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US 4,227,420 AGranted
Pressure coupling mechanism in a pressure monitoring assembly
AssigneeBaxter Travenol Laboratories, Inc.
InventorRene G. Lamadrid
Life of this patent
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AssigneeBaxter Travenol Laboratories, Inc.
InventorRene G. Lamadrid
Estimating the term…
The pressure monitoring assembly monitors changes in pressure of a fluid passing through the assembly. This is accomplished by passing a liquid through a pressure transfer device having first and second chambers therein separated by a flexible diaphragm. The first chamber has air therein and pressure changes are transmitted across the diaphragm from the second chamber through which the liquid flows. The assembly further includes a pressure transducer and a pressure coupling mechanism for coupling the pressure transfer device to the pressure transducer. The pressure coupling mechanism includes a body having a cylindrical chamber and a piston positioned for movement therein with a piston shaft protruding from a coupling end of the body. The shaft is biased outward from the coupling end of the body by a spring. The coupling end has an O ring seal which forms a seal with the pressure transfer device around an orifice in a wall of the second chamber when the pressure coupling mechanism is mounted to the pressure transfer device. The piston shaft has a through-bore to the cylindrical chamber so that air is trapped in an air passageway comprising the first chamber, the through-bore and the cylindrical chamber. As the pressure transfer device is latched to the pressure coupling mechanism, the shaft and piston are pushed against the spring toward the pressure transducer which is mounted to the body at one end of the cylindrical chamber thereby compressing the trapped air in the air passageway.
Pressure coupling means for coupling a first chamber in a fluid pressure transfer device to a pressure transducer, the chamber having one wall thereof defined by a flexible diaphragm against which fluid pressure to be monitored acts, for establishing a fluid tight air passageway communicating the first chamber in the pressure transfer device to the pressure transducer and for establishing, when coupled between the pressure transfer device and the pressure transducer, a biasing force in said air passageway and the first chamber whereby the diaphragm is urged toward the fluid to be monitored so that when such fluid is present at its expected normal pressure, the diaphragm is in a relaxed unstretched state, said pressure coupling means comprising means for trapping a volume of air in said air passageway and the first chamber when said pressure coupling means is coupled to the pressure transfer device and means for compressing the volume of air in said air passageway and the first chamber to establish a biasing pressure in said air passageway and the first chamber.
A pressure monitoring assembly comprising a fluid pressure transfer device having a first chamber therein which has one wall thereof defined by a flexible diaphragm against which fluid pressure to be monitored acts, a pressure transducer and pressure coupling means for coupling said first chamber to said pressure transducer, for establishing a fluid tight air passageway communicating said first chamber to said pressure transducer and for establishing, when coupled between said pressure transfer device and said pressure transducer, a biasing force in said air passageway and said first chamber whereby said diaphragm is urged toward the fluid to be monitored so that when such fluid is present at its expected normal pressure said diaphragm is in a relaxed unstretched state, said pressure coupling means comprising means for trapping a volume of air in said air passageway and said first chamber when said pressure coupling means is coupled to said pressure transfer device and means for compressing the volume of air in said air passageway and said first chamber to establish a biasing pressure in said air passageway and said first chamber.
Dependencies are inferred from the claim text.