Quick-Disconnect Valve

The invention relates generally to valves that may be easily connected or disconnected, and more specifically to such valves employed in medical intravenous fluid delivery systems.

Several prior art check valves, such as those shown in U.S. Pat. Nos. 5,020,562 to Richmond et al., 3,831,629 to Mackal et al., 3,570,484 to Steer et al., 3,429,338 to Mackal et al., and 3,192,949 to De See, normally prevent flow through the valve and allow flow when actuated by a cannula. Although these valves have pistons that move within the fluid passageway, sealing does not occur at a sealing ring mounted on the periphery of the piston adjacent the passageway wall, but rather at the end of the piston or on a shoulder of the piston (not at the periphery of the shoulder). Thus, these valves do not need channels to permit flow past the sealing ring when the valve is opened.

U.S. Pat. No. 4,683,916 to Raines shows a normally closed valve wherein sealing is accomplished by a disk, which is deformed, when a cannula is inserted into the valve, in order to permit flow through the valve.

U.S. Pat. No. 4,143,853 to Abramson also shows a normally closed valve. A disk having a central axially extending slit normally prevents flow through the valve, and when actuated by a cannula, permits flow through the opened slit.

The present invention provides a valve for normally preventing flow of fluid therethrough and permitting flow therethrough when actuated by a cannula. The valve has a fluid passageway disposed therethrough, and the passageway is bounded by a wall. One end of the passageway is adapted to receive a cannula; the other end of the passageway is preferably in fluid communication with an intravenous line.

Disposed in the passageway is a movable member, preferably cylindrical in shape. The movable member is displaceable in a direction parallel to overall fluid flow through the valve. The movable member may be displaced to an open position, wherein fluid may pass through the valve, or to a closed position, wherein fluid is prevented from passing through the valve. When the movable member is in the closed position, it is closer to the end of the passageway that receives the cannula, than when it is in the open position. The movable member may be moved from its closed position to its open position by a cannula inserted into the passageway.

A spring, or other biasing means, urges the movable member away from the open position towards the closed position, so that the valve is normally closed. A seal, mounted on the perimeter surface of the movable member, prevents flow between the passageway wall and the perimeter surface of the movable member when the movable member is in the closed position. A channel, mounted in the passageway wall, permits flow between the seal and the passageway wall when the movable member is in its opened position.

In a preferred embodiment of the invention, a second seal is also mounted on the perimeter surface of the movable member. This second seal also prevents flow between the passageway wall and the perimeter surface of the movable member when the movable member is in the closed position. The first seal is mounted closer to the end of the movable member that is pushed by the cannula than the second seal. A second channel is mounted in the passageway wall and permits flow between the second seal and the passageway wall when the movable member is in the open position.

FIG. 1 is a cross-sectional view of a valve according to the present invention in the closed position.

FIG. 2 is a cross-sectional view of the valve shown in FIG. 1 in the open position.

FIG. 3A is a top plan view of the valve housing's upper portion.

FIG. 3B is a cross-sectional view of the housing portion shown in FIG. 3A.

FIG. 3C is a bottom plan view of the housing portion shown in FIG. 3A.

FIG. 4A is a top plan view of the valve housing's lower portion.

FIG. 4B is a cross-sectional view of the housing portion shown in FIG. 4A.

FIG. 4C is a bottom plan view of the housing portion shown in FIG. 4A.

FIG. 5A is a top plan view of the piston.

FIG. 5B is a cross-sectional view of the piston shown in FIG. 5A.

FIG. 5C is a bottom plan view of the piston shown in FIG. 5A.

FIG. 6 shows a detail of a cross-section of a modified version of the value in the closed invention.

The valve shown in FIG. 1 has a fluid passageway 10, having two ports 6 and 7. The wall of the passageway 10 may be formed by two parts, 16 and 18, making up the valve housing. The lower part 16 of the valve housing may be connected in fluid communication with an intravenous line and may be made an integral part of an integral intravenous fluid delivery device, such as that shown in application Ser. No. 07/614,806, referenced hereinabove. Thus, port 7 may be attached to an intravenous fluid line, and in such an arrangement, port 6 permits fluid to be introduced into the line or drawn from the line.

