PACKING RING FOR ANNULAR BLOW-OUT PREVENTER CARRYING RIGID INSERTS WHICH HAVE IRISING ACTION

An annular blowout preventer having a housing with a vertical bore therethrough, a packer within the housing including a resilient annulus and upper and lower series of irising metal inserts adapted to increase the support for the annulus when it is deformed axially and extended radially to constrict the vertical bore, a support ring in the annulus under the outer ends of the irising metal inserts to support against upward movement of the inner ends of the inserts on closing of the annulus and an annular piston movable in the housing to apply an axial deformation load to the packer to move it to closed position sealing the bore.