Abstract: Pneumatic device for applying the upper end of a pantograph, termed a horned slipper holder, against the overhead contact wire with an appropriate pressure, characterized in that the pneumatic cushion (4) has, inside the leaktight enclosure (28) which is formed by the two cover plates (21, 22) and the rubber bellows (23), a connecting rod (32) exerting on the movable cover plate (22) a translational displacement which is reproducible as a function of the air pressure prevailing in the enclosure (28). This translational movement is transformed, via the two arms (34) acting on two ropes (38) and on two cams (39), into a rotation of the shaft (7) of the lower arm (8) of the pantograph.