Cover of a gas spring with an extra volume and method for producing the same

The pneumatic spring has a cover (2), a rolling bellows and a piston that commonly enclose a variable pneumatic spring interior. The cover consists of two aligned shells (2a,2b) with an intermediate extra volume (4). The connecting point between the two shells is in the form of a strong, pressure-tight double flanged seam. The connecting point has a flange clamp and a preferably annular trough for a sealing ring (8). AN Independent claim is also included for the following: (a) a method of joining the shells of a pneumatic spring cover consisting of two shells.