Patent GB-822819-A (GB)
Title: Improvements in apparatus for transferring liquid from one aircraft to another in flight
Inventor: GOODLIFFE ARTHUR WALTER
IPC: B64D39/02
Filed: 1956-06-11
Abstract: 822,819. Transferring liquids between aircraft in flight. FLIGHT REFUELLING Ltd. June 11, 1957 [June 11, 1956], No. 18037/56. Class 4. Flight refuelling or other liquid transferring apparatus comprises a pod detachably securable to a parent aircraft, the pod including a tank, a reel carrying a hose terminating in a drogue and pipe coupling for connection to a pipe coupling on another aircraft, a pump for transferring liquid from the tank to the hose, a valve between the pump and hose, a wind motor providing power for the pump and a reel motor, and an electrical system controlling the reel motor, valve, and reel and including a detachable multi-channel connector adapted for connection to a complementary connector on the parent aircraft. Fig. 1 shows the pod which may be jettisonable, fitted with a mounting lug 12 and locating spigots 14, 16. The pod wall, with bulkheads 18, 20 forms the tank which contains the pump 24 and its inlet and outlet pipes 26, 28, the latter containing a venturi section 32 controlling a flow regulating valve 30. A variable pitch wind motor 62 which may be replaced by an electric motor for ground testing, is attached to a nose section 64 mounted on the pod by hinges 68, and drives the fuel pump. A valve 96 connects pipe 28 with the hose 76 on reel 74 through a rotary pipe joint 92. Trailing of the hose and drogue 80 is initiated by a spring 236 and by air flow through a duct in the pod containing a hydraulic fluid cooler, Fig. 4 (not shown). While pump 24 is working, but valve 96 is closed, over-heating is prevented by an outlet pipe from the pump which sprays fuel (or other liquid involved) against the sides of the tank, promoting circulation within the tank and loss of heat to the atmosphere, Fig. 3a (not shown), When valve 96 is closed, the hose is connected to the tank by a vent pipe 98. Fig. 5 shows a hydraulic control system. A pump 48 (see also Fig. 1) is driven by the wind motor, and draws fluid from a reservoir 54 with relief valve 162, pressurized through a pressure reducing valve 154 and manual pressure relief valve 164, by a compressed air bottle 156 chargeable through a non-return valve 158. The pump pressure main 104 is connected through a non-return valve 108, pressure relief valve 118 manually adjustable through a pilot valve 230, and a valve 120 controlled by a solenoid 182, to a hydraulic reel motor 82, the outlet of which is connectable either to the inlet through a throttling valve 124 and valve 120, or to the hydraulic return main 106 through a cooler 128 with a thermostatic by-pass valve 130. The pressure main 104 is also connected through non-return valves 108, 114 and pressure reducing valve 116 to a conduit 112 supplying an actuator 86 controlling a gear box 84 between the reel motor 82 and the reel drive 88, and controlled by a pilot valve 136 and solenoid 178. Conduit 112 also supplies reel brake actuators 142 and 218 through a valve 146 controlled by a solenoid 184, and the actuator 100 of the fuel valve 96, Fig. 1, controlled by valve 226 and solenoid 180. An accumulator 166 connected to conduit 112 is pressurized by the compressed air bottle 156 through a non return valve 170 and pressure reducing valve 168. Fig. 8 shows the electrical control system, connections between parts in the aircraft and parts in the pod being made through a multi-channel connector. A switch M on the aircraft control panel has three positions, in one of which, the " trail " position T, a relay T<SP>1</SP> is energized, closing contacts T, energizing relay 182 thus by-passing motor 82. Unwinding of the hose is initiated by spring 236 as described above, and continued by drag on the drogue. Solenoid 178 is de-energized, and actuator 86 selects a low reel speed /motor speed gear ratio. Contacts T<SP>2</SP> of relay T<SP>1</SP> energize solenoid 184, Fig. 8, which actuates valve 146, Fig. 5, to release the reel brake actuators 142, 218, unless the reel overspeed governor switch o energizes relay 0, Fig. 8, opening contacts 0<SP>1</SP>. A device for braking the reel when the hose is fully payed is provided as in Specification 727,065 [Group XXX]. On moving switch M to the " refuel position R relay T<SP>1</SP> is de-energized and a relay R<SP>1</SP> is energized. Solenoid 184 remains energized by contacts R<SP>2</SP> and the reel brakes are released as before, subject to overspeed braking. Relay 182 is de-energized, connecting motor 82 to the fluid pressure supply, and contacts R<SP>1</SP>, close, energizing solenoid 178, selecting the high gear position of gear box 84, thus reducing the " wind-in " torque of the motor on the reel. The pilot valve 230, Fig. 5, should be adjusted so that relief valve 118 operates to keep the hose taut when coupled to a following aircraft. Contacts R 3 , Fig. 8, close, and energize solenoid 180, which opens the fuel valve 96, Fig. 1, through actuator 100, Fig. 5, and valve 226. A switch #, relay F, and contacts F<SP>1</SP> are operated by the reel to prevent opening of the fuel valve until a predetermined length of hose is trailed. On moving switch M to the rewind position W, relays R<SP>1</SP> and T<SP>1</SP> are de-energized. Fuel flow is cut-off, the reel brakes are applied, and gear box 84 is in the low gear, high torque position. The reel motor 82 winds in the hose, free wheel devices permitting the winding in which the reel brakes prevent paying out. A green lamp on the aircraft control panel is energized by a reel switch g when the hose is at full trail. A red lamp 194 in the pod visible to the following aircraft, and a red repeater lamp on the aircraft control panel are energized by a reel switch r when the hose starts to trail, or when it is at full trail. An amber lamp 196 in the pod visible to the following aircraft and an amber repeater lamp on the aircraft control panel is energized by contacts R 1 , R 2  on selecting the refuel position of switch M. The red lamps may be extinguished when the amber lamps are energized. A switch J on the aircraft control panel operates a hose-jettisoning device as in Specification 766,084 [Group XXVIII]. The pod tank may be refilled from the parent aircraft tanks by operation of a switch P which controls relay P<SP>1</SP> contacts P 2  and solenoids 214, 216 acting on a valve in a feed pipe from the aircraft tanks to the pod, which pipe contains a releasable connector. " Tank full " and " tank empty " float operated switches 198, 200, the latter shown in Fig. 1 operate lights on the parent aircraft control panel. Suitable vents allow filling or emptying the pool tank on the ground, and the air space in the tank has a pressure relief valve, and is connected to the parent aircraft tank vent system through a detachable connector. Specifications 676,430 and 753,106 [Group XXX] also are referred to.