SLIDING COUPLING HAVING NARROWING 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 of borehole treatment with fluid medium. Sliding coupling opened by released plug, comprises forming first channel housing and forming discharging opening connecting first channel with housing ambient medium; inner coupling forming second channel with engagement point and movable in axial direction inside first channel from closed position into open position in relation to discharging opening; and located in sliding coupling seat and having plurality of segments, displaceable to outside relative to each other. Each of segments has upper end and lower end, these segments in first axial position are spread outwards in housing first channel and form first internal size for initial engagement with released plug. Seat is made with possibility of displacement from first axial position in housing first channel into second axial position in inner coupling second channel in response to fluid medium pressure applied to engaged with seat released plug. Segments in second axial position are combined inside in inner coupling second channel and form second inner size for subsequent engagement with released plug, wherein second inner size is smaller than first inner size. Segments lower ends transfer from first inner size into second inner size until segments upper ends transition from first inner size into second inner size. Segments upper ends are locking released plug, when upper ends transit and then compressing to inside towards second inner size next to released plug. Seat in second axial position engages in inner coupling engagement point and moves inner coupling into open position in response to applied fluid medium pressure.

EFFECT: technical result consists in provision of cap jammed setting in order to receive high pressure, facilitation of cap drilling out, excluding its chipping or cutting at edges.

20 cl, 16 dwg