Patent ID: 6446364
Filing Date: 2002-09-10
Classification: E02F

Abstract:
A grab for excavators of foundation walls and rectangular piles, comprising:a frame; two substantially symmetrical jaws articulated onto the frame, said jaws open and close with respect to each other; wherein said grab has at least two elements for support against the walls of a hole the grab is digging; means for moving at least two supporting elements between a folded-in position in which at least two supporting elements remain alongside the frame and an unfolded position in which at least two supporting elements are pressed against the walls of the hole; further comprising, at least one kelly section, attached to the frame with the jaws, said kelly section moves vertically between an upper stop and a lower stop, so that when the grab is not resting on the ground the frame is suspended from the kelly, and when the grab is resting on the ground the kelly rests on the frame; wherein the means for moving the supporting elements include a kinematic chain that links the kelly, the frame and the supporting elements, said means for moving being structured and arranged so that when the jaws and the frame reach the bottom of the hole the kelly descends until it rests on the frame, and during this descending movement the kinematic chain causes travel of the supporting elements until the supporting elements rest pressing against the walls of the hole.