Patent ID: 8794355

Claim:
A core barrel head assembly having a longitudinal axis and configured to be removably received within a drill string, comprising: a sleeve having a plurality of latch openings extending there through; a driving member positioned at least partially within the sleeve, the driving member having an outer surface defining a plurality of discrete driving surfaces that are spaced circumferentially about the outer surface of a distal end of the driving member and that are distally tapered relative to the longitudinal axis of the core barrel head assembly, wherein, in cross-section of the driving member, each portion of each driving surface of the plurality of discrete driving surfaces has a radius relative to the longitudinal axis of the core barrel head assembly, and wherein the radius of at least a portion of each driving surface varies across the cross-sectional width of each driving surface; and a plurality of wedge members, each wedge member of the plurality of wedge members being positioned on a portion of a respective driving surface of the plurality of driving surfaces, the plurality of wedge members extending within the plurality of latch openings about and between a released position and a locked position; wherein each wedge member of the plurality of wedge members is unattached to other portions of the core barrel head assembly, and wherein, when the plurality of wedge members are positioned in the locked position, the driving member is configured to wedge the plurality of wedge members between portions of the inner surface of the drill string and respective portions of the plurality of driving surfaces to axially and rotationally lock the core barrel head assembly relative to the drill string.