Safety against rearming for fire extinguishing heads

摘要

The fire extinguisher has a reservoir (2) and a pressurised gas cartridge (11) for discharging the extinguishing agent through the head (1). A pressure lever (6) acts on a percussion element (9) when released from a control ring (23). The percussion element is immobilised in the head by a locking pin (26) in a hole (21). The pin is fixed in place by the control ring. The outer end of the pin allows the condition of the extinguisher to be seen. The inner end of the locking pin has a conical tip which engages with a triangular-section recess in the percussion element. Its central section has an annular recess to receive the ends of two rods (24) connected to the control ring. Once the control ring has been removed the lever can be depressed to actuate the percussion element, pushing out the locking pin so that it indicates that the extinguisher has been used.