Flow control valve

Abstract: A valve (12) for fluids employs two telescoping parts (18,20) which cooperate with one another to block fluid flow when pulled partially apart and open a flow path therethrough when pushed together. A plunger component (20), having a central bore (38), a closed off end (40) and perforated walls (42), is slidingly and sealingly received within the collar (24) of the hollow valve body (18). When the plunger's (20) closed end is pushed far enough into the valve body (18) so as to expose the apertures (42), fluid is free to flow from within the valve body (18) into the plunger component (20). When pulled apart so as to cause the perforations (42) to be positioned within the confines of the collar (24), flow is blocked. An actuation mechanism integrated into a housing (50) serves to automatically pull the valve's components apart to stop flow when its cover is swung open and conversely causes the two components to be pushed together to open flow when the cover is closed.

Description: BACKGROUND OF THE INVENTION The present invention relates generally to valves and more particularly, to valve configurations that are suitable for intravenous (IV) administration set applications while readily lending themselves to mechanized activation. The control of fluid flow through an IV administration line from a fluid source to a patient is of primary concern in infusion systems. In many cases, infusion devices such as pumps or controllers are used with the IV administration set in the infusion of medical solutions to patients. These devices typically include a means which continually occludes the IV tubing to prevent free flow, although the position of occlusion may move during operation. For example, in the case where a peristaltic mechanism of some type is used, the mechanism creates a moving zone of occlusion to move the fluid at a controlled rate from the fluid source to the patient. The tubing is always occluded at one position or another. Other types of infusion devices may use valves to sequentially occlude the tubing. Thus, while the tubing of the administration set is engaged with the infusion device, most, if not all, infusion devices occlude the tubing thereby preventing free flow of the supply fluid to the patient. However, before and after the tubing is engaged with the infusion device, free flow of the IV fluid is possible and is a concern. A large variety of valve mechanisms and valve configurations have been devised to fulfill a variety of different requirements. The requirements specific to IV set applications include low cost, as such devices are typically intended to be disposable, and ease of manipulation, preferably such that the valve can readily be actuated by a simple automated mechanism as well as manually. Many devices utilized in IV set-type applications have either been of simple, consequently inexpensive design and rather awkward to manipulate or alternatively, relatively easy to actuate but inordinately complex and therefore expensive. An example of the former is a pinch clamp that is fastened about the exterior of resilient tubing. Opposing surfaces are brought to bear against the tubing's exterior to pinch its walls shut to prevent flow while two adjoining, appropriately configured surfaces cooperate to function as a ratchet mechanism in order to maintain the clamp in a closed or partially closed position. Squeezing the two opposing surfaces together shuts off flow while separating the two adjoining surfaces permits flow. Although such a device is of one-piece construction, two very different movements are required to open and to close the valve thereby rendering the valve rather difficult to adapt to a simple automated actuation mechanism. An example of a device that requires a relatively simple movement to actuate is that disclosed in U.S. Patent No. 3,971,541 to Griffin. A pulling action on a pull ring causes the valve to open while release thereof allows the valve to automatically return to its closed position. However, the valve employs numerous parts including a plunger, sealing plug, two biasing means, O-rings, etc. thereby resulting in a rather expensive unit. The valve provided by Cloyd, U.S. Patent No. 3,806,086 relies on fewer parts than does the Griffin valve but actuation calls for somewhat more complex movement, requiring the insertion of a supply line thereinto in order to depress a stem element which serves to open a flow path. Removal of the supply line allows a spring to urge the stem back into its closed position thereby preventing flow. While this mechanism is very simple to actuate manually, it appears rather ill-suited for mechanical manipulation. In addition, no less than four parts are incorporated in the design. Another known device for controlling the flow of fluid between a first and second conduit is described in German Patent 2 936 496 of Gambro Dialysatoren GmbH & Co KG). In this patent a connection device for providing selective fluid communication between two conduits is disclosed. The connection device includes a first member having a fluid passageway and a second member also having a fluid passageway, and in which a second member's end is disposed