WO1995023002A1

WO1995023002A1 - Control of fluid flow

Info

Publication number: WO1995023002A1
Application number: PCT/US1994/001850
Authority: WO
Inventors: Joseph R. Paradis
Original assignee: Paradis Joseph R
Priority date: 1990-05-29
Filing date: 1994-02-28
Publication date: 1995-08-31

Abstract

A flow control device (10') with at least one flow channel (11) in a housing (14) that contains a pre-biased flow control diaphragm (10d) that is stabilized by a flexible contact member (14c). Any flow channel, including that with an injection site, may include a plug (24) acted upon by an external actuator (30), which can be self-sealing. The injection site with a flexible plug (24) is used for needleless infusion of fluids.

Description

CONTROL OF FLUID FLOW Background of the Invention

This invention relates to flow control and more particularly, to the precision control of fluid flow and injected fluids.

It often is desirable to control the flow of fluid such as liquids and gases. A common device for that purpose is known as a "check" valve, which functions by the deflection of an elastomeric element towards and away from a valve seat. The deflection is towards the valve seat in order to prevent flow, and away from the seat to permit flow.

Some flow control devices desirably operate with low "cracking" pressures, i.e. the pressure at which a control diaphragm moves away from its seat. For such devices, it is advantageous to use relatively thin diaphragms.

Unfortunately, thin diaphragms pose problems of stability. The diaphragm may move slightly away from its central position against a side wall, and because of the thinness of the diaphragm, may tend to stick, causing a problem of leakage.

One attempt to stabilize diaphragms is disclosed in Raines U.S. patent 4,535,820 which issued August 20, 1985. In Raines, the diaphragm is held in place by a transverse bar that extends completely across the valve body and opposite a triangular support which partially deforms the center of the diaphragm in an attempt to restrain the diaphragm against inadvertent sideways movement. The deformation of the diaphragm is variable due to manufacturing tolerances and is undesirable, as it introduces other problems, such as interference with proper sealing and subsequent operation.

Some fittings can include both a check valve and an injection site, and the control of fluid flow is with respect to a multiplicity of channels that have varying degrees of convergence with one another. A typical multichannel arrangement makes use of connectors which permit the intercoupling of flow channels as desired.

The inclusion of control valves in the various lines leading to a coupler can pose a number of complications, and the inclusion of separate control elements can cause difficulties in assuring proper sealing. A common point of leakage often occurs where lines are severed to receive multiple control elements.

One solution for overcoming difficulties associated with prior art valves that control flow on multiple channels is set forth in U.S. Patent 4,610,276 (" '276") which issued September 9, 1986. While the diaphragm of the *276 patent operates properly in most cases, there is the possibility that the diaphragm will fail to seat properly.

Another valve arrangement for dealing with main and branch channels is disclosed in U.S. patent 4,874,369 which issued October 17, 1989. This arrangement employs an injection site in conjunction with a duck-bill valve in a configuration that is complex, costly and difficult to manufacture, and often unreliable in practice. Another objection to existing arrangements is that their activators are not interchangeable. Thus injection sites that require needle injection cannot be used without needles; conversely injection sites that are externally actuated by inserting a member that opens a diaphragm cannot be used with needles. In addition, the non-needle injection sites present problems of sterility.

Accordingly, it is an object of the invention to achieve enhanced diaphragm stabilization in check valves. A related object is to achieve such stabilization without diaphragm deformation, which can distort the seal of the diaphragm against its seat. Still another related object is to stabilize low cracking pressure valves. A further object is to stabilize diaphragms of relative thinness. Still another related object is to overcome the disadvantages that occur when a diaphragm is held in place by a transverse bar that extends completely across a valve body, and opposite a triangular support which partially deforms the center of the diaphragm in an attempt to restrain the diaphragm against inadvertent sideways movement.

Another object of the invention to enhance the control that can be achieved over fluid flow. A related object is to enhance flow control where fluid infusion or combination is to take place. Another related object is to enhance flow control where fluid flow is diverted in direction.

Yet another object is to achieve precision control at reduced cost and simplification, particularly for low cracking pressure diaphragms which are relatively thin. SUMMARY OF THE INVENTION

In accomplishing the foregoing and related objects the invention provides a flow control device which includes an inlet channel for the flow of fluid; an outlet channel connected to the inlet channel and disposed with respect thereto to serve as a conduit for at least a portion of the flow; a member between the inlet and outlet channels for controlling flow; and a cantilever for stabilizing the flow controlling member.

