Apparatus for shaving tap hole surface of blast furnace or the like

An apparatus for shaving a tap hole surface of a blast furnace comprising:

• a surface shaving unit that is pressed against a tap hole surface (a front surface of a tap hole and an area around it) of a blast furnace or the like and is used for shaving and smoothing the tap hole surface, and that has bits;
• and
• a rotating mechanism unit that, when the surface shaving unit is pressed against the tap hole surface, rotates the surface shaving unit, by utilizing the pressing force, by a predetermined angle in a predetermined direction substantially parallel to the tap hole surface, and holds the surface shaving unit at the rotated position,
• wherein the rotating mechanism unit includes
• a movable body to an end of which nearer to the tap hole surface the surface shaving unit is attached or fixed,
• a tubular body that houses the movable body movably toward and away from the tap hole surface,
• a first gear unit that is provided in the movable body and that moves toward a below-described second gear unit when the surface shaving unit is pressed against the tap hole surface,
• a second gear unit that is provided in a portion of the tubular body that is farther from the tap hole surface than the first gear unit,
• a third gear unit that is provided in a portion of the movable body that is nearer to the tap hole surface than the first gear unit, and that, when the surface shaving unit is separated from the tap hole surface, moves toward a below-described fourth gear unit, and
• a fourth gear unit that is provided in a portion of the tubular body that is nearer to the tap hole surface than the third gear unit, and
• wherein teeth of the first gear unit and teeth of the second gear unit are each formed in a saw-tooth shape such that, in the process in which the first gear unit approaches the second gear unit and then the teeth of the first gear unit and the teeth of the second gear unit mesh with each other, the first gear unit and the movable body to which the first gear unit is fixed rotate by a predetermined angle in a predetermined direction substantially parallel to the tap hole surface, and
• teeth of the third gear unit and teeth of the fourth gear unit are each formed in a saw-tooth shape such that, in the process in which the third gear unit approaches the fourth gear unit and then the teeth of the third gear unit and the teeth of the fourth gear unit mesh with each other, the third gear unit and the movable body to which the third gear unit is fixed rotate by a predetermined angle in the predetermined direction.