Ultrasonic surgical instrument

An ultrasonic surgical instrument, comprising:

• an ultrasonic transducer coupled to the housing, the ultrasonic transducer including a horn having a first engagement member disposed at a free end thereof;
• and
• a movable handle pivotably coupled to the housing, the movable handle including a grasping portion extending from the housing and a driving portion extending into the housing;
• and
• an elongated assembly configured to releasably engage the handle assembly, the elongated assembly including:
• a waveguide defining a blade at a distal end, a second engagement member at a proximal end, and including a torque adapter fixedly engaged thereabout towards the proximal end;
• a fixed sleeve disposed within a movable sleeve, each sleeve disposed about the waveguide and defining a proximal end and a distal end;
• a jaw member pivotably supported at the distal end of the fixed sleeve and operably coupled to the movable sleeve such that translation of the movable sleeve relative to the fixed sleeve pivots the jaw member relative to the blade between an open position and a clamping position;
• a drive assembly configured to operably couple to the driving portion of the movable handle and including a drive tube longitudinally fixed about the proximal end of the movable sleeve and slidably disposed about the fixed sleeve such that translation of the drive tube pivots the jaw member between the open position and the clamping position, the drive tube slidably receiving the torque adapter therethrough;
• a torque housing slidably disposed about the drive tube, longitudinally fixed about the proximal end of the fixed sleeve, and fixedly engaged about the torque adapter;
• and
• a rotation knob longitudinally fixed about the torque housing and operably coupled to the torque housing such that the torque housing and the rotation knob cooperate to define a torque wrench configured to impart rotation to the waveguide in response to rotation of the rotation knob to facilitate engagement of the first and second engagement members up to a torque limit, and to decouple the rotation knob from the torque housing to inhibit application of additional torque to the waveguide above the torque limit.