GB581333A - Apparatus for damping swivelling oscillations in caster wheels - Google Patents

Abstract

581,333. Vehicle castor wheels; dashpots. BISHOP, A. E. J. Aug. 17, 1943, No. 13336. Convention date, July 29, 1942. [Classes 108 (ii) and 108 (iii)] Also in Group XXXIII] Swivelling oscillations of a castor wheel, such as a landing wheel of an aircraft undercarriage, are damped by a rotary dashpot on one of the relatively movable elements and comprising a radial arm with an open-ended slot which is engageable by a pin on the other element. The invention is shown as applied to an aircraft landing wheel 12 carried by a telescopic shock absorber leg 14, 15, the movable members being provided with collars 23, 18, connected by pivotal links 22, 20, the collar 18 being integral with the recoil cylinder 15. A bracket 16 on the fork 13 of the wheel stock 14 carries the rotary dashpot 17, of which the open-ended slot 35 in the radial arm 34 is engageable by a downwardly projecting pin 25 carried by the collar 23. The dashpot comprises a rotor 29 with diametral vanes 28, and with upper and lower ports 32, 32a, respectively, the ports being connected by a vertical axial duct 32b fitted with an adjustable control valve. The dashpot is effective only during the period in which the pin 25 is in contact with the arm 34, i.e., for a wheel movement of approximately 30 degrees on either side of the in-line position. Movement of the wheel is limited to 180 degrees in either direction by one of a pair of stops 38 on the dashpot cylinder cover and a stop 42 on the collar 23, which engage recesses 37 in the sides of the arm 34. Modifications are described in which the dashpot is carried by the bearing and the pin by the wheel stock.