ROOF BOLTING Russian patent published in 2003 - IPC

FIELD: mining; applicable in support of mine workings. SUBSTANCE: roof bolting is effected with use of securing bushing, anchor including load-carrying rod with supporting member of screw and tip, supporting washer and nut. Securing bushing covers one or more cartridges of mineral fixing agents of anchors. Supporting member of load-carrying rod of anchor is made in form of length of single - or multithreaded screw sections. Tip is made in form of n-sided pyramid. Mineral fixing agent is cartridged in water-permeable shell filled with expanding cement mixture immersed in water before its installation in borehole. Expanding cement mixture may consists of portland cement, alumina slag, gypsum and setting accelerator in form of soda ash. Parameters of supporting member of single-or multithread screw sections, number of pyramid sides and angle at vertex of tip pyramid are selected depending on conditions of roof bolting application and physico- mechanical properties of cartridged mineral fixing agent of anchors. EFFECT: reduced time taken for roof bolting installation and reduced labor input of its manufacture. 5 cl, 2 dwg