| 摘要 |
<p>A nut assembly comprises an inner sleeve (3) and an outer nut member (2). The inner surface of the inner sleeve includes a first thread portion (8) having a first thread pitch adapted to form a first threaded connection between the inner sleeve (3) and the bolt (4). The outer surface of the inner sleeve has a second thread portion (7) having a second thread pitch. The outer nut member (2) has a third thread portion adapted to cooperate with the second thread portion of the inner sleeve (3) to form a second threaded connection between the nut member (2) and the inner sleeve (3). The first thread pitch is longer than the second thread pitch such that the first threaded connection provides greater axial movement per turn than the second threaded connection. The nut assembly further comprises rotation locking means in the form of one or more shear pins (5) to at least temporarily prevent relative rotation of the nut member on the inner sleeve to cause the nut member and the inner sleeve to rotate together. The nut assembly is especially suitable for threading onto the tail end of a rock bolt to be tightened against the exterior of the rock face to tension the bolt.</p> |
