MECHANICAL DRIVE PACKER

摘要

An annular blowout preventer packer unit is disclosed having an annulus of elastomeric material in which is embedded metallic drive inserts provided in an outward circle about the axis. Metallic lead inserts are provided in an inward circle about the axis. The top and bottom plates of the drive inserts have two angled longitudinal forward surfaces which interface with reverse angled adjacent longitudinal rearward surfaces of the top and bottom plates of the lead inserts, respectively. When the BOP piston is closed, the drive inserts cause the lead inserts to advance inwardly a greater radial distance than the advance of the drive inserts. The result is that less stroke may be required to close the blowout preventer, and a controlled, predictable, uniform movement of the lead inserts is achieved. The drive inserts top plates are broad across their rearward longitudinal surface operably covering the area behind the lead inserts on closure of the packer unit. The shape of the drive inserts allows the lead inserts to be driven to a smaller diameter without opening up the back side and causing outer diameter elastomer loss to the unit.