An inspection apparatus for viewing and making video recordings of the interior of an enclosed space of an enclosure having an elongated body. A pair of housings are mounted on the lower end of the elongated body and respectively contain a light source for illuminating an area of the enclosed space and a video camera for creating an image of the illuminated area of the enclosed space. The video camera includes a video magnetic tape media for recording the images illuminated by the light source. A television monitor is mounted on the upper portion of the elongated body for simultaneously viewing the images created by the video camera.

A motorized mirror assembly attaches to a borescope insertion tube for rotating a mirror to provide side viewing capability. A housing for a motor/gearbox has an access port at one end that provides access to a shaft driven by the motor/gearbox for attachment to a side-viewing mirror. The assembly includes a battery enclosure into which a battery is inserted. The housing and battery enclosure have diameters that do not exceed the diameter of the borescope insertion tube. Power is switchably supplied to the motor/gearbox by an arrangement in which a ring retainer is connected to the housing, and a compression spring is mounted in electrical contact with one of the battery terminals and with an electrical terminal on the motor/gearbox. The tension exerted by the spring urges the motor/gearbox against a surface of the housing, and also pushes the battery against the wall of the battery enclosure to establish secure electrical continuity therebetween. A switch arrangement includes a rotatable contact ring, immobilized by slots that engage studs projecting from an external ring that rotates about the ring retainer to urge the contact ring into rotation therewith, the contact ring coming in and out of electrical contact with a second electrical contact terminal. The battery enclosure is connected to the other end of the external ring and has a removable cap to allow installation and removal of the battery. Thus a battery can be removed and a replacement battery installed without disturbing the contact ring.

Apparatus for measuring surface defects or the distance from the apparatus to a surface comprising means (37,38,43,44) for passing a beam (48) of light to the surface (11) at an angle other than normal, means (51) for viewing the area (47) of the surface (12) illuminated by the beam (48) and means (53-50) for measuring the movement of the illuminated area (47) whereby the measure the position of the illuminated area (47), means (17) being provided to rotate the apparatus and means (53) being provided to derotate the image of the illuminated area so as to enable, for example, the interior of cylinders (10) to be inspected.

A method of and an apparatus for investigating subterranean boreholes especially in bituminous coal mining. Optical fiber cables carry light for illuminating the hole into the latter and an image of the wall of the borehole from the latter to an evaluating means external of the borehole.

A device for remote detection of surface flaws in enclosed cavities that have been treated with a photoluminescent medium. The device has a non-rotating ultraviolet radiation source, an offset rotary drive means, a passive rotary scanning means that includes a plurality of lenses, reflectors and an optical filter, a non-rotating solid-state photodiode, and support electronic circuitry. Ultraviolet radiation from the illumination source is projected onto the test-part surface and causes dye penetrant that has been previously deposited onto the test-part surface to fluoresce at a different wavelength, thus revealing the presence of surface cracks and flaws. The receiving lenses capture the fluorescent light and project it onto the photodiode, which generates a series of electrical pulses that correspond to the presence of surface flaws. By encoding the linear and angular position of the scanning means, an accurate and quantitative map of the flaw pattern can be constructed.