A nut and rock bolt assembly

摘要

A NUT AND ROCK BOLT ASSEMBLY A nut (1) is formed from a nut body (2) and an insert (3). An aperture (6) extends longitudinally between first and second aperture openings (7, 8) disposed on opposing first and second end faces (4, 5) of the nut body (2). The aperture (6) defines an aperture peripheral wall (9) which includes a threaded first wall portion (10) and a second wall portion (11) that has a continuous generally annular transverse cross-section tapering towards the second aperture opening (8). The insert (3) is located in and extends across the aperture (6) to inhibit passage of a rock bolt (21). The second wall portion (11) is configured to restrain the insert (3) from passing through the second aperture opening (8). When a threaded rock bolt (21) is threadingly received in the aperture (6) at a torque in excess of a predetermined torque when a torque is applied to the nut (1), the insert (3) is ejected from the second aperture opening (8) allowing passage of the rock bolt (21) through the second aperture opening (8). 20 5 to