Sterilization

@ Agent: Simonnot, Rinuy, Santarelli.

D

Sale of booklets at IMPRIMERIE NATIONALE, 27, rue de la Convention - 75732 PARIS CEDEX 15

The present invention relates to an improved method of storing sterile objects, while they are sterilized, they are stored while waiting to use them, they are in use and after they are used and in waiting for them to be re-sterilized.

The most common method used to sterilize surgical and other medical instruments is to place them in towels which are enclosed in a sheet and folded to place in a sterilization autoclave. The steam introduced into the autoclave enters the porous material surrounding the instruments to be sterilized. The moisture is removed by a drying cycle carried out in the autoclave. The sterile package is then either used immediately or put away until it is used later. If the package has not been us ed for a certain period, for example about twenty days, it must be reintroduced into the autoclave to be sterilized again. It is estimated that two-thirds of the items sterilized in many hospitals are made up of instruments that have not been used during the storage period of the package.

This is naturally an expensive and inefficient process.

Another disadvantage of using towels is that, unless proper labeling is used, the contents of the towel are unknown. As soon as the package is opened to check the contents, the effects of sterilization naturally disappear unless the contents are used immediately. If the content does not correspond to that desired by the user, then this particular package must be re-sterilized.

Thus, it would be advisable to have a practical and reliable system allowing to handle sterile objects and to maintain their sterility · It would be possible to hermetically close a container incurring the objects to be sterilized before placing them in the autoclave, but the contents would then not be subjected to sterilization vapor. On the contrary, the atmosphere contained in the hermetically sealed container would be closer to dry heat sterilization which requires higher temperatures and longer periods of time than humid heat. Also, an autoclave undergoes, for example, significant variations in pressure as a result of the suction phases intended for removing the air and the water vapor and of a pressurized phase applying the water vapor. Thus, these pressure variations would apply to the exterior of a hermetically sealed container, which could break or damage it.

In the prior art, a system is known in which a container is placed in an autoclave by keeping its lid slightly open and by providing devices making it possible to close the lid automatically after a predetermined time near the end of the sterilization cycle. .

Although this system is very advantageous, it is quite difficult to move the entire cover at the desired time.

The present invention relates to a closed container intended to contain the objects to be sterilized and to be stored and to a new valve which is open during sterilization and which closes automatically at the desired time. The valve is held open by a temperature sensitive fuse element which is rigid at room temperature. After being subjected to the sterilization temperature for a predetermined time, the fusible element melts and allows the valve to close before the container is removed from its sterilization medium. Thus, the container can then be stored for a long time, keeping its contents in a sterilized state until it is used.

In one embodiment, the valve can be opened manually to break the vacuum inside the container, thereby allowing the lid to be removed to access the contents. As soon as the valve is open, the fusible device, which is rigid at ambient temperature, keeps the valve in the open position and the latter is therefore armed and ready for a new sterilization, without additional attention being necessary. This feature is very important since it eliminates a possible human error, namely forgetting to open the valve when the container is to be reused in a sterilization operation.

According to another characteristic of the invention, a seal interposed between the cover and the container handle fulfills the function of a non-return valve which prevents a fluid from entering the container, but allows it to exit in the presence of a sufficient pressure difference, Thus, during the suction phase used by most autoclaves at the end of the application phase of high pressure steam, some of the water vapor in the tightly closed container may escape from the gasket. This also applies limited vacuum to the interior of the container, which is desirable during storage. The depression provides an indication that there is a vacuum and therefore that the contents are still sterile. When the valve is opened to break the vacuum, a noise is usually heard which indicates the presence of the vacuum and which informs the user of the sterility of the contents.

In another embodiment, the valve used is to be discarded after use. A rubber valve fits into a wall of the container to close one or more orifices leading to the interior of the container. After the introduction of the valve, it is equipped with a fusible element which maintains it in a form preventing it from closing the orifices opening out inside the container. This fusible element melts at a desired instant close to the end of the sterilization phase, allowing the valve to move into the normally closed position in which it closes the orifices of the container. When the container needs to be opened, the valve can simply be removed from the container and discarded. A new valve is then installed to reuse the container.

