Patent attributes
A locking mechanism includes a support rod, inserted into a first unit shaft at a first end thereof and locked to a second unit shaft at a second end thereof, with threads formed around the outer circumferential surface thereof; and a pressure locking unit movably engaged with the threads of the support rod and having longitudinal slits formed to open in one direction and at least two pressure parts formed in a longitudinal direction. The locking pressure of the pressure locking unit is imposed on the unit shafts at multiple longitudinally spaced points, thus dispersing or distributing the locking strength in the longitudinal direction and increasing both the locking strength and the resistance against both longitudinal compressive force and longitudinal tensile force, thereby preventing the locked unit shafts from suddenly slipping towards each other.