HYDRAULIC PROP OF MINE SUPPORT Russian patent published in 1994 - IPC

FIELD: mining industry; supporting of stopes as bearing member of individual and powered supports. SUBSTANCE: hydraulic prop has cylinder 1, extensible part 2, pilot-controlled check valve 3 whose loading hollow accommodates unloading stop 4 and differential safety device 8 provided with shutoff device in form of check valve 10, pusher 12 and spring 1. Prop working hollow is hydraulically communicated with under-valve hollow of check valve 10 through inlet 9 and longitudinal channels 17, and with atmosphere, through longitudinal channels made in body of pusher 12. Differential safety device 8 fulfills the function of loading, unloading and safety devices. Individual support prop is distinguished in that used instead of hydraulically controlled unloading stop 4 is, e.g., eccentric with manual drive. EFFECT: higher efficiency. 3 dwg