Sterile container

The invention relates to a sterile container, in particular for the receipt and sterile storage of surgical instruments or material, comprising a receiving chamber and a gas exchange opening that can be sealed using a sterile filter. The aim of the invention is to prevent undesired liquid from reaching the sterile filter. To achieve this, the exterior of the lid is provided with at least one inflow edge, which faces away from the gas exchange opening, and falls away towards the exterior in relation to a lid plane.

BACKGROUND OF THE INVENTION

The invention relates to a sterile container, in particular for the holding and sterile storage of surgical instruments or material, comprising a holding space, which is defined by a container base and container walls, a lid for closing the holding space and a gas exchange opening, which can be closed off by a sterile filter.

Sterile containers of the type described in the introduction, once they have been filled, for example with surgical instruments and/or material, are sterilized in a sterilizer using steam or other media. Consequently, the problem frequently arises whereby the lid, after the sterilizing operation, is wetted with liquid, in particular with residual condensate. This can then reach the sterile filter in an undesired manner. The same problem arises if the sterile container is inadvertently exposed to any liquid.

Therefore, it is an object of the present invention to improve a sterile container of the type described in the introduction in such a manner that it is impossible for any liquid to reach the sterile filter in an undesired manner.

SUMMARY OF THE INVENTION

According to the invention, this object is achieved by virtue of the fact that on the outer side of the lid there is provided at least one inflow edge which faces away from the gas exchange opening and slopes downward toward the outside relative to a lid plane.

This configuration allows gas or steam to flow along the inflow edge to the gas exchange opening and through the latter into the holding space, or vice versa. By contrast, a liquid which reaches the lid can flow off away from the gas exchange opening. This prevents water from accumulating on the lid, and consequently there is no risk of liquid being able to flow onto the sterile filter.

To ensure that the liquid can flow off reliably and under all conditions, it is advantageous if an angle of inclination which is included by the inflow edge and the lid plane is at least 1°.

There is advantageously provided a protective element which covers the sterile filter at a spacing therefrom. This protects the sterile filter from mechanical loads and from being acted on by liquid; a protective element which curves convexly away from the lid has proven advantageous with a view to avoiding accumulations of liquid on the protective element.

To make it easier for liquid which is present on the protective element to flow away, it is expedient if the protective element is disposed on an outer side of the sterile container.

According to a preferred embodiment of the invention, it is possible to provide that the lid, on its outer side, has a seating surface for seating the protective element, which surrounds the gas exchange opening. This allows the protective element to be attached or connected to the lid in a defined way. Furthermore, it advantageously fits into the lid, for example in order to form a common surface.

To ensure as flat an overall shape as possible, it is advantageous if the seating surface comprises an annular surface which runs parallel to the lid plane and is set back in the direction of the holding space.

To ensure that it is impossible for any liquid to reach the sterile filter in an undesired way, it is advantageous if the protective element completely covers the gas exchange opening and the seating surface. Liquid which is present on the protective element can then flow off the protective element without reaching the seating surface surrounding the gas exchange opening or the sterile filter covering the gas exchange opening.

It is preferably possible for there to be provided support surfaces for the purpose of supporting the protective element connected to the lid. The protective element is supported on the lid via these support surfaces.

To ensure that a defined spacing can be maintained between the protective element and the lid, it is preferable for the protective element to comprise spacer elements.

It is expedient if the protective element comprises a reinforcing frame. In particular in the case of protective elements made from soft or elastic materials, or also in the event of exposure to hot steam, the protective element is stabilized in its desired shape by the reinforcing frame.

It is particularly advantageous if the reinforcing frame comprises webs which cross one another and run substantially parallel to the lid surface. A reinforcing frame of this type can be produced particularly easily and offers sufficient stability while consuming only minimal material.

To keep the structural outlay and number of components of the sterile container small, it is expedient if the spacing elements are formed by projections and/or at least in part by the webs. Therefore, the projections and/or webs fulfil a dual function. Firstly, they reinforce the protective element, and secondly they ensure a desired spacing between the protective element and the lid.

To facilitate assembly of the sterile container and to increase the ease of maintenance, in a preferred embodiment of the invention there is provided at least one snap-action connection for connecting the protective element to the lid.

