Treating instrument

A treating instrument for at least medical or industrial treatment, comprising:

• an insertion section insertable into a cavity to be treated, the insertion section having a distal end and an operator-side end;
• a treating unit provided at the distal end of the insertion section;
• an operation member provided on the treating unit and movable between a standby position and an operative position to treat a target region in the cavity;
• drive means including:
• a direct action type actuator means mounted to one of (i) an end portion of the distal end of the insertion section and (ii) the treating unit, for directly applying a linear pushing force to the operation member;
• and
• converting means for converting said linear pushing force to a moving force for moving the operation member between the standby position and the operative position;
• and
• means provided on the operator-side end of the insertion section, for outputting a control signal for controlling an operation of the drive means for thereby controlling said pushing force;
• and wherein:
• the insertion section includes a flexibly bendable multiarticulated structure, and an end capable of being disposed proximal to the target region in the cavity;
• the treating unit comprises one gripper including a flexible sheath having a forward end, a fixed frame secured to the forward end of the sheath and having a forward end, a first gripping member fixed to the forward end of the fixed frame, and a second gripping member having a rotation shaft on the forward end of the fixed frame, rotatably connected to the forward end of the fixed frame and serving as the operation member which is opened or closed relative to the first gripping member;
• the direct action type actuator means of the drive means and the means for converting said pushing force move the second gripping member of the treating unit between opened and closed positions relative to the first gripping member;
• the direct action type actuator means comprises a pair of piezoelectric units, each piezoelectric unit being formed of a plurality of stacked piezoelectric elements which are stacked in their thickness directions, each of the piezoelectric elements of a stack being displaceable so as to be extended in a thickness direction thereof upon conduction of electrical current;
• the converting means comprises a coupling frame formed on a base end of the second gripping member, a friction member fixed to the back end of the coupling frame, the pair of piezoelectric units being fixed at one end side thereof, to a base end of the coupling frame, contacting members extending in an eccentric position toward the friction member and positioned relative to the rotation shaft on another side of the piezoelectric units;
• and
• wherein, when electric current flows through one of the piezoelectric units, the stacked elements thereof extend in their thickness direction such that a corresponding contacting member is pushed against the friction member to close the second gripping member relative to the first gripping member and, when electric current flows through the other of the piezoelectric units, the stacked elements thereof extend in their thickness direction such that a corresponding contacting member is pushed against the friction member to open the second gripping member relative to the first gripping member.