Well tool device preventing backlash of ratchet

Abstract

A well tool device includes a mandrel device; an outer setting sleeve arranged concentric outside of the mandrel device; an anchoring device arranged radially outside the mandrel device; and a ratchet system configured to allow relative longitudinal movement between the mandrel device and the setting sleeve in a first direction and to prevent relative longitudinal movement between the mandrel device and the setting sleeve in a second direction opposite to the first direction. The well tool device is configured to be: in a run state, in which the anchoring device is radially retracted; and, in a first set state, in which the anchoring device is radially expanded. The well tool device is configured to move from the run state to the first set state by relative longitudinal movement between the mandrel device and the setting sleeve. The well tool device has a link system that includes a first actuation sleeve mechanically connected to the outer setting sleeve; a second actuation sleeve mechanically connected to the anchoring device; a first arm having a first end and a second end, wherein the first end is pivotably connected to the first actuation sleeve at a first pivoting axis; and a second arm having a first end and a second end, wherein the first end is pivotably connected to the second actuation sleeve at a second pivoting axis; and wherein the second end of the first arm is pivotably connected to the second end of the second arm at a third pivoting axis. A first distance is defined as the radial distance between the third pivoting axis and the first pivoting axis or as the radial distance between the third pivoting axis and the second pivoting axis. The well tool device is configured to be in a second set state, in which the first distance is smaller in the second set state than in the run state and in the first set state.