Apparatus for the remote examination of faults emerging on the inner surface of a deep cavity

An apparatus for remotely examining faults emerging at an inner surface of a deep cavity using photoluminescence of a substance fixed selectively in the faults of said surface, said apparatus comprising:

• a monochromatic radiation source;
• a single optical fiber having one end connected to the radiation source and another end connected to an observation probe, said single optical fiber transmitting monochromatic radiation from the source to the observation probe and also transmitting photoluminescent return radiation from the probe to a processing means;
• separating means placed on the optical fiber for separating said photoluminescent radiation from said monochromatic radiation;
• said observation probe having a mirror inclined with respect to the inner surface so as to direct the monochromatic radiation transmitted by the optical fiber to the inner surface and so as to reflect the photoluminescent return radiation to said optical fiber which conducts it to said processing means, said mirror being mounted in rotary manner with respect to the observation probe;
• a drive motor for rotating said mirror;
• a rotary optical connection placed on the optical fiber so as to permit advance of the probe without any corkscrewing of said optical fiber;
• and means for propelling said observation probe into said deep cavity;
• said rotary optical connection comprising a cylindrical box, a ring mounted in fixed manner within a bore of the box, screws for adjusting the position of said ring in a longitudinal direction within said bore of said box, a first base mounted in fixed manner on the box, screws for regulating the position of said first base with respect to the box in a longitudinal direction, screws for regulating the position of said first base with respect to said box in an axial direction, a second base which rotates within the ring by means of a bearing and an intermediate ring on which said bearing is mounted, screws for regulating the position of said second base in an axial direction and screws mounted on an intermediate ring for regulating the position of said second base in a radial direction, and a thrust ball bearing inserted between the box and the intermediate ring via compression springs so as to take up play of the bearing.