Closure System For Sterile Medical Liquid Container

Abstract

A closure system for a sterile medical liquid bottle that has a neck with external threads and an annular neck bead below these threads. This closure system includes an inner screw cap, an outer tear-off cap, and a rubber cup disposed between these two caps. The rubber cup is crimpingly held against the bottle neck bead in a bacteria-tight joint to protect the threaded area of the inner screw cap. In a procedure for opening the container to reduce chance of contamination, the outer closure is first torn off and crimping pressure relieved from the rubber cup, and then the cup is rotated to break loose the inner screw cap without completely removing it. Next, the rubber cup is vertically separated from the screw cap while the screw cap is still engaged with the bottle threads. After removal of the resilient cup the screw cap is easily unscrewed from the sterile threaded area.

Description

BACKGROUND

Sterile medical liquids have been used extensively in various hospital and medical procedures. Examples of such liquids are intravenous liquids fed directly into a patient's vein to replenish body liquid or correct electrolyte imbalance. Another type of sterile medical liquid is a "pouring" liquid used for washing wounds, incisions, etc., during surgery. Both intravenous solutions and pouring solutions require an extremely high degree of sterility protection from the container in which they are shipped, stored and dispensed.

One of the most critical portions of a sterile medical liquid container is in its closure system. This is because the closure is the portion of the container system that is handled most during opening for connecting to other containers, administration sets, etc., and also during pouring liquid in surgery. Manufacturers of sterile medical liquid container systems are constantly striving to improve the quality and reliability of such container systems. In the past it has been common practice to use a double closure system that included an inner cap over a neck or spout of a bottle and an outer sterility protective cap to protect the inner cap prior to opening the container for dispensing its sterile medical liquid. One such container with its double closure system is shown in the Olson U.S. Pat. No. 3,443,711.

A particular problem with such double closures is that once the outer closure is removed the inner closure is often so securely tightened on the bottle neck it is difficult to break loose and thus increases the chances of accidentally contaminating the threads and neck portion of the bottle by the operator touching them with his hand. Also, if the inner and outer closures are not firmly sealed to each other, a liquid contacting an outside of the closure system might work its way underneath the outer closure and wet the external surface of the inner closure.

SUMMARY OF THE INVENTION

I have overcome the previously mentioned problems in double closure systems for sterile medical liquid by providing a resilient rubber cup disposed between the inner and outer closures of such medical liquid container systems. This rubber cup has a skirt that is compressed against a neck bead of the container by the outer closure and protects the sterility of an inner screw cap skirt even if the outer closure should come in contact with a nonsterile liquid. Upon removal of the outer closure to gain access to the container the rubber skirt is relieved from the bead and can rotationally slide against this bead and act as a protective cover for the entire structure of the inner screw cap closure. This rubber cup has a portion of its skirt that overlies and frictionally engages the inner screw cap so an operator can grasp the rubber cup and use it to break the inner screw cap loose from the bottle while it is still encased by the sterile inner surface of the rubber cup.

The opening procedure continues with vertically lifting the rubber cup from the inner screw cap while such cap is still intermeshed with the screw threads (but loosened). This vertical lifting of the rubber cup leaves a sterile outer surface over the entire inner screw cap. Since the screw cap has been previously loosened the operator can then very easily use thumb and forefinger to completely unscrew the screw cap and lift it from the bottle neck. There is no need to manually wrestle with the bottle and screw cap to break it loose.

The various forms of my invention will be understood relative to the attached drawings.

THE DRAWINGS

FIG. 1 is a front perspective view of the sterile medical liquid container and closure as it is ready for shipment and storage;

FIG. 2 is an enlarged exploded front perspective view showing an embodiment of the three elements of the closure system;

FIG. 3 is a further enlarged sectional view through the closure system of FIG. 2 mounted on a glass bottle;

FIG. 4 is a top perspective view showing the combination of another embodiment of an outer cap structure and resilient cup;

FIG. 5 is a perspective top view of the combination of still another embodiment of an outer cap and a resilient cup;

FIG. 6 is an enlarged sectional view taken along line 6--6 of FIG. 5;

FIG. 7 is a top perspective view showing another embodiment of the outer cap structure and its relationship to the resilient cup member;

FIG. 8 is an enlarged sectional view taken along line 8--8 of FIG. 7;

FIGS. 9 through 12 show the sequences of steps in opening the closure system of this invention so as to lessen the risks of contaminating the screw threads and mouth structure of the bottle.

