Patent ID: 8579023

Claim:
A downhole tool device disposable in a casing of an oil or gas well, comprising: a) a mandrel with an element disposed thereon compressible and radially expandable to seal between the mandrel and the casing, and with a slip ring disposed thereon radially expandable to engage the casing, and with a cone adjacent the slip ring to radially displace the slip ring, and the element, the slip ring and the cone being pressable between an upper push sleeve assembly and a lower anvil on the mandrel; b) the upper push sleeve assembly including a lock ring having one or more interior teeth on an interior of the lock ring with an inclined surface inclined with respect to a longitudinal axis of the mandrel and facing towards the anvil, and a blunt surface essentially perpendicular to the longitudinal axis and facing away from the anvil; c) a recess formed in the mandrel and comprising a shallow annular recess in the mandrel and a deeper annular groove at one end of the shallow annular recess; d) a mandrel sleeve at least partially received within the recess in the mandrel and affixed with respect to the mandrel, and having one or more exterior teeth on an exterior of the mandrel sleeve with an inclined surface inclined with respect to the longitudinal axis of the mandrel and facing towards the upper push sleeve assembly, and a blunt surface essentially perpendicular to the longitudinal axis and facing towards the anvil, and having one or more interior teeth on an interior of the mandrel sleeve that grip the mandrel; e) the mandrel sleeve comprising a cylinder disposed in the shallow annular recess of the mandrel and an interior projecting annular lip projecting into the deeper annular groove; and d) the one or more interior teeth of the lock ring being located longitudinally away from the one or more exterior teeth of the mandrel sleeve when unset, and the blunt surface of the one or more interior teeth of the lock ring engaging the blunt surface of the one or more exterior teeth of the mandrel sleeve when set.