within an open end of the first member. The first and second members are movable relative to one another between an open position, in which the first member fluid passageway and the second member fluid passageway are in fluid communication with one another, and a closed position. Closure means are provided for closing one of the passageways to prevent the fluid communication therethrough. In the prior art, manually actuated flow stop clamps have been used to prevent free flow during periods when the administration set is not engaged with the infusion device. However, operation of the manually actuated clamp requires further responsibility on the part of the operator to assure that the clamp is in the correct position. For example, before engagement with the infusion device, the operator must assure that the clamp is closed to prevent flow. After engagement with the infusion device, the operator must assure that the clamp is open to permit flow so that the infusion device can move the fluid to the patient. And, before removal of the tubing from the infusion device, the operator must once again assure that the clamp is closed to prevent flow. A system which automatically performs the above operations would be preferable. Additionally, a flow control device which indicates its current operational status to the operator is desirable. For example, a positive click indicating that the valve has been placed in the open or "flow" position and a positive click indicating the valve has been place in the closed or "flow stop" position are desirable. Some degree of confidence is then instilled in the operator that the flow control device is actually in the desired configuration. Hence, those concerned with infusion systems have recognized that it would be of value to provide an automated system which would prevent free flow through an IV administration set connected between a fluid supply and a patient during times when the administration set is not engaged with an infusion device, which will permit flow when the administration set is engaged with the infusion device and which will simplify the infusion procedure. Additionally, it has been recognized that it would be of value to provide a flow control valve which is relatively easy and inexpensive to manufacture and which clearly indicates to the user its operational configuration. The present invention as defined in claim 1 fulfills these needs. SUMMARY OF THE INVENTION According to one aspect of the invention there is provided an apparatus for controlling the flow of fluid between a first and a second conduit, comprising a valve body having a first port, a second port, and an interior cavity, wherein both the first and second ports are in fluid communication with the interior cavity and the first port is connected to the first conduit, the cavity having a section of reduced diameter; a plunger component having a closed end, a hollow interior and a port connected to the second conduit and to the hollow interior, the plunger component having a side wall connecting the port with the closed end, the side wall having an aperture positioned along the side wall such that a flow path is established between the cavity of the valve body and the hollow interior of the plunger component when the plunger component is inserted into the valve body through the second port to a predetermined position; and a seal located on the plunger component, the seal having a size such that it has an interference fit with the reduced diameter section of the cavity, and is located in relation to the aperture such that the seal blocks the flow of fluid between the cavity and the aperture when the plunger component is positioned in the valve body such that the aperture is within the section of reduced diameter. Briefly and in general terms, the flow control valve according to the present invention comprises a hollow valve body and a perforated plunger component. The valve body connects at one end to a first conduit and has an opening at its other end in the form of an elongated collar of reduced diameter. The plunger component has a central bore, connects at one end to a second conduit and is closed off at its other end. The plunger is perforated and has a plurality of apertures formed in the plunger component's walls between the open and closed-off ends. The plunger is dimensioned such that its closed end is inserted into the valve body's interior through the collar. Annular ridges formed on the plunger's surface serve to sealingly engage the collar's inside surfaces. Annular ridges on the collar also aid in sealing and cooperate with the ridges on the plunger component to aid in positioning the two in relation to each other and positively indicate to the operator that position. The flow control valve in accordance with the invention is opened to permit flow by telescoping its two parts into one another and closed to prevent flow by telescoping its two parts partially out of one another. By pushing the plunger component far enough into the valve body such that its perforations clear the reduced diameter of the collar, fluid in the valve body received from the first conduit is free to flow through the apertures into the