AN HYDRAULIC WHEEL STEERING SYSTEM FOR A TANDEM ROAD ROLLER

摘要

1,207,119. Steering road rollers. ADAMOVSKE STROJIRNY NARODNI PODNIK. 22 Aug., 1969 [17 Oct., 1968], No. 41902/69. Heading B7H. An hydraulic steering system for a tandem road roller having front and rear rollers controlled by the same system comprises a slide valve 61 shiftable by a hand control lever 62 to either one of two positions in one of which a steering wheel 41 through a proportioner 4 controls the movement of the front roller and in the other position the same steering wheel through the proportioner controls the rear roller. For this purpose fluid from a reservoir 51 is pumped through a conduit 8 to the proportioner 4 there being a return conduit 9 from the proportioner and a safety valve 10 coupled between the two conduits 8, 9. With the slide valve 61 in the position illustrated fluid from the proportioner 4 passes into chambers 11, 11SP1/SP which communicate with chambers 12, 12SP1/SP coupled to a piston and cylinder 22, 2 controlling one of the rollers. Simultaneously the conduits and chambers 13, 13SP1/SP coupled to the piston and cylinder 32, 3 controlling the other roller are closed and that roller maintained in its previously set position. Consequently having adjusted one roller by the steering wheel 41 the operation of the slide valve 61 causes the one roller to be maintained in position and allows the other roller to be controlled by the same steering wheel.