Patent attributes
A gas-lift plunger includes a body having an upper end, a lower end, a bore extending axially from the upper end to the lower end, and a port therein that is in communication with bore, and an obstructing member positioned in the bore. The obstructing member includes a valve stem and is movable between a closed position, in which the obstructing member substantially prevents fluid flow through the bore from the port to the upper end, and an open position, in which fluid flow through the bore from the port to the upper end is permitted. The plunger includes an end nut connected to the lower end of the body, and a clutch assembly including arcuate members that are positioned at least partially around and configured to engage the valve stem to impede movement thereof. The clutch assembly is positioned at least partially within the end nut.