CONTROLLED PLUMB LINE Russian patent published in 1995 - IPC

FIELD: instrument engineering. SUBSTANCE: plumb line has massive elongated case with sharpened lower part, coil with two side jaws which is mounted inside slit of the case for rotation about horizontal axis which crosses vertical axis of the plumb line, and flexible thread reeled upon the coil. According to the first variant of manufacture each jaw of the coil is provided with a protrusion which is aligned with the coil. Generating surface of the protrusion is conjugated with surface of through wedge-shaped groove made in case additionally, which has specific sizes and is turned with its narrow part up and crosses slit in case at perpendicular. According to the other variant of manufacture, each jaw of the coil is provided with cylindrical protrusion aligned with the coil; generating line of the protrusion is conjugated with surfaces of through slit in case, which is made if form of wedge-shaped recess with specific sizes and turned with its narrow part up. EFFECT: improved reliability of operation in mines. 2 cl, 5 cl, 7 dwg