Another type of elastic valve, which plugs a hole in a wall of the container, uses a retractable strip, one end of which is fixed to the outside of the stopper. The strip extends around the edge of the valve and is anchored to a fusible element located on the internal side of the plug to maintain the valve in the open position. When the fusible element melts, the strip retracts allowing the valve to close.

The invention will be described in more detail with reference to the accompanying drawings by way of non-limiting examples and in which:

Figure 1 is an exploded perspective view of the container of the invention showing the cover, an internal tray and the base;

Figure 2 is a cross section of the container; Figure 3 is a section along line 3-3 of Figure 1 showing a vacuum indicator;

Figure 4 is a top view of the valve of the container;

Figure 5 is a cross section of the valve of .figure 4 showing the latter in the closed position;

Figure 6 is a cross section of the valve showing it in the open position;

Figure 7 is a perspective view of an element used to hold the valve in the open position;

Figure 8 is a cross section of a second embodiment of a valve for the container of Figure 1, the valve being shown in the open position;

Figure 9 is a cross section of the valve of Figure 8, said valve being in the closed position;

FIG. 10 is a partial view on a large scale showing a part of the valve of FIG. 8 in its open position in solid lines and in its closed position in dotted lines;

Figure 11 is a side view of another embodiment of an elastic valve which is plugged into a wall of a container and which has a cylindrical shape as well as another form of packing;

Figure 12 is an exploded perspective view of the valve of Figure 11;

Figure 13 is a perspective view of the valve of Figure 11 in the armed position in which it is ready to be mounted on the container; and Figure 14 is a graph showing a current operating cycle of the autoclave.

Referring now to the drawings, the container shown in FIG. 1 comprises a base 10, a cover and an internal support or tray 14. As can be seen, the container is elongated and relatively flat and has rounded corners 5 so that have substantially the shape of a closed racing circuit. The base has a bottom wall or bottom 16 and a side wall 18 ending in a rounded top edge 19 and a flange 20 inclined downwards, and another horizontal flange 22. The cover 12 has a top wall 10 with a flat central part 24 and a rounded part inclined downwards 25 as well as a surrounding edge 26 which inclines upwards, extends horizontally, then downwards and downwards. 'outside to have a shape which fits on the upper edge 19 of the base 10. The cover further comprises a short peripheral flange 28 extending outward.

A large flexible lining 30, shown more in detail in FIG. 2, is fixed to the cover 26 and has a flexible part oriented downwards which elastically comes into contact with the wall 20 oriented downwards and outwards. the base · When the lid is pressed tightly on the base, a tight seal is formed at the point where the lower edge of the lining 30 is in contact with the wall 20, as seen in FIG. 2. Also, the upper end of the gasket fits tightly in the cover to form a seal in this region. As also seen in FIG. 2, the base has several feet 34 supporting its bottom slightly above the support surface.

The container is further equipped with two flexible retaining straps 36, one at each end of the container.

The strap 36 has a retaining stud 37 at each end which fits into a slot 38 formed in the flange 22 and which keeps the end of the strap in this position. Said strap passes over the lid to hold it in position and to keep the container closed after sterilization.

The tray 14 has a configuration allowing it to fit inside the base 10 and has a protruding handle 40 sized and configured to come into contact with the internal surface of the cover 12, when the latter is hermetically closed on the base . The handle provides additional support for the lid when a high vacuum is imposed inside the container.

A vacuum indicator device 42 is mounted at one end of the cover 12. The device 42 comprises an upper elastic element 43 which is held in hermetic position against the cover by a plate 44 which fits in a recess of the flexible element 43 · The plate is biased towards the cover by a screw screwed through the latter from its underside. The screw 46 is pierced with a longitudinal channel making it possible to expose the interior of the element 43 to the pressure prevailing in the container.

As can be seen in FIG. 1, one or more orifices 50 are formed in the bottom 16 of the base 10. Referring now to FIG. 5, it can be seen that the bottom of the container has an annular protuberance 52 projecting towards the outside and having an external face 53 · The wall then extends slightly inwards, thus forming a shallow circular cavity or recess 54 and a circular wall 55.

