Patent ID: 8038413

Claim:
A pressure washer configured to output a pressurized fluid to a point of use, the pressure washer comprising: an engine having a throttle configured to move between an idle position that reduces the engine speed to an idle speed, and a normal speed position at which the engine runs at a speed greater than the idle speed; a pump having an inlet, and an outlet that discharges fluid, said pump powered by said engine and configured to pressurize the fluid; an unloader valve positioned to divide a flow path between the pump and the point of use into an upstream side that extends from the pump outlet to the unloader and a downstream side that extends from the unloader to the point of use, the unloader movable between a first position in which the discharged fluid flows to the point of use and a second position in which the discharged fluid flows to the inlet; a manifold positioned on the upstream side of the flow path to receive the fluid discharged from the pump outlet such that a manifold pressure is substantially equal to a pump discharge pressure at all times of operation; a pressure sensor configured to continuously detect the manifold pressure without flow passing through the sensor; an actuator including a piston and a spring, responsive to the detected manifold pressure, configured to move between a first position when the detected manifold pressure is a low pressure, and a second position when the detected manifold pressure is a high pressure; and a linkage connected between the actuator and the throttle, configured to move the throttle to the idle position when the actuator is in the first position in response to a sensed low pressure by the pressure sensor.