A bumper system includes a rear wall of a bumper beam provided with hole portions, and a bumper stay including tubular portions extending in the longitudinal direction, the tubular portions being inserted into the hole portions and joined to the hole portions by pipe expansion joining. The bumper stay includes a pulling-out obstructing portion protruding from the outer surfaces of the tubular portions in a cross section perpendicular to the longitudinal direction. The pulling-out obstructing portion abuts on the rear wall of the bumper beam in the direction in which the bumper stay is pulled out from the hole portions.

A forming assembly for forming a wick is disclosed. The forming assembly includes a tube inflatable to an inflated configuration. A wick mesh is configured to be wrapped about the tube. The forming assembly further includes a sheath positionable about the tube and the wick mesh. The tube and the sheath are configured to compress the wick mesh and form the wick based on the tube inflating towards the inflated configuration.

A method and a device for obtaining a joint between two surfaces of two parts that have a simple curvature are proposed in which a mandrel is placed below the first surface, which contains a moving stamp in its interior. A template is placed above the second surface, which has a deep drawing opening. The stamp is moved along the surface normals of the two surfaces, such that material forming the two surfaces is forced into the deep drawing opening, wherein the deep drawn and compressed portion of the first surface engages behind the remaining part of the second surface to obtain a form-fit connection between the two surfaces. The stamp blocks a channel inside the mandrel until pressure from a medium therein causes the stamp to move.

A method of forming a wick using a mandrel is disclosed. The method includes positioning a wick mesh about the mandrel, positioning a sheath about the mandrel and the wick mesh, coupling a first fitting to the mandrel, wherein the first fitting comprises an adapter configured to couple with a source of pressure, and pressurizing the mandrel with the source of pressure to hydraulically expand the mandrel such that that mandrel compresses the wick mesh against the sheath and forms the wick.