Hypodermic syringe with protective holder

Claim 1

A hypodermic syringe of the type used to inject liquid, comprising: a) a barrel for receiving liquid; b) a hollow needle mounted in a needle support at one end of the barrel, said needle cooperating with said barrel to allow passage of liquid from said barrel through said needle; c) a plunger supported in said barrel by a rubber sealing ring, said rubber sealing ring forming a liquid-tight seal with said barrel and allowing slidable, reciprocal movement of said plunger within said barrel; d) means for locking said plunger to said needle support when said plunger is displaced substantially fully into said barrel; e) a protective holder dimensioned to slidably receive said barrel where said barrel is slidably movable in said holder from an initial retracted position where the needle is within the holder and said barrel is full of liquid to an extended position where the needle projects from the holder for injecting the liquid and then to a final retracted position where the liquid has been expelled from the barrel and the needle is within the holder, said holder being open at one end to receive said barrel and the opposite end thereof having portions defining an aperture through which the needle can pass when said cylinder is slidably moved in the holder; and f) a rubber plug covering the aperture to occlude the needle and to isolate the needle from the user in both the initial retracted and final retracted positions.