Fluid container

Claim 1

A FOUNTAIN PEN COMPRISING A FLUID CONTAINER AND A WRITING UNIT ASSEMBLY MOUNTED FORWARDLY OF SAID FLUID CONTAINER, SAID FLUID CONTAINER HAVING A VENTED HOLLOW BODY PORTION AND A FILM-LIKE LAYER OF FLEXIBLE MATERIAL FORMING A FLACCID SACK ENGAGING THE INTERIOR SURFACE OF SAID BODY PORTION, THE INTERIOR SURFACE OF SAID SACK DEFINING A WRITING FLUID RESERVOIR, THE EXTERIOR SURFACE OF SAID SAC HAVING AN ADHESIVE QUALITY CAUSING IT TO RELEASABLY STICK TO THE INTERIOR SURFACE OF SAID BODY PORTION, SAID WRITING UNIT ASSEMBLY HAVING CONDUIT MEANS PROVIDING THE SOLE MEANS FOR FLUID PASSAGE FROM SAID WRITING FLUID RESERVOIR, SAID CONDUIT MEANS BEING SMALL ENOUGH IN CROSS-SECTION TO PREVENT PASSAGE OF AIR THERETHROUGH INTO SAID RESERVOIR WHILE WRITING FLUID IS DISPOSED WITHIN SAID CONDUIT MEANS, THE ADHERENT ATTACHMENT OF SAID SACK TO THE INTERIOR SURFACE OF SAID BODY PORTION BEING SUFFICIENT TO RESIST SEPARATION THEREOF AND THE CONSEQUENT FREE DISCHARGE OF WRITING FLUID THROUGH SAID CONDUIT MEANS UNDER THE INFLUENCE OF THE NORMAL WEIGHT OF THE FLUID IN THE RESERVOIR, AND SAID SACK BEING SEPARABLE FROM AND DISPLACEABLE WITHIN SAID BODY PORTION TO REDUCE THE VOLUMETRIC CAPACITY OF SAID RESERVOIR IN RESPONSE TO WITHDRAWAL OF WRITING FLUID FROM SAID CONDUIT BY CAPILLARY ACTION.