Flexible self-locking sternum ribbon and tightening device thereof

The flexible self-locking type sternum binding belt comprises a toothed belt and a tightening mechanism, a lock catch is arranged at one end of the toothed belt, a puncture needle is arranged at the other end of the toothed belt, a square through hole is formed in the lock catch, an embedded piece with a sharp corner at the end is arranged in the square through hole, and a plurality of protrusions matched with the embedded piece are arranged on the outer wall, opposite to the embedded piece, of the toothed belt. The tightening mechanism comprises a handle, an ejector rod arranged at one end of the handle and a handle cover plate arranged at the other end of the handle, a cavity with a sliding block is formed in the handle, sliding grooves are formed in the upper end and the lower end of the handle, a locking knob penetrating through the sliding grooves to be in threaded connection is arranged at the upper end of the sliding block, and a U-shaped clamping groove is formed in the side face of the end close to t