THE PRESENT INVENTION RELATES TO AN IMPROVED NEEDLELESS HYPODERMIC INJECTION DEVICE (10). ACCORDINGLY, THE NEEDLELESS HYPODERMIC INJECTION DEVICE (10) INCLUDES: (A) AN INJECTOR (12) HAVING A HOUSING (13) FORMED BY FIRST AND SECOND HOUSING SECTIONS (B) A SPRING INJECTOR MECHANISM (14) IN ASSOCIATED WITH A PISTON (16) DISPOSED WITHIN THE INJECTOR (12) (C) A TRIGGER (20) HAVING A STOPPER (22) AND IN ASSOCIATED WITH A RETURN SPRING (23) PIVOTALLY MOUNTED TO THE INJECTOR (12) (D) A SAFETY LOCK (30) SLIDABLY ATTACHED TO THE INJECTOR (12) TO PREVENT UNDESIRED RELEASE MOVEMENT OF THE TRIGGER (20) WHEREIN THE PISTON (16) IS IN ASSOCIATED WITH A COMPRESSION SPRING (15) AND IS CAPABLE TO PROVIDE TWO DIFFERENT SETTING OF SPRING LOADED FORCE FOR BOTH LOW AND HEIGHT DOSES INJECTION. THE MOST ILLUSTRATIVE DRAWING: FIG. 3B
