| 摘要 |
A control pattern selection arrangement for two control joysticks or levers 34,36 hydraulically connected to boom and crowd hydraulic cylinders of a backhoe (fig 1) has an electrically operated valve 220 operated by an electric control switch 39 in the cab (fig 2). The levers 34,36 each operate four two-position pilot valves 40,42 for directional control spools 208,212. Changing the switch state actuates the valve 220 to modify the hydraulic connections to reverse the correspondence between the control levers and the boom and crowd functions for selecting a backhoe pattern or an excavator pattern. The valve 220 can include two two-position four way solenoid valves 260,262. |
