SLIDING COUPLING WITH NARROWING, DUAL-SEGMENTED BALL SEAT Russian patent published in 2017 - IPC E21B34/14 E21B43/26 

FIELD: mining.

SUBSTANCE: group of inventions relates to sliding couplings and methods for treatment of borehole with a fluid medium. Sliding coupling opened by a discarded plug comprises a housing forming the first channel and an outlet hole connecting the first channel with the housing ambient medium; an inner coupling forming the second channel and moved in the axial direction from the closed position into the open position inside the first channel in relation to the outlet opening; and a seat located in the second channel of the inner coupling. Seat comprises a seat ring arranged in the second channel in the first axial position and having the first contact size and a compressed ring arranged in the second channel and forming a space between the upper expanded section of the compressed ring and the second channel. Seat ring in the first axial position is engaged with the discarded plug in the first contact size and moves the inner coupling into the open position in response to the fluid medium pressure applied to the engaged plug. Seat ring moving into the second axial position is placed in the space between the upper expanded section of the compressed ring and the second channel and narrows the upper expanded section of the compressed ring inward. Upper expanded section of the compressed ring narrowed inward to the second contact size, more narrow than the first contact size, is jammed on the engaged plug.

EFFECT: technical result is ensuring a jammed resting of the plug in the seat to receive high pressure, facilitate crushing of the plug, exclude its chipping or cutting at edges.

27 cl, 16 dwg