Automatic flow control device
First Claim
1. An intravenous fluid flow control device comprising:
- a rigid casing having a fluid entrance and a fluid exit, a portion of said casing comprising a flow restrictor;
a pin disposed inside said casing and axially movable within said flow restrictor, said pin having an interior passageway and at least one upstream opening for a fluid to pass from said casing fluid entrance to said interior passageway of said pin, said upstream opening being elongated in a direction parallel to a pin longitudinal axis, the pin elongated opening being axially movable within said flow restrictor to variably restrict a flow of the fluid passing through the interior passageway of said pin, said pin having a downstream opening for fluid to pass from the interior passageway of said pin to exit said device; and
biasing means for biasing said pin against a pressure of the fluid entering from said casing fluid entrance to cause said pin elongated opening to move with respect to said fluid restrictor to variably control the flow of fluid through said pin interior passageway such that, as the fluid pressure variably increases to a predetermined value, the fluid flow through the elongated opening also increases, and, as the fluid pressure variably increases the above-predetermined value, the elongated opening moves within the flow restrictor causing the flow fluid through the elongated opening to decrease.
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Accused Products
Abstract
An intravenous fluid flow control device includes a rigid casing having a fluid entrance and a fluid exit. A portion of the casing has a flow restrictor. A pin is disposed inside the casing and axially movable within the flow restrictor. The pin has an interior passageway and at least one upstream opening for a fluid to pass from the casing fluid entrance to the interior passageway of the pin. The upstream opening is elongated in a direction parallel to a pin longitudinal axis, the pin elongated opening being axially movable within the flow restrictor to variably restrict a flow of the fluid passing through the interior passageway of the pin. The pin has a downstream opening for fluid to pass from the interior passageway of the pin to exit the device. Biasing structure (preferably a spring) biases the pin against a fluid pressure of the fluid entering from the casing fluid entrance to cause the pin elongated opening to move with respect to the fluid restrictor. As the incoming fluid pressure increases to a predetermined value, the fluid flow through the elongated opening also increases. As the fluid pressure further increases above the predetermined value, the elongated opening moves within the fluid restrictor to cause the fluid flow through the elongated opening to decrease.
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Citations
21 Claims
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1. An intravenous fluid flow control device comprising:
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a rigid casing having a fluid entrance and a fluid exit, a portion of said casing comprising a flow restrictor; a pin disposed inside said casing and axially movable within said flow restrictor, said pin having an interior passageway and at least one upstream opening for a fluid to pass from said casing fluid entrance to said interior passageway of said pin, said upstream opening being elongated in a direction parallel to a pin longitudinal axis, the pin elongated opening being axially movable within said flow restrictor to variably restrict a flow of the fluid passing through the interior passageway of said pin, said pin having a downstream opening for fluid to pass from the interior passageway of said pin to exit said device; and biasing means for biasing said pin against a pressure of the fluid entering from said casing fluid entrance to cause said pin elongated opening to move with respect to said fluid restrictor to variably control the flow of fluid through said pin interior passageway such that, as the fluid pressure variably increases to a predetermined value, the fluid flow through the elongated opening also increases, and, as the fluid pressure variably increases the above-predetermined value, the elongated opening moves within the flow restrictor causing the flow fluid through the elongated opening to decrease. - View Dependent Claims (2, 3, 4, 5, 6, 21)
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7. An intravenous fluid flow control apparatus comprising:
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a rigid casing having a fluid entrance and a fluid exit; a fluid restrictor disposed inside said casing; a pin disposed inside said casing and axially movable with respect to said fluid restrictor, said pin having an interior passageway and at least one upstream opening for a fluid to pass from said casing fluid entrance to said interior passageway of said pin, said upstream opening being elongated in a direction parallel to a pin longitudinal axis, the pin elongated opening being axially movable within said fluid restrictor to variably restrict a flow of the fluid passing through the interior passageway of said pin, said pin having a downstream opening for the fluid to pass from the interior passageway of said pin to said casing fluid exit; a pin flange disposed on an upstream end of said pin for contacting the fluid entering from said casing fluid entrance; and biasing means for biasing said pin flange against the fluid entering from said casing fluid entrance to cause said pin elongated opening to move with respect to said fluid restrictor such that, as the fluid pressure variably increases to a predetermined value, the fluid flow through the elongated opening also increases, and, as the fluid pressure variably further increases above the predetermined value, the elongated opening moves within the fluid restrictor causing the fluid flow through the elongated opening to decrease. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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14. Intravenous fluid flow control apparatus comprising:
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a rigid plastic casing having a fluid entrance and a fluid exit; a fluid restrictor disposed inside of said casing; a hollow cylindrical pin disposed inside said casing and axially movable With respect to said fluid restrictor, said pin having an interior and a flange which is disposed on an upstream end thereof for contacting a fluid entering from said casing fluid entrance, said pin having at least one slot elongated in a direction parallel to a longitudinal axis of the pin and disposed downstream of said pin flange to allow fluid to pass from said casing fluid entrance to the interior of said pin, said pin elongated slot being disposed with respect to said fluid restrictor to variably restrict a flow of fluid passing to the interior of said pin, said pin being open at a downstream end thereof for the fluid to pass from the interior of the pin to said casing fluid exit; and a spring disposed between said pin flange and said casing fluid exit to bias the pin flange against a pressure of the fluid entering from the casing fluid entrance to cause the pin elongated slot to move with respect to the fluid restrictor such that, as the fluid pressure variably increases to a predetermined value, the fluid flow through the elongated opening also increases and, as the fluid pressure variably increases above the predetermined value, the elongated opening moves within the fluid restrictor causing the fluid flow through the elongated opening to decrease. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification