GB554162A - Improvements in or relating to steering arrangements for vehicles having crawler driving tracks - Google Patents

Abstract

554,162. Driving and steering endless-track vehicles. CLARKE, R. E., and NEAL & CO., Ltd., R. H. Dec. 19, 1941, No. 16404. [Class 79 (ii)] [Also in Group XXXIV] An endless-track crane or other turntable machine or vehicle is driven and steered by means of an epicyclic gear and clutch unit provided in the drive to each track and controlled by brakes so that the speed of each track may be independently varied between a maximum and zero, a single steering control member being provided movement of which in one direction affects the brakes on one gear unit while movement in the other direction affects only the other unit. In the construction shown a transverse shaft 14 is driven through bevel gearing 12 from a vertical shaft 11 co-axial with the turntable pivot. Each end of the transverse shaft carries a sun pinion 15 of an epicyclic clutch comprising a toothed annulus 24 controlled by a brake 23a and planet pinions 20 mounted on a carrier 18 fixed to a stub shaft 16 driving the corresponding track 26 through a spur gear train 25. Each planet carrier is provided with a brake 18a. Normally both brakes 18a are free and both brakes 23a are applied by springs 51 so that both tracks are driven as the same rate through the epicyclic gears. To steer the vehicle the brake 23a on one side is wholly or partially released and the corresponding brake 18a is applied. To stop the vehicle both brakes 18a are applied and both brakes 23a are released. A steering wheel or other device in the superstructure (not shown) can impart a sliding movement to a sleeve 28 on the vertical shaft 11, this sleeve acting through a bellcrank lever 30, 33 and link 34 on a lever 35, 38 connected by links 39 to T-levers 43 one for each side of the vehicle. The T-levers are connected by rods 47, 48 to the brakes 23a, 18a and are normally kept by springs 51 in the position shown in Fig. 3 in which the brakes 23a are applied. When the steering wheel is rotated the lever 35, 38 is rocked and pushed one rod 39 and pulls the other. The pushed rod has no effect on its brakes, due to a pin-and-slot connection 41, 42 but the other rod rocks its lever 43 and releases its brake 23a and applies the brake 18a. To apply both brakes 18a simultaneously a vertical rod 54 passing through the shaft 11 is operated and acts on both levers 43 through a lever 55, shaft 61, arms 63, rods 64, and pin-and-slot connections 56, 66. The two sets of pin-and-slot connections allow operation of the brakes either by the steering wheel on the rod 54 'independently of each other. The brakes comprixe shoes 23a, 23b connected at one end by a bolt 23c and a spring 23d, and anchored by a link 23f and springs 23e. The free ends of the brake shoes are pivoted to toggle links 49, 50 connected at their other ends to the horizontally-moving operating rods 47 or 48.