PNEUMATIC BALLOON OF MOVABLE MINE SUPPORT Russian patent published in 1998 - IPC

FIELD: mining industry. SUBSTANCE: this is intended for use in developing thin coal seams for roof support and control. Pneumatic balloon of movable mine support has toroidal rubber-cord sheathing. Middle part of sheathing is made up of two cylinders located one inside other at clearance. Cord threads of internal cylinder are positioned at angle of 30-35 deg., and cord threads of external cylinder are arranged at angle of 45-50 deg. Internal and external parts of cord framework are connected to each other in overlapping manner. Diameters of cylinders are related as follows: $$$ = 0.85-0.9, where d - diameter of internal cylinder; D - diameter of external cylinder; $$$ - thickness of sheathing wall. EFFECT: higher efficiency. 5 dwg