DETAILED DESCRIPTION

Turning now to the drawings, FIG. 1 shows the bottle 1 with one embodiment of the closure system 2 attached to the bottle neck. In the enlarged exploded view of FIG. 2 the closure system is shown as three separate elements, an inner screw cap 3, an outer tear-off cap 4, and a rubber cup 5 spaced between the screw cap and outer tear-off cap. The inner screw cap fits over a neck 6 of the bottle which has external screw threads 7. There is an annular neck bead 8 spaced below these threads. The bottle includes a depressed groove system 9 adjacent its bottom for receiving a conventional bail and band system for suspending the bottle upside down if desired. The bottle 1 shown in FIG. 2 is of a rigid glass construction but could be made of other materials such as thermoplastis if desired.

The three part closure system assembled to the bottle neck is best shown in the enlarged sectional view of FIG. 3. Here the glass bottle neck 6 terminates at its upper end in a dispensing mouth 10 surrounded by a lip 11. The screw cap 3 includes a top wall 12 and a depending threaded skirt 13 that threadingly engages with screw threads 7 of the bottle neck. The bottom of the screw cap's skirt 13 is turned outwardly to form a protruding flange 14. Directly below flange 14 is neck bead 8 which is integral with the bottle. The screw cap has a resilient disc-like gasket member 15 which seals against lip 11 of the bottle neck to provide a bacteria-tight seal with the bottle.

The rubber cup member 5 that fits over the screw cap 3 includes a top wall 16 and a depending skirt 17 that overlies the threaded skirt portion of the screw cap. Skirt 17 of the rubber cup engages both the protruding flange 14 of the screw cap and bead 8 of the bottle neck.

Fitting over the rubber cup member is the outer tear-off cap 5 that includes a top wall 19 and a depending skirt 20. This depending skirt 20 is crimped inwardly at a lower portion 21 to crimpingly squeeze the rubber cup skirt 17 against annular glass bead 8 to form a bacteria-tight seal below the threaded portion of the screw cap skirt 13. With this arrangement the threaded area of the screw cap and bottle are protected from bacterial contamination even if the outer portion of the bottle enclosure system should come in contact with nonsterile liquids or become contaminated by manually handling the system. Several different embodiments of the outer cap and resilient cup sub-combination of the three part closure system are shown in the drawings.

FIG. 4 shows one embodiment of the combination. Here the outer tear-off cap includes a top wall 22 with a depending skirt 23. The top wall has generally U-shaped groove 24 that extends only partially through said top wall 22. The purpose of this groove is to provide a tear-out portion of the top wall without having a cut extending completely through the top wall to provide a bacterial contamination path. This U-shaped groove extends down skirt 23 groove legs 25 and 26. The grooves in skirt 23 likewise do not proceed through the entire thickness of the skirt. A pull ring 27 is attached to the tear-out center portion and when pulled with sufficient force rips apart the center portion 28 and breaks at least one of the grooves 25 or 26 completely to the bottom of skirt 23. Thus the outer tear-apart cap can be removed from the inner rubber cup.

The rubber cup construction shown in combination with the outer tear-off cap in FIG. 4 includes a top wall 30 and a depending skirt 31. This rubber cup also has a series of ribs 32 and 33 that extend partially across its top surface and partially down its skirt. The purpose of these ribs are two-fold. First they add structural rigidity to the rubber cup member. Secondly, and very importantly, they provide a vent system between the rubber cup and the outer tear-off cap during assembly. This venting in a space between ribs 32 and 33 prevents the rubber cup from acting as a pressure piston inside the outer tear-off cap creating a pressurized air pocket during assembly.

