Latch means for well tools and components

In a well tool or component adapted to be landed on a support in the upright bore of a well apparatus and releasably secured in its landed position by coaction with an inwardly opening groove in the wall of the upright bore,

• a body having
• a transverse annular downwardly directed shoulder to engage the support, and
• a transverse annular outwardly opening segment-retaining groove located above the shoulder,
• the segment-retaining groove having upper and lower side walls which are flat and uninterrupted;
• a plurality of arcuate latch segments disposed in an annular series in the latch-retaining groove and each having
• a flat upper surface,
• a flat lower surface,
• a first cylindrical outer surface portion extending downwardly from the upper surface,
• a frusto-conical camming surface which tapers upwardly and inwardly and terminates at the bottom of the first cylindrical outer surface portion,
• a second cylindrical outer surface portion extending downwardly from the bottom of the camming surface,
• a latching shoulder located at the bottom of the second cylindrical outer surface portion and extending outwardly therefrom, and
• an outer surface portion extending downwardly from the latching shoulder;
• the axial dimensions of the segment-retaining groove and the latch segments, and the flat nature of the upper and lower walls of the segment-retaining groove and the upper and lower surfaces of the segments, being such that each segment can be inserted into the groove at any circumferential location in the groove and when so inserted will be in free sliding contact with the body;
• spring means carried by the segments and disposed to act in compression between the segments and the bottom wall of the segment-retaining groove to urge the segments outwardly;
• the radial dimensions of each segment and the location of the segment-retaining groove on the body being such that, when the body has been landed with the shoulder of the body operatively engaging the support in the upright bore, the spring means will cause the segments to slide outwardly in the segment-retaining groove until the latching shoulder of each segment is engaged with a coacting shoulder presented by the inwardly opening groove in the upright bore,
• the first cylindrical outer surface portion of the segment then being spaced inwardly from the wall of the upright bore;
• and
• combination segment retracting and retaining means carried by the body above the latch-retaining groove and comprising an annular member having
• a lower end dimensioned to engage the camming surfaces of the latch segments, and
• a cylindrical inner surface dimensioned to embrace the first cylindrical outer surface portions of the segments;
• the segment retracting and retaining means being movable between an upper position, in which the annular member embraces the first cylindrical outer surface portions of the segments and the segments are held in the segment-retaining groove by that engagement, and a lower position, in which the annular member embraces the second cylindrical outer surface portions of the segments,
• movement of the annular member downwardly from its first position to its second position causing the segments to be retracted into the segment-retaining groove and out of engagement with the inwardly opening groove of the upright bore as a result of coaction of the lower end of the annular member with the camming surfaces of the segments.