Patent ID: 8621708

Claim:
A surface cleaning apparatus, comprising: a housing and a fluid delivery system mounted to the housing, the fluid delivery system comprising: a water supply tank for holding a supply of water; a cleaning solution supply tank for holding a supply of cleaning solution; a dispenser for distributing at least one of the water and cleaning solution from their respective supply tanks to a surface to be cleaned; a mixing manifold for selectively controlling the proportion of cleaning solution delivered to the dispenser, the mixing manifold comprising a conduit having: a first inlet in fluid communication with the first fluid supply tank for delivery of water to the conduit; a second inlet in fluid communication with the second fluid supply tank for delivery of cleaning solution to the conduit; a third inlet in fluid communication with the second fluid supply tank for delivery of cleaning solution to the conduit; and one outlet in fluid communication with the first, second, and third inlets through the conduit and coupled to the dispenser; a first valve selectively movable between an open position and closed position for controlling the flow of fluid to the second inlet and comprising a first orifice having a fixed size, wherein the cleaning solution flows through the first orifice at a first flow rate when the first valve is in the open position and no cleaning solution flows through the first orifice when the first valve is in the closed position; and a second valve selectively movable between an open position and closed position for controlling the flow of fluid to the third inlet and comprising a second orifice having a fixed size that is larger than the first orifice, wherein the cleaning solution flows through the second orifice at a second flow rate higher than the first flow rate when the second valve is in the open position and no cleaning solution flows through the first orifice when the first valve is in the closed position; whereby the various combinations of open/closed positions of the first and second valves provide four different, discrete mixing ratios of cleaning solution and water to the surface to be cleaned.