PISTON DEVICE FOR OIL RECOVERY Russian patent published in 2002 - IPC

FIELD: oil producing industry, particularly, technology of oil recovery by piston pumps. SUBSTANCE: piston device has rubberized metal body with central hole and slots. Rubberized metal body having flexible lugs with varying thickness. Body is mounted on rod with head and bayonet with rubber seal for body. Body is made wavy with two and more bosses and hollows. Thickness of lugs in zone of bosses exceeds their thickness in hollows. Body upper and lower parts are made in the form of flange with through holes. Rod length is selected to ensure motion of body for free passage of liquid through it in device lowering and self-sealing of said device in its hoisting. EFFECT: prolonged service life of device due to high wear resistance of body, and higher efficiency due to increased reliability of body sealing in hoisting of device. 2 cl, 2 dwg