Self-advancing endoscope

A self-advancing intracavity viewing instrument including:

• an elongated insertion tube having a longitudinal axis;
• and
• a propulsion unit connected to said insertion tube comprising:
• at least three axially aligned washers including a leading washer and a trailing washer disposed on said insertion tube and being independently slidable thereon, said washers projecting radially beyond said insertion tube whereby said washers can contact the walls of a passageway;
• and
• at least three cams and at least three cam follower means associated with said cams, said cam follower means being operatively connected with said washers for imparting nonuniform reciprocating axial motion to said washers such that at any point in time more washers are moving in one direction than in an opposite direction;
• drive means for revolving said cams about the longitudinal axis of the insertion tube;
• means for restraining said cam follower means from rotating about said insertion tube when said cams are being revolved;
• whereby said insertion tube is propelled when said washers are in contact with the walls of a passageway and are in reciprocating axial motion.

A self-advancing intracavity viewing instrument comprising:

• an elongated insertion tue having a longitudinal axis;
• at least three cams each comprising paired members in face-to-face contact, said cams being rotatable about said longitudinal axis and disposed in a fixed longitudinal position with respect to aid longitudinal axis;
• at least three cam followers each disposed between one of said paired members in engagement with a profile formed by said paired members, said cam followers being movable along said longitudinal axis and fixed from rotation thereabout;
• at least three axially reciprocating washers including a leading washer and a trailing washer, each washer being slidably mounted on said insertion tube, for propelling said insertion tube along a passageway when said reciprocating washers are in contact with a wall of said passageway;
• at least three rigid cables connected to said reciprocating washers and to said cam followers;
• and
• drive means for revolving said cams about the longitudinal axis of said insertion tube, said cams and cam followers imparting nonuniform reciprocating axial motion to said washers along the axis of said insertion tube such that at any point in time more washers are moving in one direction than in an opposite direction.