A valve 58 is fixed to the circular wall 55 by a suitable device. The valve 58 comprises a shutter element 60 of rubbery material having a flat circular lower surface 62 and an annular side wall 64 facing upwards, the internal surface of which comes in elastic contact with the wall 53 to prevent access from the outside to the interior of the container through the opening 50 of the valve. Two stiffening plates 65 and 66 are embedded in the bottom wall 62 of the shutter element 60 to give it a certain rigidity. Two mounting screws or studs 68 are fixed to the plate 65 and pass through support tubes 70, holes in the wall 55 and are fixed to the latter by suitable nuts 72 screwed onto the end of the screws 68. The connection is of such a nature that the annular wall 64 of the shutter element 60 is urged in tight contact with

Ί the surface of the wall 53 in a normally closed position.

One edge of the shutter member 60 has an upward and outwardly extending portion which forms a lever 74 for opening the valve which can be operated by hand. An extension of the plate 66 is embedded in the lever so that, when the lever 74 is lowered manually, the shutter can be put in the open position, as seen in FIG. 6. As indicated, the elasticity of the shutter 60 is such that it normally seeks to occupy the position shown in FIG. 5 · Optionally, it is possible to use suitable elastic elements to exert an additional thrust on the shutter element to put it in the closed position. In one embodiment, a helical spring (FIG. 4) can be housed in the upper surface of the wall 60 of the shutter element, one end of the spring being in contact with the plate 65 and its other end in contact with the plate 66 so as to exert a force which urges the shutter element in the closed position.

To keep the valve in the open position, a retaining or arming device is provided which comprises a support element 76 which is suitably fixed to the plate 66 and to the bottom wall 62 of the shutter element 60. The support element has two arms 77 facing upwards as seen in FIG. 4. A locking lever 78 is articulated on a stud 80 supported by the arms 77 of the support 76. A suitable spring 81 mounted on the stud 80 biases the locking lever 78 dextrorsum while observing FIGS. 5 and 6..

A small housing 82 is fixed to the other half of the shutter element 60 and to the plate 65 by the mounting screws 68. The support housing forms a shallow housing 83 containing a metal fuse 84 which melts at a desired temperature .

The metal is enclosed in the housing by a cover plate 85 also held by the mounting screws 68. A lock 86 of irregular shape is articulated on the housing 82, one end of said lock 86 journalling near the metal fuse 84 and a tab 87 of said latch 86 being placed in the metal of fuse 84. One end of a spring 91 is fixed to latch 86, the opposite end being anchored below one of the support tubes 70. The spring 71 biases the lock 86 sinistrorsum while observing FIG. 5.

A small, substantially U-shaped member 88 is secured to the latch 86 and has a locking leg 89 and a shorter cam leg 90 which both cooperate with the end of the locking lever 78 to hold the shutter member in position open and release it from the latter.

Referring now to the operation of the embodiment of Figures 1 to 7, it will be assumed that the container is empty and that the cover 12 is separated from the base 10. The objects to be stored are placed in the container and the cover is positioned on the base. The cover is held in this position by passing the straps 36 over the top of the cover and hooking their ends into the notches 38 of the base. We will assume that the shutter element 60 is in the open position of the. Figure 6 and that the metal fuse 84 is solid. Thus, the shutter element 60 is kept in the open position because the end of the locking lever 78 is in contact with the side of the locking branch 89 as seen in FIG. 6.

