Abstract: A ratchet assembly includes a threaded rod and a support collar that defines a bore. A portion of the threaded rod is disposed in the axial bore of the support collar. A ratchet pawl is pivotable carried by the support collar between locked and unlocked positions. The ratchet pawl has at least one tooth that threadably engages the threaded rod when the ratchet pawl is in the locked position to allow the threaded rod to threadably rotate with respect to the support collar for fine position adjustments. The ratchet pawl automatically pivots to the unlocked position when the threaded rod is forced in a direction from the first end toward the second end to allow for gross position adjustments.