Clamp arm of surgical instrument with adjustable coupling stability and related methods

A surgical instrument, comprising:

• (a) an acoustic waveguide;
• (b) an end effector, including;
• (i) an ultrasonic blade in acoustic communication with the acoustic waveguide,
• (ii) a clamp arm,
• (iii) an outer sheath;
• and
• (iv) a hinge configured to pivotably couple the clamp arm to the outer sheath, the hinge being configured to be selectively resistant to pivoting.

A surgical instrument, comprising:

• (a) a shaft assembly, the shaft assembly comprising:
• (i) an outer sheath, and
• (ii) an ultrasonic waveguide secured relative to outer sheath, wherein the ultrasonic waveguide is at least partially housed within the outer sheath;
• (b) an end effector, the end effector comprising:
• (i) an ultrasonic blade attached to and extending distally from the ultrasonic waveguide, and
• (ii) a clamp arm configured to pivot relative to the ultrasonic blade between an open position and a closed position, wherein the clamp arm comprises an elongated coupling body defining a shank coupling through hole;
• (c) a shank comprising a clamp arm support dimensioned to receive the elongated coupling body of the clamp arm to assist attachment of the clamp arm to the shank, wherein the shank defining a clamp arm coupling through hole;
• (d) a first coupling pin extending through the shank coupling through hole of the clamp arm and the clamp arm coupling through hole of the shank, wherein the shank and the first coupling pin are configured to pivot relative to the shaft assembly in order to drive the clamp arm between the open position and the closed position;
• and
• (e) a clamp arm alignment structure configured to promote alignment of the clamp arm relative to the ultrasonic blade in the closed position, wherein the clamp arm alignment structure comprises:
• (i) a pivotal coupling body located on the outer sheath, wherein the pivotal coupling body extends away from the outer sheath in a direction facing away from the shank,
• (ii) a shaft coupling through hole defined by the elongated coupling body of the clamp arm, and
• (ii) a second coupling pin configured to directly pivotally couple the clamp arm with the outer sheath via the pivotal coupling body of the outer sheath and the shaft coupling through hole defined by the elongated coupling body.