Visual indicator for correct torsion of a rock bolt
AssigneesSandvik Mining and Construction Tools AB, Sandvik Mining and Construction Australia Pty Ltd
InventorsSteven Weaver, Mieczyslaw Rataj, Osvaldo Vallati
Life of this patent
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Abstract
A rotation indication device for a rock bolt including a central rod with a threaded trailing portion. The rotation indication device includes a blind nut having a threaded central recess for engaging the threaded trailing portion and a visual indication means provided at a bottom portion of the central recess and configured such that upon movement of the threaded trailing portion of the central rod into the bottom portion of the central recess, the central rod forces at least a portion of the visual indication means to move through a passage in the blind nut between the bottom portion of the central recess and the outside of the blind nut.
Claims20
A rotation indication device for a rock bolt comprising:
- a central rod with a threaded trailing portion;
- a blind nut including a threaded central recess arranged for engaging the threaded trailing portion and an inner projection at a bottom thereof;
- and
- a visual indication means provided at a bottom portion of the central recess and configured such that upon movement of the threaded trailing portion of the central rod into the bottom portion of the central recess, the central rod forces at least a portion of the visual indication means to move through at least one passage in the blind nut between the bottom portion of the central recess and the outside of the blind nut, wherein the blind nut is permanently blind, wherein the blind nut is first screwed onto a thread at the threaded trailing portion of the central rod, and wherein the central rod is arranged to abut the projection at the bottom of the blind nut, thereby preventing further movement of the central rod within the blind nut.
Dependencies are inferred from the claim text.