Variable aperture fluid flow control apparatus

Claim 2

In a device for controlling the flow rate of fluid in an infusion assembly, the improvement comprising: a resilient deformable diaphragm having an aperture normally too small to pass fluid; a generally hollow transparent female fitting having fluid egress means and internally receiving the diaphragm in fluid tight relation at a point spaced from said egress means comprising a passage in essentially axial alignment with the aperture so as to define a drip chamber within said female fitting; and a male fitting threadedly coupled into the female fitting adjacent the diaphragm and having fluid ingress means, the male fitting accommodating advancement into the female fitting to induce a tensile load in the diaphragm and to maintain the induced load when the advancing force is removed thereby dialating the aperture a preselected amount whereby a known volume of fluid is transferred by the ingress means to the egress means in a predetermined time period.

Claim 3

A catheter assembly comprising: a flexible tube for communicating intravenous fluid to a patient; a catheter at one end of the tube for placement in the venous system of the patient; a flow-regulating mechanism interposed between the ends of the flexible tube, the flow-regulating mechanism defining a generally linear flow path essentially axial with the flow path of the flexible tube and comprising threadedly connected male and female coupling members, the threads being disposed at respective adjacent overlapping ends of the male land female coupling members, a yieldable diaphragm sealed to the interior walls of the female member and spanning therebetween across a hollow interior thereof, the diaphragm comprising a closed slit when in an unstressed condition, one end of the male coupling member being juxtaposed the diaphragm and comprising a rounded configuration without sharp edges, the male coupling member defining a central axial passageway which opens within the female coupling member at the rounded end of the male coupling member adjacent the slit in the diaphragm, whereby threaded advancement of the male coupling member with respect to the female coupling member engages, displaces and stresses the diaphragm proportional to the amount of said advancement, bringing the diaphragm into corresponding rounded configuration with the round end of the male coupling member to the extent that the two become contiguous and the slit is opened and fluid is able to flow therethrough to a regulated degree proportional to said advancement.

Claim 4

A catheter assembly comprising: a flexible tube for communicating intravenous fluid to a patient; a catheter at one end of the tube for placement in the venous system of the patient; a flow-regulating mechanism interposed between the ends of the flexible tube, the flow-regulating mechanism defining a generally linear flow path essentially axial with the flow path of the flexible tube and comprising threadedly connected male and female coupling members, the threads being disposed at respective adjacent overlapping ends of the male land female coupling members, a yieldable diaphragm sealed to the interior walls of the female member and spanning therebetween across a hollow interior thereof, the diaphragm comprising a closed slit when in an unstressed condition, one end of the male coupling member being juxtaposed the diaphragm and comprising a rounded configuration without sharp edges, the male coupling member defining a central axial passageway which opens within the female coupling member at the rounded end of the male coupling member adjacent the slit in the diaphragm, whereby threaded advancement of the male coupling member with respect to the female coupling member engages, displaces and stresses the diaphragm proportional to the amount of said advancement, bringing the diaphragm into corresponding rounded configuration with the round end of the male coupling member to the extent that the two become contiguous and the slit is opened and fluid is able to flow therethrough to a regulated degree proportional to said advancement.