Method of grinding concrete block and machine for grinding concrete block

A machine for grinding concrete blocks comprising:

• a conveyor which transports the concrete blocks to a position where they are ground,
• a frame disposed to be above the conveyor,
• two vertical bars suspended from said frame and facing each other in the direction in which the conveyor is advanced suspended from said frame,
• a rotating shaft which is rotationally supported by said two vertical bars, and
• means for rotating said rotating shaft,
• whereby said ridge line portions and/or side surfaces of the concrete blocks on the upper and the bottom surfaces of the concrete block can be ground by positioning the concrete block so as to protrude from the conveyor and positioning the axis of the rotating shaft to be laterally and above the said conveyor and then lowering the grinding machine so as to abut its surface against the said ridge line portions and/or side surfaces.

A machine for grinding a surface of a concrete block comprising:

• a rotation shaft which is vertically and horizontally movable;
• a plurality of chains angularly spaced apart from each other in the circumferential direction and arranged to be closely adjacent from each other in the longitudinal direction, one end of each of which is fixed to a peripheral surface of said rotation shaft,
• and a means for rotating said rotation shaft,
• whereby a surface of a concrete block is ground by abutting an outer circle of a rotation trace formed by the other ends of said rotating chains against the side surface of the concrete block, while at the same time said rotating shaft is vertically moved.

A method for grinding a surface of a concrete block comprising:

• a step of disposing the concrete block so as to arrange its surface to be ground to be a side surface,
• a step of providing a plurality of chains whose one ends are fixed to a rotation shaft;
• a step of positioning the rotation center of the rotating shaft to be a predetermined lateral position with respect to said side surface in such a way that an outer circle of a rotation trace formed by the other ends of chains during the rotation of the rotation shaft can grind the side surface of the concrete block, and
• a step of grinding the side surface by moving the rotating shaft from above to below at the grinding position.