Rotation knob assemblies and surgical instruments including the same

A handle assembly of a surgical instrument, comprising:

• a housing defining a body portion, a fixed handle portion depending from the body portion, and a distal nose extending distally from the body portion;
• a drive assembly disposed within the housing;
• a trigger pivotably connected to the housing and operably associated with the drive assembly, the trigger movable relative to the fixed handle portion of the housing from an un-actuated position to an actuated position to actuate the drive assembly;
• and
• a rotation knob assembly extending distally from the distal nose of the housing, the rotation knob assembly including:
• an outer knob including a body defining a lumen extending longitudinally therethrough, the lumen including a proximal lumen portion and a distal lumen portion, the body defining a plurality of grooves disposed on an interior surface thereof surrounding the distal lumen portion, at least one groove of the plurality of grooves configured to receive a corresponding indexing protrusion of an elongated assembly inserted through the rotation knob assembly and into the distal nose of the housing to rotationally fix the elongated assembly relative to the outer knob;
• an inner collar engaged with the distal nose of the housing in fixed rotational orientation relative to the housing, the inner collar disposed within the proximal lumen portion of the outer knob and rotatably engaged with the outer knob, the inner collar defining a waist including a floor recessed from an exterior annular surface of the inner collar;
• and
• a plurality of ball bearing assemblies protruding radially inwardly into the proximal lumen portion of the outer knob, each ball bearing assembly of the plurality of ball bearing assemblies including a head and a ball bearing captured within the head, each ball bearing received within the waist of the inner collar such that, upon rotation of the outer knob relative to the inner collar and the housing, the ball bearings roll about the floor of the waist of the inner collar.

A surgical instrument, comprising:

• a handle assembly;
• and
• an elongated assembly extending distally from the handle assembly and supporting an end effector assembly at a distal end portion thereof, the elongated assembly including an indexing protrusion disposed towards a proximal end portion thereof;
• wherein the handle assembly includes:
• a housing defining a body portion, a fixed handle portion depending from the body portion, and a distal nose extending distally from the body portion;
• a drive assembly disposed within the housing;
• a trigger pivotably connected to the housing and operably associated with the drive assembly, the trigger movable relative to the fixed handle portion of the housing from an un-actuated position to an actuated position to actuate the drive assembly;
• and
• a rotation knob assembly extending distally from the distal nose of the housing and disposed about the elongated assembly, the rotation knob assembly including:
• an outer knob including a body defining a lumen extending longitudinally therethrough, the lumen including a proximal lumen portion and a distal lumen portion, the body defining a plurality of grooves disposed on an interior surface thereof surrounding the distal lumen portion, one groove of the plurality of grooves configured to receive the indexing protrusion of the elongated assembly to rotationally fix the elongated assembly relative to the outer knob;
• an inner collar engaged with the distal nose of the housing in fixed rotational orientation relative to the housing, the inner collar disposed within the proximal lumen portion of the outer knob and rotatably engaged with the outer knob, the inner collar defining a waist including a floor recessed from an exterior annular surface of the inner collar;
• and
• a plurality of ball bearing assemblies protruding radially inwardly into the proximal lumen portion of the outer knob, each ball bearing assembly of the plurality of ball bearing assemblies including a head and a ball bearing captured within the head, each ball bearing received within the waist of the inner collar such that, upon rotation of the outer knob relative to the inner collar and the housing, the ball bearings roll about the floor of the waist of the inner collar.