FIG. 5 shows another embodiment of the outer cap and rubber cup combination. Here the outer tear-off cap 35 has a series of louvers 36 and 37 in its skirt. The purpose of these louvers which are shown in large sectional view in FIG. 6 is to allow air to dry out any liquid that might get between the rubber cup 40 and the outer tear-off cap 35. As shown in FIG. 5, the inner rubber cup 40 does not include the ribs as shown in the FIG. 4 version. Thus, during assembly of these two parts any piston action of the air will force it out through louver 36 or C-shaped slot in top of outer cap. This louver structure is formed by stamping operation which displaces a metal portion 42 from skirt 43 and provides a passage at 44. If desired, punched holes in the outer cap skirt could be used in lieu of the louvers.

Still another embodiment of the outer tear-off cap and rubber cup combination is shown in FIG. 7. Here the rubber cup 45 is identical to that shown in FIG. 4. However, the outer tear-off cap 46 includes a top wall 47 that has a C-shaped slot 48 extending completely through top wall 47. This slot 48 connects with grooves 49 and 50 which extend partly down the skirt 51 of the tear-off closure cap. A center portion 52 of the closure cap can be grasped and pulled to rip apart skirt 51 at either groove 49 or 50. This is the preferred embodiment in that it is easy to assembly the two parts and the C-shaped slot aids in easy tearing apart of the outer cap.

In all versions of the outer tear-off cap and rubber cup combination it is important to note that at least one (tear-off cap or rubber cup) includes a coated wall system across its entire top wall and depending skirt. In FIGS. 4, 5 and 6 the rubber cup is such closed member. The venting structure occurs outside the rubber cup. In the FIG. 2 embodiment the rubber cup 5 includes a vent hole 53. Here, the outer cap 4 forms the closed wall system and air is forced out through hole 53 during subassembly of the rubber cup and outer cap. The outer cap 4 is identical with that of FIG. 4, but in FIG. 2 the rubber cup does not have the ribs. It is also possible to use different combinations of the outer tear-off cap and rubber cup shown in these drawings.

The rubber cup 45 of FIG. 7 is shown in enlarged cross-sectional view in FIG. 8. Here it is shown that the top wall 54, which is 0.100 to 0.150 inch, is substantially thicker than the depending skirt 55 that is from 0.020 to 0.080 inch thick. The purpose of the thicker top wall is to provide structural ridigity in handling the cup during assembly. The thinner skirt is to provide easier sealing and compressibility control when sealing against the glass bead 8 of the bottle. At a bottom end of resilient rubber cup 45 is an internal beveled surface 56 for providing an easy assembly onto inner screw cap 3. The rubber cup is of a natural rubber with a 40-70 Shore A hardness, and a 10 - 40 percent compression set according to ASTM Test No. D395-61. Preferably the rubber has a 60 Shore A hardness with a 20 percent compression set. If the compression set is below 10 percent the rubber tends to uncrimp the metal outer cap. With more than 40 percent compression set the rubber does not make a good seal. The rubber cup combines with the outer cap and inner screw cap to provide an improved closure system for a sterile medical liquid bottle.

FIGS. 9 through 12 show the unique sequence of opening the closure system of this invention to reduce risks of contaminating the outer pouring lip and thread structure of the bottle. This sequence of steps begins with FIG. 9, shown with the outer cap and cup combination of FIG. 7 fitting over the inner screw cap and bottle shown in FIG. 2. Here the outer tear-off cap 46 is ripped apart and separated from the bottle. This leaves the rubber cup 45 disposed over the inner screw cap on bottle 1.

By removing the outer tear-off cap an important thing happens. The annular band-like skirt of the rubber cup member which overlies both the screw cap skirt and glass bead 8 is relieved from its firm compressive grip about glass bead 8 on the neck of the bottle. Since its compressive outer cap has been removed, the rubber band-like skirt can rotatably slide against the glass bead 8 while it is still overlying both the threaded skirt 13 and bead 8. It is noted in FIG. 3 that the external flange 14 slightly gouges into the skirt. This allows the operator to firmly grip the inner cap's screw thread through the slip resistant rubber skirt of the rubber cup. Thus, by rotating the rubber cup slightly the inner screw cap can be broken loose from its tight threaded engagement with the bottle. With this easy way of breaking loose the inner screw cap the operator is not tempted to band the screw cap against a hard surface to break it loose after the outer cap is removed. Such banging should not be done because it could break the bottle or the inner seal of the screw cap and destroy its sterile barrier.

