MODULAR DOWNHOLE TOOL Russian patent published in 2016 - IPC E21B23/14 E21B4/04 

FIELD: mining.

SUBSTANCE: invention relates to a downhole tool extending in a longitudinal direction, comprising a tool housing; arm assembly pivotally mounted about a pivot point fixed in relation to tool housing and movable between a retracted position and a projecting position in relation to tool housing; arm activation assembly for moving arm assembly between retracted position and projecting position. Arm activation assembly is arranged inside tool housing and has a first end face and a second end face adapted for being connected with end faces of other arm activation assemblies. Arm activation assembly comprises a piston housing having a piston chamber extending in longitudinal direction of downhole tool and comprising: first piston housing part; second piston housing part is detachably connected to first piston housing part; piston member arranged inside piston housing and connected with arm assembly. Piston member is movable in piston housing in longitudinal direction of downhole tool.

EFFECT: higher reliability of downhole tool.

15 cl, 9 dwg