APPARATUS AND METHODS FOR LIMITING MOVEMENT OF GRIPPING MEMBERS

摘要

An apparatus to limit movement of gripping members relative to an elevator includes a locking arm coupled to the gripping members and a first engagement arm. The locking arm includes a set of teeth disposed longitudinally thereon, and the first engagement arm includes a first set of complimentary teeth configured to engage with the set of teeth of the locking arm. The first engagement arm is moveable between a disengaged position, in which the first engagement arm and the locking arm are relatively moveable, and an engaged position, in which the first engagement arm allows the locking arm to move in a first direction but prevents the locking bar from moving in a second direction by more than a selected distance. The teeth of the locking arm engage the first set of complimentary teeth of the first engagement arm when the first engagement arm is in the engaged position.