The container is then placed in an autoclave or other sterilization device. If an autoclave is used, one or two vacuum phases are applied inside it to remove the contaminated air from the container. Since the valve is open, the air contained in the container is evacuated through the hole 50 of the bottom wall 55 · When water vapor or other sterilizing fluid is introduced inside the container, there may enter freely through port 50. The high temperature associated with sterilization melts the metal of fuse 84 after a predetermined time which is selected so that melting occurs some time after sterilization of the container and its contents. Preferably, this corresponds to an instant close to the end of the heating cycle, but before the final vacuum cycle which is applied to an autoclave to remove the water vapor from the latter. When the metal of the fuse 84 melts, the elasticity of the shutter element 60 plus the force exerted by the spring 75 is exerted against the branch 89 by pivoting the element 86 against the action of the weaker spring 91. The tab 81 can move in the fusible metal, since the latter is no longer solid. When the U-shaped element 88 pivots with the element 86, the branch 90 comes into contact with the upper surface of the locking lever 78 by pushing it down against the action of the spring 81 until that the end of the lever 78 slides on the lower edge of the branch 89 · Then, the shutter element quickly reaches the position shown in Figure 5 in which its flexible wall 64 is again applied in a sealed manner against the wall surface 53. The lever 78 is lowered under the end of the locking branch 89 · It should be noted that the spring 91 biases the element 86 in the position shown in which the end of the lever 78 is in contact with the end of the branch 89 · It should also be noted that the end of the branch 89 is bevelled according to the approximate angle of orientation of the lever 78 in the closed position of the valve.

The container is now hermetically sealed with its sterilized contents, so that it can be removed from the sterilized atmosphere. However, as indicated above, if the device is sterilized in an autoclave, it is usually subjected to an additional phase of vacuum after closing the valve. If the pressure prevailing in the autoclave around the container reaches a value greater than the pressure prevailing in the container, the atmosphere contained in the latter may escape from the container through the flexible lining 30. This is due. to the configuration of the surface of the flange 20 of the base 10 and to the size and flexibility of the lower end of the lining. Since the relationship between the flexible wall 64 and the surface 53 is quite similar, it is possible that there may also be some release of the pressure in this region. This leakage is advantageous because there can be a certain amount of water vapor in the container, and it is preferable that the latter is relatively dry.

When a high vacuum is applied to the outside of the container, a vacuum is created inside. Thus, as soon as the pressure is brought back to atmospheric pressure, there is a vacuum inside the container and the gasket and the valve prevent any leakage inside the latter. The curvilinear configuration of the container is such that these walls can; withstand a fairly large pressure difference between the inside and outside of the container. However, as an additional precaution with large containers, it may be desirable for the handle 40 of the tray. 14 is in contact with the internal upper face of the cover, as indicated in FIG. 2, to reinforce it.

The container and its contents can now be put in any desired place to store it while waiting to use it or it can be transported directly to where. its content must^- be used, when opening the container, you must first break the vacuum which can reign inside 1 * For this purpose, simply lower the lever 74 to open the valve, the noise that accompanies the vacuum breaker indicates that the contents of the container are still sterilized. Conversely, if there is no leakage, the absence of noise warns the operator opening the container that the contents are no longer sterile. The flexible element 43 of the indicating device 42 also gives an indication of this state by being lowered when there is a vacuum and raised when there is no vacuum.

Thanks to the excellent seal provided by the lining 30, it is very likely that even if air molecules can infiltrate the container facing the lining after a certain time, most micro- organisms are larger and cannot pass through the joint. Thus, in this measurement, the lining acts as a filter even if there is ultimately no more vacuum.

Shortly after the start of the drop in sterilization temperature, the metal of the fuse re-solidifies while maintaining the branch 89. in the position shown in FIG. 6. Thus, when the valve is open, the end of the locking lever 78 slides away from the end of the branch 89 and is biased slightly dextrorsum by the helical spring 81 au. contact of the return branch 90. When the lever 74 is li—. béré, the end of the lever 78 again comes into contact with the side of the branch 89 while maintaining the valve in the green ou5 position. Thus, the lowering of the lever 74 not only breaks the vacuum inside the container, but simultaneously arms the shutter element in the open position, so that the container is ready to be sterilized again. This characteristic is very important, since it is not necessary to remember that the valve must be opened before replacing the container in the sterilization apparatus. Thus, if the container has been used to sterilize surgical instruments for example and if the container is transported directly to the operating room, the instruments can be removed directly from the container, used, washed if necessary and replaced in the container to be sterilized again.

If it is preferable not to transport the container directly to the operating room, it is possible to open it just before entering the operating room and to introduce into it only the sterilized tray and the instruments placed on it. After using the instruments, they can be replaced on the tray and it can be reintroduced into the container to be re-sterilized.

