A drill bit for a drill assembly including a friction bolt defining a longitudinal axial passage, the drill bit being adapted to be releasibly attached to the friction bolt and comprising: (i) a leading end including a cutting part; (ii) a following end; and (iii) an outer surface defining a friction bolt engaging means adapted to releasibly engage with the leading end of the friction bolt.

A setting device for a self-drilling anchor bolt of the present invention includes: a drive shaft, one end thereof having a shank for connecting to an impact tool, and another end being a setting part for pushing the self-drilling anchor bolt axially; a coupling, partially surrounding the drive shaft along an axis, and being supported on the drive shaft in such a way as to be incapable of relative rotation while being axially moveable at least locally; and a releasable locking component, disposed between the drive shaft and the coupling; in a locked position, the locking component is coupled to an extremity of an anchor rod such that the anchor rod is fed axially with rotational striking into a receiving material, and in a released position, the drive shaft strikes a sleeve to advance axially along the anchor rod and expand at an expansion part.

A drilling assembly is disclosed for drilling a borehole in a rock body and inserting a rock bolt within the borehole in a single pass. The drilling assembly includes an elongated drill string having a downhole end. A drill bit is detachably joined to the downhole end of the drill string, with the drill bit having an external screw thread extending in an axial direction of the drill string. The drill string is surrounded by a rock bolt sleeve that has a thread engaging formation at or near its downhole end and that is arranged to cooperate with the external screw thread of the drill bit so that the drill bit is able to be screwed into the rock bolt sleeve.

A locally-anchored, self-drilling, deformable, hollow rock bolt has one or more intermediate local anchors each of which is flanked by two relatively elongateable shank segments. After grout is supplied through the hollow interior of the rock bolt while the rock bolt is in the drilled borehole, each anchor fixes the bolt to the rock mass, whereas the adjacent smooth shank segments can deform and even yield to accommodate rock fracture. The local anchors may be of relatively short extent when compared to the shank segments. One or more of the intermediate anchors could be formed by a coupler connecting adjacent bolt sections together and/or by shaping the bolt and/or by providing an external anchor. The innermost end of the rock bolt may be formed from or bear a drill bit. The drill bit can have dual functions of drilling the borehole and serving as the innermost anchor of the bolt.

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, e.g., 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 to engage an abutment or shoulder on the outer or external periphery of the anchor rod to prevent its 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.

The invention provides an adaptor for connecting a drill bit to a hollow shank of a self-drilling rock bolt, the adaptor including a body which extends in an axial direction between a distal end and a proximal end, a tubular conduit which extends between the ends, an abutment surface formed in an outer surface of the body that divides the body into a proximal portion and a distal portion, wherein at least a part of the proximal portion includes a first taper which tapers towards the proximal end, wherein at least a part of the distal portion includes a second taper which tapers towards the distal end, and wherein the first taper and the second taper are adapted for friction fit in a bore of the shank and a recess in the drill bit respectively.

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, e.g., 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 to engage an abutment or shoulder on the outer or external periphery of the anchor rod to prevent its 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 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.

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.

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.