US Patent 6910531 Rotating drilling stripper

A stripper assembly for sealing around a drill pipe includes an outer housing having a lateral outlet. The outer housing is mounted at an upper end of a well for receiving an upward flow of drilling fluid and diverting the drilling fluid through the lateral outlet. An inner member is rotatably mounted in the outer housing. A rigid cartridge housing is mounted to the inner member for rotation therewith. The cartridge housing is open to drilling fluid. An annular elastomeric seal member is located in the cartridge housing. The cartridge housing limits upward, downward and outward movement of the seal member as it deforms against the drill pipe due to drilling fluid pressure.