US Patent 7614412 Washer fluid spraying apparatus

In the present washer fluid spraying apparatus, when the amount of the remaining washer fluid in the tank is reduced, the buoyant force of the float does not have an effect to the valve member, and therefore the cross-sectional area of the flow passage of the valve member is reduced. Consequently spraying amount is limited compared to a case where there is a plenty of amount of remaining washer fluid. Therefore, compared to the structure that controls the washer pump driving status by detecting the remaining amount by a sensor, the driver of the vehicle can know that the amount of the remaining washer fluid in the tank is reduced while limiting the manufacturing costs.