Abstract: A vandal-proof door and a vending machine equipped with the unique door. The door strengthens and reinforces coin operated vending machines, while providing the customer with a clear, unobstructed view of the product selection inside the machine. The door comprises a rigid, generally rectangular frame having a pair of spaced-apart sides that border a product viewing aperture. An outer, arcuate impact panel having a convex vertical cross section overlies the viewing area. The impact panel is flexibly mounted to the door by elongated, resilient extrusions secured to the frame edges. Similar resilient extrusions receive the top and the bottom of the impact panel. A separate, spaced apart translucent window is internally mounted on the door frame adjacent the viewing area. Gasket sealing material is secured about the panel and window edges to complete a seal. An isolated air pocket is thus defined between the outer impact panel and the inner window.

Abstract: A smelting process for blending hazardous and non-hazardous inorganic industrial wastes with carbon or aluminum reducing agents to simultaneously recover metal alloys (reducible metals), metal oxides (volatile reducible metals), carbon dioxide and man-made vitreous fiber (non reducible metals). Wastes including hazardous wastes of U.S. EPA Series D, F, P, K, and U are pulverized and blended with liquids such as water or waste water to produce a homogeneous mass. The mass is formed into briquettes and melted in a cupola or plasma arc furnace in the presence of carbon or aluminum to reduce metals. Other types of furnaces such as an electric arc furnace may be used to avoid the steps of forming and curing briquettes. Reduction is carried out at temperatures between 1660 and 3100 degrees Fahrenheit. Calcium flux from calcium-stabilized wastes enhances mineral wool quality, lowers the sulfur content of metals and raises pH to facilitate metal reduction. Reducible metals are reduced and drawn off into molds.

Abstract: A surgical instrument for performing tissue biopsies with a single tissue penetration. The elongated instrument comprises a hollow aspirate needle for aspirating bone marrow fluid, a hollow biopsy needle telescoped within the aspirate needle, and a solid stylet removably telescoped within the biopsy needle, all of which coaxially fit together. The stylet comprises a sharp distal end extending outwardly from the biopsy needle for initially penetrating body tissue and occluding the interior of the biopsy needle. The biopsy needle comprises a distal end normally projecting from the aspirate needle for thereafter penetrating a bone and obtaining a solid bone marrow sample. The bulbous, biopsy needle distal end is sharpened for captivating a specimen. It has a pair of relief slots dividing it into bulbous halves that are compressed together when the needle coaxially moves through the aspirate needle after withdrawal from tissue.

Abstract: A torsionally stabilized automatic grade control system for finishing plastic concrete is capable of controlling a variety of different elongated, multi-section concrete finishing tools such as a vibratory screed or the like, with or without forms. Skis that support the device facilitate sliding, winch driven movement over and through plastic concrete. Spaced apart, vertically upwardly extending towers support the device; they are disposed periodically along the length of the finishing tool. Each tower comprises a pair of extensible, spaced apart stanchions hinged to the skis and disposed on opposite sides of the tool. An upper strut extends between the stanchions. A sleeve coaxially fitted to each stanchion is synchronized with the opposite sleeve by a rigid transverse bridge. The bridge is adjustably coupled to the strut. The upper portion of the stanchions comprises a hydraulic cylinder. Each cylinder is controlled by an adjacent sensor secured to the strut to maintain the attached tool level.