Seals and method of sealing for a sterilization container system

At least one seal for a sterilization container system, wherein the sterilization container system comprises a base, a lid, and a gasket for providing a microorganism proof seal between the lid and the base. The seal comprises a belt of shrinkable material having an anchor at each end. Corresponding anchor openings are provided in the base of the sterilization container system for the seal's anchors. The seal is installed by engaging one of its anchors in a corresponding anchor opening on one side of the sterilization container system's base, passing its belt over the lid of the sterilization container system, and then securing its other anchor in a corresponding anchor opening on the opposite side of the sterilization container's base. The seal's belt is formed from a shrinkable material which, when exposed to a shrinking agent, shrinks to urge the sterilization container system's lid, base and gasket tightly against each other to provide a microorganism proof seal therebetween to prevent the entry of microorganisms into the interior of the sterilization container system. Also disclosed are a method of using the seal, and a method of using at least one agent which simultaneously shrinks the seal's belt and sterilizes the sterilization container system and its contents.

BACKGROUND OF THE INVENTION 
The invention relates to seals for sterilization container systems. More 
particularly, it relates to new and innovative seals and methods of 
sealing for the same which do not involve a mechanical latching device of 
the type typically used on conventional sterilization container systems 
SUMMARY OF THE INVENTION 
A sterilization container system is a reusable device used to hold 
materials, such as surgical instruments, while they are being sterilized, 
and to keep them sterile until they are ready to be used. A typical prior 
art sterilization container system is a container comprising a base; a 
removable lid; a gasket for providing a microorganism proof seal between 
the base and lid; and filter means which are arranged to permit the entry 
of the sterilant (such as steam or ethylene oxide) into the container, but 
which do not permit the entry of microorganisms. The gasket is typically 
affixed to the lid or the base, as by a compression fit. 
Since, as mentioned, one of the primary functions of a sterilization 
container system is to keep its sterilized contents sterile until they are 
needed, it is apparent that when the sterilization container system is 
sealed, its base, lid and gasket must be held tightly together so they do, 
in fact, form the desired microorganism proof seal therebetween. 
Conventional prior art releasable closures for the base and lid of a 
conventional prior art sterilization container system are typically 
mechanical latching devices. Such mechanical latches suffer from numerous 
drawbacks. Among them are that they are relatively complex and thus they 
are costly to manufacture, assemble and install. They are also costly 
because they are likely to be made from expensive stainless steel, since 
stainless steel is not likely to be adversely affected by the sterilant 
used to sterilize the sterilization container system. 
In addition, being what they are--mechanical devices--such mechanical 
latches are inherently subject to mechanical wear, damage, breakage and 
failure. 
Further, such mechanical latches are typically installed on the base and 
lid of the sterilization container system by the use of rivets. 
Unfortunately, since rivets require rivet holes, it is apparent that 
either by improper installation or wear over time, such rivet holes may 
leak and permit the insidious, undetected entry of microorganisms into the 
sterilization container system, thereby contaminating the contents and 
possibly resulting in the illness or even the death of the patient upon 
whom the supposedly sterile contents were used. And even if the rivet 
holes don't leak, the wear, damage, breakage or failure of such mechanical 
latches could result in a poor seal between the base, lid and gasket, 
thereby leading to the undetected entry of microorganisms into the 
sterilization container system with harmful and even fatal consequences 
for the patient upon whom the supposedly sterile contents were used. 
Further, such mechanical latches are typically provided with safety seals 
to provide an indication as to whether or not they have been opened, since 
if they are inadvertently opened prematurely the contents of the 
sterilization container system must be presumed to be contaminated, to be 
on the safe side. Such safety seals are additional expense items which are 
inconvenient to install and which take costly time to install. And if they 
are not installed because of an oversight, the result is that the 
sterilization container system must be presumed to have been opened and 
thus contaminated, necessitating the costly resterilization of the 
sterilization container system and its contents. 
Despite all of the above disadvantages inherent with such mechanical 
latches for sterilization container systems, they are the typical means 
presently in use in the industry to releaseably seal the base, lid and 
gasket of a sterilization container system together. 
The present invention is intended to avoid all of the above problems since 
it completely eliminates the need for such conventional mechanical latches 
to releasably seal together the base, lid and gasket of a sterilization 
container system. 
Instead of such mechanical latches, the present invention employs at least 
one, and preferably two or more seals to releasably seal the base, lid and 
gasket of a sterilization container system together. Each seal comprises a 
length of conventional prior art shrinkable material, such as heat shrink 
polyvinyl chloride (PVC). Each seal has a pair of anchors, one at each 
end. For each pair of anchors, there is provided, in the sides of the base 
of the sterilization container system, a corresponding pair of opposed 
locking recesses designed to releasably engage their respective anchors. 
