Patent ID: 8485253
Filing Date: 2013-07-16
Classification: E21B,G01V

Abstract:
1. An anti-lock system for use with a downhole tool for logging a wellbore having a wellbore wall and at least one subterranean formation thereabout, the anti-lock system comprising: a first arm having an arm first end connected to a tool body of the downhole tool and an arm second end connected to a first end of a pad; a second arm having an arm first end connected to the tool body of the downhole tool and an arm second end connected to a second end of the pad; a swivel bearing between the first arm and the pad for pivotally connecting the first arm to the pad; and an anti-locking device coupled to the swivel bearing, the anti-locking device having an anti-lock biasing member for maintaining a connection between the first arm and the pad at the swivel bearing in an engaged position during normal logging and for allowing the connection to rotate toward a biased position when a binding force is encountered in the arm system.