US Patent 7255293 Hose-end sprayer assembly

A sprayer assembly for connection to a container of liquid chemical to be sprayed has a manually operable rotary valve mounted within the housing of the assembly and has a carrier liquid duct and a product duct opening into the liquid duct, the valve being selectively rotatable to an ON position in which the carrier liquid inlet passage is connected with the liquid product inlet opening, and the valve being selectively rotatable to an OFF position in which the carrier liquid passage is not connected with the liquid product inlet opening, the housing have a vent port, and an external vent control member mounted on the housing for movement by the valve to close the vent port in the OFF position and to open the vent port in the ON position.