A Cardan shaft with safety device for agricultural or industrial use, the Cardan shaft comprising a shaft (2) which is connected, at each of its axial ends, to a corresponding universal joint (3a, 3b), the safety device comprising a safety cover (4) that comprises a tubular body (5) of variable length that is arranged around the shaft (2) and is provided, at its axial ends, with two bell-shaped elements (6a, 6b) that are adapted to extend beyond the corresponding axial end of the shaft (2), the safety cover (4) being uncoupled from the rotation of the shaft (2) about its own axis (7), each one of the bell-shaped elements (6a, 6b) being slideable, with respect to the shaft (2), along the axis (7) of the shaft (2), from an active position, in which it is extended beyond the corresponding axial end of the shaft (2) so as to cover at least partially the corresponding universal joint (3a, 3b), to an assembly position, in which it is retracted in the direction of the central region of the shaft (2) with respect to the active position, the Cardan shaft with safety device according to the invention comprising, further, safety means (8) for locking each one of the bell- shaped elements (6a, 6b) in the active position.Linvention concerne un arbre à cardan qui possède un dispositif de sécurité pour un usage agricole ou industriel et qui comporte un arbre (2) qui est relié, au niveau de chacune de ses extrémités axiales, à un joint universel correspondant (3a, 3b), le dispositif de sécurité comportant un couvercle de sécurité (4) qui comprend un corps tubulaire (5) de longueur variable qui est agencé autour de larbre (2) et qui est pourvu, au niveau de ses extrémités axiales, de deux éléments en forme de cloches (6a, 6b) qui sont conçus pour sétendre au-delà de lextrémité axiale correspondante de larbre (2), le couvercle de sécurité (4) étant découplé de la rotation de larbre (2) autour de son propre axe (7), chacun des éléments en forme de cloches (6a, 6b) pouvant coulisser pa
