GB2027169A

GB2027169A - One-way low pressure valve

Info

Publication number: GB2027169A
Application number: GB7919541A
Authority: GB
Original assignee: Imed Corp
Current assignee: Imed Corp
Priority date: 1978-06-02
Filing date: 1979-06-05
Publication date: 1980-02-13
Also published as: GB2027169B; DE2922940A1

Abstract

The valve housing comprises interfitting parts 10 and 12 of which part 10 has a tube 14 whose end projects into the housing and is covered by a resilient cap 32. A radial slot 18 allows incoming fluid to pass between the outer surface of the tube 14 and the tubular portion 34 of the cap as shown by arrows 40. Flow in the opposite direction is prevented because the fluid pressure forces the cap against the end of the tube 14. <IMAGE>

Description

SPECIFICATION One-way low p#ressure valve This invention relates to valve for providing the passage of fluid at low pressures in a particular direction and for preventing the passage of fluid at any pressures in the opposite direction. The valve is especially adapted to be used in the introduction of intravenous fluids to a patient. The valve is also advantageous because it includes a resilient cap which serves as the control member for the valve and which is free at each position for displacement at such position relative to other members in the valve so that the valve is adaptable for optimum operation under all conditions.

Care of patients is becoming increasingly complex and increasingly refined as the medical profession discovers the subtleties involved in such care. For example, the introduction of intravenous fluid into a patient has become of increasing concern in the medical profession. It is important that such intravenous fluid be introduced into the patient at a controlled rate dependent upon the body characteristics of the patient. These body characteristics can vary as the patient recovers from a serious operation.

Equipment has been provided for controlling introduction of fluid into a patient at a controlled rate. In such equipment, fluid is introduced from a source into a storage member such as a chamber at first intervals and the fluid from the storage chamber is then introduced into the patient at second intervals which alternate with the first intervals. During the time that the intravenous fluid is introduced from the source into the storage chamber, flow of fluid from the source or from the storage chamber to the patient must be prevented. During the flow of fluid from the storage chamber to the patient flow of fluid from the source to the storage chamber must be prevented in order to make certain that the amount of fluid introduced to the storage chamber, and transferred from the storage chamber to the patient, is precisely controlled.

Various attempts have been made to provide a satisfactory valve which will operate without any moving parts and which will insure that fluid will flow at low pressures in a first direction and will not be able to flow at any pressures in an opposite direction. Although considerable effort has been made to provide such a valve, such efforts have not been entirely successful. For example, it has not been entirely possible to insure, in a valve without any moving parts, that the fluid will flow even at low pressures in the first direction and will not flow in the opposite direction regardless of the pressures imposed. Furthermore, one-way in the prior art without moving parts have been difficult to manufacture and assemble.

This invention provides a one-way valve which overcomes the disadvantages set forth above. The one-way valve of this invention insures, without any moving parts, that the valve will pass fluid in a first direction even at low fluid pressures and that the valve will not pass fluid in the opposite direction whether at low or high pressures. The valve is also relatively simple in construction and is easy to assemble.

In one embodiment of the invention, a one-way valve operative at low pressures is formed from first and second members. Each of the first and second members has a hollow tube. An aperture is disposed at a first end of the first tube in transverse communication with the hollow opening in the tube. An aperture may also be disposed at one end of the second tube in transverse communication with the hollow opening in the tube. Means are provided for retaining the first and second members in interfitting relationship with the two tubes spaced from each other. A cap made from a resilient material is disposed on the first end of the first tube in pressed-fit relationship with the tube. The cap includes a barrel portion and a cover disposed across the first end of the tube.The cap is free at each postion for displacement at each such position relative to the tube. The cover on the cap is disposed adjacent the aperture in the second tube. In this way, fluid is able to flow at a low pressure from the first tube into the second tube but is not able to flow from the second tube into the first tube at any pressure.

In the drawings: Figure 1 is an exploded sectional view of one embodiment of the invention; and Figure 2 is an end view of one of the members in the embodiment shown in Figure 1 and is taken substantially on the line 2-2 of Figure 1; Figure 3 is and end view of another of the members in the embodiment shown in Figure 1 and is taken substantially on the line 3-3 of Figure 1; Figure 4 is an enlarged sectional view in assembled relationship of the embodiment shown in Figure 1 and illustrates the path in which fluid flows in one direction through such embodiment: and Figure 5 is an enlarged sectional view similar to that shown in Figure 4 and illustrates how fluid is unable to flow in the opposite direction through such embodiment.

