Trailer to transport devices

The trailer has a lifting unit (10) comprising two arms (16, 17) between a chassis and a plate. The arms have lower ends guided in the plate and upper ends guided on a cross piece (8) of the chassis. The arms are articulated with each other in their intermediate central points by an axle (19). A hydraulic jack (29) inserted between the arms control the lowering of the plate in order that the plate rests on the ground.