Abstract: Track (2) serves the stations of a line. A plurality of pallets (1) travel on track (2). The track and the pallets have guide elements (4, 54, 55) working with one another. The track is bordered by at least one marginal driving belt (7). The pallet (1) has on at least one of its sides an element for gripping the belt (7). The gripping element has at least one heavy element (8, 18, 20) resting by gravity on belt (7) so that a movement of this belt (7) relative to pallet (1) produces by friction a movement of this heavy element (8, 18, 20), triggering the engagement of the gripping element of pallet (1) with belt (7).

Abstract: The device includes, on the one hand, a main body with a base (2) and, on the other hand, screen-type dialogue means (7) which are placed in a flat casing connected to the main body (2) by support means, and means for maintaining the angular position (14) which can be regulated both for height and for angle. Said means for maintaining the angular position (14) are arranged coaxially to a pivoting axis XX' of a support arm (15) on the body (2) and include a free-wheel device mechanically located in series with a friction angular coupling device. The invention makes it considerably easier to adjust the position of the dialogue means.