plunger's central bore and out into the second conduit. Conversely, pulling the two components partially apart so as to position the plunger's apertures entirely within the collar prevents the entry of fluid into those apertures and shuts off flow. The plunger component's ridges engage the collar's interior surface prevent the escape of fluid to the valve's exterior as well as prevent the seepage of fluid into the plunger's central bore while the valve is in its closed position. Additionally, as mentioned above, the ridges formed on the plunger component aid in sealing, positioning and indicating the relative position of the two components. Shoulders molded into the exterior surfaces of the two components allow the two components to be easily grasped by an actuating mechanism, and by virtue of the one dimensional or telescoping interaction of the two components, only a simple reciprocating movement of such actuating mechanism is required to actuate the valve. The actuating mechanism may optionally be spring loaded such that movement in one direction is automatic. The design of the flow control valve readily lends itself to mechanical manipulation as, for example, by a device integrated into a housing and cooperating with the movement of a door or cover such that flow is automatically stopped when the door is opened and permits manual actuation for priming and for other reasons. The invention will become apparent from the following detailed description and accompanying drawings, illustrating by way of example the features of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a flow control valve in accordance with the present invention, connected between first and second conduits; FIG. 2 is an enlarged cross-sectional view of the interior of the valve body and plunger component; FIG. 3 is a perspective view illustrating the valve as accommodated in an automated actuation mechanism installed in an infusion device; FIG. 4 is a cross-sectional view of the valve of FIG. 1 showing the valve urged into its closed position by an actuation mechanism; and FIG. 5 is a cross-sectional view of the valve and actuation mechanism of FIG. 2 in which the valve has been urged into its open position by the actuation mechanism. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings with more particularity, wherein like reference numerals designate like or corresponding elements among the several views, there is shown in FIG. 1 a fluid control valve 12 according to the present invention. The valve 12 is installed in-line between a first conduit 14 and a second conduit 16 to control the flow of fluid through the conduits. The valve is especially well suited for an IV administration set application. Referring now to FIG. 2, valve 12 comprises two components, a hollow valve body 18 and a perforated plunger component 20. A first port 22 includes a Luer-type connector formed at one end of the body 18 so as to enable interconnection with the first conduit 14. In the embodiment illustrated, this interconnection is achieved by an interference fit between the conduit's exterior surface and the interior wall of the connector. The interior walls of the valve body 18 are cylindrical and include an elongated collar 24 having walls 26 of reduced diameter. A cavity 28 is thus formed which is in fluid communication with the first port 22. A second port 30 is formed at the other end of the valve body 18. In the embodiment illustrated, the exterior of the valve body 18 is generally cylindrical and additionally incorporates two annular shoulders 32 and 34 of rectangular cross-section. The plunger component 20 of the valve 12 includes a port 36 formed at one end so as to facilitate interconnection to the second conduit 16. In the embodiment illustrated, the conduit 16 is fitted about the exterior of the plunger component's end. The plunger component 20 has a hollow interior comprising a longitudinal bore 38 formed in its interior which is in fluid communication with the second conduit 16 connected at its port 36. The opposite end of the plunger component 20 is closed off 40 and the walls near the closed-off end 40 are perforated with a plurality of apertures 42. Part of the exterior of the plunger component 20 is dimensioned to be slidingly received within the valve body's collar 24 and is of sufficient length so that the apertures 42 in the wall of the plunger component 20 clear the reduced diameter collar 24 and extend into the cavity 28. Thus, when telescoped into the cavity 28, fluid can flow into the apertures 42 from the cavity 28, through the hollow interior of the plunger component and through the second conduit 16. The plunger component also includes a shoulder 43 to limit its movement into the valve body 18. A series of annular ridges 44 are formed on the plunger components' 20 exterior wall to provide for a sealing engagement with the collar's 24 interior surface 26. An interference fit is established between the annular ridges 44 and the interior surface 26 of the collar 24. The ridges may be formed of a pliable material such as Hytrel®. In this embodiment, two ridges 44 are positioned above the apertures 42 and two below. Additionally, in the embodiment