Sphere, in particular a pneumatic sphere, for example for automotive hydropneumatic suspensions

A sphere comprising a rigid jacket (11) having an upper portion (11a, 21a) adapted to be filled with pressurized gas and a lower portion (11b) in communication with an hydraulic circuit, and a pliable, deformable membrane (2) arranged inside said jacket so as to delimit an upper chamber (3) and a lower chamber (4), said membrane being attached in a junction area (11c) between said upper and lower portions and being movable between (a) an extreme lowered position in which said membrane most closely approaches said lower portion, and (b) an extreme raised position in which said membrane most closely approaches said upper portion, as a result of an increase in fluid pressure from said hydraulic circuit, wherein at least said upper portion of said jacket (11) has a flattened overall shape, and said jacket comprises means to ensure that, in the extreme raised position, said membrane substantially coincides with an inner surface of said upper portion (11a, 21a) of said jacket, so as to reduce unused volume in said upper chamber to a maximum possible extent and, accordingly, to reduce blistering of said membrane and to minimize deformations thereof.