Cutter unit for a wood planing machine

A cutter unit for a wood planing machine, comprising:

• a rotating axle formed with an axially extending retaining groove confined by a groove-confining wall that has two opposing wall portions;
• two positioning bars mounted securely in said retaining groove, and respectively having opposing end faces that are spaced apart from each other to define an axially extending cutter-receiving chamber therebetween;
• and
• a cutter set mounted detachably in said cutter-receiving chamber, and including a cutter with two opposite end faces and two opposite abutting side faces, and a cutter positioning block having two opposite end faces respectively abutting against said opposing end faces of said positioning bars, and two opposite first and second side faces, said first side face of said cutter positioning block being indented to form a cutter-holding recess that receives said cutter therein and that is defined by a recess-confining wall with two opposing wall portions, said opposite end faces of said cutter respectively abutting against said wall portions of said recess-confining wall of said cutter positioning block, one of said abutting side faces of said cutter being distal from said cutter positioning block and being disposed outwardly of said cutter-holding recess, the other one of said abutting side faces of said cutter abutting against said recess-confining wall of said cutter positioning block, said cutter set further including an adjusting unit that is disposed between and that abuts against said second side face of said cutter positioning block and one of said wall portions of said groove-confining wall of said retaining groove and that is adjustable to move said cutter positioning block and said cutter in a transverse direction relative to said wall portions of said groove-confining wall so as to press said one of said abutting side faces of said cutter against the other one of said wall portions of said groove-confining wall of said retaining groove, thereby securing said cutter in said cutter-receiving chamber.