RATCHET/RELEASE MECHANISM FOR A RETRIEVABLE WELL APPARATUS AND A RETRIEVABLE WELL APPARATUS

摘要

A ratchet/release mechanism for a retrievable well apparatus and a retrievable well apparatus includes a split ratchet ring engaging threads on a mandrel. Split ring wedge members engage an inclined end of the ratchet ring to maintain the ratchet ring in engagement with the mandrel. The wedge members are prevented from radial outward movement by a sleeve. A resilient elastomer ring is positioned between the ratchet ring and an internal shoulder on the sleeve. The ring compresses to enable the inclined end of the ratchet ring to slide up the wedge members upon movement of the mandrel in a first direction. The release of the ratchet ring is effected by moving the sleeve. When the wedge members are no longer confined by the sleeve they move radially away from the ratchet ring allowing the ratchet ring to disengage from the mandrel.