US Patent 7913717 Fast acting gate

The invention can be used in pipelines, any devices, man holes and arrangements, at any pressures and working conditions for closable large-diameter pipes. The object of the present invention is to improve serviceability of a gate. The inventive gate comprises a lid consisting of a flange and a bottom which is caved-in inwards the pipe, a sleeve provided with a supporting ring which is welded to the bottom, arresting elements in the form of sectors inserted into a circular recess of the pipe when they are radially displaced on the flange along clamping bolts and on the supporting ring by the action of the inclined surface of a drive nut, are arranged on the end face of the flange and on the supporting ring. The nut is embodied in the form of a truncated pyramid provided with T-slots on lateral surfaces thereof. The sectors are provided with T-shaped tenons enabling movement of the sectors along the end surfaces of strengthening ribs, control markers are mounted on the sectors, a locking plate provided with a lever, said plate lowering into a gap embodied between the sectors and locking them by the action of a pneumatic cylinder in the presence of excessive pressure inside a closable pipe is arranged inside the lid. The nut may be embodied in the form of a truncated cone. The lid is mounted on articulated joints; the pipe with the lid is covered by a casing.