Abstract: Disclosed is a rolling unit for a test rig for testing an automatic underground train, including: two rolling belts, each one provided for a wheel of the train to roll thereon, the wheels driving the movement of the belts; and a rotary inertial body; each belt including: a pinion that is rotatably connected to the inertial body; two rollers; and a grooved rolling surface mounted on the rollers, meshed with the pinion, and forming a rolling area for a respective wheel between the rollers.

Abstract: The invention relates to a rolling unit (8) for a test rig (1) for testing an automatic underground train, comprising: two rolling belts (27), each one provided for a wheel (6) of the train to roll thereon, the wheels driving the movement of the belts; and a rotary inertial body (28); each belt comprising: a pinion (31) that is rotatably connected to the inertial body; two rollers (33); and a grooved rolling surface (32) mounted on the rollers, meshed with the pinion, and forming a rolling area (34) for a respective wheel between the rollers.

Abstract: A negative pressure installation for treating charged fluids, comprising at least one pipe (2) conveying said charged fluids, a tank (4) for holding the solid and liquid matter, a conduit (5) for evacuation of the gases from the tank (4) to a purifier (6) connected on the one hand to the exterior air by a tube (7) and on the other hand to the pipe (2) by a recycling pipe (10).Application in sanitary installations of aircraft.

Abstract: A fluid filter clogging display comprising a case of non-magnetic material divided into an upper housing, at atmospheric pressure, and a lower housing by an impermeable membrane, a piston movable in the lower housing and dividing the lower housing into a high chamber and a low chamber, the high chamber communicating with an upstream side of a filter and the lower chamber communicating with a downstream side of the filter, a magnet mounted on the piston and disposed in the high chamber, a magnetizable detector in the upper housing for sensing a position of the magnet, a return spring located in said low chamber biasing the piston towards the impermeable membrane and a helical spring made of a shape memory alloy (SMA) which is stiff above a specific temperature and compliant below such a temperature and mounted such that the SMA spring joins the magnet to the piston depending upon the temperature thereof.