Patent Publication Number: US-2023159234-A1

Title: Closure mechanism with locking device for sterile containers, and sterile container comprising same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is the United States national stage entry of International Application No. PCT/EP2021/059018, filed Apr. 7, 2021, and claims priority to German Application No. 10 2020 109 765.4, filed Apr. 8, 2020. The contents of International Application No. PCT/EP2021/059018 and German Application No. 10 2020 109 765.4 are incorporated by reference herein in their entireties. 
    
    
     FIELD 
     The present invention relates to a closing mechanism for a sterile container having a container pan and a container lid lockable to the container pan via the closing mechanism, wherein the closing mechanism comprises a bar element for undercutting engagement with an engagement element forming an undercut on the container pan or on the container lid, respectively, wherein the bar element is positionable into a closed position, in which it is in undercutting operative connection with the engagement element, and into a release position, in which the bar element and the engagement element are disengaged. 
     BACKGROUND 
     Sterile containers described at the beginning are known from the prior art, which have a container pan that is hermetically sealable via a container lid as well as a closing mechanism, via which the lid is lockable to the pan in a fluid-tight manner. The so-called swing stopper is known for this purpose. It has an actuating lever which is pivotably mounted, for example on the lid, and to which a bracket or claw fastener/clamping jaw is hinged, which engages in an undercutting manner with a rail projecting laterally, for example on the container pan, and thus pulls the container lid against the container pan when the actuating lever is turned over. A sealing ring is arranged between the lid and the pan, which is pressed against the pan and the lid when the lid is tightened, thus sealing the contact area between the pan and the lid. Even small tolerances can be compensated for in the process. 
     For sterile containers, it is important that their internal pressure is at a predetermined ratio to the ambient pressure. In order to achieve this, sterile containers with a pressure equalization valve are known. In order to allow fluid (air, gas) to flow into the container interior from the environment (via a sterilizing filter device) and/or to allow fluid (air, gas) to flow out of the container interior into the environment (bypassing the filter device), it is known, for example, to arrange a valve device in the container lid. Decisive for a correct function of such a valve device is safe and fluid-tight locking of the lid on/at the container pan, in order to avoid unintentional leakages into/from the container at the contact point between pan and lid. 
     Another way of achieving pressure compensation in such sterile containers is to configure a closure mechanism in such a way that the lid can lift slightly from the container pan, even in the locked state, to compensate for excessive internal pressure in the container, so that fluid can flow out of the interior space. For this purpose, a sterile container is known having a closing/locking mechanism (hereinafter referred to as closing mechanism), a container pan and a container lid which is lockable to the container pan via the closing mechanism. The closing mechanism has an actuating lever, which is preferably pivotably mounted on the container lid or on the container pan, a pulling bracket/claw fastener/clamping jaw (hereinafter referred to as pulling bracket), which is coupled directly or indirectly to the actuating lever, and an engagement element on the container pan or on the container lid, which forms an undercut and with which the pulling bracket can be brought into undercutting operative connection in order to exert a tensile force on the engagement element in the direction in which the lid is placed on the container when the actuating lever is actuated. The pulling bracket is mounted so as to be displaceable transversely, preferably at a right angle to the tensile force to be exerted. A pre-tensioning element is also provided, for example in the form of a spring, which is arranged in an operative position relative to the pulling bracket in such a way that it only applies a compressive force to the pulling bracket in the direction of the tensile force to be exerted, i.e. in the direction in which the lid is placed on the container, when the actuating lever is in a predetermined actuating position and consequently in a predetermined/pre-determinable displacement position of the pulling bracket, in which the pulling bracket already engages behind the engagement element. 
     It is important for closing mechanisms and sterile containers that:
         the container pan/the lower container part and/or the container lid/the upper container part and/or the closing mechanism is protected from damage as a result of unintended/incorrect actuation of the closing mechanism, in particular if the closing mechanism is provided with a lever function, wherein very large forces can arise,   the largest possible area for marking the container/sterile container remains free on the front side of the lower container part despite the closing mechanism,   accidental opening of the closure unit is prevented as far as possible,   larger manufacturing tolerances can also be compensated for, and   a minimum tightening force between the lid and the tray is ensured.       

     Furthermore, it would be desirable if:
         the tensile force does not increase suddenly but continuously as the actuating lever is moved, in particular in order to prevent damage to the closing mechanism and/or to the seal,   the closing mechanism can also assume a pressure relief valve function at the same time,   the actuating lever is located in an easily accessible position, preferably on the upper side of the container lid, in order to avoid lateral protrusion also during the opening/closing process and not to cover the front side of the container pan,   the closing mechanism is fixed in its closed/locked end position as stably as possible and is secured against unintentional/accidental opening, and   the closing mechanism is particularly easy and quick to open from the closed/locked end position when it is deliberately actuated.       