The inner screw cap can also be loosened by first removing the outer cap, lifting the rubber cup upwardly slightly until it clears the bottle neck bead but still is fitting around the screw cap skirt. A twisting motion then breaks loose the screw cap.

Once the inner screw cap has been broken loose by either of the above sequence of the steps, but while it is still threadingly engaged with the threads of the bottle neck, the rubber cup skirt 31 is pulled vertically from the inner screw cap 3. The flange 54 causes the frictional engagement between the screw cap and resilient cup skirt to be concentrated over a sufficiently small area so that it is easy to lift off the cup. This leaves a sterile inner screw cap that fits loosely on the bottle neck but which has not been touched by the operator's hands.

In the next step shown in FIG. 12 the operator gently unscrews the cap taking care not to contaminate the threaded or lip portion of the bottle. Since the screw cap 3 has been loosened the operator need not wrestle with the bottle and screw cap such as trying to hold the bottle from rotating by squeezing it between his knees, under his arm, or banging the screw cap against the table to try to break it loose. The method shown in FIGS. 9 to 12 eliminates this and provides less of a risk of contamination when opening the closure system of this invention.

The various elements of this invention including the container and closure system can be made of various materials. However, I have found that the invention works very satisfactorily when the bottle is of glass, the inner screw cap is of aluminum, the resilient cup is of natural rubber, and the outer tear-off cap is of aluminum.

In the foregoing specification I have used specific embodiments to describe my invention, However, it is understood by those skilled in the art that certain modifications can be made to these examples without departing from the spirit or scope of the invention.

Claims

I claim:

1. For maintaining medical liquids in a sterile condition the combination of: a container having a dispensing mouth and an external annular bead adjacent to said mouth; an inner cap with a skirt removably secured to the container between the mouth and bead; a resilient annular band fitting over said inner cap, said resilient band overlying at least a portion of said inner cap skirt and at least a portion of said bead; and an external cap with a skirt crimpably compressing said resilient band against said bead, said resilient band that overlies said inner cap skirt adapted to be manually compressed against said cap for breaking the inner cap loose from the container after the external cap has been removed.

2. The combination as set forth in claim 1 wherein the combination includes a resilient cup overlying the inner cap and the resilient band is a depending skirt portion of the resilient cup and at least one of the external cap and resilient cup is imperforate across its top and at its skirt area between the bead and mouth of the container.

3. The combination as set forth in claim 2 wherein the resilient cup and external cap form a unit with a vent means on said unit to eliminate a pressure piston effect when the resilient cup is forced inside the external cap.

4. The combination as set forth in claim 3 wherein the resilient cup is imperforate and the external cap has an opening therethrough for providing an air vent means.

5. The combination as set forth in claim 4 wherein the vent means is a C-shaped opening in a top wall of the external cap.

6. The combination as set forth in claim 4 wherein the vent is comprised of one or more louvered openings in a skirt of said external cap.

7. The combination as set forth in claim 3 wherein the external cap is the imperforate member and the resilient cup has a vent opening therethrough.

8. The combination as set forth in claim 3 wherein the external cap is the imperforate member and the resilient cup member has one or more rib means for spacing a portion of the resilient cup skirt a sufficient distance from the external cap skirt to permit air passage during telescopic assembly of the external cap and resilient cup.

9. The combination as set forth in claim 8 wherein the resilient cup has a top wall and a depending skirt, and has at least one rib that extends along an external portion of said top wall and downwardly along an external portion of said skirt.

10. The combination as set forth in claim 1 wherein the external cap has a frangible section and a pull tab for breaking loose the skirt of the external cap to relieve the resilient band from the bead so the inner cap can be broken loose from the container.

11. In a medical liquid container for sterile liquids having a threaded neck with a removable screw cap thereon and an external annular bead on the container below said screw cap, the improvement of: an annular resilient band encircling said container and overlying at least a portion of said bead and at least a portion of said screw cap; external annular compression means compressingly sealing the annular resilient band against said bead; and an imperforate sterility closure member fitting over said screw cap and integrally joined to one of said annular compressive means and said resilient band.

