Patent ID: 8418756

Claim:
A well plug for use in a wellbore, the well plug comprising: a ball valve disposed in a central straight passage along a main axis of rotation of the well plug, a flexible expandable seal and a metallic gripping member operable by rotating a hollow leadscrew around the main axis and relative to an outer housing, a transmission shaft rotatable about the main axis and having a through axial bore forming part of the passage, wherein the transmission shaft and the leadscrew are connected by at least one peg on one of them slidably inserted in at least one groove in the other, the groove extending perpendicular to the main axis along a circumference and defining an angle of free motion wherein the transmission shaft can be rotated relative to the leadscrew, the at least one peg is slidably inserted in at least one cam track on an activating sleeve, the cam track comprising a middle part extending perpendicular to the main axis along part of the circumference of the activating sleeve and two ends at an axial distance from the middle part, and the activating sleeve is connected to a ball of the ball valve through means for converting axial movement of the activating sleeve to rotation of the ball, wherein the ball valve is open when the at least one peg is near an end of the at least one cam track and closed when the at least one peg is near the middle part of the at least one cam track.