GB2157805A

GB2157805A - Floating valve member

Info

Publication number: GB2157805A
Application number: GB08500465A
Authority: GB
Inventors: Thomas F Kiedrowski; Richard M Boyd
Original assignee: Minnesota Rubber Co
Current assignee: Minnesota Rubber and Plastics
Priority date: 1984-04-18
Filing date: 1985-01-08
Publication date: 1985-10-30
Also published as: IT1182136B; JPS60222677A; PT79662A; SE8501893L; NO845166L; DK554484A; IT8547576A0; IT8547576A1; ZA849402B; SE8501893D0; AU3662784A; NL8403749A; GB8500465D0; DE3445265A1; BE902234A; PT79662B; DK554484D0; FR2563315A1

Abstract

A valve member 22 floats in a liquid within a dispensing container 21 e.g. an IV bottle containing a saline solution. With the liquid level suitably receded the member 22 seals off the outlet of the dispensing container 21 by means of the sealing surface 26 resting on the valve seat 27. The maximum horizontal dimension of the member 22 is greater than the maximum vertical dimension so that the member is constrained to float in the attitude in which surface 26 engages seat 27. Thus surface imperfections, such as the parting line 28 and/or the gate member 30, will never engage seat 27. <IMAGE>

Description

SPECIFICATION Liquid floating check Background of the Invention Floating liquid check valves have heretofor been known, particularly in medical and industrial applications in which it has been important that no leakage whatever occurs once the floating valve engages the valve seat. For example, in medical applications it is frequently imperative and essential to the well being of the patient that no leakage occurs, and that the flow is cut off as the discharging container approaches empty condition, else air may be permitted to enter the blood vessels of the patient, with severely adverse consequences.

In such applications as described hereinabove, the check valve is generally molded of rubber which floats and engages the valve seat which surrounds the discharge port of the container as the upper level of fluid within the container approaches the discharge port.

Since all molded items have mold parting lines in the the form of a slight protrusion of rubber constituting an annular rib, such valves frequently leak. If the check valve orients itself in such a way that its parting line engages the valve seat, then fluid escapes along both sides of that parting line. In addition, although some parts may be molded by compression and hence will not have a gate, most molded items have a gate which is comprised of a small outwardly extending protrusion of rubber at the point at which the fluid rubber material is introduced into the interior of the mold. In the event the valve becomes so oriented that the gate engages the valve seat, again an imperfect seal will result with serious adverse consequences.

Various patents pertinent to the invention which are known include U.S. Pat. No.

4,188,173 issued to Lindsey; No. 4,276,898 issued to Ross; and No. 3,796,230 issued to Meripol.

Brief Summary of the Invention The invention is comprised of a floating fluid seal comprising a molded float body constructed and arranged to have major and minor dimensions with a pair of opposed upper and lower sides extending generally in the direction of the major axis and between which its minor dimensions are measured, the body having at least one surface extending along at least one of the sides which engages the valve seat which conventionally surrounds the discharge port of the dispensing container.

The float body is molded so that the parting line is located between the opposite sides and does not intersect the sealing surface. Likewise, it is molded so that its gate does not intersect its sealing surface. As a consequence, a higher improved seal is provided.

It is an object of our invention to provide an improved floating liquid valve for sealing off the valve seat of a fluid outlet which automatically, because of the construction, will oboviate the usual instances of leakage which are occasioned by engagement of the valve seat by the parting line or gate of the valve.

It is a further object of our invention to provide an improved liquid check valve for sealing off the valve seat of the fluid outlet of a dispensing container having an upright axis in which the valve is so constructed and arranged so that the hydrostatic pressures which play thereupon automatically and most effectively orient the valve so as to obviate engagement of the valve seat by either the parting line or the gate of the valve.

Brief Description of the Drawings Figure 1 is a side elevational view of a medical apparatus in which our improved fluid seal may be utilized.

