Abstract: A camera housing unit including an adjustable camera support means for supporting a camera and a protective, substantially opaque enclosure surrounding the support means and having an elongate opening therein. A separate, elongate transparent glass window covers the opening and defines a curved surface, the center of curvature of which is located on the optical centerline of the camera when the camera is mounted on the support means. The support means includes either manual or power means for pivoting the camera about the center of curvature of the curved surface in the plane of the longitudinal centerline of the window. The mounting means for the camera is supported by an inner post surrounded by an exterior sleevelike support on which the enclosure is mounted. The sleevelike support is mechanically isolated and spaced-apart from the inner post.

Abstract: Rotary and axial forces are transmitted through a chuck to a rotary drill string. The chuck clampingly engages the drill string to transmit rotary and axial forces. A multiplicity of jaw elements in the chuck contact the drill string. The chuck includes a lower jaw retaining means and an upper jaw retaining means. Disengageable means are provided connecting the lower jaw retaining means and the upper jaw retaining means. Jaw actuating means are provided for moving the jaw elements to and from a rod gripping and rod release position.