Disclosed is a resin bolt which includes an elongate shaft which extends between a leading end and a trailing end and a positioning head which is integral to the shaft at the leading end and which extends in the elongate axis of the shaft from a perimeter rim to a crown, with the head formed with a plurality of projections, with each projection extending laterally, beyond the radial dimension of the shaft and each projection having a leading surface which slopes, at least partially, from the crown to the perimeter rim, and a trailing surface from the perimeter rim to the shaft.

The present invention provides a retainer device 1 for retaining or holding an anchor rod 11 of a rock anchor, especially a self-drilling anchor, in a hole H drilled above horizontal. The retainer device 1 comprises: a body portion 2 configured to be mounted on the anchor rod 11, and especially on an outer or external periphery of the anchor rod, and at least one locking arm or tab 6, 7 that projects from the body portion 2 in a direction transverse to a longitudinal extent of the anchor rod 11. The body portion 2 is configured for movement relative to the anchor rod 11 in use, and the at least one arm or tab 6, 7 is configured to deform so as to engage and bear against an inner wall W of the hole H when the retainer device 1 mounted on the anchor rod 11 is driven into the hole H. The invention also relates to a rock anchor system 10, comprising: at least one elongate anchor rod 11; a drill bit 12 configured for attachment to one end region 13 of the elongate anchor rod 11 for drilling the anchor rod 11 into rock strata R; and at least one retainer device 1 according to the invention described above for retaining or holding the anchor rod 11 in a hole H drilled in the rock strata R above horizontal. The invention also provides a method for installing a rock anchor.

A friction rock bolt assembly is arranged to frictionally engage an internal surface of a bore formed in rock strata. The rock bolt includes an expander mechanism having at least two radially outer wedge elements engageable by an inner wedge element. The expander mechanism is configured for symmetrical displacement of the expander elements to provide controlled enlargement by the rock bolt within the borehole for secure anchorage.

A friction rock bolt assembly is arranged to frictionally engage an internal surface of the bore formed in rock strata. The rock bolt includes a loading mechanism provided at a rearward end of the rock bolt having a load absorber to absorb an initial predetermined loading force followed by transfer of the force to a main load element.

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.

A system for securing different first and second drill tools to a drill head including a socket is provided. The system includes a chuck adapted for positioning at least partially within the socket of the drill head, the chuck including a first opening for receiving the first drill tool. An adapter is configured for forming a selective locking engagement within the first opening of the chuck, the adapter including a second opening for receiving the second drill tool. The selective locking engagement may comprise a twist lock engagement, and the adapter may be arranged for receiving a roof bolt. Related methods are also disclosed.

A tool aiding the installation of a rock bolt assembly in a rock hole includes: a drive shaft having a proximal end to engage with a drilling rig, and a distal end with a recess to receive a trailing end portion of the rock bolt and which has a first seat against which an axially pre-set component of the rock bolt assembly abuts; and a tubular sleeve telescopically engaged with the shaft with a first end for receiving an axially moveable component of the rock bolt assembly and which has a second seat against which the axially moveable component abuts, and a second end. The sleeve is reciprocally moveable relatively to the shaft between a biased forward position in which the axially pre-set component and the axially moveable component are spaced, and a retracted position in which the axially pre-set component engages or connects to the axially moveable component.

A tool aiding the installation of a rock bolt assembly in a rock hole includes: a drive shaft having a proximal end to engage with a drilling rig, and a distal end with a recess to receive a trailing end portion of the rock bolt and which has a first seat against which an axially pre-set component of the rock bolt assembly abuts; and a tubular sleeve telescopically engaged with the shaft with a first end for receiving an axially moveable component of the rock bolt assembly and which has a second seat against which the axially moveable component abuts, and a second end. The sleeve is reciprocally moveable relatively to the shaft between a biased forward position in which the axially pre-set component and the axially moveable component are spaced, and a retracted position in which the axially pre-set component engages or connects to the axially moveable component.

An M-type energy-absorbing rockbolt includes an anchorage structure, wherein two ends of the anchorage structure are respectively provided with a mixing blade and a threaded fastening section; a nut is screwed to the threaded fastening section; a plate is mounted at one end, which is close to the threaded fastening section, of the anchorage structure in a sleeving manner; one side of the plate abuts against the nut; the anchorage structure consists of first anchorage structure parts and second anchorage structure parts, wherein the second anchorage structure parts are arranged between two first anchorage structure parts; each of the second anchorage structure parts adopts an elliptical rod-shaped structure; a plurality of inwardly-concave arc-shaped grooves are formed in an outer wall of the second anchorage structure part in an axial direction, and a reinforcing rib is convexly formed at an intersection of two adjacent arc-shaped grooves.

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.