GB850124A - Improvements relating to fluid-pressure reciprocatory motors - Google Patents

Abstract

850,124. Controlling aircraft. SHORT BROS. & HARLAND Ltd. May 4, 1959 [May 5, 1958], No. 14370/58. Class 4. [Also in Group XXIX] A hydraulic motor for tilting the jet engines of a vertical take-off aircraft comprises a differential piston 11, Fig. 1, which is slidable in a cylinder 10 and linked to an output member, a main pressure fluid supply 15 connected to each side of the piston, a control valve 17, 18 interposed between the supply and the side of the piston having the greater effective area to couple that side of the piston to the supply or to an exhaust 19, means 28 for connecting an emergency supply 27 to the cylinder, and fluidpressure operated stop means 25 automatically effective where the cylinder is connected to the emergency supply to limit the movement of the piston in one direction from an intermediate position in its stroke. The main supply 15 is connected by a shuttle valve 13 to one end A of the cylinder and by the valve 17 and a pipe 16 to the other end B of the cylinder, the pipe 16 also being connected by the valve 18 to the exhaust 19. Operation of the valves 17, 18 by the pilot connects the end B of the cylinder to the supply or exhaust to tilt the engines to assist acceleration or deceleration during the transition from vertical to forward flight or vice versa. The emergency supply 27 is connected by the valve 28 to the shuttle valve 13 which, depending on which is at the higher pressure, connects the supply 15 or emergency supply 27 to the end A of the cylinder to move the piston to the left. The emergency supply is also connected by the valve 28 to a piston 30 which opens a valve 29 to connect the end B of the cylinder 10 to exhaust 19 and to a cylinder 20, the piston 22 of which moves a rod 23 to the right to radially displace segmented stops 25 in a tube 24 in the cylinder 10 to limit the movement of the piston to the left and tilt the engine rearwardly to a position 5 degrees from the vertical if the aircraft is decelerating. If the aircraft is accelerating with the piston 11 in a position to the left of the stops 25 when the emergency supply is connected to the cylinder, the piston will move to its fully contracted position (the stops 25 not being effective) and the engines positioned to give increased acceleration. In an alternative embodiment, the hollow rod 34, Fig. 3 in the cylinder 10 has a normally closed valve 33 at one end and a normally open valve 35 at the other. When the emergency supply 27 is connected to the cylinder to move the piston 11 to the left, the valve 33 is opened and the shuttle valve 13 is closed to prevent discharge from the cylinder through the normal lines. Liquid in the end B then passes through a transfer port 36 to the interior of the hollow piston rod 12 and closes the valve 35. Further movement of the piston rod to the left closes the transfer port 36 to provide a hydraulic lock which prevents further movement of the piston.