FRICTION BOLT

A friction bolt (10), for frictionally engaging the internal surface of a bore drilled into a rock face. The friction bolt comprises an elongate, generally circular tube (11) which is expandable radially. The tube has a leading end (12) and a trailing end (13). An expander mechanism (14) is disposed within the tube for applying a load tending to expand at least a section of the tube radially. An elongate tendon (19) is disposed longitudinally within the tube and in connection at or towards one end of the tendon with the expander mechanism and in connection at or towards an opposite end of the tendon with an anchor arrangement (13). The tendon is actuatable to expand the expander mechanism and to remain connected between the expander mechanism and the anchor arrangement while the expander mechanism is expanded.The expander mechanism comprises a pair of expander elements (15,16), a first of which is secured relative to the tube and a second of which is secured to the elongate tendon, actuation of the tendon being operable to cause relative movement between the first and second expander elements to cause the expander mechanism to expand.