GB590320A - Improvements in or relating to apparatus for research on landing gears for aircraft - Google Patents

Abstract

590,320. Testing aircraft undercarriages. SOC. D'INVENTIONS AERONAUTIQUES ET MECHANIQUES, S.I.A.M. April 14, 1942, Nos. 4781 and 4782. Convention dates, April 11, 1941, and July 24, 1941. [Class 4] Apparatus for testing aircraft landing gears comprises a carriage resembling an aircraft fitted with the gear to be tested under taxying conditions, the gear being capable of various adjustments by the pilot during use and the carriage having means for varying the weight distribution. The machine illustrated is fitted with a tricycle undercarriage comprising two main wheels 3, 4 and a forward wheel 1. The carriage has a weight 27 movable by screw gear in the fore-and-aft direction, and a wing structure 7, carrying two engines and propellers 5, 6, and which is also adjustable in the fore- and-aft direction. If desired, the - distance between the engines may be varied. The forward wheel, Fig. 5, comprises a shockabsorbing strut 12 rotatable in a sleeve 18 connected by links 20 to a lever 22 pivoted on the airframe at 23, the top of the strut having a ball joint connection 24 with a projection on the lever 22. A jack 25 enables the angle of the strut to be varied and an electric motor 17 enables the trail of the wheel fork to be adjusted, the motor acting on the fork spindle through worm gear. The jack 25 may be replaced by a strut, the rear end of which is traversable along the fuselage by a screwed shaft. The upper end of the strut may have a cross-arm connected by jacks to a forwardly projecting bracket on the sleeve 18 to enable the landing wheel to be steered by hydraulic jacks. Alternatively, the oil in the jacks may be used to damp shimmy oscillations of the front wheel. In another form, the wheel fork swivels about an axis adjustable with respect to the axis of the main strut, the angle of the fork of the fork also being adjustable. Fig. 9 shows another form in which the main shockabsorber 96 has two additional shock-absorbers 103, one on each side of it. The angle of the castoring head 93 is adjustable by tilting it about the lower end of the castoring spindle. In another form, the last two adjustments are omitted. Fig. 7 shows a main wheel in which the axle 57 is mounted on parallel links 62, 63, means being provided for measuring the tension in the link 63 to indicate the load on the wheel. Load-measuring devices may be fitted to other parts of the structure.