Figure 2 is a vertical sectional view of one form of fluid dispenser having a floating check valve which constitutes part of the prior art, and illustrates the likelihood of an ineffective seal being provided.

Figure 3 is a vertical sectional view of a somewhat similar dispensing container with one of our improved liquid check valves being utilized therewith in.

Figure 4 is a fragmentary detailed view of the valve and valve seat shown in Fig. 3 on an enlarged scale and with the valve in sealing position.

Figure 5 is a side elevational view of the valve shown in Figs. 3 and 4 on an intermediate scale.

Figure 6 is a side elevational view of a second form of our invention.

Figure 7 is a side elevational view of a third form of our invention; and Figure 8 is a side elevational view of a forth and preferred form of the invention.

Detailed Description of the Invention Fig. 1 illustrates one application in which our invention may be readily utilized. As shown, it is comprised of the conventional support stand 10 which supports by means of a bale 11, a dispensing container 12 commonly known as an l.V. bottle. Such a container may hold any one of a number of solutions such as, for example, a saline solution. As shown in Fig. 1, the container 12 has a discharge tube 13 to which is applied a conventional stop cock or clamp 14, by means of which the discharge may be controlled. Carried at the lower end of the conduit or tube 13 is a dispensing container 15 in the form of a transparent observation tube having markings thereon to indicate the volume of the liquid which may be dispensed therethrough.Within the dispensing container 15, is a ball check valve 16 which is designed to act as a check valve when the level of the fluid within the container 15 approaches the discharge outlet 1 7. A second clamp or valve member 18 is applied to the discharge conduit 9 as a final control over the flow of fluid from the dispensing container.

Fig. 2 is an enlarged view of the dispensing container similar to the dispensing container 15 shown in Fig. 1 and better illustrates the conventional heretofore utilized ball check valve and associated valve seats. As shown, the check valve is in the form of a rubber ball 16 which floats in the liquid so as to extend slightly above the upper level 19 of the liquid.

A A valve seat 20 is provided at the discharge outlet and is located so that as the level of the the liquid descends, the ball 16 will engage the valve seat and seal off the same effectively, provided the parting line or gate of the ball valve does not engage the valve seat. In the latter event, leakage will occur with serious adverse consequences as hereinbefore described.

A second valve seat 20A may be provided, if desired, so that flow therethrough may be interrupted by the ball 16 when the top level of liquid rises sufficiently to cause the ball to bear thereagainst.

Fig. 3 shows a vertical sectional view of a dispensing container 21 similar in construction to the container 15 except that the valve seat is somewhat different. One of our improved liquid check valves is shown being utilized therewithin, however, to provide a more effective seal may be made of a flexible resilient elastomeric or of a plastic material.

This check valve 22, as shown, it has a specific gravity slightly less than the liquid 23 in which it is carried. It is generally spherical in shape, except that it has a pair of opposed planar upper and lower sides identified by the numerals 24 amd 25 respectively. These upper and lower sides, as shown, are parallel. In general, the valve element 22 has the shape of a ball having opposed upper and lower portions cut away therefrom. The annular area surrounding the periphery of the lower side 25 is slightly radiused to form an excellent sealing surface 26. This sealing surface is designed to engage and cooperate with the valve seat 27 provided at the lower end of the container 21. This can best be seen by reference to Fig. 4.

As best shown in Fig. 4, the valve member 22 is molded in such a way that its parting line 28 is disposed between the opposed sides 24 and 25 in such a way that it will never engage the valve seat 27. This is true because of the play of hydrostatic forces upon the unique shape of the valve element 22, since such forces will cause the valve member to orient itself so that its annular sealing surface 26 will always engage the valve seat 27. Preferably, the area surrounding the periphery of the upper side 24 is also slightly radiused in order to provide a second annular sealing surface 29 around the upper side 24 so that in the event that the check valve becomes upended because of unanticipated agitation within the fluid, the valve member will properly seal, even though it may become inverted.The sealing surface 29 will also serve to engage a valve seat located such as seat 20A, in the event such an application is desired.