A further advantage ensues if the at least one snap-action connection is provided for connection of the protective element to a rim, which includes latching recesses, of the gas exchange opening. In particular in the case of protective elements which are not of rotationally symmetrical configuration, it is in this way possible to achieve a defined positioning of the protective element on the lid. The snap-action connection makes it easy to connect the protective element to the lid and release it again from the latter.

A particularly compact overall shape of the sterile container results if the at least one snap-action connection comprises elastic spring arms which project away from the protective element toward the lid and are provided with a latching projection. Moreover, it is in this way easy for the protective elements to be clipped to the lid, for example to the rim of the gas exchange opening.

The protective element itself could be provided with openings in order to allow gas exchange with the filter unit through the protective element to the gas exchange opening. However, it is particularly advantageous if there is provided, between the protective element and the lid, at least one opening for the passage of gas, which is in fluid communication with the gas exchange opening. This means that there is no need for any additional perforation in the protective element. The opening for the passage of gas is formed solely by the corresponding shape of the protective element and of the lid. Liquid which is present on the protective element can completely flow off the protective element without further covering of apertures in the protective element.

To additionally suppress penetration of liquid onto the sterile filter, it is advantageous if the opening for the passage of gas is arranged in such a way that it becomes possible for gas to flow in a direction of flow running substantially transversely with respect to the flow-permitting direction through the sterile filter.

A particularly flat overall shape results if the opening for the passage of gas, in cross section, has a double-convex lens shape. Furthermore, a run-off channel for liquids is formed by the lid surface, which is curved concavely in order to form the double-convex lens shape.

To allow gas exchange through the gas exchange opening with stacked sterile containers, it is expedient if the lid has at least one spacer element for stacking a further sterile container on the sterile container.

It is preferable for the inflow edge to be disposed between two spacer elements. This allows sufficient inclination of the inflow edge to enable liquid which has reached the lid to flow off.

To enable a plurality of sterile containers to be stacked safely on top of one another, it is expedient if the spacer elements comprise at least three projections facing away from the outer side of the sterile container.

In an advantageous embodiment of the invention, it is possible to provide that the seating surface is delimited by the at least one inflow edge and the at least one spacer element. This enables liquid to flow from the spacer element onto the inflow edge and then to be directly discharged from the latter.

To enable the protective element to be fitted into the lid surface without free edges being visible in the transition between the protective element and the lid, it is expedient if the spacer elements comprise or adjoin the support surfaces.

The sterile container can be produced particularly easily and inexpensively if the lid, the at least one spacer element, the seating surface and the at least one inflow edge are formed integrally.

To further simplify construction of the sterile container, it is advantageous if there is provided a filter unit, which comprises the sterile filter, a carrier and a holding element, and if the sterile filter is held between the carrier and the holding element.

The filter unit can be exchanged particularly easily, thereby increasing ease of maintenance of the sterile container, if the filter unit is in single-piece form, and if the carrier, the sterile filter and the holding element are nonreleasably connected, in particular by welding or adhesive bonding, to one another.

In a further preferred embodiment of the invention, it is possible to provide that the filter unit is mounted moveably, that the filter unit, in a closed position, closes a flow path and, in a flow-permitting position, opens the flow path, so that gas exchange in the closed position is possible only through the sterile filter and in the flow-permitting position is possible through the sterile filter and/or through the flow path. This means that the filter unit can be transferred into the closed position or the flow-permitting position on demand, depending on the level of gas and/or steam throughput which is desired.

To avoid damage to the sterile container and to simplify its overall structure, it is advantageous if there is provided a pressure-relief valve, if the pressure-relief valve is disposed in such a way that in a basic position it adopts a closed position, if it adopts a flow-permitting position when a pressure in a vicinity of the sterile container exceeds a pressure in the sterile container by a predetermined pressure difference, and if the pressure-relief valve forms the filter unit. The filter unit therefore serves firstly as a filter and secondly as a pressure-relief valve. Therefore, separate provision of a pressure-relief valve is no longer required.

To increase the stability of the lid, which is advantageous in particular in the case of large gas exchange openings, the gas exchange opening comprises at least one stiffening element for stiffening the lid. This can be achieved, for example, by webs or carriers which span the gas exchange opening.

It is preferable for the at least one stiffening element to be formed by a web spans the gas exchange opening. This web simultaneously serves as additional protection for the sterile filter.

