Hydro-pneumatic positioner for removal/or installation of wing engines of aircrafts and the like

A hydro-pneumatic positioner for a wheeled trailer provided with a cradle for supporting or receiving a wing engine of an aircraft, to be used for the installation or removal of the engine of an aircraft, said positioner comprising:

• a basic structure underneath of which are fixed four air-cushion devices, and on which are mounted four hydraulic cylinders mounted on the corners thereof, said four cylinders including a front pair of cylinders and rear hydraulic cylinders, each being provided with a hoisting chain;
• and a frame suspended from said chains and adapted to receive and lift the trailer together with the cradle carrying the engine or without engine between a lowered and an elevated position, said lifting cylinders being designed to perform vertical operative strokes, the front pair of said cylinders being fixed to the basic structure, while the rear hydraulic cylinders are mounted on said structure so as to be able to be simultaneously brought and held in their vertical position, or be simultaneously tilted until they come into contact with the ground in substantial prosecution of the basic structure and vice versa, by a third pair of hydraulic cylinders;
• the central and rear portions of the positioner having a maximum width less than the inner facing surfaces of the wheels of the trailer, while the height of said central and rear portions of the positioner in the lowered position is less than the level of the distance between any lowermost part of the trailer placed between the wheels and the ground;
• said basic structure housing and/or supporting:
• a pneumatic circuitry and means for connecting said circuitry to an external source of compressed air, and for supplying said compressed air to the air cushion devices, as well as to an air driven motor driving a main oil rotary pump;
• an oil circuitry for supplying the oil to all the hydraulic cylinders, as well as to control, protection and adjusting means and to said main pump as well as to hand pumps for supplying the oil to the hydraulic cylinders and alternatively to the main pump.