Rock cutting tool having eccentric drive

A rock cutting tool which includes:

• a sleeve equipped with cutting elements and supported on a first rotating shaft, the sleeve being separately rotatable and eccentrically arranged in relation to the first shaft whereby rotation of said first shaft imparts a radially oscillating motion on the sleevef
• a second shaft separately rotatable in relation to the first shaft connected to effect said rotation of the sleeve with respect to the first shaft;
• and
• at least one adjustable counterweight connected to the first shaft and located within the sleeve for the purpose of dynamic balancing of the shaft and sleeve assembly.

A rock cutting tool which includes:

• a first sleeve equipped with cutting elements;
• a rotatable shaft having an axis of rotation;
• means including an intermediate cylindrical sleeve having an axis of rotation mounting said first sleeve on said rotatable shaft, said first sleeve being separately rotatable and eccentrically arranged in relation to the shaft, said intermediate sleeve having an inner bore and an outer periphery, said inner bore being in eccentric relationship with said outer periphery whereby rotation of said shaft imparts a radially oscillating motion on the first sleeve, rotation of said intermediate sleeve and said shaft with respect to each other about their respective axes providing adjustment of the amplitude of oscillation of said first sleeve;
• and
• at least one adjustable counterweight connected to the shaft and located within the sleeve for dynamically balancing the shaft and first and intermediate sleeves.