Abstract: Methods for manufacturing high precision arrays of curved features (e.g. lenses) in the surface of a workpiece are described utilizing orthogonal sets of inter-fitting locating grooves to mate a workpiece to a workpiece holder mounted to the spindle face of a rotating machine tool. The matching inter-fitting groove sets in the workpiece and the chuck allow precisely and non-kinematically indexing the workpiece to locations defined in two orthogonal directions perpendicular to the turning axis of the machine tool. At each location on the workpiece a curved feature can then be on-center machined to create arrays of curved features on the workpiece. The averaging effect of the corresponding sets of inter-fitting grooves provide for precise repeatability in determining, the relative locations of the centers of each of the curved features in an array of curved features.

Abstract: In a mineral insulated electric cable the powdered insulating material is impregnated with a quantity of a hydrophobic material, for example a silicone, which has been introduced into the powder in liquid form. The added hydrophobic material serves as a barrier against the ingress of moisture, and liquid dimethylpolysiloxane has been found particularly effective, the pressure of even a small quantity of this preventing any significant degree of moisture penetration into the cable.

Abstract: A door hanger (140) is disclosed for use in installation of a door assembly (100). The door hanger (140) includes a jamb arm (142) with a triangular shaped edge (144), and proximate shorter edges (145) formed inwardly from the triangular shaped edge (144) and perpendicular to each other. A pair of opposing faces (143) are formed by the triangular shaped edge (144) and the proximate edges (145), and a central hole (146) is located substantially in the center of the opposing faces (143). An alignment flange (150) is perpendicular to the jamb arm (142) and includes a distal arcuate edge (152). The arcuate edge (152) has a configuration substantially conforming to the legs of a triangle. Formed inwardly from the distal arcuate edge (152) are a pair of opposing sides (154), with sets of alignment notches (156) formed on the opposing sides (154).