In accordance with one aspect of the invention a second inlet channel can be included and connected to the outlet channel. The second inlet channel is sealed by a movable member having a central portion for regulating flow at the second inlet by the extent to which the central portion is moved. The movable regulating member can be bell- shaped member with an upper portion at the entry of the inlet channel and walls facing the interior of the inlet channel.

In accordance with another aspect of the invention, the movable regulating member is activatable by a member that is external to the flow control device.

In accordance with a further aspect of the invention the cantilever member extends from a wall of the inlet partially thereacross into flexible contact with the flow controlling member in the form of a diaphragm which is bowed under pressure into the inlet channel. The inlet channel has an axial direction and the controlling member diaphragm has opposed sides, one of which is bowed under pressure by a flattened prong extending in the axial direction, and the other side is freely and tangentially contacted by the spherical cantilever member. The diaphragm is positioned by the prong against an annular seat and is movable therefrom, while the cantilever member is flexible and limits lateral movement of the diaphragm. The cantilever member contacting the diaphragm has a curved surface engaging it tangentially to the engagement of the flat-surface prong with the diaphragm.

An additional flow control device can be connected to the outlet to adapt the outlet channel as a common channel for a plurality of flow control sites.

In a method of controlling fluid flow the steps include (1) stabilizing a freely-movable diaphragm sealing an inlet channel; and (2) depressing the stabilized diaphragm to permit the flow of fluid to an outlet.

The method can further include the step of connecting the outlet as a common channel for a plurality of flow control devices and the step of stabilizing the diaphragm by flexing a cantilever that freely and tangentially contacts the diaphragm on the flat surface of the pressure prong under the diaphragm.

In a method of directionally controlling the flow of fluid the steps include (a) providing a branch channel connected to an outlet for serving as a conduit for at least a portion of flow and (b) controlling flow into the branch channel. In a method of fabricating a flow control device of the invention the steps include (a) molding a first member of the flow control device, including a flexible cantilever and a seat for contacting a fluid pressure control member; (b) molding a second member of the flow control device, including a support for the control member; (c) inserting the control member into the first member with respect to the seat; and (e) joining the second member to the first member with the fluid pressure control member in opposed contact with the flexible cantilever and the seat.

In the flow control device the regulating member can have a surface coincident with an outer surface at the entry of a second inlet channel, and the regulating member can be a bell-shaped member with a slotted side wall engageable by a fitting that maintains the second inlet channel in open condition.

In a method of controlling the flow of fluid in accordance with the invention other steps include (a) providing a branch channel connected to an inlet channel for serving as a conduit for at least a portion of flow and (b) preventing the diaphragm from being sucked into the branch channel.

A flow control device in accordance with the invention can include a ring seat within an inlet channel, an arm for a cantilever extending within the inlet channel from a ring seat for a control diaphragm and terminating in a cantilever prong, with the control diaphragm in tangential contact with the ring seat and the cantilever prong. DESCRIPTION OF THE DRAWINGS First Embodiment

Fig. 1A is a side view of a directional flow-control valve and coupling device with an injection site plug in accordance with the invention;

Fig. IB is a top view of the flow control device of Fig. 1A showing the stabilizing cantilever used in the device of Fig. 1A.

Fig. 1C is a key diagram showing the relationship between Fig. ID and Fig. IE;

Fig. ID is a sectional view of the flow control device of Figs. 1A and IB taken along the lines D-D in Fig. IB;

Fig. IE is a sectional view of the flow control device of Figs. 1A and IB taken along the lines E-E in Fig. IB;

Second Embodiment

Fig. 2A is a side view of an alternative flow-control valve with an infusion site in accordance with the invention;

Fig. 2B is a top view of the flow control device of Fig. 2A;

Fig. 2C is a cross-sectional view of the alternative infusion site device in accordance with the invention taken along the lines C-C of Fig 2B;

Fig. 2G is a partial assembly view of the infusion site device of Fig. 2C.

Third Embodiment

Fig. 3A is a side view of a fitting in accordance with the invention for actuating the infusion site device of Figs. 2A and 2B; Fig. 3B is a bottom view of the actuator fitting of

Fig. 3A;

Fig. 3C is a cross-sectional view of an infusion site activator device in accordance with the invention taken along the lines C-C of Fig 3B;

Fig. 3F is an enlarged bottom view of the infusion site activator device of Fig. 3B;

Fig. 3G is a partial sectional view of an alternative infusion site activator to prevent flow through the activator when disengaged from an injection site.

