Patent GB-303816-A (GB)
Title: Improvements relating to internally sprung wheels and the like
IPC: B60G15/02
Filed: 1927-10-10
Abstract: 303,816. Dowty, G. H. Oct. 10, 1927. Fluid - pressure; blocks and shoes acting on drums; compensating for wear.- A wheel, particularly for use on aircraft, comprises an outer part mounted on a non-rotary inner part through which the axle passes with freedom for vertical displacements, resilient shock - absorbing and brake devices fitted to the inner part being arranged within the side limits of the wheel. In the construction shown, the rim 1 is carried by discs 2 mounted through ball-bearings on the inner non-rotary part 5 which is slotted at 6 for the passage of the axle 7. An axle sleeve 10 is formed with a yoke 12 having side-bars 13 guided between plates 19 fixed to the part 5 and connected at their upper ends by a beam 14. Helical springs 25 (or rubber buffers &c.) are mounted on tubes 22 which are fixed at their lower ends to lugs 24 on the plates 19 and are guided through holes in the beam 14. Fig. 2 shows an additional shock-absorber in the form of an oleo-gear. The bars 13 are connected to an oil-feed cup 27 mounted on the upper end of a tube 28 the lower end of which is formed as an apertured piston 29 sliding in the tube 30. The latter is mounted on the brake-cylinders 32 which are fixed to the part 5 by plates 20. The effective opening of the pistonaperture may be varied by the adjustment of a tapered needle 31. For braking the outer wheel part, brake-shoes 33, connected to the plates 20 on the non-rotary part 5 by pivoted links 35 and normally pulled off by springs 37, are actuated by plungers 39a in cylinders 32 into which oil is forced by a pump 41. The inward movement of the shoes is limited by the abutment of the links 35 with adjustable cams 39, and the abutment of the lower ends of the shoes with the plungers 39<a>. The pump 41 is actuated by a rocker-arm 42 pivoted on the plates 20 and operated by a cam-track 44 on the outer wheel-part. The cam 44 wipes a roller 45, Fig. 5, on an arm 46 fixed to the spindle 43 of the rocker-arm 42 to give the outward (suction) stroke to the pump, the return (operative) stroke being effected by a spring 50, Fig. 7. behind the pump-piston 48. Figs. 7 and 9 show the means for controlling the brake-pressure. Oil is supplied from an inlet 51, through a non- return valve 53, to the pump cylinder 47 and discharged through a non-return valve 54 to a chamber 56 having an outlet 52 leading to the brake-operating cylinders 32. A valve 57 between the inlet-chamber 55 and the pressure-chamber 56 is normally held to its seat by a spring 60, the load on which can be varied by a pivoted arm 62. The position of the arm 62 is adjusted by means of a cam 65. To prevent relative vertical movement between the wheel parts affecting the brake-device, the operating-arm 68 on the spindle 66 of the cam 65 is connected by a link 75, Fig. 6, to a bar 73 which is pivoted through parallel links 74 to the non-rotary wheel part 5. The angular adjustment of the arm 68, to vary the load on the relief-valve 57, is effected by a manually-controlled pivoted arm 71 which is fitted with a cam or roller 72 to co-operate with the bar 73.