It will also be noted that the gate member 30 of the valve 22 is located on the upper side 24. If desired, the gate may be located anywhere upon the exterior of the valve element, between the two annular sealing surfaces 27 and 29. All that is required is that it be located in such a manner that when the hydrostatic forces of the liquid come into play, the gate member will never engage the valve seat 27. In this manner, we are assured that neither the parting line 28, nor the gate 30, will at any time engage the valve seat 27 and therefore, a perfect seal will always be provided.

Fig. 5 shows a sealing member 22 in side elevation in a slightly smaller scale as compared to Fig. 4. It will be noted that the parting line 28 is disposed along the maximum dimensions of the valve member and that the distance between the upper side 24 and the lower side 25 constitutes the minor dimensions of the valve member. The minor dimensions (the distance between the sides 24 and 25) are approximately 75% of the major dimensions of the valve element. We have found that the relationship between the minor and major dimensions may vary. Thus, the minor dimensions may be within 10%-90% of the major dimensions. We have also found that the valve member will right itself more readily if the upper and lower sides are convex in shape as shown in Figs. 6 and 8.

Fig. 6 illustrates a second form of our invention. It will be noted that it has convex opposed upper and lower sides identified by the numerals 31 and 32 respectively. An annular radiused sealing surface 33 and 34 is carried by each of the sides and the parting line 35 is located along the major dimensions of the sealing member which has been identified generally by the numeral 36. The gate member 37 is carried by the upper side 31 within the annular sealing surface 33. It will be noted that the distance between the upper and lower sides 31 and 32 is approximately 40% of the major dimensions of the sealing member 36, as measured along the parting line 35.

Fig. 7 illustrates a third form 40 of our invention. As shown, it has opposed planar upper and lower sides identified by the numerals 41 and 42 respectively. It carries an annular sealing surface 43 surrounding its lower side 42 and an annular sealing surface 44 surrounding its upper surface 41. The parting line 45 is located along its major dimensions and its gate 46 is carried by its upper surface and is located within its annular sealing surface 44. The distance between the upper and lower sides 41, 42 constitutes the minor dimension which is approximately 25%-30% of its major dimension, as measured along the parting line 45.

The fourth and preferred form of our invention is shown in Fig. 8. By reference thereto, it will be seen that this valve member 50 is characterized by the convex upper and lower sides 51 and 52 respectively, having annular sealing surfaces 53 and 54 respectively. The parting line 55 is located along the major dimension of the valve member and the gate member 56 is carried by the upper surface 51. It will be noted that the minor dimension as measured between the upper and lower sides 51 and 52 is approximately 70% of the major dimensions as measured along the parting line 55.

Wherein herein we have used the term "float body" it is intended to connote a specific gravity slightly less than that of the liquid in which that body is to be utilized.

Thus, if the liquid is to be water, the specific quantity of the body will be slightly less than 1.0. The float bodies which we have found to be satisfactory have been moulded of elastomeric materials.

In use, our novel valve member functions similarly to the conventional upper ball check valve in that it floats within the liquid 23 which is to be dispensed and does not engage the valve seat 27 unless and until the upper level 19 of the liquid approaches the valve seat 27. When this occurs, the annular sealing surface of our liquid check valve engages the valve seat 27 and perfects a seal, along which no leakage will occur because the valve member will have been previously oriented by the hydrostatic forces which play thereupon so that it will be impossible for the parting line or the gate member of the valve to engage the valve seat 27. Thus, the user of the invention is at all times assured of a perfect seal since the hydrostatic forces, when the valve member is so shaped, forces the valve member to be automatically oriented within the fluid in such a manner that neither the parting line nor the gate member can come into contact with the valve seat.

