Valve having small quantity flow passages

Claim 1

IN A VALVE HAVING A BODY WITH INLET AND OUTLET PASSAGES COMMUNICATING WITH A PLUG CHAMBER IN WHICH A PLUG HAVING A THROUGH PORT IS MOUNTED FOR ROTATION TO POSITION THE PLUG IN AND OUT OF REGISTRY WITH THE INLET AND OUTLET PASSAGES OF THE BODY, THE IMPROVEMENT COMPRISING, A SEAL OF DEFORMABLE MATERIAL AT THE END OF THE INLET PASSAGE ADJACENT THE PLUG CHAMBER, THE INLET PASSAGE HAVING A SEAT TO RECEIVE THE SEAL, THE SEAL BEING AN ANNULAR RING HAVING A CONCAVE FACE TO ENGAGE AND SEAL AGAINST THE ROTATABLE PLUG, AND MEANS FOR FORCING THE PLUG INTO SEALING ENGAGEMENT WITH THE SEAL AT SAID INLET PASSAGE END TO PREVENT FLOW FROM THE INLET PASSAGE TO THE PLUG PORT WHEN THE PLUG OCCUPIES A SELECTED OUT OF REGISTRY POSITION, SAID SEAL HAS A PLURALITY OF HOLES EXTENDING THERETHROUGH, OPENING TO THE SEAL SET AND THE CONCAVE FACE OF THE SEAL, AND ARRANGED IN A PATH RELATED TO THE CROSS-SECTIONAL SHAPE OF THE PLUG PORT TO DISPOSE DIFFERENT NUMBERS OF SAID HOLES IN REGISTRY WITH SAID PORT AT DIFFERENT ANGULAR POSITIONS OF THE PORT IN AN INTERMEDIATE ZONE OF THE RANGE OF MOVEMENT OF SAID PLUG, AND SAID PLUG BEING SHAPED TO DISPOSE SAID SEAL SO AS TO ADMIT SEEPAGE FLOW OF FLUID FROM SAID INLET PASSAGE BETWEEN SAID SEAT AND SEAL AND THROUGH SAID HOLES INTO SAID PLUG PORT AND THENCE TO SAID OUTLET PASSAGE WHEN SAID PLUG OCCUPIES SAID INTERMEDIATE ZONE TO PROVIDE CONTROLLED SMALL QUANTITY FLOW THROUGH SAID VALVE.