US 12,083,703 B2
Wood chipper knife
Mats Engnell, Iggesund (SE)
Assigned to Andritz AB, Ornskoldsvik (SE)
Appl. No. 17/278,162
Filed by Andritz AB, Örnsköldsvik (SE)
PCT Filed Jan. 14, 2020, PCT No. PCT/SE2020/050032
§ 371(c)(1), (2) Date Mar. 19, 2021,
PCT Pub. No. WO2020/149781, PCT Pub. Date Jul. 23, 2020.
Claims priority of application No. 1950034-7 (SE), filed on Jan. 14, 2019.
Prior Publication US 2021/0347085 A1, Nov. 11, 2021
Int. Cl. B27L 11/00 (2006.01); B02C 18/18 (2006.01); B27G 13/04 (2006.01)
CPC B27L 11/005 (2013.01) [B02C 18/18 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A wood chipper knife, comprising:
a knife body having a chip guiding portion; and
at least one cutter side, which comprises a top cutting edge portion and a bottom cutting edge portion that intersect at an acute angle (a) to form a cutting edge,
wherein the bottom cutting edge portion comprises a planar wood attacking portion, which begins at the cutting edge and towards the knife body is followed by a recess,
the recess includes a first transition portion, a bottom, and a second transition portion,
the first transition portion is contoured to abruptly turn from the wood attacking portion to the bottom of the recess,
at least a portion of the bottom of the recess is planar,
the second transition portion is contoured to curve from the bottom of the recess to the chip guiding portion, and
the chip guiding portion is contoured so as to turn from the second transition portion of the recess towards the knife body.
 
18. A wood chipper knife, comprising:
a knife body having a chip guiding portion; and
at least one cutter side, which comprises a top cutting edge portion and a bottom cutting edge portion that intersect at an acute angle (a) to form a cutting edge,
wherein the bottom cutting edge portion comprises a planar wood attacking portion, which begins at the cutting edge and towards the knife body is followed by a recess, and
the recess includes a straight portion adjacent to the wood attacking portion and a concave curve portion between the straight portion and a bottom of the recess.
 
20. A wood chipper knife, comprising:
a knife body having a chip guiding portion; and
at least one cutter side, which comprises a top cutting edge portion and a bottom cutting edge portion that intersect at an acute angle (α) to form a cutting edge,
wherein the bottom cutting edge portion comprises a planar wood attacking portion, which begins at the cutting edge and towards the knife body is followed by a recess,
the recess includes a first transition portion, a bottom, and a second transition portion, and
the first transition portion of the recess includes a concave curve portion between the wood attacking portion and the bottom of the recess, a radius of curvature of the concave curve portion being 0.1-1.5 mm.