Latching device

A latching device for selectively locking and retrieving a well tool from a tubular receiver having an internally projecting locking shoulder with an upper and lower angularly beveled surfaces, the latching device comprising:

• a substantially cylindrical body having an enlarged upper portion and a lower portion configured for attachment of the body to an upper portion of the well tool;
• a locking sleeve mounted circumferentially about the cylindrical body and adapted for slidable axial movement being limited by the upper enlarged portion of the cylindrical body and an upper end of the well tool, said locking sleeve having an upper shoulder to facilitate retrieval of the latching device from the tubular receiver, said locking sleeve further having an intermediate shoulder, a lower shoulder and an enlarged diameter lower portion, said enlarged diameter lower portion forming a cylindrical back-up surface, said locking sleeve further defining a reduced diameter portion located below said lower shoulder, said locking sleeve further defining an annular spring retainer recess located between said intermediate and lower shoulders;
• an annular locking ring mounted on said locking sleeve, the internal diameter of the locking ring being greater than the diameter of said cylindrical back-up surface and being adapted for axial movement in relation to the cylindrical body and the locking sleeve and having a non-interference relation with said cylindrical back-up surface permitting pivoting of sad locking ring to an angulated relation with said locking sleeve, said locking ring having upper and lower angularly beveled surfaces which are angled to be complementary to the beveled surfaces of the locking shoulder of the tubular receiver and which contact the locking shoulder of the tubular receiver during locking and retrieving of the well tool;
• and
• a compression spring being compressively arranged to urge said locking ring toward said well tool, said spring being compressed by the locking ring when the locking ring passes the locking shoulder of the tubular receiver and being released after passing of the locking shoulder by the locking ring, said compression spring being mounted circumferentially about the locking sleeve below the intermediate shoulder formed on the locking sleeve, and defining an upper coil of smaller dimension than other coils thereof and being received in retained relation within said spring retainer recess to thus retain said compression spring in assembly with said locking sleeve.