Self-evacuating fluid sampling device

Claim 1

AN INSTRUMENT FOR DRAWING FLUID FROM THE HUMAN BODY, COMPRISING; AN INNER HOUSING AND AN OUTER HOUSING MEANS, SAID OUTER HOUSING SLIDABLY AND LONGITUDINALLY RECEIVING SAID INNER HOUSING AND OUTER HOUSING DEFINING A VARIABLE VOLUME CHAMBER RECEIVING A FLUID RECEPTACLE, SAID OUTER HOUSING HAVING AN ORIFICE COMMUNICATING WITH THE VARIABLE VOLUME CHAMBER SO THAT BY CLOSING SAID ORIFICE WHEN LONGITUDINAL MOVEMENT IS IMPARTED TO SAID OUTER HOUSING RELATIVE TO SAID INNER HOUSING A VACUUM IS CREATED WITHIN A RECEPTACLE PLACE WITHIN SAID INNER HOUSING, A FLUID RECEPTACLE HAVING AN OPENING AT ONE END RECEIVING A PLUG MEANS, THEREBY DEFINING A FIXED VOLUME CHAMBER WITHIN SAID VARIABLE VOLUME CHAMBER, PLUG MEANS FOR SAID FLUID RECEPTACLE MOUNTED IN SAID CHAMBER, SAID PLUG MEANS HAVING A PASSAWAY PROVIDING COMMUNICATION BETWEEN SAID RECEPTACLE AND A PORTION OF SAID VARIABLE VOLUME CHAMBER EXTERIOR OF SAID RECEPTACLE, A HOLLOW BORED NEEDLE MEANS FOR PUNCTURING THE SURFACE OF THE BODY AND MOUNTED IN SAID PLUG MEANS TO DEFINE A CONDUIT FOR SAID BODY FLUID TO SAID RECEPTACLE WHEN FLUID IS TO BE WITHDRAWN FROM THE BODY, WHEREBY LONGITUDINAL MOVEMENT OF SAID OUTER HOUSING RELATIVE TO SAID INNER HOUSING CREATES A VACUUM WITHIN SAID RECEPTACLE, ALLOWING BODY FLUID TO FLOW IN SAID HOLLOW BORED NEEDLE FROM THE BODY TO SAID RECEPTACLE.