SWAB Russian patent published in 1999 - IPC

FIELD: pump building; lifting of liquid from well. SUBSTANCE: proposed device has check valve, housing with sealing members installed for radial displacement, limiting beads and plate with radial projections getting into mating slots on upper end faces of sealing members. Projections of jumpers made with radius of other surface equal to that of sealing members get into side slots of sealing members. Jumpers are arranged on inner surface of sealing members. Flexible collar is placed between jumpers and housing. Additional radial projections made on plate get mating slots on upper end faces of jumpers. Swab consists of number of sealing members differing in radial of outer surfaces. Radius of upper row in less than that of lower row. Organized displacement of sealing members and jumpers increases value of radial displacement without opening of through channel and without leakage in between which makes it possible to use swab in pipes with maximum deviations of motion bore, reduces clearances and leakage between swab inner surface of pipe. EFFECT: increased reliability in operation. 2 cl, 4 dwg