12. The combination as set forth in claim 11 wherein the screw cap has a depending skirt with an externally protruding flange portion that contacts the resilient band, whereby said resilient band can be manually grasped to break the screw cap loose from the container after removal of the annular compression means.

13. The combination as set forth in claim 11 wherein the annular resilient band is generally cylindrical in shape prior to being compressed against said bead.

14. The combination as set forth in claim 11 wherein the resilient annular band is rubber.

15. In a sterile medical liquid container having a dispensing outlet closed off by an inner cap, an outer tear-off cap superimposed over said inner cap, and a protruding annular external bead on the container below said inner cap, the improvement of: a resilient cup disposed between said inner and outer caps, said resilient cup having a depending skirt overlying said annular bead; and said outer tear-off cap crimpingly compressing said resilient cup skirt against said bead.

16. The combination as set forth in claim 15 wherein the resilient cup has a top wall that is integral with the skirt and said top wall is substantially thicker than the skirt for structural support of said compressible skirt.

17. The combination as set forth in claim 16 wherein the skirt has a thickness of from 0.020 to 0.080 inch.

18. The combination as set forth in claim 16 wherein the top wall has a thickness of 0.100 to 0.150 inch.

19. The combination as set forth in claim 15 wherein the resilient cup is of natural rubber with a Shore A hardness of from 40 - 70.

20. The combination as set forth in claim 15 wherein the resilient cup is of natural rubber and has a compression set of 10 to 40 percent.

21. The combination as set forth in claim 15 wherein the resilient cup skirt has an inner surface and an outer surface and a lower edge surface, said lower edge surface being upwardly beveled towards its inner skirt surface, thereby providing a substantial annular beveled throat for telescopic assembly of resilient cup over said inner cap and protruding annular bead of said container.

22. A sterile medical liquid container having a dispensing outlet closed off by a three part closure system that includes a removable inner closure member; an outer cup-shaped protective closure superimposed over said removable inner closure, which outer closure includes a top wall and a depending skirt secured to said container; said outer closure including a score line penetrating only partially through the top wall of the outer closure, which score line defines a removable portion of said top wall; a pull tab means connected to said removable portion for breaking the removable portion out from said top wall for gaining access to said inner closure, said top wall and depending skirt of the outer closure being imperforate for providing a bacterial sterility barrier for the inner closure prior to breaking the score line; and a resilient cup confined between the outer closure and inner closure for providing a watertight seal between the two closures when the container and closure system is subjected to steam sterilization.

23. The combination as set forth in claim 22 wherein the score line forms a generally U-shaped pattern in the top wall with spaced apart legs of the score line continuing down the skirt of the outer closure.

24. The combination as set forth in claim 22 wherein the container has an external bead below the inner closure and the skirt of the outer closure is crimped around this bead.

25. For use in surgical or other medical procedures the combination of: a rigid glass bottle with a tubular dispensing neck having external screw threads located between an upper lip surface surrounding an outlet opening and an external annular neck bead below said lip; a sterile medical liquid within said bottle; a metal screw cap with a top wall, and a skirt threadingly received on said bottle neck, a gasket liner inside said screw cap held in pressure contact with the bottle lip; a rubber cup having a top wall engaging a top wall of the screw cap and an integral depending rubber skirt completely encircling and overlying the skirt of the screw cap and extending below said screw cap skirt to overlie the annular neck bead of the bottle; a tear-apart metal cup-shaped outer cap telescoped over said rubber cup, said outer cap having a top wall and a depending skirt overlying the rubber cup skirt and compressingly urging it into bacteria-tight contact with the annular neck bead; said outer cap having a break-apart section with a pull tab connected thereto for ripping apart the outer cap skirt to relieve compressive forces on the rubber cup skirt, whereby the rubber cup can thereafter be rotated for breaking loose the screw cap from the threaded bottle neck.

26. The combination as set forth in claim 25 wherein the screw cap has an external flange at a lower portion of the skirt, which external flange extends outwardly beyond a major portion of the screw cap skirt and engages the rubber cup when breaking loose the screw cap, said flange causing the frictional engagement between the screw cap and rubber cup to be sufficiently small that the rubber cup can be vertically lifted and separated from the screw cap after said screw cap has been broken loose but still remains engaged with the screw threads of the bottle neck.