The device for drilling holes in the ground comprises a body (1), a drive and a base member (3), connected with the body by means of a thread (4) and provided a with a lug (7) located on an external side surface (6). The lug (7) is intended for locking the base member (3) relative to the body (1) and is projected beyond the latter. One of the sides (10) is inclined to the generatrix of the side surface (6) of the base member (3) in the direction creating a turning-in moment at the connecting thr...

A compression-vacuum action percussive machine is proposed, which has a casing (1) accommodating a tool (7) and a cylinder (2) with a drive piston (3) and a striker (4) having a chamfer (10) on the end face engageable with the tool (7), and also a means for trapping the striker (4), which means is made in the form of a sleeve (11) with an annular groove (13), wherein a resilient ring (14) is mounted. The sleeve (11) has an inner annular rib (15), the diameter of which is smaller than the diamete...

A pneumatic impact tool comprising a casing having an interior space in which is mounted a piston for reciprocations under the action of compressed air for delivering useful blows, and ports of at least two exhaust passages opening into the interior space, one of the exhaust passages permanently communicating with atmosphere and the other with a chamber for preliminarily reducing the exhaust pressure. The chamber for preliminarily reducing the exhaust pressure is permanently connected through at...

A percussive tool has a working tool mounted for reciprocations in a barrel. A collar is arranged between a shank and a working portion of the working tool. The shank of the working tool reciprocates in a guide bushing secured in the barrel to ensure reciprocations of the working tool. There is provide4d a member for determining the angular position of the working tool during the reciprications, the member comprising either the barrel proper in case of concrete breakers, or a hood, e.g. in chipp...

The steel according to the invention consists of 0.12-0.20% by weight of carbon, 0.15-0.37% by weight of silicon, 0.3-0.8% by weight of manganese, 1.6-2.7% by weight of chromium, 0.8-2.0% by weight of nickel, 0.5-1.0% by weight of molybdenum, 0.05-0.15% by weight of vanadium, 0.002-0.08% by weight of cerium, 0.01-0.10% by weight of copper, 0.0005-0.009% by weight of antimony, 0.0005-0.009% by weight of tin, 0.001-0.02% by weight of sulphur, 0.002-0.02% by weight of phosphorus, 96.246-92.862% by ...

A pneumatic percussive tool has a barrel in which is inserted a hammer piston imparting blows at a working tool at regular intervals. A floating sleeve surrounding the working tool is provided in the front end portion of the barrel, the sleeve having a projection defining with a barrel groove a damping chamber communicating with a source of compressed gas. There is provided a shell rigidly secured to the barrel, which surrounds the sleeve so as to define in the zone of its projection an auxiliar...

A method of continuously extracting magnesium by subjecting chloride electrolytes to electrolysis consists of enriching an electrolyte in magnesium chloride and refining the same, mixing the enriched electrolyte with the recycled electrolyte containing the magnesium extracted in electrolytic cells, separating the magnesium from the resultant electrolyte, dividing the electrolyte into two flows of which one is fed to be enriched, while the other is delivered to a bank of electrolytic cells series...

The cooling arrangement comprises spaced apart cooling tubes arranged in a frame and interconnected with metallic tie plates. For decreasing thermal stresses without loss of strength throughout the structure, each tie plate is tangentially welded with its edge portions to the adjacent cooling tubes on both the shell and the furnace sides thereof. Each tie plate may be tangentially welded to one adjacent cooling tube and to the other it may be welded on the portion of its surface defined by an ar...

A steel containing in percent by weight: the total amount of phosphorus and arsenic contained in said composition is expressed by the following relationship:

The apparatus comprises a cooled mould mounted on a bottom plate, a roof mounted on the mould, non-consumable electrodes connected to a power source and introduced into the melting chamber of the mould through sealed apertures in the roof, and a liquid metal pouring system incorporating a metal conduit with a funnel mounted in an aperture in the roof and an inclined chute positioned above the metal conduit funnel. The roof is provided with a gas exhaust pipe and with input funnels for feeding sl...