GB893013A - Improvements relating to multi-wheel aircraft undercarriages - Google Patents

Abstract

893,013. Aircraft undercarriages. DOWTY ROTOL Ltd. Dec. 2, 1959 [Dec. 2, 1958], No. 38888/58. Class 4. In a bogie type undercarriage in which the bogie frame is pivotally mounted on the lower end of the leg and is biased to ensure that the rear wheels only are spun up at touch-down, the bogie frame is connected to the leg by a spring loaded biasing element having sufficient free travel to ensure that initial pivoting of the beam during landing takes place without contraction of the leg and the final pivotal movement of the beam, to bring all wheels into contact with the ground, is accompanied by the initial compression of the leg. The elements 5, 8 of the leg are connected by a scissors linkage 9, 11, the link 11 being connected at 12 to the leg and extended by an arm 21 to provide a pivotal connection 23 for a telescopic link 22 normally extended by a compression spring 29, and attached at 24 to the bogie beam 14. Interengaging faces 27, 28 on the parts of the link limit its extension. In operation, and upon touch-down, wheel 19 engages the ground first and the beam 14 rocks about pivot 15 until link 22 is fully compressed. Then further rocking of the beam to bring wheels 18 into contact with the ground will be accompanied by initial compression of the leg, thereby ensuring that the wheels 18 are not brought into contact with the ground at twice the velocity of descent of the aircraft. It is stated that the link shown may be replaced by a tensioned link connected between the beam and an extension of scissors link 9.