Additional Embodiments

Fig. 4A is a top view of a dual port infusion site device formed by coupling two devices of the kind shown in Fig. 2A to a common throughput channel;

Fig. 4B is a side view of the dual port infusion site device of Fig. 4A;

Fig. 4C is a top view of a tri-port infusion site device formed by adding a third port to the device of Fig. 4A; and

Fig. 4D is a top view of a tri-port infusion site device of Fig. 4A.

DETAILED DESCRIPTION (a) First Embodiment of the Invention

With reference to Figs. 1A and IB, a coupling device 10 in accordance with the invention is shown in side view in Fig. 1A, and in top view in a Fig. IB. The device 10 is formed by a base 10b and a cap 10c and incorporates the structure of the flow control device shown in Fig. IE. The cap 10c contains inlets 11a and 12a, respectively for a flow channel 11 and an auxiliary flow channel 12.

In Figs. 1A and IB, the inlet 12a of the auxiliary flow channel 12 serves as an infusion or injection site. The site 12a can be used for the needless infusion of liquids, as described below. Either the channel 11 or the channel 12 may be an inlet channel.

The mounts 14 and 15 receive a flow input and output connections (not shown in Fig. 1A) , such as tubing or Luer fittings. In the latter case, the mounts are adapted accordingly. Flow into the channel 11 is controlled in accordance with the operation of a control diaphragm lOd shown in Fig. IE, which gives details of the structure between the mounts 14 and 15.

As indicated in Fig. IE, the diaphragm lOd seals the channel 11 when there is upward flow in the channel 13. When there is downward flow through the housing 14, the diaphragm lOd is unseated. Conversely, when pressure against the member lOd is withdrawn, it is reseated. While this kind of diaphragm operation is commonly provided in a check valve, in the ordinary check valve there is a danger that the diaphragm lOd will not seat properly, causing a malfunction, such as leakage.

In accordance with the invention, to properly seat the diaphragm lOd on a ring seat lOr when there is no downward flow, the mount 15 includes a prebiasing flattened prong lOp on a platform lOf. "Prebiasing" means that a small force, i.e., bias, is exerted against the diaphragm lOd by the flat prong lOp when the diaphragm is in its equilibrium position. In addition to having the diaphragm lOd opened by flow, the invention provides the flexible cantilever 14c which stabilizes the diaphragm lOd, particularly when it is relatively thin, and restricts the extent to which the diaphragm lOd can be shifted sideways. The cantilever 14c is shown in sectional view in Fig. IB.

With respect to the cantilever 14c as shown in Figs. IE, it extends into the channel 11 from a side wall 14w by an arm 14a. The arm 14a of the cantilever 14c terminates in a spherically tipped prong 14p that makes touching contact with the diaphragm lOd. The cantilever is proportioned to provide spring tension against the diaphragm lOd without deforming it. Any such deformation could distort the diaphragm and interfere with its seating against the ring seat lOr. While the cantilever 14c is needed only for relatively thin diaphragms, it is of use generally for thicker diaphragms, even where the structure relative to the ring seat lOr is otherwise suitable for preventing undesired diaphragm shifts. In essence the cantilever 14p acts to stabilize the diaphragm against inadvertent lateral shifts in position with respect to the flattened prong lOp.

Flow from the respective channels 11 and 12 is selectively combined in the output channel 13 in accordance with the operation of the control diaphragm lOd shown in Fig. IE, which is related by Fig. 1C to Fig. ID, the latter giving details for the infusion site below the inlet 12a.

As indicated in Fig. ID, a bell-shaped plug 24, with an interior void 24v, is positioned within the auxiliary flow channel 12. The neck of the plug 24 protrudes through the inlet 12a, and the shoulder of the plug 24 forms a seal just below the inlet 12a.

As indicated in Fig. ID a bell-shaped plug 24, with an interior void 24v, is positioned within the auxiliary flow channel 12. The neck 24n of the plug 24 does not protrude through the inlet 12a, and the shoulder 24r of the plug 24 forms a seal with the cap 10c, just below the inlet 12a. The bottom 24b of the plug 24 outwardly diverges into a flange 24f, which rests upon supporting buttresses 26 in the base member 10b.