When installed on the sterilization container system, a portion of each 
seal passes completely over the lid of the sterilization container system. 
Then, when the sterilization container system is exposed to the sterilant, 
such as the heat within a heat or steam based sterilizing device, the 
seals shrink, thereby automatically pulling the sterilization container 
system's base, lid and gasket together into a tight, microorganism proof 
seal. In addition, the seals automatically form a safety seal type 
indicating device since by their very presence when unbroken, they 
indicate the sterilized sterilization container system has not been opened 
or compromised. 
If the sterilant is of such a nature that it will not cause the seals to 
shrink to the degree necessary to safely seal the sterilization container 
system, then prior to the sterilization container system being sterilized, 
the seals would be exposed to an environment suitable for causing them to 
shrink to the desired degree. 
For example, if the seals were made from heat shrink PVC, and if it were 
desired to use a cold sterilizing process to sterilize the sterilization 
container system, then prior to the sterilizing of the sterilization 
container system and its contents, the installed seals would be shrunk 
with any convenient heat source, such as a hair dryer. 
Preferably, the seals do not pass under the bottom of the sterilization 
container during use, thereby making them easy to install since the 
sterilization container system, which can be quite heavy when full of 
objects to be sterilized, would not have to be lifted up during the 
installation of the seals. 
As a safety measure, each seal is preferably provided with a corresponding 
recess in the lid of the sterilization container system, so that during 
use the seal is received by its recess in the lid, thereby helping to 
prevent the seal from being accidentally cut or otherwise broken. 
The present invention also comprises an ingenious way to secure the anchors 
to the seals which is quick, easy, economical and reliable. First, a large 
loop of shrinkable material is provided. Then the large loop of shrinkable 
material is flattened down so its opposite sides are touching, thereby 
forming a small anchor loop at each end of the flattened large loop. Next, 
the anchors are each inserted into a respective anchor loop, and are then 
secured therein by fastening together the opposite sides of the large loop 
closely adjacent to the anchors, so that the anchors are retained in their 
anchor loops by a snug friction fit. 
The foregoing is intended to be but a brief summary of, not a detailed 
catalog of, the objects, features, advantages and characteristics of the 
present invention, since these and further objects, features, advantages 
and characteristics of the present invention will be either expressly or 
inherently disclosed to those of ordinary skill in the art to which it 
pertains, in view of the disclosures herein.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Turning now to FIG. 1, it diagrammatically illustrates a sterilization 
container system 10 comprising a base 12 and a lid 14. As mentioned 
earlier, sterilization container system 10 normally includes filter means 
in base 12 and/or lid 14 which permit the entry and exit of sterilant into 
and out of sterilization container 10 while it is being sterilized, but 
which do not permit the entry of microorganisms into sterilization 
container system 10. Such filter means are not illustrated in the figures 
for sake of clarity since their construction and operation are entirely 
conventional and are well known in the art, and since they form no part, 
per se, of the present invention. Naturally, however, such filter means 
would be located in sterilization container system 10 in such a manner 
that they are not covered by seals 16,17 when seals 16,17 are installed on 
sterilization container system 10. 
Referring now to FIGS. 1-3, base 12 comprises a bottom wall 18; a pair of 
side walls 20, 21; and a pair of end walls 22, each having an outwardly 
projecting handle 24. Extending completely around the top of base 12 is an 
outwardly projecting rim 25 (see FIG. 3). Located in the top of rim 25 is 
a gasket channel 26 which extends completely around the top of base 12. 
Held in the bottom of gasket channel 26, as by a compression fit, is a 
gasket 28, which also extends completely around the top of base 12. 
A flange 30, which projects downwardly from rim 25, extends completely 
around the top of base 12, except where it is interrupted by anchor 
openings 32. Flange 30, along with rim 25, serves to strengthen and 
stiffen the top portion of base 12. There are four anchor openings 32 in 
flange 30 on side walls 20, 21 of base 12. The two anchor openings 32 in 
flange 30 on side wall 20 are located opposite their two corresponding 
anchor openings 32 in flange 30 on side wall 21. 
As best seen in FIG. 3, adjacent to each anchor opening 32 the bottom of 
rim 25 is provided with an anchor recess 33 which is sized to receive a 
corresponding anchor 48. Anchor recesses 33 are slightly longer than 
anchors 48, to help ensure the easy fit of anchors 48 therein. 
