GEAR TO SEAL BOREHOLE Russian patent published in 2001 - IPC

FIELD: construction industry, operation of oil and gas wells. SUBSTANCE: given gear is related to devices meant to seal pipe and hole clearances of boreholes which is necessary, for example, to maintain collector properties of productive seam while mounting cement bridges in shaft of borehole above productive seam, to isolate lying above water-bearing seams, to plug boreholes for replacement of operational equipment, etc. Gear includes hollow sectional body, tail part coupled to lower part of this body, sealing unit placed outside of body, bushing with location seat. Bushing is mounted inside body for axial movement and is tied up with body by means of shear lockpin. Gear also has branch pipe with through ducts that is located between bushing and body. Body has internal annular groove positioned opposite to through ducts of branch pipe. Supporting balls are located in through ducts by one part of them, other part of balls is located in internal annular groove of body. Bushing is located opposite to through ducts of branch pipe. Transportation column is linked to this branch pipe. Body has additional annular groove above its internal annular groove. Sealing unit comes in the form of set of sections of self-sealing collars mounted for interaction while their sealing tabs are in operational position of gear. Upper part of tabs has larger curvature than their lower part. EFFECT: simplified design of gear, enhanced operational reliability and widened functional capabilities of gear. 1 cl, 1 dwg