Fecha de publicación: 17/06/1998 Fuente: WIPO "meat" A positioning system comprising at least two position control assemblies (41-44), each assembly being independently actuable between contracted and expanded configurations defining a respective stroke length. The assemblies (41-44) are coupled together such that actuation of one of the assemblies causes movement of another assembly. The stroke lengths of at least two of the position control assemblies (41-44) are different.