Bolt centralizer

A bolt centralizer for a rock bolter that installs bolts into a rock surface, the rock bolter establishing a work axis along which drilling and bolt-setting equipment traverse and aligning a bolt and associated bolt plate with the work axis after a hole into which the bolt is to be driven has been drilled along the work axis, the bolt centralizer comprising:

• an arm having an arm first end and an arm second end, said arm first end being mounted to the rock bolter;
• a bolt-directing hand having a hand first end and a hand second end, said hand first end being pivotably attached to said arm second end so as to pivot about a hand pivot axis;
• a pair of fingers pivotably attached to said hand second end such that said fingers can pivot with respect to each other about a finger pivot axis between a closed position and an open position, said finger pivot axis being substantially normal to said hand pivot axis;
• a spring for biasing said pair of fingers to said closed position;
• a recess in each of said fingers configured such that, when said fingers are in said closed position, said recesses in combination form a centralizer passage sized to slidably engage the bolt when the bolt is positioned in said recesses, said fingers also being configured such that, when said fingers are in said open position, the bolt can be passed therebetween into or out of said recesses;
• means for rotating said bolt-directing hand about said hand pivot axis between a first hand position, where said centralizer passage is aligned with the work axis when the bolt-setting equipment is aligned therewith, and a second hand position, where said bolt-directing hand and said fingers are positioned so as to not obstruct
• the advancement of the bolt-setting equipment and the bolt plate along the work axis;
• and
• means for locking said bolt-directing hand in said first hand position.