Lid 14 comprises a top wall 34, a pair of opposed side walls 36 and a pair 
of opposed end walls 38. Located in top wall 34 and side walls 36 of lid 
14 are a pair of seal recesses 40. As best seen in FIG. 2, seal recesses 
40 are deep enough so that when seals 16, 17 are in use, their belts 46 
are located within their corresponding seal recesses 40. This helps to 
protect belts 46 of seals 16, 17 from damage during the use and handling 
of sterilization container system 10. 
As best seen in FIG. 3, the rim portion of lid 14 has a generally C-shaped 
cross section to give the rim portion of lid 14 strength and rigidity. 
Said rim portion of lid 14 comprises a portion of lid 14's top wall 34, 
lid 14's side walls 36, and rim bottom wall 37. 
Extending completely around lid 14, and projecting downwardly from rim 
bottom wall 37, is a gasket lip 42. Gasket lip 42 is sized to be snugly 
received in gasket channel 26 and to seal against gasket 28 when lid 14 is 
sealed to base 12 in the manner which will be described below. Each end 
wall 38 of lid 14 includes a handle indentation 44 having a back wall 45. 
When lid 14 is in place on base 12, handle 44's back wall 45 is coplanar 
with base flange 30. 
Base 12 and lid 14 may be made from any suitable strong, durable metal 
and/or plastic material which is not adversely affected by the sterilant 
or by the sterilizing conditions, such as stainless steel; aluminum; or 
P-1404 Noryl or P-101 polycarbonate plastic made by the General Electric 
Co. located in Pittsburgh, Pa. Base 12 and lid 14 are each preferably 
molded or formed in one piece, although they could be formed from separate 
components which are then assembled together, such as by gluing or by 
welding, in such a manner that they will not leak. 
Each seal 16,17 comprises a belt 46 having an anchor 48 secured to each end 
thereof. Each anchor 48 is preferably a rod of stainless steel or some 
other strong, stiff material which is not adversely affected by the 
sterilant or by the sterilizing conditions, such as nylon having glass 
fiber filler. The length of each anchor 48 is greater than is the width of 
its corresponding anchor opening 32. 
Each pair of anchors 48 could be secured to the ends of its respective belt 
46 by any conventional means or techniques. However, it is preferred that 
each pair of anchors 48 be secured to its respective belt 46 by the 
following method, which offers the advantages of being quick, easy, 
economical and reliable. 
First, a belt 46 is provided in the form of a large loop of strip material. 
The large loop of strip material is flattened down until its opposite 
sides are touching, thereby forming a small anchor loop 50 at each end of 
the flattened large loop. An anchor 48 is then inserted into each of the 
small anchor loops 50. Next, each anchor 48 is then secured in place in 
its respective anchor loop 50 with a snug friction fit by fastening 
together the opposite sides of the large loop which are closely adjacent 
to it. If belt 46 is made from heat shrink PVC, then it is prefered to do 
such fastening by an ultrasonic welding process. It has been found that it 
is preferable to tack said opposite sides together in four spaced welded 
locations, rather than running a continuous weld, since a continuous weld 
has been found to interfere somewhat with the proper shrinking of belt 46 
when its respective seal 16, 17 is shrunk. 
Belts 46 are preferably composed of any conventional material which shrinks 
under the influence of heat, such as, by way of non-limiting example, heat 
shrink polyvinyl chloride (PVC). But it is within the scope of the present 
invention that belts 46 could be composed of any one of a variety of other 
materials or substances which shrink under the influence of heat, or which 
shrink under the influence of some other shrink inducing agent such as, by 
way of non-limiting example, radiation, visible or invisible 
electromagnetic radiation, chemical(s) and/or drying. Belts 46 can be 
transparent, translucent or opaque. 
By way of non-limiting example, if sterilization container system 10 were 
about two feet long, about one foot wide and about five inches thick, 
seals 16, 17 would be about about seventeen add one-half inches long. In 
addition, if belts 46 of seals 16, 17 were made of PVC, the PVC used would 
be about four and one-half inches wide and about three and one-half mills 
thick. Of course, the portions of belts 46 which are located between their 
small anchor loops 50 for their anchors 48 are twice as thick (seven 
mills). This is because if anchors 48 are secured to their belts 46 in the 
preferred way described above, the opposite sides of the large loop of 
three and one-half mill PVC material are brought into contact with each 
other when the large loop of PVC material is flattened to make small 
anchor loops 50. Thus, the total thickness of the two sides when they are 
brought into contact with each other is seven mills. 