Disposed in the passageway 10 is a movable piston 2, which in one embodiment may be made of two components: a rigid inner piston 23, and a flexible, resilient sleeve which the inner piston 23 fits into snugly and which is preferably made of silicone. Alternatively, the whole piston 2 may be made of a single flexible, resilient material, as shown in FIG. 5B. The piston may be made slightly longer so that its top extends slightly beyond the top of the housing's upper portion 18, and so that the bottom of the channel 27 is flush with the top of the housing's upper portion 18, as shown in FIG. 6; such an alteration makes it easier to wipe and clean the top of the valve. Sealing protrusions 25 and 26 made of the resilient material are located at opposite ends of the piston 2 around its perimeter. The piston 2 is held in the closed position, shown in FIG. 1 by a spring 24, or other biasing means, as well as by fluid pressure in the intravenous line. In the closed position, two seals are formed between the piston 2 and the housing 18 by the sealing rings 25 and 26. The sealing rings 25 and 26 contact the housing wall 18 at the outermost perimeter of the sealing rings. These two seals prevent fluid from flowing through the valve, and therefore prevent the leaking of intravenous fluid from the intravenous line.

When a cannula is inserted into the external port 6 (as shown in FIG. 11 of the Parent Application), the piston 2 is pushed into the valve against the force of the spring 24, until the piston 2 reaches the open position shown in FIG. 2. The diameter of the external port 6 gradually decreases from the uppermost portion of the valve to the channel 11; this shape permits the use of a standard luer-type tapered cannula. (The description of the valve herein uses directional terms such as top, bottom, upper and lower in order to clearly explain the figures; the valve may, of course, be oriented in any direction and still work properly, and the use of such directional terms is not meant to imply otherwise.) Once the piston 2 is pushed into the open position, fluid may pass through the cannula, around the piston 2 and through the valve by means of a series of channels. A channel 27 on the top of the piston 2 permits fluid to flow from (or into) the inserted cannula and around the top of the piston 6, in a way similar to how fluid passes around the top of the pin shown in FIG. 11 of the Parent Application. Fluid may flow between the housing 18 and upper sealing ring 25 (which is compressed by the tapered walls of the fluid passageway, when the piston 2 is pushed into the open position) by passing through one or more upper channels 11. Likewise, fluid may flow between the housing 18 and 16, and lower sealing ring 26 by passing through one or more lower channels 12. The channels 11 and 12 provide fluid communication past the sealing rings when the piston 2 is in the open position. The channels 11 and 12 may be formed as tubes passing through the housing wall, but such a structure is more difficult to manufacture than the simple open-face grooves cut in the passageway walls, as shown in FIGS. 1 and 2. Between the channels 11 and 12 in the upper portion of the housing, the diameter of the passageway 10 increases so as to permit the lower sealing ring 26, and therefore the piston 2, to move up and down. The smaller diameter of the passageway at the location of the channels 11 prevents the lower sealing ring 26 from moving up too far, and thereby prevents the piston 2 from falling out of the housing 18.

As noted above, the housing may be made of two portions 16 and 18. In the embodiment shown in FIGS. 1 and 2, channel 12 is disposed in the inner walls of both of these portions. The cross-section of the housing shown in FIGS. 1 and 2 shows the two housing portions 16 and 18 aligned so that the section of channel 12 in the upper housing portion 18 is aligned with the section of the channel 12 in the lower housing portion 16. In order to avoid the necessity of having to align the upper and lower housing portions 18 and 16, an annular channel 121 may be located at the boundary between the upper and lower sections of channel 12. This annular channel 121 is also shown in FIG. 4A, which is a top plan view of the housing's lower portion. This annular channel 121 permits flow through channel 12 when the upper and lower sections of the channel 12 are not aligned.

When the cannula is removed from port 6, the spring 24 pushes the piston 2 back up to the closed position (as shown in FIG. 1). The spring 24 must apply enough force to overcome the friction between the housing 18 and the piston 2, in particular the piston's upper sealing ring 25, which is compressed when the piston 2 is in the open position (as shown in FIG. 2).

FIGS. 3A-5C show various perspectives of three of the components that make up the valve shown in FIGS. 1 and 2. FIGS. 3A-4C show the two portions of the housing, and FIGS. 5A-5C show a piston made from a single material.

The valve shown in the figures and described above may be altered so that the upper sealing ring is attached to the passageway walls and the upper channels are placed in the piston. Unlike the preferred embodiments, where the upper sealing ring moves and the channels do not move, in this embodiment the upper channels move and the upper sealing ring does not move. This embodiment is not preferred, because it is much more difficult to clean properly--a very important consideration for intravenous fluid delivery systems. In this embodiment, the sealing ring is mounted some distance from the top of the valve. As the cannula is removed from the port and the piston returns to the closed position, fluid may collect in the space between the passageway wall and the piston where it is exposed to the air. In the preferred embodiment shown in the figures, the sealing ring 25 is located near the top of the valve when the valve is closed, and the fluid between the piston 2 and the passageway wall 18 is thereby sealed off from the air by the sealing ring 25, as shown in FIG. 1.