Just put the cover back in position while holding it with the straps and replace the container in the autoclave to sterilize it.

As an alternative to this procedure, it is possible to place the container in a sterilization bag (not shown) during the sterilization cycle. Such a bag is available on the market and is sold by GE Bord Inc., and is described in U.S. Patent No. 5,595,465, a bag in which the container could be placed and inserted into the autoclave. The bag allows water vapor to enter it during the sterilization cycle, but is largely sealed during the said cycle. In this case, simply remove the container from the bag just before transporting it to the operating room. Thus, the entire container is still reasonably sterile and the instruments are removed directly from the bottom of the container. The top edge of the base is still sterilized just in case. a person's hand touches it in this area to remove the instruments.

One of the advantages of the embodiment described above is that the valve, as well as the container, are reusable. However, another embodiment, such as that shown in FIGS. 8 to 10, comprises a simplified valve or flap to be discarded after use, also using the principle of the fuse. As can be seen in FIG. 8, a small annular protuberance 100 is formed in the wall 101 of a container similar to that shown in FIG. 1. One or more holes 102 are provided in the annular wall 100 to allow access to the interior of the container. An additional hole is made in the middle of the annular wall 100 to introduce there a shutter 106 to be discarded after use, in order to regulate access to the interior of the container through the holes 102. More particularly, the shutter 106 has an integral projection 108 extending inwards, which is rounded and dimensioned so that it can be pushed into the hole provided in the center of the annular wall 100, as seen in the figure. 8. A peripheral shoulder 108a comes into contact with the internal wall of the container to maintain the valve in position on the latter.

The shutter member 106 is made of an elastic material similar to rubber which allows the projection 108 to be pressed into the hole in the wall of the container. The element 106 is molded in the form shown in FIG. 9 which comprises a circular part, the periphery of the element curving upwards in the form of a bowl coming into close contact with the external surface of the wall annular 100 and closing the orifices 102 of the container. Thus, in the position shown in FIG. 9, the calpet is closed, which can be considered to be its normal position, the fact that this is the position that the rubber shutter element 106 naturally tends to occupy. It should also be noted that if there is a void inside the container, this void helps hold the shutter member tightly against the holes 102.

. To keep the valve in the open position, a fuse 110 is provided in the form of a ring similar to a flat washer. As can be seen in FIG. 10, the obturator element 106 has an internal slot 107 as well as a small diagonal incision 109 forming two elastic flaps 112 and 114. After the shutter element has been molded in the form shown in FIG. 9, the fusible element is introduced into the slot inside the shutter element by lowering its periphery so that the fusible washer can be introduced into the slot 107 through the gap 109. It should be noted that the fusible material occupies only the external part of the slot 107. When the fusible material occupies this position, the obturator element both shown in FIG. 8, in which the external periphery of said element is kept away from the orifices 102. The valves are normally supplied in this form. Thus, a user of the container can simply grab a valve of this type and insert it into the container in the position shown in Figure 8. The container is then ready to be sterilized.

- At the appropriate time in the sterilization cycle, the fusible washer melts, allowing the obturator element to occupy its normal position, coming from molding, as indicated by dotted lines in FIG. 10. Thus, the valve is closed seen in Figure 9. The closing movement of the shutter element and gravity cause the molten metal to flow from the fusible washer towards the internal end of the slot 107 inside the shutter element, as seen in Figure 9. Thus, when the fusible metal solidifies again, it does not prevent the valve from fulfilling its sealing function.

On the contrary, it tends to keep the.calpet in the closed position.

When it is desirable to break the vacuum inside the container, a tab 118 secured to one edge of the obturating element is pulled away from the container, thereby allowing the vacuum to be broken through the adjacent hole 102. Thus, the container lid is removed. The shutter member 106 can also be removed by simply pulling a little harder on the tab of the valve. When it comes to re-sterilizing the container, it is possible to quickly put a new obturator element in position. It is naturally possible to place a new obturator element as soon as the old one has been removed.

