Abstract: The invention concerns a universal flexible sheath with bellow for articulated joint and equipment for fixing said sheath. The protective sheath consists of a tubular element (4, 5, 6, 7, 8) with fixing zones at its ends and a central conical bellow (1), whereof the folds comprise sloping flanks forming an angle of 0 to 45° with the sheath axis on the large diameter side and of 60 to 80° on the small diameter side, said sheath being associated with flexible or ductile mounting cones whereof the base diameter is variable. The invention concerns equipment for repair shops and the sheath is designed for protecting lubricated joints for transmitting movement to mobile members, and in particular to transmission elements in motor vehicles.