Abstract: A clamp device adapted in particular to be secured on members of variable section. The device has a pair of jaws articulated with one another at their first end in order to oscillate from and to a closed position in which respective inner surfaces provided on the jaws substantially face one another. An adaptor member is mounted on at least one of the jaws and is hinged on that jaw in order to rotate between a first operating position in which it projects from the inner surface of the jaw and a second operating position in which it is housed within the jaw or in which it projects from the inner surface to a smaller extent than in the first operating position.