Abstract: The invention relates to a method of manufacturing barium sulphide from barites or barium sulphate. The method of manufacturing barium sulphide as per this present invention involves using finely divided calcium carbide for the reduction at a temperature above 873 K. It is preferred to use carbide mixed with coke. It is also preferred to use an addition of borax to carbide or carbide coke mixture.

Abstract: Method of manufacture of sound box stringed instruments, particularly violins, wherein a state of stress is produced in the arc-shaped sound box by providing a curvature opposite to that produced by the stretched strings, the side rim is elastically bent, suitable battens are cemented on to preliminarily bent sides, the side rim is bent to the final shape and cemented to the arc-shaped top plate with the arc-shaped bass beam cemented into it in a traditional way and the said sound box is closed by an arc-shaped bottom plate.The device for shaping the side rim consists of an oval ring (1) with at least four holes (2) situated in the axis of the said ring (1). The device is preferably provided with at least four threaded sleeves (3) to receive set screws (4), (5) and adjusting screws (6) at the point of the holes (2).

Abstract: A device for safety guiding of hauling chain, especially for a ranging drum shearer in coal mining equipment having chain haulage means, consists of chain screening /5/ at a guard /6/ of conveyor /7/ and of chain guides /11/ fixed to a ranging shearer /1/, wherein said guides /11/ travel along the route of conveyor /7/ inside the screening placed at chain guard /6/. The screening of hauling chain /5/ is confined by screening plates /12/, /13/ and /14/ at the upper part of chain guard /6/, having its uncovered side closed by screening end /20/ of a double end lever /15/, pivoted in hub /16/ below the lower screening plate /12/. The retaining end /20/ of double end lever /15/ is closed by the tension of spring /17/, attached by one end to the retaining end /18/ of lever /15/ and by another to a grip /19/ fixed to the body of the guard /6/.

Abstract: The work-pieces are mechanically cleaned, degreased and washed, and then etched in an aqueous solution containing 0.5-1.0% by weight of citric acid, and 16-24% by weight of hydrochloric acid, having a temperature of 15.degree.-30.degree. C., preferably of 20.degree.-25.degree. C., for the time of 1-20 minutes, preferably 2-5 minutes, whereafter the work-pieces are neutralized in an aqueous ammonia solution having a concentration not exceeding 1% by weight, at a temperature of 15.degree.-25.degree. C., in a time not shorter than 1 minute. After being washed in water at a temperature not exceeding 35.degree. C. in a time not shorter than 1 minute, they are dipped in an agitated aqueous solution of the flux, containing 1.8-2.5% by weight of potassium fluoride, 0.8-1.5% by weight of sodium fluoride, and 1.5-3.0% by weight of potassium fluorozirconate, having a temperature of 40.degree.-80.degree. C.

Abstract: A method of producing coatings of copper alloys in hot-dip process on workpieces made of ferrous alloys comprising dipping the workpieces to be coated into baths of molten alloys of Cu with Si, Sn, Al, P, In, Ca, Be, having a temperature within the range of 700.degree.-1100.degree. C., with a single-stage or a two-stage movement, the workpieces then being held in the bath for from 15 seconds to 60 minutes and taken out of the bath and cooled at any desirable rate.

Abstract: A sprocket wheel arrangement adopted particularly for drives in mining machines as, for example, push-plate conveyors and mining equipment. The number of teeth on the sprocket wheel is smaller than the number of seats between the working surfaces of the teeth and cooperating with chain links passing over the sprocket wheel. The seats are open from one side, and are provided with retaining walls only from the side of the teeth. The planes of bottom lands of adjacent seats intersect and form, thereby, an edge. The sprocket wheel arrangement may be used in driving systems of both coil chains and fish-plate chains.

Abstract: A process for simultaneously heat treating and aluminizing ferrous alloy products comprising pre-heating and immersing such products in a molten aluminum metal bath for a necessary period to both heat treat and aluminize, followed by a vibratory removal of any excess molten aluminum metal on said products.

Abstract: A furnace for manufacturing a high-calorific gas and coke from coal, provided with two walls 1 perforated in their upper portion, which form a rectangular chamber 2 filled with a coal charge. These walls are provided with channels 3 with inlet pipes 4 for supplying hot combustion gases and the furnace is furnished in its upper zone with inlet pipes 6 for delivering coal to the furnace and ramming pistons 7 having imparted free reciprocating motions. At the side of the furnace in its upper zone are inlet pipes 8 for supplying a hot circulating gas to the direct heating chamber where a coal charge is directly heated. Inside of the gas chamber 10 of the furnace there is an outlet pipe 9 for withdrawing cold circulating gas to a blower 14, which then becomes successively heated to the required temperature in a heat exchanger 13.

Abstract: An inorganic fireproof protective coating composition consisting of 5 to 15 percent by weight of a powdered silicate-oxide sinter or alloy, 15 to 35 percent by weight of an anhydrous powdered alumosilicate substance, and 50 to 80 percent of the acid phosphates of aluminum, chromium, magnesium or calcium, or mixtures thereof. All three ingredients of the coating form a suspensoid upon mixing and thereafter they are subjected to self-hardening at room temperature. The hardening process may be accelerated by heating up to 150.degree.C. The coating is designed for protection of products made of readily inflammable materials, particularly of wood and of wood-like materials, against destruction by fire or glow.