Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
134 words
A longitudinal dental twist drill comprising a plurality of cutting blades extending at an angle to the principal axis of the drill; a plurality of bearing surfaces supporting said cutting blades; said bearing surfaces extending helically along the drill; the outer bearing surfaces extending parallel to the main axis of the drill and defining, when rotated, a cylindrical surface; a plurality of flutes separating said bearing surfaces; an additional bearing section extending along the main axis of the drill; and a recess between said additional bearing section and said first mentioned bearing surface, serving as a pocket for the reception of debris transferred from the cutting members by the flutes along the axis of said drill; whereby a parallel-sided cylindrical deep hole is formed in a tooth when drilled with said dental twist drill.
Claim 2
Dependent Claim
134 words
A longitudinal dental twist drill comprising a plurality of cutting blades extending at an angle to the principal axis of the drill; a plurality of bearing surfaces supporting said cutting blades; said bearing surfaces extending helically along the drill; the outer bearing surfaces extending parallel to the main axis of the drill and defining, when rotated, a cylindrical surface; a plurality of flutes separating said bearing surfaces; an additional bearing section extending along the main axis of the drill; and a recess between said additional bearing section and said first mentioned bearing surface, serving as a pocket for the reception of debris transferred from the cutting members by the flutes along the axis of said drill; whereby a parallel-sided cylindrical deep hole is formed in a tooth when drilled with said dental twist drill.
Claim 3
Dependent Claim
82 words
A dental twist drill according to claim 1, said additional bearing section also comprising a plurality of helically arranged bearing surfaces which extend and define a cylindrical wall parallel to the main axis of the drill and equal to the cylindrical wall defined by the first mentioned bearing surfaces; said second mentioned bearing surfaces also being separated by a plurality of flutes which act on rotation of the drill to transfer debris from said recess further along the axis of said drill.
Claim 4
Dependent Claim
30 words
The dental twist drill of claim 1, wherein a pilot point is provided axially of the end of said drill having said cutting blades and extending beyond said cutting blades.
Claim 5
Dependent Claim
27 words
The dental twist drill of claim 3, said cutting blades extending at an angle of 30° from a plane transverse to the main axis of said drill.
Claim 6
Dependent Claim
16 words
A dental twist drill of claim 4, said drill being adapted to form a non-tapered hole.
Claim 7
Dependent Claim
39 words
The dental twist drill of claim 5, wherein said first mentioned set of flutes extend axially for a distance of 1/2 mm and said recess for receiving debris extending axially for a distance of the order to 2 mm.
Claim 8
Dependent Claim
34 words
The dental twist drill of claim 6, having a bench mark on said drill at a distance from the cutting blades of said drill of the order of 6 mm from said cutting blades.
Claim 9
Dependent Claim
26 words
The dental twist drill of claim 2, wherein said mentioned second bearing section and set of flutes extend axially to transfer debris out of the hole.