The unique 3-leaf expansion unit has exclusive features that ensure positive anchorage under the most arduous conditions.
The expansion unit, which is available as a ‘bail type’ unit or a ‘regular type’ (loose leaf) unit, is a 3-leafed mechanical anchor which conforms to the hole diameter. This feature ensures a more even load distribution between the anchor and the rock at the anchor point.
The bail type unit incorporates a pop-out top. This feature will not allow the bolt to slip past the bail as often happens with a narrow strap bail.
The pop-out holds until initial anchorage is achieved, then pops away to let the bolt pass freely and secure the bearing plate firmly against the rock face.
The serrations on the shell are rounded off. This is done to reduce point loading at the contact point between the shell and the surface of the borehole. This reduces crushing of the rock and breaching of the hole, thus taking maximum advantage of the strength of the undisturbed rock at the anchor point.