Automatic self-protecting hypodermic needle assembly

An automatic self-protecting hypodermic needle assembly comprising:

• a hypodermic syringe including a housing, a moveable plunger in said housing, a medicant chamber formed between said housing and said plunger, and a hollow needle extending from said housing, said hollow needle in communication with said medicant chamber and having a tip at a distal end of said needle;
• a needle guard assembly attached to said syringe housing, said needle guard assembly including:
• a guard housing disposed adjacent said needle;
• protective cap means removeably attached to said guard housing, said protective cap means having an aperture therethrough, said needle extending through said aperture;
• said guard housing having propellant means disposed therein in communication with said protective cap means, said propellant means includes a first chemical propellant means which, when activated, expands and applies a pressure to said protective cap means;
• activating means in selective communication with said propellant means to selectively activate said first chemical propellant when said activating means comes into contact with said first chemical propellant means;
• and
• control means in communication with said activating means and actuated by depression of said plunger to activate said first chemical propellant means and produce a pressure which dislodges said protective cap means from said guard housing and moves said protective cap means along the length of said needle until said protective cap means engages the tip of said needle and said needle tip becomes embedded in said protective cap means.