engaging the groove defined in the pilot drill bit, the compression spring being concentrically disposed around the bit and the first disc slidably disposed about the fluted cutting edges.    
   
   
       2 . The hole saw slug removal device as recited in  claim 1 , further comprising a plurality of resilient internal teeth formed on the inner circumference edge of said second disc, the teeth releasably engaging the annular groove.  
   
   
       3 . The hole saw slug removal device as recited in  claim 2 , wherein said second disc is convexly shaped.  
   
   
       4 . The hole saw slug removal device as recited in  claim 1 , wherein said first and second discs are planar.  
   
   
       5 . The hole saw slug removal device as recited in  claim 1 , wherein said first and second discs are welded to said compression spring.  
   
   
       6 . The hole saw slug removal device as recited in  claim 1 , wherein said compression spring is frustoconical, tapering from a wide diameter adjacent said second disc to a narrow diameter adjacent said first disc.  
   
   
       7 . The hole saw slug removal device according to  claim 1 , further comprising: 
 a hollow, elongated, cylindrical body having a base at one end and a plurality of cutting teeth at an opposing end, the cylindrical body defining a hole saw; and    an arbor attached to the base, the arbor being releasably attached to the upper shank portion of said pilot drill bit, said first and second discs and said spring being disposed within the hole saw, whereby said spring is compressed when said hole saw cuts into a work surface and expands when the hole saw is withdrawn from the work surface in order to eject a slug cut from the work surface out of the hole saw.    
   
   
       8 . A hole saw slug removal device for automatic slug ejection, comprising: 
 a hole saw pilot drill bit having an upper shank portion defining at least one flat, a lower portion having fluted cutting edges, and an annular groove disposed between the upper and lower portions; and    an ejector assembly having: 
 a helical compression spring having opposed first and second ends;  
 a first annular disc attached to the compression spring at the first end of the spring, the first disc being slidable over the fluted cutting edges; and  
 a second disc attached to the second end of the compression spring, the second disc being annular and defining an inner circumference, the second disc having means for releasably engaging the groove defined in the pilot drill bit in order to attach the ejector assembly to the pilot drill bit, the compression spring being concentrically disposed around the bit and the first disc slidably disposed about the fluted cutting edges.  
   
   
   
       9 . The hole saw slug removal device according to  claim 8 , wherein said means for releasably engaging the groove comprises a plurality of resilient teeth formed on the inner circumference of said second disc.  
   
   
       10 . The hole saw slug removal device according to  claim 8 , wherein said compression spring is frustoconical, tapering from a wide diameter adjacent said second disc to a narrow diameter adjacent said first disc.  
   
   
       11 . The hole saw slug removal device according to  claim 8 , wherein the upper shank portion of said pilot drill bit has an elongated hexagonal shape, defining a plurality of flats defining bearing surfaces for an arbor set screw.  
   
   
       12 . A hole saw slug removal device for automatic slug ejection, comprising: 
 a hole saw pilot drill bit having an upper shank portion defining at least one flat, a lower portion having fluted cutting edges, and an annular groove disposed between the upper and lower portions; and    an ejector assembly having: 
 a helical compression spring having opposed first and second ends;  
 a slug bearing surface attached to the first end of the compression spring; and  
 means for releasably attaching the second end of the compression spring to the pilot drill bit, the second disc being annular and defining an inner circumference, the means for releasably attaching engaging the groove defined in the pilot drill bit, the compression spring being concentrically disposed around the bit and the first disc slidably disposed about the fluted cutting edges.  
   
   
   
       13 . The hole saw slug removal device according to  claim 12 , wherein said slug bearing surface comprises a flat, annular disc.  
   
   
       14 . The hole saw slug removal device according to  claim 12 , wherein said compression spring is frustoconical, tapering from a wide diameter adjacent said second disc to a narrow diameter adjacent said first disc.  
   
   
       15 . The hole saw slug removal device according to  claim 12 , wherein said means for releasably attaching comprises a second disc attached to the second end of the compression spring, the second disc being annular and defining an inner circumference, the inner circumference resiliently engaging the groove.  
   
   
       16 . The hole saw slug removal device according to  claim 12 , wherein said means for releasably attaching comprises a second disc attached to the second end of the compression spring, the second disc being annular and defining an inner circumference, the inner circumference having a plurality of teeth resiliently engaging the groove.  
   
   
       17 . The hole saw slug removal device according to  claim 12 , wherein said second disc is convex and formed from resilient material.