Abstract: In prior art designs, single-flight cast double worms with angles of contact >720.degree. with large balance hollows at both ends and worm lengths of whole multiples of the pitch operate in the medium rotation speed ranges (.about.3000 min.sup..about.1) without imbalance. The desired use of special uncastable materials and the manufacturing complexity and the necessary dimensional stability even for extreme profile geometries pose additional problems in balancing which are solved by the present invention. Here, it is possible, by varying the angle of contact of the worm and any balance hollows and/or by altering the contour of the worms in the medium engagement region, to reduce the size of the balance hollows, sometimes to "zero", and with the possible use of additional masses. Besides the advantage of simple raw component manufacture, worms balanced in this way also permit the use of special materials and extreme worm geometries for fitting in pumps used in the chemical, medical and food sectors.
Abstract: The present construction includes outer walls, roofs and/or floors in the form of an assembly of modular units. Each modular unit comprises a peripherally closed rectangular supporting frame with intermediate frame elements, several open compartments having all the inner breadth of the supporting frame and having respective heights equal to an integer submultiple of the height of said frame or to an integer multiple of said submultiple. Construction elements including a central embrasure part are arranged in said compartments and at least two facing parts are placed, respectively, on opposite sides of the supporting frame and fixed to the central embrasure part and/or to the supporting frame.
Abstract: A method for making tubular members, each of which is coated with a decorative layer that has a randomly distributed chip pattern, includes the steps of: (A) preparing tube products, each of which having two ends and an intermediate portion between the two ends; (B) preparing a mold having a plurality of mold cavities; (C) sleeving detachably a pair of positioning members around the two ends of each of the tube products for enclosing and centering the two ends, and placing each of the tube products and the positioning members associated therewith in a respective one of the mold cavities; (D) forming a covering around the intermediate portion of each of the tube products by filling each of the mold cavities with a coating composition containing chips; (E) removing each of the covered tube products and the positioning members associated therewith from the mold, and detaching the positioning members from each of the covered tube products; and (F) machining and polishing the covered tube products, and cutting off