Safety trocar for use by surgeons

摘要

The trocar cutter bit (28) can slide in a sleeve (12). An extension of the cutter bit has a recess with square edges with which a spring-loaded locking pin (34) can be pushed into engagement, when the cutter is pushed out. The axial force of the cutter during cutting acts against the side of the pin and keeps it in position. When there is no axial force on the cutter bit, e.g. when the cutter has passed through the abdominal wall, there will be no retaining force on the pin which will be pushed out by its spring. A spring (30) which acts on the extension of the cutter will pull the cutter back into the sleeve (12).