In principle, the stiffening element could adjoin the seating surface, which runs parallel to the lid plane and is set back toward the holding space, and could therefore likewise be set back toward the holding space. However, it is expedient if the at least one stiffening element is offset in a direction away from the holding space relative to the outer side of the lid. This enables the condensed fluid which forms on the stiffening element to flow away from the stiffening element without reaching the sterile filter through the gas exchange opening.

To provide the sterile filter with even better protection against the penetration of fluids, in a preferred embodiment of the invention it is provided that there is a fluid-retaining element for preventing fluid from flowing in from the outer side of the lid through the gas exchange opening. This prevents any form of fluids, in particular including condensate, from being able to reach the sterile filter.

In principle, the fluid-retaining element could be disposed on an inner side of the lid. However, it is advantageous if the fluid-retaining element is disposed on the outer side of the lid and surrounds the gas exchange opening at least in sections. This right from the outset prevents fluids from being able to reach the region of the gas exchange opening.

In principle, the fluid-retaining element could also be formed by a membrane which spans the gas exchange opening. However, better gas exchange can be achieved if, in a preferred embodiment of the invention, the fluid-retaining element is formed as a rim which protrudes from the outer side of the lid. Moreover, a rim of this type can be produced particularly easily and inexpensively.

To keep fluids as far away from the gas exchange opening as possible, it is expedient if the fluid-retaining element is disposed at a spacing from the gas exchange opening. Furthermore, the region which adjoins the gas exchange opening and is protected from the penetration of fluids can serve, for example, as a seating surface.

It is preferable for the protective element to completely cover the gas exchange opening and the fluid-retaining element. Consequently, fluids which flow off the protective element must first overcome the fluid-retaining element before they are able to reach the sterile filter through the gas exchange opening.

The sterile container can be produced particularly easily and favorably if the lid is made from a plastic, in particular from polyether ether ketone (PEEK) or polyphenyl sulfone (PPSU).

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1illustrates a sterile container, which is denoted overall by reference numeral10and comprises a substantially tub-like, cuboidal container12for holding, for example, surgical instruments or material, and a lid14. Pivotably mounted carry handles16are disposed at the end faces of the container12.

The structure of the lid14is explained in more detail with reference toFIGS. 2 to 9.

The lid14is provided with an encircling rim18which projects perpendicularly from a lid plane15, so that the lid14completely covers and partially engages around the container12. A sealing rim20, between which and the rim18a seal (not shown) can be inserted, runs parallel to and at a spacing from the rim18. When the lid14has been fitted, the sealing rim20is located inside the container12. The seal makes it possible to produce a gastight connection between the lid14and the container12.

At its narrow end sides, the lid14in each case has a bearing bracket22, on which a resilient closure flap24can pivot about a pivot axis running parallel to a pivot axis of the carry handle16when the lid14is seated on the container12.

The lid14has two symmetrically disposed circular openings26, which have an opening rim28which faces parallel to the lid plane15and on which four webs30, which run perpendicularly toward one another and meet in the center of the opening26, for stiffening the lid, are disposed symmetrically. Between each pair of webs30disposed at the opening rim28, two indentations32and33are cut symmetrically into the opening rim28.

The opening26is surrounded by an annular surface34, which runs parallel to the lid plane15but is set back toward an underside36of the lid. As a result, an inner annular edge38is formed on a top side37of the lid and an outer annular edge39is formed on the underside36of the lid. The annular edge38is adjoined by four inflow edges40and four support surfaces42which alternate with one another. The inflow edges40are curved concavely away from the lid top side37and are inclined outward, so that an inclined plane with an angle of inclination44between the inflow edge40and the lid plane15of approximately 2° is formed.

The support surfaces42run parallel to the lid plane15and, when seen in plan view, are approximately in the shape of a trapezoid, but in each case with concavely curved base edges. The longer of the two base lines of the support surface42is adjoined by a three-sided pyramid46, which has a base area which is substantially in the shape of an isosceles right-angled triangle. An apex48of the pyramid lies just above the base sides, which intersect at right angles, of the base surface, slightly offset toward the opening26.

This results in the formation of a run-off surface50which is approximately in the shape of an isosceles, right-angled triangle which is inclined toward the support surface42. The support surface42is offset away from the lid top side37, parallel to the lid plane15.