In one embodiment of the invention, a low pressure one-way valve is formed from a pair of members generally illustrated at 10 and 12. The members 10 and 12 are made from a suitable material preferably having resilient properties. The member 10 includes a first tube 14 preferably having a cylindrical configuration. The tube 14 is provided with an axial opening 16 extending through the tube. An aperture 18 is disposed at a first end of the tube 1 6 in transverse and communicative relationship with the opening 16.

For example, the aperture 1 8 may be disposed radially. A flange 20 extends from the tube 14 at an intermediate position along the length of the tube. A lip 22 from the outer periphery of the flange 20 and in concentric relationship with the tube 14.

The member 12 includes a tube 24 having an axial opening 26 extending through the tube. An aperture 27 may be disposed at one end of the tube 24 in transverse and communicative relationship with the opening 26. A flange 28 is provided at one end of the tube 24. A collar 29 extends from the outer periphery of the flange 28 in a direction opposite to the tube and in concentric relationship with the tube. A stop 30 extends outwardly from the collar 29 at an intermediate position along the length of the collar.

The collar 29 is shaped to be disposed on the tube 14 and to be extended into the space between the tube 14 and the lip 22 in pressed-fit relationship to the tube and the lip. Furthermore, the stop 30 on the collar 29 is disposed to abut the end of the lip 22 so as to limit the travel of the collar into the space between the tube 14 and the lip 22.

A cap generally indicated at 32 may be made from an elastomeric material such as silicone rubber, rubber or a flexible vinyl. The cap 32 is defined by tubular or barrel portion 34 and a cover 36. The tubular or barrel portion 34 is preferably cylindrical and is provided with dimensions to be press-fit on the tube 14 at the end of the tube adjacent the transverse aperture 18. When the tubular portion 34 is disposed on the tube 14, the tubular portion and the cover 36 close the transverse opening 18.

When fluid flows through the opening 16 in the member 10, the fluid is able to leak outwardly through the opening 16 and the aperture 18 and along the inner wall of the tubular portion 34. This is illustrated by arrows 40 in Figure 4. This fluid fills the space between the tubes 10 and 12 and then flows through the opening 26 in the tube 24 to the patient. The rate of flow of the fluid through the opening 26 in the tube 24 to the patient corresponds to the rate at which fluid flows through the opening 16 and the aperture 18 in the tube 14.

Since the fluid leaks through the transverse opening 18 and along the inner wall of the tubular portion 34 of the cap, the flow of fluid from the tube 10 through the tube 12 to the patient occurs at low pressures. However, no fluid is able to flow the tube 12 to the tube 10 even at high pressures.

This results from the fact that, when fluid flows through the tube 12 toward the tube 10 the fluid acts on the resilient cap 32 to press the cap tightly on the tube 10. This is illustrated by the arrows 42 in Figure 5.

The one-way valve of this invention offers certain advantages over the prior art. It provides for a flow of fluid in a first direction at low pressures but prevents a flow of fluid in the opposite direction even at high pressures. It is easy to assemble, particularly since the cap 32 is not attached to any other member in the valve but is press-fit on the tube 10. Since the cap 32 is not attached to the tube 10 or the tube 12, it is adaptable in position on the tube 10 to assure that it operates reliably under different conditions which may be encountered. It is formed from a minimum number of parts and is reliable even though it it simple in construction. It is also quite easy to assemble.

The one-way valve also has other advantages of some importance over the prior art. For example, the cap 32 has a distinct ability to be sealed or seated on the tube 10 in the presence of foreign matter. The cap 32 also has a distinct ability to be sealed or seated on the tube 1 0 even with irregularities in the dimensions of the tube.

Even under such circumstances, the one-way valve of this invention is able to provide for a controlled flow of fluid at low pressures in one direction and to prevent the flow of fluid in the opposite direction.

Although this application has been disclosed and illustrated with reference to particular applications, the principles involved are susceptible of numerous other applications which will be apparent to persons skilled in the art. The invention is, therefore, to be limited only as indicated by the scope of the appended claims.

