Double action trigger sprayer

A continuous action trigger sprayer for spraying liquid material therefrom, which comprises:

• a) a housing having means for connection to a container and having a liquid chamber aligned with an operation cylinder;
• b) a pumping element located in said operation cylinder and being driven to reciprocate in horizontal forward and rearward strokes to dispense liquid from said liquid chamber, said pumping element having a predetermined shape, volume and displacement and having a first position and a second position within said operation cylinder, said first position resulting from forward movement and establishing a minimum portion of volume of said pumping element within said liquid chamber and permitting a predetermined maximum available volume within said liquid chamber for liquid material, said second position resulting from rearward movement and establishing a maximum portion of volume of said pumping element within said liquid chamber and permitting a predetermined minimum available volume within said liquid chamber for liquid material due to volume displacement by said pumping element, and said pumping element including thereon a valve seat, a one way valve and a pumping rod such that said valve seat, said one way valve and said pumping rod move together with said pumping element when said pumping element is moved, said one way valve permitting liquid material to pass therethrough in a relative direction toward a spray nozzle, but not toward said liquid chamber, both said valve seat and said one way valve being located on a rearward portion of said pumping element such that said one way valve does not contact the wall of said operation cylinder, said spray nozzle being located on said housing and being connected to a liquid conducting means which allows liquid to flow from said pumping element to said spray nozzle, said pumping rod being located on a forward portion of said pumping element;
• and
• c) a relief valve connected to a trigger and having a seat with an opening therethrough and a relief passage to bleed liquid back to the container and to allow atmospheric air to be drawn in through said spray nozzle at the end of the rearward movement of said pumping element whereby said spray nozzle is cleared of liquid, said relief valve seat cooperating with said pumping element to close said opening through said seat when said pumping element is in its forward position, said trigger being located on an upper surface of said body and having a first position and a second position corresponding to said pumping element first position and second position;
• such that when said trigger is reciprocated to prime and when said trigger and therefore said pumping element is moved from said first position to said second position, liquid material passes through said one way valve and seat and at least a portion thereof passes successively through said liquid conducting means and said spray nozzle, and when said trigger and therefore said pumping element is then returned to said first position, liquid material is sucked upwardly from said container and liquid material in the area forward the closed valve exits through said liquid conduction means and said spray nozzle, thereby creating a continuous action spray on forward and rearward strokes of said trigger.