Abstract: Hitherto mechanical lever systems and cams were used to effect the necessary relative movements between the workpiece and the grinding disc. In order to attain a higher production rate at improved quality, it is proposed to use electronic means for shaping the profile of a tool. The generating profile is once or several times provided in a convex configuration on the grinding disc. The workpiece is shaped by respectively definable translatory, rotatory and angularly-dependent relative positions between the workpiece and the grinding disc.

Abstract: The conversion operation of a cooking apparatus which is initially operated using heated air at approximately 250.degree. C. to an operation using water vapor is made possible in a short period of time and without danger by lowering the temperature to approximately 100.degree. C. in the cooking space wall prior to steam or water vapor operation.

Abstract: The conversion operation of a cooking apparatus which is initially operated using heated air at approximately 250.degree. C., to an operation using water vapor is made possible in a short period of time and without danger by lowering the temperature to approximately 100.degree. C. in the cooking space wall prior to steam or water vapor operation.

Abstract: A process for production of castings is provided employing patterns combining gasifiable pattern parts, for the creation of nonconforming contours, with reusable pattern parts. After molding, only the reusable pattern parts are removed from the mold, while the gasifiable pattern parts are destroyed during casting.

Abstract: An article for mixing a tray holder has a generally rectangular side panel having upper and lower edges and inner and outer faces, a generally rectangular roof panel projecting generally perpendicular from the inner face of the side panel along the upper edge thereof, and a generally rectangular floor panel projecting generally perpendicular from the inner face of the side panel along the lower edge thereof. These panels are formed along a plane perpendicularly to and bisecting all panels with a weakened region and the roof and floor panels have straight outer edges remote from the side panel that are complementarily shaped to opposite sides of the plane. Thus according to the invention the article can be subdivided into two complementary and interfitting pieces along the plane adn joined together to make a half-depth holder by bonding together the complementary outer edges. A full-depth holder can be made by bonding together the outer edges of two such articles.

Abstract: A muffle oven for the heating of foodstuffs has a closed housing with a treatment chamber separated by a perforated partition from an air-circulating compartment which forms rear and lateral air spaces surrounding that chamber on three sides. A radial blower, driven by an external motor located at an intermediate level in the rear air space, is bracketed by an upper and a lower baffle each having two aerodynamic deflecting surfaces converging at a flow-dividing edge which cause the air discharged by the blower to spread symmetrically into the lateral air spaces after passing two sets of heating elements. The flow-dividing edges of the two baffles are relatively offset and lie on opposite sides of a vertical axial plane of the rotor so as to point toward the rotor at locations where the flow of the discharged air is essentially vertical. The heated air, after entering the treatment chamber from the sides, is returned to an axial intake of the blower.

Abstract: A grinding apparatus comprises a base, a chuck on the base for supporting a workpiece for rotation about an axis, a first on the base to one axial side of the chuck for grinding an internal surface of the workpiece in the chuck, a second grinder on the base for grinding an external surface of the workpiece in the chuck, and fasteners for retaining the grinders releasably on the base adjacent the chuck. Thus both axial sides of the workpiece remain exposed for machining both ends of the workpiece simultaneously. The chuck is of the centerless type which engages the workpiece externally on its outer diameter between its ends, thereby leaving these ends free for grinding.

Abstract: A method of operating a monovalent alternative absorption heating plant an apparatus operated by this method in which above a predetermined ambient temperature, the system is operated in a heat pump mode and at lower temperatures, in a direct heating mode. The system uses a coolant (refrigerant) circulation path in which the coolant is driven out of a solvent enriched with the coolant, is liquefied, is vaporized by heat exchange with the environment and is absorbed by coolant-poor solvent. The system also has a heat carrier circulation in which the heat carrier is heated by heat exchange with the continuing coolant and thus takes up absorption heat. According to the invention, in the direct heating mode, the heat carrier bypasses the coolant condenser and absorber and is passed through a heat exchanger separate from the coolant condenser and is there heated directly by combustion heat in a heat generator or by heat exchange with the coolant-poor solvent.

Abstract: A cast-iron or steel pipe is coated with a two-component epoxy resin and then, prior to curing of the resin, is coated with a relatively thick layer of hydraulic concrete. A layer of a water-impervious bitumen is then applied over the concrete. The concrete layer does not extend over the spigot in a bell-and-spigot pipe, and a special fitting is provided for such a piece of pipe when the spigot end must be cut off.

Abstract: A so-called stack stove, especially for the burning of solid fuels and particularly wood has a hood or apron extending downwardly and outwardly along the upper portion of at least its front above the opening into the combustion chamber. A window door is mounted so as to be shiftable upwardly into the hood and locked therein so that it is substantially completely concealed by the hood when the stove is operated in a fireplace mode. In its lower position the door closes the chamber opening and the stove can function as a sealed stove with limited air entry for efficient combustion.