Firing member retraction devices for powered surgical instruments

A surgical instrument, comprising:

• a firing member assembly including a portion supported for selective axial movement in a distal direction and a proximal direction;
• a drive unit, comprising:
• a motor including a motor shaft;
• and
• a gear assembly drivingly coupled to the motor shaft and including an output shaft assembly configured to interface with the firing member assembly such that upon rotation of the motor shaft in a first rotary direction, the portion of the firing member assembly is axially driven in the distal direction and upon rotation of the motor shaft in a second rotary direction, the portion of the firing member assembly is axially driven in the proximal direction;
• a retraction assembly interfacing with the firing member assembly for manually applying other rotary motions to the firing member assembly in the second rotary direction when the motor is deactivated;
• and
• locking means interfacing with the retraction assembly and the drive unit for preventing transfer of the other rotary motions to the motor shaft during operation of the retraction assembly and while the gear assembly remains drivingly coupled to the motor shaft;
• further comprising a housing and wherein the motor includes a motor housing that is non-movably supported within the housing and wherein the gear assembly comprises:
• a gear box housing coupled to the motor housing;
• a gear train assembly operably supported within the gear box housing in driving engagement with the motor shaft;
• and
• a lockable ring gear rotatably supported by the gear box housing and in driving engagement with the gear train assembly and the output shaft assembly and wherein said locking means comprises a movable shift ring assembly being movable from a locked position wherein said shift ring assembly lockingly engages the lockable ring gear to prevent rotation thereof relative to the gear box housing to an unlocked position wherein the lockable ring gear is free to rotate relative to the gear box housing.

A surgical instrument, comprising:

• a housing;
• a firing member assembly comprising a portion supported for selective axial movement;
• a drive unit, comprising:
• a motor comprising a motor shaft and a motor housing;
• and
• a gear box, comprising:
• a gear box housing non-movably coupled to the motor housing;
• and
• a gear assembly drivingly coupled to the motor shaft, wherein the gear assembly is configured to interface with the firing member assembly such that a rotation of the motor shaft is configured to drive the portion of the firing member assembly;
• a retraction assembly interfacing with the firing member assembly for retracting the portion of the firing member assembly when the motor is inactive;
• and
• locking means interfacing with the retraction assembly and the drive unit for preventing the transmission of torque between the firing member assembly and the motor shaft during operation of the retraction assembly and while maintaining an operable connection between the firing member assembly and the motor shaft, wherein the motor housing and the gear box housing are supported within the housing for rotation relative thereto as a unit during operation of the retraction assembly.

A surgical instrument, comprising:

• a housing;
• a firing member assembly comprising a firing rod;
• a drive unit rotatably supported within the housing, wherein the drive unit comprises:
• a motor comprising a motor shaft and a motor housing;
• and
• a gear box, comprising:
• a gear box housing non-movably coupled to the motor housing;
• and
• a gear assembly drivingly positioned intermediate the motor shaft and the firing member assembly;
• a retraction assembly configured to selectively retract the firing rod without the assistance of the motor;
• and
• a locking assembly movable between a locked position and an unlocked position upon actuation of the retraction assembly, wherein the locking assembly is configured to permit rotation of the motor housing and the gear box housing relative to the housing when in the unlocked position, and wherein the locking assembly is configured to prevent rotation of the motor housing and the gear box housing relative to the housing when in the locked position.

A surgical instrument, comprising:

• a housing;
• a firing member assembly comprising a firing rod;
• a drive unit rotatably supported within the housing, wherein the drive unit comprises:
• a motor comprising a motor shaft and a motor housing;
• a gear box, comprising:
• a gear box housing non-movably coupled to the motor housing;
• a gear assembly drivingly positioned intermediate the motor shaft and the firing member assembly;
• retraction means for retracting the firing rod without the assistance of the motor;
• and
• locking means for preventing rotation of the motor housing and the gear box housing relative to the housing when the locking means is in a locked position, wherein actuation of the retraction means is configured to move the locking means from the locked position to an unlocked position.