Roller cutter

In a roller cutter mountable on earth moving machines to penetrate hard ground material for fracturing and loosening such ground material, the roller cutter including a circularly shaped rotor adapted to rotate about an axis perpendicular to the circumference of the rotor, and a stator for antifrictionally and rotatably supporting the roller on earth moving machines, the improvement comprising:

• a plurality of cutter teeth integrally formed with the rotor and equally spaced apart along the length of a plurality of helical rows, each of said helical rows being disposed along the length of said rotor in uniform helix angles and said helical rows being equally spaced apart about the circumference of the rotor so that the tooth located at each end of each helical row is longitudinally aligned along the length of the rotor with a tooth at the opposite end of a next adjacent helical row, and with the exception of the teeth located at opposite ends of adjacent helical rows being aligned with each other, each of said teeth being spaced a uniform angular distance apart from each other about the circumference of the rotor;
• and
• each of said teeth including an outwardly converging, frustoconical base portion extending radially outwardly from the outer circumference of said rotor, an outwardly diverging, frustoconical intermediate portion extending outwardly from said base portion and an outwardly converging, conical tip portion extending outwardly from said intermediate portion.

A multiple cutter unit carried by earth moving equipment for penetrating hard ground material to fracture and loosen such material, the cutter unit including a mounting plate disposed transversely of the line of travel of the earth moving equipment, a plurality of scoop teeth spaced along and extending forwardly of the mounting plates, and a plurality of roller cutters mounted on, spaced along, and extending forwardly of the mounting plate, each of the roller cutters including an annularly shaped rotor disposed transversely of the length of travel of the earth moving equipment, and a stator for antifrictionally supporting the rotor for rotation about its longitudinal axis, the improvement comprising a plurality of cutter teeth integrally formed with and extending radially outwardly from the outer surface of the rotor, said cutter teeth being arranged along the length of the rotor in a plurality of helical rows with:

• the cutter teeth of each helical row being evenly spaced apart along the length of each helical row to define a first cutter tooth disposed adjacent one end portion of the rotor, a last cutter tooth disposed adjacent the opposite end portion of the rotor, and a plurality of intermediate cutter teeth disposed between said first and last cutter teeth of each helical row;
• and
• the helical rows being disposed along a uniform helix angle relative to the longitudinal axis of a rotor such that the first tooth of each helical row is longitudinally aligned along the rotor with the last tooth of an adjacent helical row, and with the last tooth of each helical row being longitudinally aligned along the rotor with the first tooth of the other adjacent helical row so that other than the alignment of the first and last tooth of each helical row with a last and first tooth, respectively, of adjacent helical rows, each of said teeth of the rotor being equally angularly spaced about the circumference of the rotor and the tip-to-tip spacing between the teeth in each of the plurality of rings being substantially uniform throughout to uniformly and sequentially penetrate into the ground one at a time and at a time other than the time at which the teeth at opposite ends of adjacent helical rows penetrate into the ground.