US Patent 7470178 Air-conditioner for vehicle

A vehicle air-conditioner includes an airflow regulator disposed in a duct for regulating a rate of flow of temperature-controlled air to be discharged from an air outlet of the duct. The airflow regulator is formed by a plurality of hollow frustoconical members placed one over another in a nested condition. Each of the frustoconical members is open at a small end and a large end thereof and has at least one opening formed in a sidewall thereof. The frustoconical members are rotatable relative to one another about a common central axis thereof.