Dual-Cut Saw Blade
A saw blade having a concavely curved sawing edge and two oppositely-directed sets of teeth. During reciprocation of the blade, a first set of the teeth may cut during a first stroke direction and the second set of teeth may cut during a second stroke direction.
1 . A saw blade comprising:
a first plurality teeth, each of said first plurality of teeth having a cutting tip directed toward a first end of the blade; and
a second plurality, each of said second plurality of teeth having a cutting tip directed toward a second end of said blade and toward said first plurality of teeth,
said first and second plurality of teeth defining a concave cutting edge.
2 . A blade according to claim 1 , said blade further comprising a transition portion extending between said first and second plurality of teeth, said transition portion being disposed inwardly from said concave sawing edge.
3 . A blade according to claim 2 , wherein said first and second pluralities of teeth are provided on a shank portion of said blade, and wherein said transition portion extends across a longitudinal midline of said shank portion.
4 . A blade according to claim 1 , wherein said first plurality is approximately equal to said second plurality.
5 . A blade according to claim 1 , wherein said first and second pluralities of teeth are provided on a shank portion of said blade and are symmetrically disposed on opposite sides of a longitudinal midline of said shank portion.
6 . A blade according to claim 1 , wherein said concave cutting edge extends from a one of said first plurality of teeth nearest said second end of said blade to one of said second plurality of teeth nearest said first end of said blade.
7 . A blade according to claim 1 , wherein said first and second pluralities of teeth are provided on a shank portion of said blade, and wherein said first plurality teeth comprises a proximal tooth adjacent a proximal end of said shank portion and having a proximal cutting tip; and said second plurality of teeth comprises a distal tooth adjacent a distal end of said shank portion and having a distal cutting tip, and wherein a straight line connecting said proximal and distal cutting tips is parallel to a cutting direction of said first and second pluralities of teeth.
8 . A blade according to claim 7 , wherein said straight line is parallel to a rear edge of said blade.
9 . A blade according to claim 7 , wherein said concave cutting edge line bows inwardly from and intersects with said straight line at said proximal and distal cutting tips.
10 . A blade according to claim 7 , wherein the ratio of the longitudinal distance between said proximal and distal cutting tips to the transverse distance between said straight line and a nadir of said concave cutting edge is between about 10:1 and 100:1.
11 . A blade according to claim 1 , wherein a nadir of said concave cutting edge occurs between said first and second pluralities of teeth.
12 . A blade according to claim 1 , wherein said first and second pluralities of teeth are provided on a shank portion of said blade, and wherein the nadir of said concave cutting edge is at a longitudinal midline of said shank portion.
13 . A blade according to claim 1 , said blade further comprising a proximal end configured for fixed engagement with a saw such that energization of the saw causes continuous reciprocation of the blade between movement in a first linear direction away from the saw, and a second linear direction toward the saw.
14 . A saw blade comprising:
a proximal portion configured for fixed engagement with a saw;
a shank portion;
a first plurality teeth on said shank portion, each of said first plurality of teeth having a cutting tip directed toward a distal end of the blade;
a second plurality on said shank portion each of said second plurality of teeth having a cutting tip directed toward a proximal end of said blade and toward said first plurality of teeth; and
a transition portion extending between said first and second plurality of teeth,
said first plurality teeth comprising a proximal tooth adjacent a proximal end of said shank portion and having a proximal cutting tip, and said second plurality of teeth comprising a distal tooth adjacent a distal end of said shank portion and having a distal cutting tip, wherein a straight line connecting said proximal and distal cutting tips is parallel to a cutting direction of said first and second pluralities of teeth,
said first and second plurality of teeth defining a concave cutting edge extending inwardly from said straight line.
15 . A blade according to claim 14 , wherein said first and second pluralities of teeth are symmetrically disposed on opposite sides of a longitudinal midline of said shank portion.
16 . A blade according to claim 14 , wherein said straight line is parallel to a rear edge of said blade.
17 . A blade according to claim 14 , wherein said concave cutting edge intersects with said straight line at said proximal and distal cutting tips.
18 . A blade according to claim 14 , wherein the ratio of the longitudinal distance between said proximal and distal cutting tips to the transverse distance between said straight line and a nadir of said concave cutting edge is between about 10:1 and 100:1.
19 . A blade according to claim 14 , wherein the nadir of said concave cutting edge is at a longitudinal midline of said shank portion.
20 . A method of sawing material comprising:
engaging a blade of a reciprocating saw with the material, said blade comprising:
a first plurality teeth, each of said first plurality of teeth having a cutting tip directed toward a first end of the blade, and
a second plurality, each of said second plurality of teeth having a cutting tip directed toward a second end of said blade and toward said first plurality of teeth,
said first and second plurality of teeth defining a concave cutting edge; and
energizing the saw to cause said continuous reciprocation of said blade with the blade in contact with the material.