Control valve assembly

A power conversion system for a power machine, comprising:na pump configured to provide a source of pressurized hydraulic fluid;a control valve assembly coupled to the pump to receive the pressurized hydraulic fluid from the pump, the control valve assembly including:na first valve element having an unactuated position and first and second actuated positions, the first valve element configured to direct pressurized hydraulic fluid to and receive pressurized hydraulic fluid from an actuator when the first valve element is in the first and second actuated positions; anda second valve element downstream of and in series with the first valve element when the first valve element is in the unactuated position, the second valve element having first and second actuated positions; andwherein the first valve element is moveable between the unactuated position and the first and second actuated positions, and wherein the control valve assembly is configured to direct hydraulic fluid received from the actuator through the second actuated position to the second valve element, and direct hydraulic fluid received from the actuator through the first actuated position to bypass the second valve element.

A power conversion system for a power machine, comprising:na pump configured to provide a source of pressurized hydraulic fluid;a work actuator for controlling a work function; anda control valve assembly in communication with the pump to receive the pressurized hydraulic fluid, including:na first spool having an unactuated position and first and second actuated positions configured to direct pressurized hydraulic fluid to the work actuator and receive pressurized hydraulic fluid returned from the work actuator;a second spool downstream of and in series with the first spool when the first spool is in the unactuated position, the second spool having first and second actuated positions; andwherein the first spool is configured to direct hydraulic fluid returned from the work actuator through the second actuated position to the second spool and direct hydraulic fluid returned from the work actuator through the first actuated position to bypass the second spool.

A power machine having a frame, a lift arm pivotally coupled to the frame, and an implement carrier pivotally coupled to the lift arm, and further comprising:na power source;an operator input device configured to provide control signals; anda power conversion system coupled to and receiving power from the power source, the power conversion system including:na pump configured to provide a source of pressurized hydraulic fluid;a work actuator; andan open center control valve assembly in fluid communication with the pump and including first and second spools, the first spool configured to direct pressurized hydraulic fluid and receive pressurized hydraulic fluid from the work actuator in response to the control signals via first and second actuated positions, the first spool being configured to direct hydraulic fluid received from the work actuator available to the second spool via the second actuated position and to direct hydraulic fluid received from the first work actuator via the first actuated position to bypass the second spool;wherein the power machine further comprises at least one hydraulic line in communication with the second spool connectable to an external actuator and wherein the second spool is configured to direct pressurized hydraulic fluid to the at least one hydraulic line in response to the control signals.