Projectile hypodermic syringes

Claim 1

A PROJECTILE ADAPTED TO INJECT LIQUID MEDICINES, DRUGS AND THE LIKE INTO ANIMALS, COMPRISING A HOLLOW BODY, A PISTON OF RESILIENT MATERIAL WITHIN SAID BODY CAPABLE OF AXIAL MOVEMENT THEREIN AND DIVIDING THE BODY INTO ANTERIOR AND POSTERIOR PORTIONS, CLOSURE MEANS FOR THE END OF SAID ANTERIOR PORTION PROVIDED WITH A BORE EXTENDING AXIALLY THEREOF, A HOLLOW NEEDLE POSITIONED IN SAID BORE FOR AXIAL MOVEMENT THEREIN, VALVE MEANS CLOSING SAID BORE FOR PREVENTING COMMUNICATION BETWEEN THE ANTERIOR PORTION AND THE INTERIOR OF SAID NEEDLE, SAID ANTERIOR PORTION BEING ADAPTED TO BE FILLED WITH THE LIQUID MEDICINE, ACTUATING MEANS WITHIN SAID POSTERIOR PORTION NORMALLY URGING SAID PISTON IN THE DIRECTION OF SAID CLOSURE MEANS AND MAINTAINING SAID ANTERIOR PORTION UNDER PRESSURE, SAID VALVE MEANS INCLUDING TWO CO-ACTING COMPONENTS, ONE OF SAID COMPONENTS BEING PROVIDED AT THE REAR END OF SAID BORE AND THE OTHER ADJACENT THE REAR END OF SAID NEEDLE COOPERABLE WITH SAID ONE COMPONENT FOR CLOSING SAID VALVE MEANS WHEN THE NEEDLE IS MOVED REARWARDLY RESPECTING THE BODY AND FOR OPENING THE VALVE MEANS WHEN THE NEEDLE IS MOVED FORWARD EFFECTIVE IMMEDIATELY SUBSEQUENT TO THE PENETRATION OF THE NEEDLE INTO THE ANIMAL BY THE RESIDUAL MOMENTUM OF THE NEEDLE CAUSING THE NEEDLE TO BE DISPLACED AXIALLY AND FOWARDLY OF THE BORE SO THAT THE ACTUATING MEANS FORCES THE PISTON TOWARDS THE CLOSURE THEREBY EXPELLING THE CONTENTS OF THE ANTERIOR PORTION THROUGH THE HOLLOW NEEDLE.