Abstract:
A method of maintaining a roadway (2) during transfer of a load from a first location to a second location by a motorised vehicle (1) is described. The vehicle (1) may be a dumper truck and has a retractable blade (8) movable relative to the vehicle (1) between a retracted position (fig. 1) and a working position (fig. 2). The load is transferred in the vehicle (1) from the first location to the second location along the roadway (2), the blade (8) is moved to the working position after dumping the load and on the return journey the vehicle (1) acts as a grader to smooth undulations and ruts. The blade (8) is pivotally mounted and located between the front axle (5) and the rear axle (6, 7) and does not extend beyond the width of the vehicle. Unmetalled roadways on construction sites, quarries and mines may be maintained in good condition without the need to employ additional vehicles or hire separate grader vehicles.
Abstract:
A system and method configured to select a control configuration for a hydraulic drive assembly (206). The assembly (206) includes a controller (124) having at least one sensor and a processor (302). The controller (124) is configured to sense a feed pressure and a return pressure of a fluid within the hydraulic drive assembly (206) and a speed of a driven set of wheels (122) and a speed of an idle set of wheels (120). The driven set of wheels (120) are drivingly coupled to an engine (202), and the idle set of wheels (120) are drivingly coupled to the hydraulic drive assembly (206). The controller (124) is further configured to select a control configuration for the hydraulic drive assembly (206) based on a ratio between the feed pressure and the return pressure, and further based on a ratio between the speed of the driven set of wheels (122) and the speed of the idle set of wheels (120).
Abstract:
A load lock valve (72) for a hydraulic system (44) is disclosed. The load lock valve may have a block (63) with a first bore (88), and a body (90) disposed within the first bore. The body may have a second bore (82), and first and second first radial ports (96, 98) in fluid communication with the second bore. The body may also have a valve seat (100), and a poppet (74) disposed within the body. The poppet may have a nose end (102), a control end (104), a balance passage (80) extending from the control end toward the nose end and terminating short of the nose end, and a third radial port (106) in fluid communication with the balance passage. The load lock valve may further have spring (78) configured to bias the poppet toward the first opening. The control end of the poppet is fluidly communicated with the first radial port when a sealing surface at the nose end is against the valve seat.