HYDRAULIC PROP Russian patent published in 2002 - IPC

FIELD: mining; hydraulic props designed for use in mines prone to rock bursts. SUBSTANCE: hydraulic prop includes cylinder, hollow rod with piston on its lower end and head on its upper end, damping device installed between head and rod upper end, member closing the hydraulic prop and provided with spring, and body with channel. Rod head has a hole for draining of fluid from hydraulic prop cavity. Member closing the hydraulic prop cavity is made in the form of slide valve whose body is located in rod cavity and rigidly connected to its head. Slide valve has blind longitudinal recesses on part of its cylindrical surface pressed by spring to rod head and located in rod body cavity to form high- and low-pressure chambers. Low-pressure chamber is communicated by means of channels in slide valve body through holes in rod head with atmosphere, and high-pressure chamber is communicated by other channels in slide valve body with rod cavity. Invention provides for faster operation of slide valve in rock bursts and increased part of rock burst energy transmitted by rod head to slide valve, ensured holding of slide valve in open position under emergency high pressure of fluid in cavity of hydraulic prop resulted from rock burst. Quick action and increased part of energy transmitted to slide valve to rock burst is attained by installation of slide valve in direct contact with rod head, its reliable holding in open position ensured by high pressure of fluid in cavity of hydraulic prop in rock burst. EFFECT: higher efficiency. 2 dwg