HYDRAULIC PROP WITH PROTECTION AGAINST DYNAMIC LOADS Russian patent published in 2004 - IPC

FIELD: mining industry, mine hydraulic props experiencing dynamic load. SUBSTANCE: hydraulic prop with protection against dynamic loads comprises cylinder, piston with rod forming piston and rod spaces, safety valve in piston space and emergency device mounted on rod on side of action of dynamic load and having no hydraulic communication with piston space. Emergency device includes sleeve housing spring-loaded control valve for passage of liquid linked to throttle needle mounted for entry into hole for overflow of liquid made in sleeve and is interference fit with hollow rod for forcing. Hollow rod and sleeve form common space. Stroke of control valve is limited from beneath with stopping ring and single throttle hole for passage of liquid is made in control valve and throttle needle. Hollow rod can embrace emergency device or emergency device can embrace hollow rod. EFFECT: enhanced protection of hydraulic prop against dynamic loads thanks to multiple effective mechanical-hydraulic extinction of value of pulse of dynamic load. 3 cl, 2 dwg