It will be appreciated that when the cap 10c is joined to the base 10b, the connection is secured by ultrasonic welding in a trough as indicated at position lOw. After plug activation, in order to permit flow F to the valve of Fig. IE throught the connector 17, the plug 24 is supported on spaced apart and radially extending buttresses 26, which are radially extending individual spokes 26-1 through 26-9, of which the spokes 26-1 through 26-5 are shown in Fig. ID. Because of arcuate spacing between the spokes, the flow into the channel 12, between the inner wall of the cap 10c and the outer wall of the bell-shaped plug 24, is directed to the bottom 26b shown in Fig. IE, and thence into the connector 17 by dual channels 16-1 and 16-2. (c) Second Embodiment of the Invention

A modification of the injection site device 10 in Fig. ID is shown in Fig. 2C, where the site 20 has been adapted for Luer operation. Accordingly, the base 10b of Fig. ID is modified to form an outlet Luer structure 20a, with a Luer taper extension prong 23p. Luer threads 23t, shown in outline, are positioned along the interior wall 23w that surrounds the Luer taper extension prong 23p.

As in the case of Fig. ID, the outlet structure 20a is welded to the mount 20b at positions 20w. However, by contrast with Fig. ID, where the flow F moved into a connector 17, in Fig. 2C the output flow is in a channel 22 since the bottom 26b of Fig. ID has been removed and replaced by an open channel indicated by the arrow D. As in Fig. ID, the valve 20 of Fig. 2C includes a compressible plug that is supported by buttresses with an arcuate spacing. However, the plug 24' of Fig. 2C is a modification of the plug 24 in Fig. ID.

Fig. 2G shows a sectional view of the device 20, taken along before final assembly, and engagement of the parts 20a and 20b by ultrasonic welding at the projection 20w shown in Fig. 2G, to produce the resulting structure of Fig. 2C.

In the modified plug 24' , a longitudinal slot 24s extends below the neck 24n to a foot portion 24f. The slot promotes the desired collapse of the plug 24' when it is activated as described below, and additionally can provide an additional flow path when the device is activated. While there are two side slots 24s in the plug 24' of Fig. 2C, it will be appreciated that other or fewer slots may be included. The slots can have varying widths depending upon the composition of the plug 24' and the nature of the adaptor with which it is used.

In addition, the head of the plug 24' does not extend outwardly of the inlet 22a, but instead, has a level surface 24e that is substantially in planar alignment with the outermost surface 20e of the mount 20b.

(d) Third Embodiment of the Invention

In order to activate the flow control device of Figs. 2A and 2C, the invention also provides the fitting 30 shown in side view in Fig. 3A and in bottom view in Fig. 3B.

As indicated in the cross sectional view of Fig. 3C, the fitting 30 is formed by a neck 32 extending from a mount 33. The neck 32 encloses a passageway 31 for the throughflow of fluid. The outflow portion of the neck 32 terminates in prongs 36-1 through 36-4, as shown in Fig. 3B, with only prongs 36-1 and 36-4 visible in Fig. 3C. The individual prongs 36-1 through 36-4 are separated by grooves 36g. The inlet portion of the mount 32 includes Luer fittings 35-1 and 35-2. The mount 33 includes channels 37-1 and 37-2, shown in Figs. 3A and 3B, with only channel 37-1 visible in Fig. 3C. Each of the channels 37-1 and 37-2 commences at an inlet in the base of the mount 33 and terminates in an opening in the side wall of the mount 33. Thus, the channel 37-1 shown in Fig. 3C and in Fig. 3B commences at an inlet 37-lb and terminates in an opening 37- la. The purpose of the channels 37-1 and 37-2 is to engage projections, such as the projections 25-1 and 25-2 of Figs. ID, 2C, 1G and 2E. As a result, the application of rotational force to the mount 33 while the channels 37-1 and 37-2 engage the projections 25-1 and 25-2 brings the prongs 36-1 through 36-4 into contact with the plug 24 of Figs. ID and 2C. Simultaneously an elastomeric washer 34 within the mount 33 an encircling the prongs 36-1 through 36-4 seals the inlets 22a of Figs. ID and 2C. The engagement operation is facilitated by the use of the knurled outer ring 35 of the mount 33. Details of the knurled ring 35 are shown in Fig. 3A which also illustrates the range over which the channel 37-1 extends. An enlarged bottom view of the fitting 31 is shown in Fig. 3F.

An alternative infusion site activator 30'is illustrated in a partial sectional view of Fig. 3G for preventing flow from the activator when disengaged from an injection site, such as the site 20 also shown in partial sectional view in Fig. 3G. As in the case of the fitting 30 of Fig. 3C, the alternative fitting 30' includes a sealing ring 34, but the channel 31 is provided with a plug 36' similar to the plug 24 of Figs. ID and 2C. In addition, the lower portion of the neck 32* terminates in a recessed surface 32r within the sealing ring 34. The recessed surface 32r is similar in configuration to the prong 36g and groove 36-1/4 arrangement of Fig. 3F. The partially illustrated infusion site device 20 of Fig. 3G includes the plug 24 and the wall 20b which is shown in detail in Fig. 2C.