Claims

1. In combination for providing a controlled flow of fluid at a low pressure in a first direction and for preventing the flow of fluid in a second direction opposite to the first direction, a first member including a first tube and an opening extending through the tube and an aperture disposed at a first end of the tube in transverse communication with the opening, a second member including a second tube and an opening extending through the tube, and a cap made from a resilient material and disposed on the first tube at a first end of the first tube in pressed-fit relationship to the first tube and free at each position for displacement at each such position relative to the tube, the first and second members being provided with portions respectively providing for a close fit between the members and being provided with portions limiting the extent of this interfitting relationship to maintain the first and second tubes in spaced relationship with the cap disposed on the first tube and to provide for a flow of fluid from the first tube into the second tube and to prevent a flow of fluid from the second tube into the first tube.

2. The combination set forth in Claim 1 wherein the first tube is provided with a cylindrical configuration and the cap is provided with a cylindrical configuration closed at one end to close the first end of the tube.

3. The combination set forth in Claim 2 wherein the closed end of the cap is spaced from the second tube with the first and second members disposed in interfitting relationship to provide for a flow of fluid from the first tube to the second tube.

4. The combination set forth in Claim 1 wherein the cap is defined by a cylindrical body and a cover disposed on the first end of the first tube and the aperture in the first tube extends into communicating relationship with the cylindrical body of the cap.

5. In combination for providing a controlled flow of fluid at a low pressure in a first direction and for preventing the flow of fluid in a second direction opposite to the first direction, a first member including a first tube and an opening extending through the tube and an aperture disposed at a first end of the tube in communication with the opening, a second member including a second tube and an opening extending through the tube, a cap made from a resilient material and disposed on the first tube at the first end of the first tube in pressed-fit relationship with the first tube and free at each position for displacement at such position relative to the tube, one of the tubes having a flange extending outwardly from the periphery of the tube and having a lip at the periphery of the flange, the other tube having a flange extending outwardly from the periphery of the tube and a collar disposed at the periphery of the flange and constructed to define a pressed fit with the lip and having a stop portion extending peripherally outwardly from the collar to limit the movement of the collar into the lip to a position where the cap is separated from the flange on the collar.

6. In the combination set forth in Claim 5, the cap being closed at one end and being provided with a tubular portion constructed to be press-fit on the first tube to close the first end of the first tube and the aperture extending to the tubular portion of the cap to provide for a flow of fluid from the first tube into the second tube.

7. The combination set forth in Claim 6, including, the first tube being cylindrical and the opening extending axially through the first tube and the aperture being radial and the tubular portion of the cap being cylindrical and the second tube being cylindrical and the opening extending axially through the second tube.

8. The combination set forth in Claim 7, including, the cap being made from a thin plastic material having properties of being easily deformed by external forces and of returning to its original form after the elimination of such forces.

9. In combination for providing for a flow of fluid at low pressures in a particular direction and for preventing the flow of fluid in a direction opposite to the particular direction, a first member including a hollow tube and a flange extending peripherally from the tube and a lip at the peripheral region of the flange, the tube being provided with a lateral aperture at a particular end, a flexible cap disposed on the tube in pressedfit relationship to the tube at the particular end and covering the lateral aperture and extending along the tube past the lateral aperture and free at each position for displacement at such position relative to the first member, and a second member including a hollow tube and a flange extending periphally from the tube and a collar portion at the peripheral region of the flange, the collar portion being constructed to be inserted into the lip on the first member in pressed-fit relationship with the lip, the second member further including a stop portion extending from the collar portion to engage the lip on the first member and limit the insertion of the collar portion into the lip so that the flange on the second member is displaced from the cap on the first member.

10. In the combination set forth in Claim 9, the flexible cap being provided with a hollow tubular portion and with a cover at one end of the tubular portion and the cover being disposed on the particular end of the first member.

1 A one-way valve comprising a housing formed in two parts one having an inlet passage and the other having an outlet passage, the inlet passage extending through a boss which projects within the housing and which has a lateral opening communicating with the passage, and a cap of resilient material being fitted over the boss whereby fluid emerging from the inlet passage through the lateral opening can pass between the cap and the boss and enter the housing whereas fluid cannot pass in the opposite direction because the cap is pressed against the boss by the fluid pressure.