The overall result, therefore, is an approximately square structure on the lid14, which is formed by four pyramids46, which are each seated in the corners of the square, the side faces of the square running parallel to sides of the lid14. The inflow edges40are therefore inclined perpendicularly toward the sides of the lid14. The structure has a total of two planes of symmetry running parallel to the sides of the lid14. On its side facing away from the opening26, the inflow edge40extends down to the level of the lid plane15. When the lid is seen from the side, therefore, the result is approximately a concave shape, facing away from the lid top side37, from the apex48of the pyramid46in a corner of the square structure to the apex48of the pyramid46in an adjacent corner of the structure.

Adjacent to the indentations32and33are disposed a total of four hollow-cylindrical, open sleeves52protruding from the underside36of the lid. A filter cartridge54is mounted resiliently on these sleeves. The filter cartridge comprises an approximately octagonal filter holder58, which is provided with a carrier rim56and has an annular filter receiver60for accommodating a circular long-term filter62. An annular recess64, which is configured with a larger diameter than the filter receiver60, is used to accommodate a holding ring66, which in cross-section has an L-shaped profile, one limb of which presses the long-term filter62into the filter receiver60and the other limb of which engages against the recess64. The holding ring66is provided with an annular ring groove, which in cross-section includes slightly more than half of a circle, for accommodating a sealing ring70.

Four mounting sleeves74, corresponding to the sleeves52disposed on the lid14, protrude from a filter holder base72toward the lid; these mounting sleeves are open from the filter holder base72, and their other, closed end face76is provided with a central through opening78whose diameter corresponds to that of the sleeve52. To mount the filter cartridge54, the four mounting sleeves74are pushed over the sleeves52, a coil spring80is in each case fitted over the sleeves52, and then the mounting sleeves74of the filter holder base72are closed off with a stopper82which has a disk-like head84whose external diameter is matched to the internal diameter of the mounting sleeves74. On account of the fact that the coil spring80is supported against the head84of the stopper82, it presses the end face76onto the underside36of the lid.

The filter holder base72is provided with a total of twenty strip-like slots86of different lengths, with in each case five slots running parallel to one another and approximately covering the area of a quarter-circle. Slots86belonging to adjacent quarter-circles are in each case positioned perpendicular to one another. A protective web88is formed between each pair of slots86. A strip90, which faces away from the filter holder base72and from which, once again running parallel to the filter holder base72, there protrudes a support web92facing away from the associated protective web88and in each case completely covering a slot86, is disposed on each protective web88. All the support webs92define a common plane on which the long-term filter62rests. Overall, the filter receiver60and the support webs92form a carrier support for supporting the long-term filter62.

The filter holder58, the long-term filter62and the holding ring66are fixedly connected to one another, for example by welding or adhesive bonding. In the assembled state, the coil springs88press the filter cartridge54onto the underside36of the lid, with the filter cartridge54being sealed against the underside36of the lid by means of the sealing ring70.

The holding ring66has an outer ring and an inner ring94running concentrically therewith, from which four holding ring webs96disposed radially and symmetrically stabilize the holding ring66.

On account of the offset arrangement of support web92and protective web88, the long-term filter62supported on the support webs92is protected from direct mechanical damage. However, the long-term filter62is virtually unprotected on its side facing toward the opening26. For this purpose, a protective cover98, which is of mirror-symmetrical configuration and has a cover surface100curved convexly away from the top side37of the cover, is provided as a protective element; when the cover surface100is seen in plan view, it is in the shape of a non-equilateral octagon with short sides102and long sides104.

An annular strip108, which comprises four cutouts110, each disposed diametrically in pairs, protrudes from an underside106of the protective cover. These cutouts110are shaped in such a manner that they can engage over the webs30and the protective cover98rests on the webs30. Two spacer strips112, which cross one another, are disposed on the underside106of the protective cover, as additional spacers, which spacer strips, in the region of the cutouts110, project outward beyond the ring strip108as far as the long sides104. When the protective cover98has been fitted, these strips rest on the annular surface34.

To secure the protective cover98there are four latching connectors114, which each comprise three limbs, which are disposed at right angles to one another, form a U-shaped frame116and two of which protrude radially outward from the ring strip108. As free ends of the spacer strips112, they form spacers resting on the annular surface34. From a transverse web118of the frame116, two latching arms120protrude parallel and at right angles from the underside106of the protective cover, which latching arms are provided at their free ends with a latching lug122protruding at right angles. The four latching connectors114are disposed in diametrically opposite pairs on the protective cover98.

