Abstract: A screw and nut assembly comprises a screw having a hollow cavity extending longitudinally throughout, a nut configured to screw onto the screw, and an extension attached to the nut. The extension traverses the hollow cavity of the screw when the nut is placed on an end of the screw without being screwed on. The extension is displaced from the hollow cavity of the screw as the nut is screwed onto the screw. The status of the screw and nut connection may thus be determined from the screw side of the assembly, without observing the nut, by observing the extent to which the extension has emerged from the hollow cavity in the screw.

Abstract: A bellows type sealing member for sealing off a piston rod opening formed at one end of an operating cylinder for accommodating reciprocal movement of a piston rod therein, in particular a diaphragm type cylinder for vehicle air-brake systems, wherein the piston rod has one end connected to a diaphragm disk and is provided at the other end with a forkhead, and the bellows can be sealingly fitted on a sleeve-like support member mounted coaxially in the piston rod opening of the diaphragm cylinder.