DEFORMED ROOF BOLTING Russian patent published in 2010 - IPC E21D21/00 

FIELD: mining.

SUBSTANCE: roof bolting for cementing in rock hole contains extended cylindrical solid shaft with the threaded area located above the shaft hole at a surface and equipped with at least one nut and at least one washer, drawing cone or end plate for preliminary tension of roof bolting in the hole. At that the shaft contains at least three extended areas each of which is followed by integrated bolt with less extension in comparison with extension of the shaft area. Note that the bolts are arranged with a pitch along the shaft length and attached at the places corresponding to hole wall areas for load reception that appears in the result of rock deformation. Shaft areas are performed with the possibility of slipping in relation to cement or hole for keeping the local deformation of the rock by means of extension of the said shaft areas between the pairs of attached at places previous and following bolts.

EFFECT: possibility to extend the roof bolt and capability to endure heavy load.

20 cl, 15 dwg