Back-up wrench for threaded connectors

Claim 1

A plier-type wrench for gripping an hexagonally-shaped member, comprising: a first handle, a first jaw forming integral part with said handle and consisting of a first wall, extending generally in the direction of said handle, and of a second wall extending inwardly and at an angle of approximately 120° from said first wall, said first jaw being adapted to grip one angle of said member; a plate having a bottom end pivotally mounted on said first handle below said first wall and a top end forming a first external cylindrical bearing surface; a second jaw having a second external cylindrical bearing surface rotatably mounted on said first bearing surface, said second jaw consisting solely of two spaced-apart lobes at the opposite ends thereof and having a large concavity therebetween such that only said lobes can grip a second angle of said member which is directly opposite to said first angle; a second handle pivotally mounted on a rearward extension of said plate; spring means coupled between said plate and said first handle tending to move said jaws apart; and manually-operated means in and between said handles for pivoting said plate toward said first handle, thereby causing said second jaw to forcibly push said member against said first jaw.