In considering the invention, it should be remembered that the present disclosure is illustrative only and the scope of the invention should be determined by the appended

Claims

claims. CLAIMS

1. A device for sealing off a fluid passage by means of a sealing surface on a floating check which engages a complementary valve seat when the level of the fluid in which the check floats brings the sealing surface and valve seat together, wherein the check is shaped to float in a stable attitude in which the sealing surface will engage the valve seat, and the maximum horizontal dimension of the check measured when the check is in the said attitude being greater than the maximum vertical dimension such that the check is constrained to remain floating in that attitude.

2. A device as claimed in claim 1, wherein any surface imperfections on the check due to limitations of manufacture, such as gate marks and parting lines, are disposed on surfaces other than the sealing surface.

3. A device as claimed in claim 1 or 2, wherein the sealing surface and the valve seat are annular about a vertical axis.

4. A device as claimed in claim 3, wherein the sealing surface consists of a radiused collar having a greater and a lesser circumference, the surface of the check bounded by the lesser circumference of the collar being substantially flat.

5. A device as claimed in claim 4, wherein the gate mark is disposed on the surface bounded by the lesser circumference of the sealing surface.

6. A device as claimed in claim 1 or 2, wherein the sealing surface consists of a convex cap.

7. A device as claimed in any of the preceding claims, wherein the check consists of similar upper and lower portions about a horizontal centre line.

8. A device as claimed in claim 7, wherein a parting line is disposed between the upper and lower portions.

9. A device as claimed in claim 8, wherein a sidewall extends between the upper and lower portions.

10. A device as claimed in any of the preceding claims wherein the check is circular about the vertical axis.

11. A device as claimed in claim 10, wherein the maximum vertical dimension of the check is between 10% and 90% of the maximum horizontal dimension.

12. A device as claimed in claim 10, wherein the maximum vertical dimension of the check is between 10% and 75% of the maximum horizontal dimension.

13. A device as claimed in claim 10, wherein the maximum vertical dimension of the check is 40% of the maximum horizontal dimension.

14. A device as claimed in claim 10, wherein the maximum vertical dimension of the check is 75% of the maximum horizontal dimension.

1 5. A device as claimed in any of the preceding claims, wherein the check is made of elastomeric material.

CLAIMS Amendments to the claims have been filed, and have the following effect:~ Claims 1, 2, 4, 7 and 10 to 15 above have been deleted and textually amended.

New or textually amended claims have been filed as follows:~

1. A device for sealing off a liquid passage by means of a sealing surface on a moulded ball valve which floats on the liquid and engages a complementary valve seat when the level of the liquid in which the ball valve floats brings the sealing surface and valve seat together, wherein the ball valve is shaped to float in a stable attitude in which the sealing surface will engage the valve seat, the maximum horizontal dimension of the ball valve measured when the ball valve is in the said attitude being greater than the maximum vertical dimension such that the ball valve is constrained to remain floating in that attitude.

2. A device as claimed in claim 1, wherein any surface imperfections on the ball valve due to limitations of manufacture, such as gate marks and parting lines, are disposed on surfaces other than the sealing surface.

4. A device as claimed in claim 3, wherein the sealing surface consists of a radiused collar having a greater and a lesser circumference, the surface of the ball valve bounded by the lesser circumference of the collar being substantially flat.

7. A device as claimed in any of the preceding claims, wherein the ball valve consists of similar upper and lower portions obout a horizontal centre line.

1 0. A device as claimed in any of the preceding claims wherein the ball valve is circular about the vertical axis.

11. A device as claimed in claim 10, wherein the maximum vertical dimension of the ball valve is between 10% and 90% of the maximum horizontal dimension.

12. A device as claimed in claim 10, wherein the maximum vertical dimension of the ball valve is between 10% and 75% of the maximum horizontal dimension.

13. A device as claimed in claim 10.

wherein the maximum vertical dimension of the ball valve is 40% of the maximum horizontal dimension.

14. A device as claimed in claim 10, wherein the maximum vertical dimension of the ball valve is 75% of the maximum horizontal dimension.

15. A device as claimed in any of the preceding claims, wherein the ball valve is made of elastomeric material.

16. A device substantially as described herein with reference to the accompanying drawing.