Prior to being shrunk, the length of each seal 16, 17 is selected so that 
it is just long enough, after one of its anchors 48 is received in its 
respective anchor recess 33, to permit its other anchor 48 to be fitted 
into its corresponding anchor opening 32. Thus, when seals 16, 17 are 
shrunk, as much of their shrinkage as is possible will go towards pulling 
base 12, lid 14 and gasket 28 into a tight, microorganism proof seal, 
rather than going towards taking up excess slack in seals 16, 17. 
The width, thickness, number and material of seals 16, 17 are selected such 
that when seals 16, 17 are shrunk, they urge base 12, lid 14 and gasket 28 
tightly against each other in a tight, microorganism proof seal. But they 
are not shrunk to the point where they break or might tend to break under 
the forces expected to be encountered during the normal handling, 
sterilization and storage of sterilization container system 10. Instead, 
their width, thickness, number and material should be selected with a 
substantial safety factor in mind. 
Seals 16, 17, and their corresponding seal recesses 40, anchor openings 32 
and anchor recesses 33 are preferably located on sterilization container 
system 10 so as to uniformly distribute the loading which seals 16, 17 
exert on sterilization container system 10 when seals 16, 17 are shrunk, 
to better ensure a secure, tight, microorganism proof seal between all 
sealing portions of base 12, lid 14 and gasket 28. 
In use, lid 14 is first placed on base 12 with its gasket lip 42 in gasket 
channel 26 on top of gasket 28. Then for seal 16, a first one of its 
anchors 48 is placed in a respective anchor opening 32 with the ends of 
said first anchor 48 being located behind flange 30. An upward force is 
exerted on said first anchor 48 by the user tugging on its respective belt 
46 until said first anchor 48 is seated in its respective anchor recess 
33, as best seen in FIG. 3. Since the length of each anchor 48 is greater 
than is the width of its respective anchor opening 32, as long as said 
first anchor 48 is tugged upwardly its ends remain firmly locked in place 
behind flange 30. 
Seal 16's belt 46 is then passed over lid 14 of sterilization container 
system 10. Next, seal 16's second anchor 48 is placed in its corresponding 
anchor opening 32. The length of seal 16's belt 46, prior to being shrunk, 
is short enough so that its belt 46 has to be stretched a little in order 
to permit the ends of seal 16's said second anchor 48 to be passed under 
the bottom of flange 30. Then, when said second anchor 48 is released, the 
elasticity of seal 16's belt 46 pulls its said second anchor 48 upwardly 
enough to keep it firmly in place in its respective anchor opening 32 with 
its ends behind flange 30, until seal 16 is shrunk. The installation of 
seal 17 is the same. 
Next, sterilization container system 10 and its installed seals 16, 17 are 
inserted into the sterilization device, such as a sterilization device 
which utilizes steam as the sterilant. Then the same heat and temperature 
which is used to sterilize sterilization container system 10 and its 
contents will automatically act as the agent which causes the heat shrink 
PVC belts 46 of seals 16, 17 to shrink to the desired degree so that seals 
16, 17 urge base 12, lid 14 and gasket 28 into the desired tight 
microorganism proof seal. When belts 46 of seals 16, 17 are fully shrunk, 
each anchor 48 is located in its respective anchor recess 33 as seen in 
FIG. 3. In order to permit belts 46 of seals 16, 17 to slide a little as 
they are being shrunk, and so they will not tend to be cut, corners 52 in 
seal recesses 40 and corners 54 on rim 25 are preferably chamfered. 
In a typical steam sterilization process, steam at a temperature of 270 
degrees Fahrenheit is used for at least several minutes to sterilize the 
sterilization container system 10 and its contents. At that temperature, 
the PVC belts 46 of seals 16, 17 shrink to the desired tightness in only 
about ten seconds, so that at the end of the sterilization cycle, 
sterilization container system 10 has long since been sealed by its shrunk 
seals 16, 17. 
In general, it is preferred that the sterilant (whatever it might be) which 
is used to sterilize sterilization container system 10 and its contents 
also be used as the shrinkage inducing agent which is used to shrink belts 
46 of seals 16, 17. This is highly desirable for economy, efficiency and 
increased ease of operation since both the sterilizing and the shrinking 
are then done in one step. 
Alternatively, the heat or other shrinkage inducing agent could, of course 
be applied to seals 16, 17 before sterilization container system 10 was 
inserted into the sterilizing device. 
When it is desired to open the sealed sterilization container system 10, 
belts 46 of seals 16, 17 are cut, as by passing a knife edge along seam 56 
between base 12 and lid 14. 
In view of the disclosures herein, various further adaptations, 
modifications, and uses of the present invention will now be apparent to 
those in the art to which it pertains, within the scope of the claims 
appended hereto; it being understood that all of the descriptions and 
figures contained herein regarding the present invention are strictly by 
way of non-limiting example.