Valve swivel fitting for coolant systems

Claim 1

A SWIVEL FITTING FOR PIPING SYSTEM COMPRISING A FITTING BOTY HAVING FIRST AND SECOND BORES ETENDING INWARDLY RESPECTIVELY FROM FIRST AND SECOND END FACES OF THE BODY, SAID BORES HAVING AXES ANGULARLY DISPOSED TO EACH OTHER AND INTERSECTING SAID BROES EACH HAVING A HARD SURFACED BORE WALL, SAID BORES BEING INTERCONNECTED WITH EACH OTHER AND CONSTITUTING A FLUID CONNECTION BETWEEN SAID END FACES, A SWIVEL MEMBER PIVOTALLY CONNECTED AT EACH OF SAID END FACES, SAID SWIVEL MEMBERS EACH HAVING AN EXTERNAL INTERMEDIATE STEPPED SHOULDER IN CONFRONTING RELATIONSHIP TO HE RESPECTIVE END FACE, A STEM PORTION EXTENDING IN ONE DIRECTION FROM SAID STEPPED SHOULDER AND ROTATABLY RECEIVED, IN THE RESPECTIVE BORE WITH A CLOSE FIT THEREIN, AND A THREADED CONNECTION PORTION EXTENDING IN THE OPPOSITE DIRECTION FROM SAID STEPPED SHOULDER, SAID THREADED CONNECTION PORTION BEING ADAPTED FOR CONNECTION IN A PIPING SYSTEM, SADI STEM PORTION OF EACH SWIVEL MEMBER HAVING A HARDENED EXTERNAL SURACE IN CONFRONTING RELATIONSHIP TO THE RESPECTIVE BORE WALL, SAID SWIVEL MEMBERS EACH HAVING A FLUID PASSAGEWAY EXTENDING THEERETHROUGH AND COMMUNICATING WITH SAID BORES, MEANS FOR ESTABLISHING A DRAG FRICTION BETWEEN EACH STEM PORTION OF THE SWIVEL MEMBER AND THE FITTING BODY FOR SUBSTANTIALLY EQUALIZING THE STARTING AND SLIDING FRICTION UPON RELATIVE ROTATION BETWEEN THEM, SAID MEANS COMPRISING AT LEAST A FIRST, SECOND AND THIRD DRAG FRICTION MEANS INCLUDING A FIRST EXTERNAL GROOVE IN SAID STEM PORTION HAVING A HARD SURFACED BOTTOM WALL AND A SET SCREW THREADABLY EXTENDING THROUGH A PORTION OF SAID BODY SUBSTANTIALLY RADIALLY INTO THE RESPECTIVE BORE AND REGISTERING WITH SAID FIRST GROOVE, SAID SET SCREW HAVING AN INNER END SOFTER THAN AND BEARING AGAINST THE SURFACE OF SAID BOTTOM WALL TO PRODUCE A FIRST FRICTION DRAG, SAID SET SCREW HAVING AN OUTSIDE DIAMETER LESS THAN THE WIDTH OF THE GROOVE BOTTOM WALL, SAID SET SCREW FORCING SAID STEM END PORTION OF THE SWIVEL MEMBER LATERALLY WITHIN SAID BORE A DISTANCE SUFFICIENT TO POSITION THE HARD OUTSIDE SURFACE OF SAID STEM PORTION IN FRICTIONAL ENGAGEMENT WITH THE HARD-SURFACED BORE WALL AT A LOCATION DIRECLY OPPOSITE THE SET SCREW AND WITH GRADUALLY DIMINISHING FRICTIONAL ENGAGEENT THEREWITH CIRCUMFERENTIALLY ON EACH SIDE OF SAID LOCATION, WHEREBY TO PROVIDE SAID DRAG FRICTION MEANS, SAID THIRD DRAG FRICTION MEANS INCLUDING A SECOND EXTERNAL GROOVE IN SAID STEMPOTION AND A DEFORMABLE RESILIENT O-RING MOUNTED THEREIN, SAID SECOND GROOVE BEING LOCATED BETWEEN THE INNER END OF SAID STEM PORTION AND SAID FIRST GROOVE AND HAVING A BOTTOM WALL DEFINING A DEPTH WITH RESPECT TO SAID BORE WALL LESS THAN THE CROSS-SECTIONAL DIAMETER OF SAID O-RING THEREBY COMPRESSING THE O-RING BETWEEN THE BOTTOM FO THE SECOND GROOVE AND SAID BORE WALL OVER ITS ENTIRE CIRCUMFERENCE TO PRODUCE AN O-RING DRAG FRICTION UPON ROTATION OF SAID STEM PORTION IN SAID BORE, SAID O-RING DRAG FRICTION BEING OF THE GREATEST DIRECTLY OPPOSITE SAID SET SCREW WITH A GRADUAL DIMINISHING DISTRIBUTION OF THE FRICTION ON EACH SIDE THEREOF, SAID FIRST, SECOND AND THIRD DRAG FRICTION MEANS EACH PRODUCING A DIFFERENT TYPE OF DRAG AND ALL COMBINING TO SUBSTANTIALLY EQUALIZE THE STARTING AND SLIDING FRICTION.