Referring now to Figure 11, there is shown a generally cylindrical container having a base 120 with a bottom 122 and a side wall 124 facing upwards. The upper part of the side wall has a shoulder 123 oriented inwards, a recessed cylindrical part 125 and a flange 126 oriented outwards at the upper edge of the wall 125.

An elastic gasket 130 is located under the flange 126 and is dimensioned so as to come closely into contact with the cylindrical wall 125. the gasket also has a flexible flange 131 oriented outwards and downwards, which is in contact with the inner surface of a side wall 132 oriented downwards and outwards of a cover 134 of the container. - Like the gasket 30 in Figure 2, the gasket 130 not only seals between the cover and the base, but also fulfills the function of a non-return valve allowing gases to escape from the container, but preventing a gas to enter it.

the bottom 122 of the container is raised and has a recess 121 on one side. A valve 140 molded from an elastic material similar to rubber is placed in the recess 121. The valve is analogous to the element 106 of FIG. 9 and comprises a projection 142 extending inwards which is rounded in shape so that it can be pushed into a hole in the bottom 122. The valve is molded in the form shown in Figure 12 which includes a normally circular configuration, the periphery of the element curving upward in the form of a bowl to come closely into contact with the external convex surface of the surrounding wall, thus closing openings 144 communicating with the interior of the container.

To keep the valve open, a strip 146 of known hot-shrinkable plastic material is provided which shrinks when it is heated to a certain temperature, then is cooled. One end of the strip has a hole

147 which adjusts to an end in the shape of an arrowhead of a tab 148 secured to the valve. As seen in FIG. 11, the strip extends around part of the edge of the valve 140 and keeps this edge in the low position and away from the bottom 122 so that the orifices 144 of the container are not closed. . One end of a metal wire 150 is fixed to the internal end of the strip, the other end of the metal wire penetrating into the central part of the valve where it is fixed to a fuse 152 placed in the central part 142. The fuse 152 is made of metal which melts at a desired temperature, in particular after its exposure for a predetermined time to the sterilization temperature of the autoclave. As indicated above, this corresponds to an instant close to the end of the heating cycle and preceding the final vacuum cycle, such as that applied in an autoclave to remove water vapor from the latter.

In service, the valve can be supplied in the form shown in Figure 13, armed and ready to be introduced into the container in the position shown in Figure 1. However, it is preferable that the valve is supplied with the metal wire 150 fixed to the fuse 152 and to the strip 146. When it comes to using the device, it is armed by hooking the strip to the tab 148 by passing the hole 147 on the tab.

when the valve occupies the position shown in Figure 11, the container is ready to be subjected to a sterilization operation. The container is placed with its contents in an autoclave or other sterilization device, the cover 134 being in the closed position. When the steam enters the autoclave, it passes freely inside the container through the holes 144 in the bottom. After the desired sterilization temperature is reached, the metal of the fuse melts, releasing the metal wire 150. The elasticity of the valve facilitates the withdrawal of the metal wire from its central part and the heat also causes the strip 146 to shrink so that the metal wire 150, as soon as it is released by the metal from the fuse, is quickly removed around the edge of the valve. Thus, said valve can close freely against the annular surface of the bottom wall surrounding the orifices 144, preventing any circulation of the fluid inside the container through these orifices.

At the end of the sterilization cycle, the container cools and the metal of the fuse held captive in the cap solidifies, the interior of the container being kept hermetically closed in the sterilized state. If a vacuum is applied to the outside of the container, the pneumatic pressure prevailing in the latter can be released between the flange 131 of the lining and the wall 132 of the lid. However, infiltration into the container, after the vacuum has been broken, is prevented, since the paression exerted inside the container keeps the flange 131 of the seal in tight contact against the wall 132. The strip 148 is then optionally removed from the tab 148.

When it is desirable to open the container, the vacuum therein can be broken by pulling on the tab 148, so that the adjacent edge of the valve 140 is away from the wall of the container allowing the air to get into it. Optionally, a filter (not shown) can be placed on the orifice 144 and the extension 142 to filter the air entering the container. .

Greater traction exerted on the tab completely tears off the valve from the wall of the container. When it is a question of reusing the container, it suffices to introduce a new valve in the armed position as shown in FIG. 13 so that the container is ready to be resubmitted to a sterilization cycle.

