Robotic surgical instrument

A robotic surgical instrument comprising:

• an end effector;
• a shaft component;
• a supporting body connected to a distal end of the shaft component at a first end and to the end effector at a second end, the supporting body comprising first and second flanges extending from the first end into the shaft component;
• a pulley facing an outer surface of the first flange;
• and
• a protrusion located within the distal end of the shaft component and extending towards the end effector, and configured to interface with an interfacing surface of one of the first or second flanges when the supporting body is moved towards the pulley;
• wherein the separation between the outer surface of the first flange and the pulley is greater than the separation between said interfacing surface of one of the first or second flanges and the protrusion;
• wherein when the instrument is in a neutral position in which no external forces are acting on the instrument, the separation between the outer surface of the first flange and the pulley is a non-zero distance, and the separation between the interfacing surface of the one of the first or second flanges and the protrusion is a non-zero distance, such that when the instrument is moved from the neutral position by the supporting body moving towards the pulley, the protrusion interfaces with the interfacing surface of the one of the first or second flanges and the first flange is prevented from coming into contact with the pulley.