A portable object includes a case forming a housing in which is arranged a device requiring air to operate. The case includes at least a first opening. The portable object further includes a closure device provided with a valve system arranged to have a first stable, open position in which the orifice is open and allows air to pass through, and a second stable, closed position, in which the orifice is closed so that the portable object is impermeable to gases and to liquids. Switching from the open position to the closed position is automatic in case of immersion.

A portable object includes a case forming a housing in which is arranged a device requiring air to operate. The case includes at least a first opening. The portable object further includes a closure device provided with a valve system arranged to have a first stable, open position in which the orifice is open and allows air to pass through, and a second stable, closed position, in which the orifice is closed so that the portable object is impermeable to gases and to liquids. Switching from the open position to the closed position is automatic in case of immersion.

A waterproof valve includes a pivot, a valve comprising a sealing end and a floating end, the pivot is rotatably connected with the valve between the sealing end and the floating end, the sealing end is released to keep the valve open when the floating end is not contact with fluids, the sealing end is driven by the floating end to close the valve when the floating end is contact with fluids, to prevent or reduce the occurrence of short circuits caused by exposure to conductive fluids.

A waterproof valve includes a pivot, a valve comprising a sealing end and a floating end, the pivot is rotatably connected with the valve between the sealing end and the floating end, the sealing end is released to keep the valve open when the floating end is not contact with fluids, the sealing end is driven by the floating end to close the valve when the floating end is contact with fluids, to prevent or reduce the occurrence of short circuits caused by exposure to conductive fluids.

A fluidic control element comprising a housing in which a fluid space is formed makes provision that at least a first and a second flow channel open into said fluid space, at least one of the flow channels comprising a closable valve seat in the fluid space. A valve body which can be swiveled about an axle is able to be pivoted in the fluid space toward the valve seat. A drive system in the form of an electroactive polymer actuator is provided.

A fluidic control element comprising a housing in which a fluid space is formed makes provision that at least a first and a second flow channel open into said fluid space, at least one of the flow channels comprising a closable valve seat in the fluid space. A valve body which can be swiveled about an axle is able to be pivoted in the fluid space toward the valve seat. A drive system in the form of an electroactive polymer actuator is provided.

A vent for a motor vehicle transmission includes a housing attached to a bell housing of the transmission. A plate is mounted in the housing, and the plate has an open position to enable heat to dissipate from the interior of the bell housing through an opening of the housing and a closed position to prevent debris or water from entering through the opening of the housing into the interior of the bell housing. The vent is a passive vent with a biasing mechanism that moves the plate to the open position when an interior temperature of the bell housing reaches a predetermined temperature threshold and moves the plate to the closed position when the interior temperature of the bell housing falls below the predetermined temperature threshold.

A vent for a motor vehicle transmission includes a housing attached to a bell housing of the transmission. A plate is mounted in the housing, and the plate has an open position to enable heat to dissipate from the interior of the bell housing through an opening of the housing and a closed position to prevent debris or water from entering through the opening of the housing into the interior of the bell housing. The vent is a passive vent with a biasing mechanism that moves the plate to the open position when an interior temperature of the bell housing reaches a predetermined temperature threshold and moves the plate to the closed position when the interior temperature of the bell housing falls below the predetermined temperature threshold.

An electric generator for an aircraft includes a sealed casing, a rotating shaft, and a ventilation device, which has at least one orifice configured to place a chamber positioned inside the rotating shaft in communication with the exterior of the sealed casing. For at least one orifice, an inertia sealing system is configured to occupy an open state when the speed of rotation of the rotating shaft is below a given threshold, in which state the sealing system is spaced from the orifice, and a closed state when the speed of rotation of the rotating shaft is above the given threshold, in which state the sealing system seals the orifice.

An exhaust-gas turbocharger (1) having a turbine housing (2), which has a bypass duct (10) with a bypass opening (9); and having a control flap (3), which is mounted pivotably between a closed position and an open position in the turbine housing (2), the control flap (3), when in its closed position, resting on a bearing region (8) of a housing wall (11) which conducts exhaust gas and contains the bypass opening (9), wherein at least one flow imperfection (12A, 12B; 23A, 23B) is arranged in the turbine housing wall (11) in the bearing region (8) of the control flap (3) and/or in the control flap (3).