This embodiment of the invention has the particular advantage of making it possible to bring the valve to a reconditioning station where. it is recycled or rearmed. The old fuse metal is then removed and a new metal wire 150 previously attached to a new fuse is introduced into the open end of the projection 142 so that it comes out from the side of the latter, the new fuse being placed in the protrusion as seen in Figure 11. The other end of the metal wire is then fixed to a new strip 146 and this is then ready to be fixed to the tab, either at the repair station or by the user.

• 2335239

One of the characteristics of the container is the automatic leveling of the lid 134 relative to the base 120. That is to say that the lid does not have to be perfectly positioned on the base when the container is placed in an autoclave. The flange formed at the upper end of the side wall 124 limits the downward movement of the cover in any particular region. During the last phase of application of a vacuum in the operating cycle of an autoclave, the air and the humidity contained in the container are sucked out of the latter opposite the flange 131 of the lining, as we explained it above. When atmospheric pressure is introduced into the autoclave, the flange 131 of the seal, as well as the valve 140 prevent air from entering the container. Thus, the pressure difference between the interior and the exterior of the container pushes the cover 134 more strongly on the base 120 of the container. During this action the flange of the upper end of the side wall · 124 limits the tilting movement of the cover, so that the cover is automatically leveled. Although the flap or valve of the three embodiments described above constitutes a means of access to the interior of the container through which the high pressure steam is introduced during the sterilization cycle, another variant of the invention ( not shown in the drawings) does not use a shutter element, but the cover of the. container is kept open during the sterilization phase to allow water vapor to enter the interior of the container. More particularly, the cover is aligned with the base of the container, but the cover and the base are sufficiently spaced that the liner is not in leaktight contact. According to one arrangement, a support post made of a temperature-sensitive fusible material is used to support part of the cover a short distance from the base, or two or more posts can optionally be used to keep the whole cover slightly away from the base. Retaining straps like those designated by 36 in Figure 1 or other suitable elements can be used to exert a closing force between the cover and the base in addition to gravity. The fusible uprights are intended to lose their rigidity or to be veiled at the desired moment during the sterilization cycle and consequently the cover is lowered under the effect of gravity and is effectively requested by the retaining bands in the hermetically closed position. , the production of the linings and the covers, as described above, ensures a good seal in this way, even if one side of the cover. can be lowered before the other. This is due to the better seal obtained when atmospheric pressure is applied to the outside of the container.

Reference has been made to the sterilization cycles of an autoclave to describe the embodiments of the invention. Although a number of different autoclave operating cycles are commonly used, a particular example is shown in Figure 14 to allow a better understanding of the invention. As can be seen in FIG. 14, step or phase I is a step of placing under vacuum beforehand in order to evacuate the contaminated air from the interior of the autoclave. Since the valves or other devices for accessing containers of the type described above are open when the container is installed in the autoclave, vacuum is naturally applied to the interior of the container. The medium is brought back to ambient conditions after stage I by introducing clean filtered air. Step II of prior vacuuming makes it possible to better ensure that only a minimum quantity of unsterilized air remains in the autoclave.

Many small autoclaves use only one pre-vacuum phase.

During phase or stage III of the process, water vapor at high temperature and at high pressure is introduced to form the sterilizing medium. Naturally, the sterilization vapor enters the interior of the container through the valve or other access device. The various fusible elements described above are chosen so that they melt or lose their rigidity near the end of this high temperature treatment step. That is, the material loses its rigidity at the temperature of the water vapor, but a predetermined time is required for the water vapor at this temperature to melt the meltable material.

Then, apply a last phase under vacuum IV. Although the cover and the flap are closed during this phase, the water vapor and moisture produced by condensation are discharged from the container opposite the seal, as described above. Since this cycle lasts for example approximately minutes, there is ample time to obtain suitable drying.

During phase V of the cycle, atmospheric pressure is again introduced into the autoclave. Since this atmosphere cannot enter the hermetically sealed container, the atmospheric pressure applied to the container pushes its circle even more tightly on the base as a result of the realization of the base cover and the trim.

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