Methods and apparatus for ventilating carriages.

摘要

A ventilation control device (1) for a high-speed train carriage is operable in conjunction with a ventilating blower. A deflectable spring flap (2) is mounted to extend across the ventilation duct in the air flow path. When deflection of the flap (2) reaches a threshold level corresponding to possible passenger discomfort, the flap (2) operates a limit switch (4) positioned behind it. This activates a driving solenoid (5) to close a shutter (7) which shuts off the flow through the duct. A timer holds the shutter closed for a predetermined period, after which it is re-opened. Use of a microprocessor-controlled continuous sensor and damper can thereby be avoided, while cutting out very large pressure fluctuations. <IMAGE>