Instrument tip assembly having self-threading back hub

An instrument tip assembly for an actuating instrument, the instrument tip assembly comprising:

• a yoke attachment thread provided at a proximal end of the instrument tip assembly, the yoke attachment thread configured to be connected to a first thread provided within an actuating shaft of an actuator of an actuating instrument;
• a back hub provided at a proximal end of the instrument tip assembly, the back hub having a rib provided on one of an inner surface and an outer surface of the back hub,
• wherein the rib comprises a plurality of circumferentially extending projections that are spaced apart from each other in a longitudinal direction of the back hub,
• wherein the rib projects from one of the inner surface and the outer surface of the back hub, and
• wherein the rib is configured to engage with a second thread provided on the actuating shaft to form an attachment thread.

A method of assembling an actuating instrument, the method comprising:

• providing an instrument tip assembly having a yoke attachment thread;
• providing an actuator having an actuating shaft, the actuating shaft having a first
• thread provided within the actuating shaft and second thread provided on the actuating shaft;
• providing a back hub at a proximal end of the instrument tip assembly, the back hub having a rib provided on one of an inner surface and an outer surface of the back hub, wherein the rib comprises a plurality of circumferentially extending projections that are spaced apart from each other in a longitudinal direction of the back hub, and wherein the rib projects from the one of the inner surface and the outer surface of the back hub;
• screwing the first thread onto the yoke attachment thread such that the back hub is drawn towards a proximal end of actuating shaft and the rib progressively engages the second thread of the shaft, thereby deforming the rib to form an attachment thread.