     The disadvantage of known closing mechanisms or of sterile containers, respectively, is that they cannot achieve all of the above-mentioned properties. 
     SUMMARY 
     Against this background, the object of the present invention is to reduce the above-mentioned disadvantages of the prior art, in particular to provide a closing mechanism which is fixed as stably as possible in its closed end position (closed position) and is secured against unintentional/accidental opening, which can be opened particularly easily and quickly from the closed end position/closed position in the event of intentional actuation, and in which all, if possible, of the above-mentioned properties can be achieved. 
     The core idea of the present invention essentially consists in equipping the container closing mechanism according to the invention with a clamping jaw-like or claw fastener-like slider/bar element which is displaceably mounted, for example, on a container lid, wherein its claw fastener portion projects (preferably in principle, i.e. in each sliding position) over the container lid edge. At least one compression spring element is arranged between the slider/bar element and the container lid, which presses the slider/bar element increasingly away (upwards) from the container lid with increasing translational movement from its release position (far outside the container lid edge) into its closed position (near the container lid edge), i.e. lifts it upwards. 
     Furthermore, at least one return spring is arranged which pre-tensions the slider/bar element in the direction of its release position. 
     Finally, the slider/bar element or the compression spring element (connected to the slider for a joint sliding movement) is provided/configured with a (preferably manually operable or releasable) retaining element/retaining portion, which can be brought into retaining engagement (directly and in a latching manner) with a (preferably manually operable or releasable) locking/engagement element at or on the side of the container lid upon/with reaching the closed position, in order to hold the slider in the closed position against the pre-tensioning force of the return spring, in which the claw fastener portion engages under a container pan edge and pulls the container lid against the container pan edge as a result of the spring force of the at least one compression spring element, until the locking/engagement element on the side of the container lid or the retaining element/retaining portion on the side of the compression spring element is manually actuated for releasing the slider/bar element, and the slider/bar element springs back into its release position due to the return spring. 
     In other words, the aforementioned object according to the present invention is solved by a closing mechanism for/of a sterile container having a container pan and a container lid lockable to the container pan via the closing mechanism, wherein the closing mechanism comprises a claw-like bar element/slider for undercutting engagement with an engagement element (container pan edge/edge collar) forming an undercut configured on the container pan or on the container lid, wherein the bar element/slider is positionable in a closed position, in which it is in undercutting operative connection with the engagement element, and in a release position, in which the bar element and the engagement element are disengaged, wherein the closing mechanism has a locking element which is operatively connected or operatively connectable to the bar element/slider and which is integrated into the closing mechanism in such a way that it locks the closing mechanism in this closed position when the closed position is reached, in particular automatically/without separate user action. 
     The object is furthermore solved by a sterile container having a container lid and a container pan and a closing mechanism according to the invention, in particular with a closing mechanism according to the present description. 
     It is a particular advantage of the invention that the closing mechanism can be or is automatically secured in the closed position as a result of the built-in locking element. In particular, the closing mechanism may be configured in such a way that the locking element inevitably performs its locking function when the bar element is moved from the release position to the closed position, for example by being arranged in a fixed position relative to the container lid and coming into direct or indirect operative connection with the bar element, or by being arranged in a fixed position relative to the bar element and coming into operative connection with a counter latching structure arranged in a fixed position indirectly or directly on the container lid. In this way, accidental or unintentional opening of the closing mechanism can be prevented in a simple and safe manner. 
     The bar element is preferably a molded part/die-cut part made of metal or a plastic part. In particular, it may be configured in the shape of a hook, with a hook portion projecting at the edge over a side edge of the container lid for engaging behind the engagement element and a portion/slider portion adjoining the hook portion and projecting into the lid plane, which is guided/mounted on the container lid so that is positionable parallel to the lid plane. The bar element is preferably slidable parallel to the lid plane, that is between the release position, in which the hook portion and the engagement element are not engaged with each other, and the closed position, in which the hook portion and the engagement element are engaged with each other, the closing mechanism is locked, and the container lid is secured to the container pan. Therefore, it can also be said that the bar element is secured and locked in the closed position by the locking element. 
     Advantageous embodiments of the invention are explained in more detail below. 
