Precompression valve for trigger sprayer

A trigger sprayer comprising:

• a body having a cylinder therein;
• liquid inlet means in communication with said cylinder;
• an outlet waterway in communication with said cylinder;
• outlet nozzle means including a nozzle;
• a piston having an elongate axis, an inner end and an outer end and being received in said cylinder;
• a fluid path including at least a part of said cylinder and said waterway and extending between said piston and said outlet orifice;
• a trigger operatively coupled to said body and acting on said outer end of said piston;
• precompression valve means in said fluid path between said piston and said outlet orifice;
• said precompression valve means being operable to allow liquid in a first part of said fluid path to reach said outlet orifice only after a predetermined pressure is established in said cylinder and to stop liquid from reaching said outlet orifice when the pressure in said cylinder falls below said predetermined pressure;
• said precompression valve means comprising a valve seat in said fluid path, a spring valve element in said fluid path and retaining means in said fluid path for retaining said spring valve element against said valve seat, whereby, when pressure is built up in said first part of said fluid path upon movement of said piston into said cylinder, said spring valve element is caused to flex allowing liquid under pressure to escape past said spring valve element into a second part of said fluid path and out said outlet orifice in said nozzle;
• biasing means for biasing said piston away from said precompression valve means;
• and, said piston having, at said inner end thereof, a protrusion which extends axially, outwardly from said inner end a sufficient distance to engage and deform slightly, at least upon the initial movements of the piston, said spring valve element upon squeezing said trigger to a fully squeezed in position.