Locking gripper

In a gripper for locking against an elongated body and subject to a relative displacement along the length of the body and capable of locking at any place therealong, said gripper comprising a rigid member, at least two jaws provided with surfaces for locking against the body and means for locking the jaws transversely on the body by wedge effect comprising, for each jaw, a pair of substantially parallel bearing surfaces inclined relative to the elongated body, one surface being arranged on the corresponding jaw, the other on said rigid member, and at least one rolling member interposed between said bearing surfaces for transmission of the locking force of the associated jaw to the rigid body, the improvement comprising at least one shoe associated with each pair of bearing surfaces, said shoe being provided with a surface for application against one of the bearing surfaces and elastic means connecting said shoe with the second bearing surface for maintaining the rolling member between said second bearing surface and a rolling surface provided on the shoe whereby force is transmitted between said bearing surfaces through said jaw, said roller and said shoe in succession.