Abstract: A knob or similar object is rotatably retained on a piece of equipment by an arrangement including a four-section hinged member which may be concealed by the knob during normal usage. The hidden retaining member is captivated around the shaft at both ends by retaining devices and by the knob and enclosure wall until the knob is released. The arrangement is applicable regardless of whether the shaft remains on the equipment or forms a part of the retained object. The center sections of the hinged member fold up on one side of the shaft when hidden, but extend to allow release of the object from the normal, attached position.

Abstract: A yoke mounting assembly provides easy yoke adjustment along the axial direction of the tube with accurate, fixed positioning in the other two dimensions. An extruded sliding support is movable along projections in a housing frame against the applied normal force of a pair of C-shaped retainer springs, the latter being easily rotated to a release position for yoke or camera tube access.