Attachment device for a retaining belt

Claim 1

An attachment device for a retaining belt which may be subjected to tensile stress, the attachment device including first connecting means for mounting the device, second connecting means for connecting the belt to the device, the second connecting means being movable with respect to the first connecting means in the direction of the tensile stress, means defining a force path between the first and second connecting means, the force path defining means including at least two generally rectilinear plastically-deformable bodies, which are movable with respect to each other, extend substantially in the direction of tensile stress on the respective deformable bodies, and are in series in the force path, and the force path defining means also including at least one tool for acting on adjacent zones of each respective plastically-deformable body along a resultant line of action at an angle to the direction of the tensile stress on the plastically-deformable body, and for plastically deforming the respective plastically-deformable body by reducing the crosssectional area and increasing the length thereof, and applying a deformation force to the plastically-deformable body which is substantially constant along a substantial proportion of the path of relative movement between the respective tool and the plastically-deformable body, thereby enabling the second connecting means to be drawn away from the first connecting means when the belt is subjected to sufficient tensile stress, and means for reducing the effect of friction between each tool and each plastically-deformable body at the beginning of the deformation movement, the deformation force exerted by one plastically-deformable body being substantially different from that exerted by the other plastically-deformable body.