Abstract: Disclosed is a self-drilling resin anchored rock bolt with an elongate body of a suitable metal material extending between distal and proximal ends; and a drill bit engaged to the distal end; which body includes a threaded portion at the proximal end, a resin bore which extends through the elongate body, opening at each of the ends, a first integral anchor on the body, including integrally formed paddle formations; wherein the drill bit engaged with the body has a resin conduit which communicates an exterior of the drill bit with the resin bore; wherein the threaded portion has a first section, with a first thread density, extending from the proximal end, and a second section, with a second thread density, starting at the end of the first section and extending towards the distal end; and wherein the first thread density is lower than the second thread density.

Abstract: Disclosed is a method of adapting a metal bar, for use as a rock bolt, to ensure that the bar will break in a predictable manner, the method including the step of removing material from the bar in a circumferential band to reduce a diameter of the bar within the band to a minor diameter thereby to provide a failure zone within which the bar will break if subjected to enough tensile load.

Abstract: Disclosed is a method of adapting a metal bar, for use as a rock bolt, to ensure that the bar will break in a predictable manner, the method including the step of removing material from the bar in a circumferential band to reduce a diameter of the bar within the band to a minor diameter thereby to provide a failure zone within which the bar will break if subjected to enough tensile load.

Abstract: A self-drilling rock anchor assembly includes: a friction fit tubular sleeve extending longitudinally between leading and trailing ends; a rod extending through the sleeve between first and second ends, and projecting from each sleeve end; a drill bit member engaged with the rod's first end having an exterior surface part of which tapers towards a back end of the member; a backstop element engaged with the rod's second end having a first drive surface; a load bearing element on the rod between the sleeve's trailing end and the backstop that has a second drive surface. The rod moves relative to the sleeve between a drill position, wherein the drill bit is spaced from the sleeve's leading end, and an insertion position, wherein the sleeve's leading end abuts the bit. The drill and insertion positions are achieved by applying a force to the first and second drive surfaces, respectively.

Abstract: A self-drilling rock anchor assembly includes: a friction fit tubular sleeve extending longitudinally between leading and trailing ends; a rod extending through the sleeve between first and second ends, and projecting from each sleeve end; a drill bit member engaged with the rod's first end having an exterior surface part of which tapers towards a back end of the member; a backstop element engaged with the rod's second end having a first drive surface; a load bearing element on the rod between the sleeve's trailing end and the backstop that has a second drive surface. The rod moves relative to the sleeve between a drill position, wherein the drill bit is spaced from the sleeve's leading end, and an insertion position, wherein the sleeve's leading end abuts the bit. The drill and insertion positions are achieved by applying a force to the first and second drive surfaces, respectively.

Abstract: A rock anchor assembly includes: a resiliently radially deformable tubular member longitudinally extending between leading and trailing ends and which has an arrestor formation integral with, or engaged to, a trailing end part of the member; an elongate element longitudinally extending through the member between first and second ends and which attaches to the tubular member at spaced distal and proximal load points and which has a failure arrestor fixed at a point within the member; and a faceplate on the tubular member or the elongate member. When the assembly is inserted in a rock hole, with the faceplate bearing against the rock face, and load is applied along the elongate element that will cause the element to sever above the point at which the arrestor is fixed, the failure arrestor engages the arrestor formation, arresting the ejectment of a proximal portion of the elongate element from the hole.

Abstract: A friction bolt assembly, such as for use with a pneumatically actuated drill, with a friction fit tubular sleeve longitudinally extending between a leading end and a trailing end, a rod which longitudinally extends through the sleeve between a first end and a second end, and which projects from either end of the sleeve to define, between the first end of the rod and the leading end of the sleeve and the second end of the rod and the trailing end of the sleeve respectively, a leading part and a trailing part, an expansion element mounted on or formed with the rod, on the leading part, a drill engaging element axially fixed in position on the second end of the bolt and engageable with a chuck or an end of the rock drill, a first load bearing formation mounted on the trailing part of the rod and which engages the trailing end of the sleeve, and a second load bearing formation mounted over the trailing part of the rod between the first load bearing formation and the drill engaging element.

Abstract: A friction bolt assembly, such as for use with a pneumatically actuated drill, with a friction fit tubular sleeve longitudinally extending between a leading end and a trailing end, a rod which longitudinally extends through the sleeve between a first end and a second end, and which projects from either end of the sleeve to define, between the first end of the rod and the leading end of the sleeve and the second end of the rod and the trailing end of the sleeve respectively, a leading part and a trailing part, an expansion element mounted on or formed with the rod, on the leading part, a drill engaging element axially fixed in position on the second end of the bolt and engageable with a chuck or an end of the rock drill, a first load bearing formation mounted on the trailing part of the rod and which engages the trailing end of the sleeve, and a second load bearing formation mounted over the trailing part of the rod between the first load bearing formation and the drill engaging element.