Abstract: A dual function day/night sight for rifles and the like having a unified body. The sight comprises a housing incorporating a power supply, an eyepiece and objective lenses for producing a target image arranged co-axially, and the combination of an image intensifier and optical array arranged in fixed parallel position one to the other and interposed between the eyepiece and objective lenses. Image beam deflecting means are interposed between the objective lenses and the parallel combination. During nighttime use of the sight, the deflecting means are used to apply the incoming image beam to the image intensifier. During daytime use of the sight, the deflecting means are used to apply the incoming image beam to the optical array.

Abstract: An optical angle measuring apparatus for measuring the angular displacement of a polygon with light reflecting facets, for use, e.g., in machine tools. The apparatus comprises an autocollimator for projecting collimated light beams onto a facet of a polygon, a matrix array detector for detecting and transducing into angle measuring data the location of the focused light reflected from the polygon facets, a processor and angle error memory unit; for computing the difference between the angles of any given facet and an adjacent facet relative to a respective angle of an ideal regular polygon, and a control unit for processing and compensating for the said angle data to yield a corrected angle measurement. The corrected angle measurement is displayed on display means. A method for measuring the angular displacement of an object relative to a reference position employing the apparatus is also disclosed.

Abstract: Balloon catheters are prepared to include a coating of body affecting chemicals on the exterior of the balloon. The coating releases from the balloon when the balloon is inflated into contact with the lumen to be treated. The device provides accurate placement of the dosage required at the location in need of treatment. The coating preferably includes drugs in microcapsules or microspheres. The catheters are especially useful in balloon angioplasty procedures.

Abstract: A process for the production of novel polyimide polymers and copolymers which comprises reacting a cyclooctadiene-1,2,5,6-tetracarboxylic acid bisanhydride, or a derivative of same, with an amine, or mixture of amines, of the formula H.sub.2 N--A--NH.sub.2 wherein A designates an aliphatic, an aromatic, an araliphatic or a heterocyclic group, which may be substituted. Novel polyimides obtained by such process.