Patent ID: 8469652

Claim:
A gripping device that is provided at an end of a working arm of a working machine including the working arm whose end is displaceable, and that grips a processing object, the gripping device comprising: a first gripping member rotatably supported at the end of the working arm; a second gripping member rotatably supported at the end of the working arm, the second gripping member being rotatable relative to the first gripping member so that, along with the first gripping member, the second gripping member grips the processing object; and a gripping driving cylinder that extends and contracts to rotate both of the gripping members relative to each other so that the processing object is gripped by the gripping members, wherein at least one of the first gripping member and the second gripping member comprises: a gripping member body that rotates relative to the other gripping member by the extension and contraction of the gripping driving cylinder; a connecting shaft secured to the gripping driving cylinder so as to follow the extension and the contraction of the gripping driving cylinder, the connecting shaft being provided at the gripping member body so as to be displaceable relative to the gripping member body only within a predetermined range in an extension direction and a contraction direction of the gripping driving cylinder, the connecting shaft extending parallel to rotation axes of the gripping members, the connecting shaft rotatably connecting the gripping driving cylinder and the gripping member body to each other; and a spring member provided between the gripping member body and the connecting shaft so that driving of the gripping driving cylinder causes a driving force to be transmitted from the gripping driving cylinder to the gripping member body while the connecting shaft and the gripping member body are held in a predetermined positional relationship; so that the gripping member body is allowed to retreat by a predetermined amount with respect to the connecting shaft by elastically deforming the spring member by an opposing force received from the processing object that contacts the gripping member body as a result of rotating the gripping member body; and so that contact pressure of the gripping member body with respect to the processing object is increased by an elastic force of the spring member as the gripping member body retreats, wherein the gripping member body has a through groove capable of receiving the connecting shaft and having a shape allowing the gripping member body to retreat with respect to the connecting shaft, and wherein, by bringing an inner surface at the through groove and the connecting shaft into contact with each other in a closing direction of the gripping members among the extension direction and the contraction direction of the gripping driving cylinder, the gripping member body is prevented from retreating by an amount exceeding the predetermined amount.