b 30 c adjacent two by two of oblong parallelepipedal shape and in which the meal carts are kept the carts hold tray meals intended for the passengers the compartments 30 make it possible to maintain the trays at a chosen preservation temperature the adjacent compartments 30 30 a 30 b 30 c each are closed by a door 20 20 a 20 b 20 c respectively pivoting around a vertical axis in this description the vertical direction is considered as the direction perpendicular to that of the floor on which the unit 10 is resting on fig2 the compartment 30 b is closed by a door 20 b pivoting around a vertical axis a the door 20 b pivots between a closing position depicted on fig2 and in which the compartment is closed and a complete opening position in which the door 20 b is in contact with the door 20 a of the adjacent compartment 30 a fig5 protection devices 40 a 40 b 40 c according to the invention are added respectively onto the outer surface of the doors 20 a 20 b and 20 c of compartments 30 a 30 b and 30 c the outer surface of a door of the door 20 b for example is the surface visible to the flight personnel it is also the surface intended to.