GB1414042A - Aircraft landing gear hydrostatic control arrangement - Google Patents

Abstract

1414042 Aircraft undercarriages MESSIER-HISPANO 6 March 1973 [7 March 1972] 10734/73 Heading B7G [Also in Division F2] An aircraft landing gear hydrostatic control arrangement comprises an hydraulic pump and a double-acting distribution valve including a slidable valve member 5, Fig. 1, movable between opposite ends and biased to a neutral position shown, an inlet port 11 receiving hydraulic fluid from the pump, transfer ports 23, 29, 35 and 41 connected to various components of the undercarriage operating system, and two exhaust ports 15, 19 connected to a reservoir. Means 27 and 33 for unlocking the undercarriage in its raised and lowered positions are exhausted through the port 15, whereas the opposite ends 39, 45 of the raising and lowering jacks are exhausted through the other port 19. Thus hydraulic pulses set up in the lines connected to the jacks at touchdown when the slide valve is in its neutral position, are isolated by the reservoir from the lines connected to the locking means, thereby avoiding accidental unlocking. The slide valve may be positively actuated by way of lever 9, or indirectly by way of electrically actuated pilot valves (109, 209), Fig. 2 (not shown), which supply actuating fluid to the appropriate end of the slide valve and exhaust through the port 15.