Ventilation system especially for stable has a hinged flap with counterweight opened by negative pressure and linked to a slider for secure closure

摘要

A ventilation system, e.g. for a stable or for any enclosed area (7) has a ventilation flap (1) hinged about a support axis (3) and swinging between the closed (1a) and open (1b) settings, backed by a counterweight (5) and pulley system. The flap is opened by the pressure difference across the flap following ventilation of the confined space by a fan etc. A slider (9) is linked to the system to provide additional security in the closed setting, e.g. caused by external wind conditions. The ventilation system is fully automatic and requires no power feed.