In operation of the alternative actuator 30', the sealing ring 34 is brought into engagement with the surface 20b of the device 20. After the seal is effectuated, the plug 24 depresses the plug 36' and thus creates a passageway for the flow of fluid through the fitting 30'. Further engagement between the fitting 30' and the device 20 brings the recessed surface 32r into contact with the tip of the plug 24, depressing it and opening a channel into the device 20 so that fluid can flow around the plug 36' into the recesses of the surface 32r and then around the plug 24. When the fitting 30' is uncoupled from the device 20, the plug 36' is reseated, preventing any further flow of fluid.

(e) Additional Embodiments

The embodiments of Figs. 1A and IB, and Figs. 2A and 2B are single port infusion devices. The invention also includes multiple port infusion devices as shown in Figs. 4A through 4D.

In particular, the device 40 of Figs. 4A and 4B has 2 circumferentially mounted ports 42a and 42b, similar to the ports 12a of Figs. 1A and IB and the port 22a of Figs. 2A and 2B. The housings 44 and 45 may or may not include the flow control diaphragm lOd of Fig. IE, and generally omit it. A tri-port infusion site device similar to that of Figs. 4A and 4B, except for having a third site 42c, is shown in Figs. 4C and 4D.

Claims

What is claimed is

1. A flow control device comprising an inlet channel for the flow of fluid; an outlet channel connected to said inlet channel and disposed with respect thereto to serve as a conduit for at least a portion of said flow; means between the inlet and outlet channels for controlling flow; and cantilever means for stabilizing the flow controlling means.

2. A flow control device in accordance with claim 1 which comprises

(a) a ring seat within said inlet channel;

(b) an arm for said cantilever means extending within said inlet channel from said ring seat and terminating in a cantilever prong; and

(c) a control diaphragm in tangential contact with said ring seat and said cantilever prong.

3. Apparatus as defined in claim l further including a second inlet channel; movable means sealing said second inlet channel and having a central portion for regulating flow at said second inlet by the extent to which said central portion is moved; and means for connecting said second inlet channel to said outlet channel; said regulating means having a surface coincident with and outer surface at the entry of said second inlet channel and comprising a bell-shaped member with a slotted side wall and engageable by a fitting that maintains said second inlet channel in open condition, further including means for permitting the activation of said regulating means by a member external to said flow control device; wherein said apparatus comprises an injection site valve for needleless infusion of a fluid and said movable means can be depressed from its seat for needleless infusion.

4. Apparatus as defined in claim 1 wherein said cantilever means extends from a wall of said inlet partially thereacross into flexible contact with said flow controlling means comprising a diaphragm which is bowed under pressure into said inlet channel.

5. Apparatus as defined in claim 2 wherein said regulating means comprises a bell-shaped member having an upper portion at the entry of said inlet channel and walls facing the interior of said inlet channel.

6. Apparatus as defined in claim 1 wherein said inlet channel has an axial direction and said controlling means comprises a diaphragm with opposed sides, one of which is bowed under pressure by a prong extending in said axial direction, and the other side is freely and tangentially contacted by said cantilever means.

7. Apparatus as defined in claim 6 wherein said diaphragm is positioned by said prong against an annular seat and is movable therefrom; and said cantilever means is flexible and limits lateral movement of said diaphragm.

8. Apparatus as defined in claim 6 wherein said cantilever means contacting said diaphragm has a spherical surface engaging said diaphragm over a smaller area than the engagement of said flattened prong with said diaphragm.

9. Apparatus as defined in claim 1 wherein an additional flow control device is connected to said outlet; thereby to adapt said outlet channel as a common channel for a plurality of flow control sites.

10. The method of controlling fluid flow which comprises the steps of:

(1) stabilizing a freely-movable diaphragm sealing an inlet channel; and

(2) depressing said stabilized diaphragm to permit the flow of fluid to an outlet; and/or

(3) connecting said outlet as a common channel for a plurality of flow control devices; and/or

(4) stabilizing said diaphragm by flexing a cantilever that freely and tangentially contacts said diaphragm; and/or

(5) directionally controlling the flow of fluid by providing a branch channel connected to said outlet for serving as a conduit for at least a portion of said flow; and controlling flow into said branch channel; and/or

(6) preventing said diaphragm from being sucked into said branch channel.