Locking mechanism for annular blowout preventer

摘要

A locking mechanism for securing the upper housing of an annular blowout preventer to the lower housing. A split latch ring having a plurality of angled teeth cut in its outer diameter is expandable into the lower housing which is provided with a plurality of locking grooves contoured to mate with the teeth. A locking ring with a tapered outer surface mates with a tapered inner surface on the latch ring for expanding the latch ring. Bolting the inner locking ring to the upper housing causes downward movement of the locking ring forcing the latch ring outwardly and down the taper of the engaging teeth. The upper housing is locked to the lower housing as the upper housing has a shoulder engaging the lower edge of the downwardly moving latch ring causing seating of the upper housing on to the lower housing and compensating for variations in machining tolerances.