To secure the protective cover98, the latter is moved perpendicularly toward the top side37of the lid and is oriented in such a way that the cutouts110each face toward a web30and the latching arms120each slide into one of the two indentations32and33. As soon as the cutouts110rest on the webs30, the closure strips112and the frames116rest on the annular surface34, the latching arms120latch to the opening rim28as a result of the latching lugs122engaging behind the opening rim28.

The size of the protective cover98is selected to be such that in the inserted position the annular surface34is completely covered. The short sides102then rest on the support surfaces42, while the long sides104run parallel to the side edges of the lid14and in each case partially cover the inflow edges40. When the protective cover98is inserted, the long-term filter62held in the filter cartridge54is also completely protected from mechanical damage from its other side.

In an alternative variant of a lid, which is indicated by dot-dashed lines inFIG. 2, the long sides104of the protective cover98are lengthened. The pyramid46then has, in its run-off surface50, an additional recess, in which the short side102of the protective cover98is fitted. This results in a seamless transition between the run-off surface50and the cover surface100.

The highest point of the protective cover98when the latter is inserted lies beneath the highest point of the four pyramids46, so that when sterile containers10are stacked on top of one another the container12which is mounted on the lid14rests only on the apexes48of the pyramids46but does not touch the protective covers98.

If, with a substantially horizontally mounted sterile container10, liquid reaches the top side37of the lid, for example reaches the protective cover98, the curvature of the protective cover98means that the liquid can flow off to the short or long sides102or104, respectively. From the long sides104, the liquid passes onto the inflow edges40, from which the liquid can flow off to the sides of the lid14on account of the inclination of these edges.

When the protective cover98is fitted, a substantially double-convex lens-shaped inflow opening124, as seen in side view, is formed, through which a gaseous fluid can flow in and out. The fluid then flows substantially parallel to the lid plane15, through the opening26substantially perpendicular thereto. In a basic position illustrated inFIG. 8, the filter cartridge54engages against the underside36of the lid, sealed off by means of the sealing ring70. If the sterile container10is exposed to hot steam, the latter flows to the long-term filter62, as described above. It passes through the long-term filter62and then follows a flow channel, defined by the support web92, the strip90and the protective web88, into the interior of the container12.

If a pressure acting from outside on the sterile container10exceeds a force which can be set by means of the coil springs80, the filter cartridge54, which is mounted resiliently on the lid14, acts as a pressure-relief valve. The filter cartridge54is lifted off the underside36of the lid and opens up a flow channel126which is closed in the basic position, as illustrated inFIG. 9. Hot steam can now pass not only through the long-term filter62but also into the interior of the container12via the flow channel126. As soon as the pressure gradient drops again, the coil springs80press the filter cartridge54back onto the underside of the lid, so that steam or gas can only flow in and out via the long-term filter62.FIGS. 8 and 9use arrows to indicate the incoming and outgoing flow of a gas or steam.

A slightly modified variant of the lid14awill now be explained in more detail with reference toFIGS. 10 and 11.

In a lid14as has been explained in connection withFIGS. 1 to 9, it is possible to provide, as an additional element, a fluid-retaining element in the form of an encircling edge130. The encircling edge130is formed as an annular projection which protrudes from the top side37of the lid and surrounds the opening26on the top side37of the lid. In the exemplary embodiment illustrated, the edge adjoins the annular edge38on the outer side toward the inflow edge40, with a short spacing between them. Alternatively, however, it would also be conceivable for the edge130to directly adjoin the opening rim28or the annular edge38. If the gas exchange openings in the lid14are not circular in form, it is preferable for the edge130to follow the contour of the opening. The long side104of the protective cover98projects beyond the edge130, so that liquid which runs off the protective cover98drops directly onto the inflow edge40but cannot pass over the edge130, which forms a barrier, through the opening26and onto the long-term filter62. Furthermore, the webs30aare offset away from the opening26and the top side37of the lid, so that, unlike in the case of the lid14described in connection withFIGS. 1 to 9, a set-back annular surface34is not formed.

The container12may optionally be made from metal or plastic. The lid14is preferably made completely from a plastic, for example from polyether ether ketone or polyphenylene sulfone. The long-term filter is preferably made from polytetrafluorethylene.