Patent ID: 7708082

Claim:
A fire fighting apparatus comprising: (a) a tapered bucket capable of being suspended from an aircraft, the bucket having a bucket wall, an open upper end to enable the bucket to be filled with a fire retardant and a bucket base comprising a valve having at least one leaflet capable of flexing about a substantially central hinging region; and (b) an actuator operable from the aircraft, the actuator including a hydraulic cylinder arrangement for flexing the at least one leaflet about the hinging region between a closed position wherein a periphery of the at least one leaflet makes a sealing contact with the bucket wall and an open position wherein a portion of the at least one leaflet extends upwardly from the hinging region permitting a volume of fire retardant to be discharged through a gap between the at least one leaftlet and the bucket wall wherein the hydraulic cylinder arrangement includes: a weight bearing cylinder operatively connected to the bucket wall for supporting the weight of the bucket; a valve opening cylinder operatively connected to the bucket base for flexing the at least one leaflet, the valve opening cylinder in hydraulic communication with the weight bearing cylinder; a recharge cylinder in hydraulic communication with the weight bearing cylinder and valve cylinder for recharging the weight bearing cylinder wherein the cylinder is recharged in response to the weight of fire retardant acting on the at least one leaflet to close the at least one leaflet and discharged in response to un-weighting the tapered bucket; a first hydraulic valve in hydraulic communication between the valve opening cylinder and the recharge cylinder; and a second hydraulic valve in hydraulic communication between the first hydraulic valve and the recharge cylinder; and, a check valve in hydraulic communication between the first and second hydraulic valves and the weight bearing cylinder; and wherein i) when the tapered bucket is weighted, opening the first hydraulic valve and closing the second hydraulic valve opens the at least one leaflet; ii) when the tapered bucket is weighted, closing the first hydraulic valve and opening the second hydraulic valve closes the at least one leaflet and recharges the recharge cylinders; and iii) when the tapered bucket is un-weighed, hydraulic fluid flows from the recharge cylinder through the check valve to the weight bearing cylinder to recharge the weight bearing cylinder.