Assembly and method for wide catch overshot

摘要

A grapple for use in an overshot has a tension ring with a reduced helix diameter. However, the helix diameter is not reduced on either sides of the control finger slot to allow the grapple to remain in contact with the control. In the alternative, a composite helix member may be utilized. Another embodiment comprises the inclusion of expansion blades on the inner diameter ("ID") of the tension ring which allow the grapple to expand substantially before the fish reaches the segments. Another embodiment provides for a control with an offset finger to allow the guide thread ID to be smaller than the bowl helix major ID. Yet another embodiment provides a spiral grapple having grooves along its axis to provide the ability to catch a larger range of fish.