Electrosurgical device with disposable shaft having translating gear and snap fit

An apparatus for operating on tissue, the apparatus comprising:

• (a) an interface assembly for use with a robotic system, wherein the interface assembly comprises:
• (i) a first drive assembly, wherein the interface assembly is configured to receive inputs from an operator to actuate the first drive assembly, and
• (ii) a bracket extending from the first drive assembly;
• and
• (b) a shaft assembly removably couplable with the interface assembly, wherein the shaft assembly is configured to insert distally within a proximal end of the interface assembly to couple with the interface assembly, wherein the shaft assembly comprises:
• (i) an end effector, wherein the first drive assembly of the interface assembly is operable to actuate the end effector of the shaft assembly, and
• (ii) a collar positioned around the shaft assembly, wherein the collar is configured to engage the bracket of the interface assembly when the shaft assembly is inserted distally within the interface assembly.

An apparatus for operating on tissue, the apparatus comprising:

• (a) an interface assembly for use with a robotic system, wherein the interface assembly comprises a first drive assembly, wherein the interface assembly is configured to receive inputs from an operator to actuate the first drive assembly, wherein the first drive assembly is positioned along a first axis;
• and
• (b) a shaft assembly removably couplable with the interface assembly, wherein the shaft assembly comprises an end effector, wherein the first drive assembly of the interface assembly is operable to actuate the end effector of the shaft assembly, wherein the shaft assembly is positioned along a second axis, wherein the second axis is substantially perpendicular to the first axis;
• wherein the first drive shaft is translatable along a path that is substantially perpendicular to both the first axis and the second axis to selectively engage the shaft assembly.