shown in FIG. 2, three annular ridges or protrusions 46 are formed on the surface 26 of the collar 24. These ridges 46 also provide a seal between the plunger component 20 and the collar 24 but are primarily used to indicate to the user the relative positions of the body 18 and plunger component 20. The ridge 44 nearest the cavity 28 cooperates with the two ridges 44 of the plunger component adjacent the closed end. When the plunger component 20 is partially telescoped out of the body 18, the top ridge 46 of the collar will be located between the two top ridges 44 of the plunger. An increased force will be felt as the plunger is telescoped out of the body and an audible click will be heard as the ridges are pulled over one another. The other two ridges of the plunger component 20 will similarly interact with the other ridges of the collar to aid in indicating the position of the components relative to each other. Similarly, as the plunger component is telescoped into the cavity 28, clicks will be heard. The ridges are also numerous enough and rigid enough to prevent inadvertent and undesirable relative movement of the body 18 and plunger 20 once positioned. FIG. 3 illustrates the valve 12 in cooperation with an actuation mechanism which has been integrated into an infusion pump housing 50 such that the valve 12 is actuated upon movement of the door 52. The plunger component 20 is firmly held in place about its external shoulder 43 by a stationary clamp 54 mounted to the housing 50 while a second clamp in the form of a movable actuation arm 56 engages the valve body between its two annular shoulders 32 and 34. The actuation arm 56 is hingedly attached to the pump housing 50 and is biased upwardly by a spring 58. A pin 60 is rigidly attached to and extends from the housing door 52 and is configured and positioned to engage the arm's actuation plate 62 and urge it downwardly as the door 52 is swung closed about its hinged axis. The leading edge 64 of the actuation plate 62 is slightly downturned to facilitate proper engagement with the pin 60. In the configuration illustrated in FIG. 3, the upwardly biased actuation arm 56 maintains the two valve components 18 and 20 in a partially pulled apart relationship until the door 52 is closed. Closing the door 52 causes the pin 60 to press the actuating arm 56 downward overcoming the bias generated by the spring 58, causing the valve body 18 to be moved towards the plunger component 20. This is shown in greater detail in FIGS. 4 and 5. Referring now to FIGS. 4 and 5, the conduits 14 and 16 are simply slipped onto or into the valve's 12 respective ends. By maintaining the two parts in the slightly pulled apart position illustrated in FIG. 4, the flow of fluid supplied by conduit 14 is blocked as the retracted closed end 40 of the plunger component 20 creates a dead end within the collar 24 of the valve body 18. The engagement of the collar's interior wall by the annular ridges 44 ensures that no fluid escapes from the cavity 28 of the valve body into the plunger component 20. By pushing the plunger component 20 further into the valve body 18 so as to position the apertures 42 within the valve body's interior as shown in FIG. 5, a flow path is provided for fluid betw en the first conduit 14 and the second conduit 16. Fluid is free to flow from the first conduit 14, into the cavity 28, around the plunger component's closed end 40, through the apertures 42, into the plunger component's interior bore 38 and on through the second conduit 16. The annular ridges 44 sealingly engage the collar's 24 interior wall 38 to preclude any leakage of fluid therefrom. The operation of the actuation mechanism shown in FIG. 3 is also shown in FIGS. 4 and 5. In FIG. 4, the pin 60 of the door is not in engagement with the actuation plate 62, thus the bias spring 58 (FIG. 3) causes the hinged arm 62 to pull the body 18 away from the plunger component 20 into the flow stop position. As mentioned above, the rigidity and number of the ridges, both on the plunger component and on the collar, prevent the plunger component from being fully pulled out of the valve body. Also, the travel distance of the actuating plate 62 is limited. In FIG. 5, the pin 60 has engaged the actuating plate 62 and forced it downward overcoming the biasing force of the spring 58 (FIG. 3). This action has telescoped the body 18 and plunger component 20 together until the stop surface 43 of the plunger component encounters the second port 30 of the body 18. In this position, the apertures 42 are positioned in the cavity of the valve body and fluid is permitted to flow through the valve 12. The valve's two components 18 and 20 are preferably injection molded wherein the valve body is preferably formed of PVC or ABS while the plunger component is formed of Hytrel. The inherent resiliency of Hytrel allows the annular ridges 36 to form a tight seal against the collar 24. While a particular form of the invention has been illustrated and described, it will also be apparent to those skilled in the art that various modifications can be made to the invention. Accordingly it is not intended that the invention be limited except by the appended claims.

