A brush chipper assembly comprising: a housing; a feeder subassembly connected to the housing; the feeder subassembly including opposed, spaced apart, left and right feeder rollers (28, 30); when the feeder subassembly is actuated, the left feeder roller is operable to rotate in a counter-clockwise direction and the right feeder roller is operable to rotate in a clockwise direction so as to draw the brush to be chipped into the housing; a chipping subassembly substantially contained within the housing behind the feeder subassembly; the chipping subassembly including left and right, opposed, spaced apart, chipping heads (36, 38) and a drive assembly for driving rotation of the left and right chipping heads; each chipping head carrying a plurality of cutting teeth for chipping the brush fed into the brush chipper assembly; when the chipping subassembly is actuated, the left chipping head is operable to rotate in a clockwise direction and the right chipping head is operable to rotate in a counter-clockwise direction; further comprising upper and lower linkage mechanisms (32, 34) connected to the left and right feeder rollers (28, 30) and the housing; each feeder roller (28, 30) being mounted between, and supported by, portions of the upper linkage mechanism and the lower linkage mechanism; wherein: the upper and lower linkage mechanisms (32, 34) are operable to move the left and right feeder rollers (28, 30) between respective first positions (334, 335) and respective second positions (336, 337) to adjust the spacing between the feeder rollers (28, 30); in the respective first positions (334, 335), the space between the left and right feeder rollers (28, 30) is at its smallest; in the respective second positions (336, 337), the space between the left and right feeder rollers (28, 30) is at its largest; the feeder subassembly is carried in front of the housing; the left and right feeder rollers (28, 30) are biased in their respective first positions (334, 335); and the upper and lower linkage mechanisms (32, 34), when actuated, cooperate with each other to allow the left and right feeder rollers (28, 30) to pivot from their respective first positions (334, 335) to their respective second positions (336, 337). a housing; a feeder subassembly connected to the housing; the feeder subassembly including opposed, spaced apart, left and right feeder rollers (28, 30); when the feeder subassembly is actuated, the left feeder roller is operable to rotate in a counter-clockwise direction and the right feeder roller is operable to rotate in a clockwise direction so as to draw the brush to be chipped into the housing; a chipping subassembly substantially contained within the housing behind the feeder subassembly; the chipping subassembly including left and right, opposed, spaced apart, chipping heads (36, 38) and a drive assembly for driving rotation of the left and right chipping heads; each chipping head carrying a plurality of cutting teeth for chipping the brush fed into the brush chipper assembly; when the chipping subassembly is actuated, the left chipping head is operable to rotate in a clockwise direction and the right chipping head is operable to rotate in a counter-clockwise direction; the upper and lower linkage mechanisms (32, 34) are operable to move the left and right feeder rollers (28, 30) between respective first positions (334, 335) and respective second positions (336, 337) to adjust the spacing between the feeder rollers (28, 30); in the respective first positions (334, 335), the space between the left and right feeder rollers (28, 30) is at its smallest; in the respective second positions (336, 337), the space between the left and right feeder rollers (28, 30) is at its largest; the feeder subassembly is carried in front of the housing; the left and right feeder rollers (28, 30) are biased in their respective first positions (334, 335); and the upper and lower linkage mechanisms (32, 34), when actuated, cooperate with each other to allow the left and right feeder rollers (28, 30) to pivot from their respective first positions (334, 335) to their respective second positions (336, 337).