Other

Jury Mikhailovich Markov

Boris Georgievich Arabei

Ivan Ivanovich Zverev

Iosif Isaakovich Khazanov

Mikhail I Korabelnikov

Samvel S Grigorian

Viktor Alexandrovich Tjurin

Mark Semenovich Zukher

Alexandr A Shakhnazahov

Pavel Fedorovich Belmer

Eduard A Akopov

Galina Nikolaevna Trokhina

Marina V Kameneva

A tapered screw joint with the thread profile whose bearing side is inclined at an angle of from about 86.degree. to about 98.degree. to the plane which is perpendicular to the thread axis. Such a tapered screw joint of parts makes it possible to disconnect them rapidly and repeatedly under the effect of axial tensile loads with subsequent reconnection under the effect of an applied torque. This screw joint will be used most effectively in a device for the emergency recovery of the boring tool from a borehole.

Tapered screw joint and device for emergency recovery of boring tool

A heat absorbing material comprising from 12 to 51 wt% of boron carbide, from 7 and 22 wt % of silicon carbide, from 1 and 10 wt % of copper, from 1 and 12 wt % of titanium diboride and from 79 and 5 wt % of carbon. The heat absorbing material disclosed displays the requisite thermophysical properties, high heat resistance and low density. The thermal conductivity of the material is from 82 and 37 W/m. deg over the range of temperatures from 20 and 1000.degree. C, the specific heat is from 0.94 and 1.74 kJ/kg deg at temperatures varying from 20 and 600.degree. C and the density of the material is from 2.32 and 2.50 g/cm.sup.3.

Heat-absorbing material

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Moscow, Russia

Jury Mikhailovich Markov