The phrase "spray pattern" refers to how liquid or particles spread out when sprayed from a container. It describes the shape, density, and direction of the spray. Full definition
That means you get a full spray pattern that gives you complete coverage from shoulder to shoulder. (geekwrapped.com)
The common rail injection system has also undergone further development: it has a maximum operating pressure of 2,000 bar and can therefore inject fuel in an extremely precise spray pattern. (topspeed.com)
That's achieved by precisely controlling the mixture motion and fuel injection spray pattern. (autoweek.com)