Floating port plate construction

Claim 1

IN A POSITIVE DISPLACEMENT FLUID HANDLING DEVICE:A HOUSING MEMBER HAVING AN INTERNAL CHAMBER WITH OPPOSITE END WALLS PROVIDING AN AXIS OF ROTATION EXTENDING THROUGH SAID CHAMBER, A ROTOR MEMBER IN SAID CHAMBER, MEANS CARRIED BY SAID HOUSING AND DRIVABLY CONNECTED WITH THE ROTOR MEMBER FOR ROTATING IT ABOUT SAID AXIS, SAID ROTOR HAVING END SURFACES FACING SAID END WALLS OF SAID INTERNAL CHAMBER AND AT LEAST ONE FLUID DISPLACEMENT CHAMBER THEREIN WITH A PORT WHICH OPENS INTO ONE END SURFACE OF SAID ROTOR, MEANS MOUNTED WITHIN SAID FLUID DISPLACEMENT CHAMBER AND SLIDABLE THEREIN FOR DISPLACING FLUID OUT OF SAID FLUID DISPLACEMENT CHAMBER THROUGH SAID PORT DURING A FIRST PREDETERMINED ANGLE OF ROTOR ROTATION AND FOR CAUSING FLUID TO FLOW INTO SAID FLUID DISPLACEMENT CHAMBER THROUGH SAID PORT DURING A SECOND PREDETERMINED ANGLE OF ROTOR ROTATION, AT LEAST TWO SLIPPER SEGMENTS SLIDINGLY ABUTTING SAID ONE END SURFACE OF SAID ROTOR DURING ITS ROTATION TO PROVIDE REACTION SURFACES AGAINST WHICH SAID ROTOR IS THRUST, SWIVEL MEANS SUPPORTING SAID SLIPPER SEGMENTS FROM ONE END WALL OF SAID HOUSING, A PORT PLATE SEPARATE FROM SAID SLIPPER SEGEMENTS IN SLIDING ENGAGEMENT WITH SAID ONE END SURFACE OF SAID ROTOR, SAID PORT PLATE HAVING A GENERALLY CRESCENT SHAPED OPENING WHICH COMMUNICATES WITH SAID PORT OF SAIR ROTOR DURING ONE OF SAID PREDETERMINED ANGLES, SAID PORT PLATE HAVING A PORTION SURROUNDING SAID CRESCENT SHAPED OPENING WHICH SLIDINGLY SAELINGLY ENGAGES SAID ROTOR MEMBER, SAID HOUSING HAVING AT LEAST ONE FLOW PORT GENERALLY OPPOSITE TO SAID CRESCENT SHAPED OPENING OF SAID PORT PLATE, SEALING MEANS FOR EFFECTING A SEALING RELATIONSHIP BETWEEN SAID CRESCENT SHAPED OPENING OF SAID PORT PLATE AND SAID AT LEAST ONE HOUSING FLOW PORT, SAID SEALING MEANS BEING SO CONSTRUCTED SO AS TO MAINTAIN SAID SEALING RELATIONSHIP WHEN SAID PORT PLATE MOVES TOWARD AND AWAY FROM ITS RESPECTIVE END WALL OF SAID HOUSING, MEANS FOR BIASING SAID PORT PLATE INTO ENGAGEMENT WITH SAID ROTOR END SURFACE WITH SLIGHTLY GREATER FORCE THAN PRODUCED BY FLUID PRESSURE TENDING TO SEPARATE SAID PORT PLATE AND SAID ROTOR MEMBER TO EWFFECT A PROPER SEAL THEREBETWEEN.