Methods and features for coupling ultrasonic surgical instrument components together

An apparatus for operating on tissue, the apparatus comprising:

• (a) a transducer assembly, wherein the transducer assembly is operable to convert electrical power into ultrasonic vibrations;
• and
• (b) a shaft assembly, wherein the shaft assembly comprises:
• (i) an ultrasonic waveguide, wherein the waveguide is configured to couple with the transducer assembly,
• (ii) a shroud, wherein at least part of the waveguide extends distally from the shroud, and
• (iii) a torque transfer assembly contained within the shroud, wherein the torque transfer assembly is configured to transfer torque from the shroud to the waveguide to thereby couple the waveguide with the transducer assembly as the shroud is rotated through a first range of motion, wherein the torque transfer assembly is configured to prevent the transfer of torque from the shroud to the waveguide as the shroud is rotated through a second range of motion.

A surgical kit, comprising:

• (a) a transducer assembly, wherein the transducer assembly is operable to convert electrical power into ultrasonic vibrations;
• (b) an ultrasonic waveguide, wherein the waveguide is configured to couple with the transducer assembly, wherein the waveguide has a distal end forming a blade;
• (c) a cap removably disposed on the blade;
• and
• (d) a torque wrench, wherein the torque wrench is operable to drive rotation of the waveguide to thereby couple the waveguide with the transducer assembly, wherein the torque wrench comprises:
• (i) a torque limiting feature, wherein the torque limiting feature is operable to restrict an amount of torque by which the waveguide may be coupled with the transducer assembly, and
• (ii) a cap engagement feature, wherein the cap engagement feature is operable to engage the cap and thereby remove the cap form the blade.