Patent ID: 8783368

Claim:
A well tool apparatus, comprising: a running tool having an axis and configured to be carried by a running string into and out of a wellbore; a collet carried by the running tool, the collet having a plurality of fingers with a radially expanded position arranged to latch against a wellbore shoulder in the wellbore, preventing upward movement of the running tool, the plurality of fingers of the collet being resiliently and radially contractible to unlatch the running tool; a shear element carried by the collet, the shear element preventing the plurality of fingers of the collet from radially contracting to unlatch the running tool while the shear element is intact, and freeing the plurality of fingers of the collet to radially contract to unlatch the running tool if a selected axial force is applied against the shear element, causing the shear element to shear; a collet cage carried by the running tool and having a plurality of windows, each of the plurality of fingers of the collet protruding partially inward into a respective window of the plurality of windows, the collet cage being prevented from axial movement relative to the collet while the shear element is intact, and the collet cage being axially movable after the shear element has sheared, with upward axial movement of the collet cage relative to the collet being configured to cause the plurality of fingers of the collet to deflect radially inward; and an inward and upward facing cam surface on the collet cage below the plurality of fingers of the collet.