Image Number 4 for United States Patent #6158505.
A blade seal for a shearing blind ram designed for use in a standard ram-type blowout preventer used in oil and gas drilling operations is disclosed. The blowout preventer has a body with an axial bore, a pair of opposing bonnet assemblies and a pair of opposing rams laterally moveable within the bonnet assemblies by a pressurized fluid source to control flow of well fluids through the blowout preventer body axial bore. The blade seal includes a generally planar shaped central member that tapers from one end to the other and is constructed of rubber. A pair of metal caps are bonded to the lateral edges of the blade seal to aid in preventing extrusion. The lower face of the rubber central member includes a groove adjacent to the metal cap to aid in preventing extrusion of the rubber. A pair of the blade seals is used in the upper ram of the shearing blind ram assembly. The opposing lower ram has a upwardly facing surface that seals against the pair of blade seals after the pipe is sheared.