HYDRAULIC PROP Russian patent published in 1996 - IPC

FIELD: mining, powered supports for reacting to dynamic loads. SUBSTANCE: hydraulic prop includes movable and immovable members made in the form of cylinder 1 and hollow steam 2 and piston 3 installed in the cylinder so as to be moved axially. The hydraulic prop includes also spring-loaded support 5 with cavity 8. The cavity has through opening 9. Safety valve made in the form of locking member 11 and seat 12 is installed in cavity 8 and sealed. Axial openings 14 open to the cavity of hydraulic prop are originated in the locking member. Locking member is spring loaded and installed so as to interact with rest 15. When dynamic load is applied the prop comes down and results in opening the locking member using the rest with releasing needed amount of liquid into the atmosphere. EFFECT: high reliability. 2 cl, 2 dwg