Claims: An apparatus for controlling fluid communication between a first conduit (14) and a second conduit (16), the apparatus comprising a valve body (18) having a first port (22), a second port (30), and an interior cavity (28), the cavity having a first portion having a diameter and a second portion having a diameter, a first end and a second end, the diameter of the second portion being substantially the same as between said first end and said second end, wherein both the first and second ports (22 and 30) are in fluid communication with the interior cavity (28) and the first port (22) is connected to the first conduit (14), wherein the diameter of the first portion of the interior cavity is larger than the diameter of the second portion, and the first portion is closer to the first port than the second portion is to the first port; a plunger component (20) having a closed end (40), a hollow interior (38) and a third port (36) connected to the second conduit (16) and to the hollow interior, the plunger component having a side wall connecting the third port (36) with the closed end, the side wall having an aperture (42) positioned therein adapted to establish a fluid communication path between a position outside the plunger component with the hollow interior; the plunger component being inserted into the valve body through the second port closed end first so that the aperture is selectively slidably situated in the first portion and the second portion of the interior cavity; and the first seal (44) located on the plunger component between the closed end and the aperture (42); said apparatus being characterized by: the plunger component (20) including a second seal (44), and the second portion of the interior cavity (28) including a first protrusion and a second protrusion (46); the first seal (44) having an exterior side and comprising at least one ridge formed on the exterior side of the plunger component (20), the ridge being located adjacent to the aperture (42); the second seal (44) comprising at least one ridge formed on the exterior side of the plunger component (20), the second seal (44) being located between the aperture (42) and the third port (36) and being of sufficient size to have an interference fit with the second portion of the interior cavity (28) when situated in the second portion of the interior cavity (28), the second protrusion being formed in the second portion of the interior cavity (28), and the first protrusion (46) being closer than the second protrusion (46) to the first portion of the interior cavity (28); wherein sliding the plunger component (20) in the interior cavity so that the first seal is moved between the first and second portions of the interior cavity (28) causes the first seal to come into and out of contact with the first protrusion, the contact providing a tactile and audible indicator of the presence or absence of fluid communication between the first and second conduits (14 and 16); and wherein the first seal (44) and the aperture (42) are selectively locatable in the first and second portions of the interior cavity (28), the first seal (44) having a size such that the first seal has an interference fit with the second portion of the interior cavity (28) when situated in the second portion of the interior cavity (28) to block fluid communication between the first and second conduits (14, 16). The apparatus of claim 1, characterized in that the plunger component (20) is formed wholly of a slightly deformable material. The apparatus of any one of the preceding claims, characterized by: a first clamp (54) attached to the plunger component; a second clamp (56) attached to the valve body; and an actuation element (60) which moves into and out of and engagement with one of the clamps (56, 62) and, when in engagement with the clamp, causes the engaged clamp (56) to move in relation to the other clamp (54) to thereby cause the plunger component (20) to move in relation to the valve body (18). The apparatus of claim 3, characterized by biasing means (58) for biasing one of the clamps (56) to a predetermined position in relation to the other of the clamps (54) when the actuation element (60) is not engaged with the one of the clamps (56, 62). The apparatus of claim 4, characterized in that the actuation element (60) is capable of moving the plunger component (20) and the valve body (18) in relation to each other so that in the first position, the first seal is moved to a position in the second portion and in the second position, the aperture is positioned in the first portion. The apparatus of claim 5, characterized in that: the biasing means (58) biases the two clamps (54 and 56) apart so that the first seal (44) is located in the second portion of the interior cavity (28); and the actuation element (60) causes the two clamps (54 and 56) to be moved toward one another so that the aperture (42) is moved to the first portion of the interior cavity (28) so that a flow path is established through the interior cavity (28), through the aperture (42) and through the hollow interior of the plunger component (20). The apparatus of claim 5, characterized in that: the first clamp (54) is rigidly integrated into a housing; the second clamp (56) includes a hinged arm (62, 64); the biasing means (58) biases the hinged arm to a predetermined position; and the actuation clement (60) is rigidly affixed to a structure mounted to the housing (50) such that the actuation element (60) swings into and out of engagement with the arm (62, 64), and when swung into engagement with the arm (62, 64), causes movement of the arm (62, 64) in relation to the first clamp (54) . The apparatus of claim 7, characterized in that: the actuation element (60) is mounted on a cover (52) which is hingedly connected to the housing (50); the actuation element engages the hinged arm as the cover is swung closed; and the hinged arm includes an angled engaging surface (64) to facilitate the movement of the hinged arm upon engagement by the actuation element.

Inventors: ANDERSON EMMETT B, DAOUD ADIB G, ANDERSON, EMMETT B., DAOUD, ADIB G.
Applicants: IVAC CORP, IVAC MEDICAL SYSTEMS, INC.
Application year: 1993
Main classification: F16L29
IPC codes: F16L37, A61M39