     According to one embodiment, the closing mechanism may have a base plate which is configured and intended for arranging/fastening the closing mechanism to the container lid. The base plate, which is configured in particular as a metal-punched part/metal-formed part, may have a bearing structure for the bar element, preferably in the form of bent edge portions or collar portions. In these, elongated holes or grooves are preferably configured in which the bar element or a bearing structure connected to it is received and guided/mounted. The bar element is mounted so that it can be positioned linearly parallel to the lid plane. In addition, it may be pivotable transversely to the lid plane so that arranging/engaging the bar element with the engagement element of the container pan is being/is facilitated. 
     According to a particularly advantageous embodiment, the closing mechanism has a spring element that pre-tensions it into the release position. This spring element ensures that, if it was not secured by the locking element, the closing mechanism or the bar element would automatically assume the release position through pre-tension. According to the invention, however, the locking element also prevents unintentional/accidental transition of the closing mechanism from the closed position to the release position in this embodiment. Such a transition/movement is only possible as a result of the invention if the locking element is unlocked, for example, as a result of an actuation by the user. It is particularly advantageous and user-friendly that the closing mechanism automatically moves from the closed position to the release position after the locking element has been unlocked as a result of pre-tension by the spring element, without any further action by the user. In particular, the spring element may act directly on the bar element, for example by being arranged/supported on the bar element on the one hand and by being arranged/held in a positionally defined/stationary manner relative to the container lid on the other hand. 
     According to a further embodiment of the invention, the locking element may be configured and/or arranged to be elastic at least in sections. Alternatively, it may be configured to be completely elastic. For example, it may be configured as a locking-spring element or a locking-spring-damper element, in particular by a leaf spring element. It is of particular advantage if the locking element is configured to be elastically pre-tensioned. In particular, it may be configured as an elastically pre-tensioned rocker lever element (rocker lever) or an elastically pre-tensioned locking press button. Preferably, the locking element is configured and arranged in such a way that, when the closing mechanism/bar element reaches the closed position, it assumes the locking state locking the closing mechanism/bar element in the closed position due to its pre-tension. It is also advantageous if the locking element is configured and arranged in such a way that it can be transferred from the locking state to a release position releasing the closing mechanism/bar element by actuation by the user against its pre-tension. 
     The closing mechanism according to a further embodiment of the invention may have an actuating lever pivotably mounted on the container lid or on the container pan, respectively. This actuating lever may be coupled directly or indirectly to the bar element in such a way that the bar element can be positioned at least into the closed position via the actuating lever and, according to a further embodiment, can be positioned between the closed position and the locking state. 
     A further embodiment is characterized in that the bar element is configured and arranged in such a way that, in operative connection with the engagement element, it exerts a force (tensile force or compressive force) on the engagement element that causes the container lid to be pressed against the container pan. It is preferably configured and arranged to exert such a force when the closing mechanism is in the closed position. In this way, a particularly secure and tight fit of the lid on the container pan can be achieved, for example, by arranging/configuring an in particular elastic seal between them, which provides an additional sealing effect as a result of the contact force caused by the closing mechanism according to the invention. 
     Another embodiment of the invention is characterized in that the locking element has a spring portion. This may be arranged in the force flow between the container lid and the bar element. It can then advantageously exert a force on the bar element when the closing mechanism is in the closed position, which causes the bar element to be pressed against the engagement element. This force then opposes the contact force exerted by the closing mechanism between the container lid and the container pan. A particularly tight and secure fit both between lid and container as well as between bar element and engagement element is a particular advantage of this embodiment. In addition, in this embodiment, the spring portion or the locking element may provide a type of compensating element that ensures that a force exerted between the bar element and the engagement element in the closed position does not exceed an intended maximum value. This maximum value is determined by the spring characteristic and/or damper characteristic of the spring portion or of the locking element, respectively, and can be/is individually selected in such a way that a critical load on container pan and/or container lid and/or closing mechanism is not reached. In this embodiment, it is advantageous if the bar element can be pivoted transversely to the plane of the lid. 
     The locking element may have a latching structure, in particular in the form of a shoulder or a hook. When the closing mechanism reaches the closed position or is in the closed position, this latching structure engages with a counter latching structure preferably arranged or formed on the container lid and thus locks the closing mechanism in the closed position in a simple and reliable manner. Alternatively, the latching structure may engage with a counter latching structure arranged or formed on the bar element and thus lock the closing mechanism in the closed position in a simple and reliable manner. The locking or unlocking preferably takes place in a direction transverse to the direction of movement of the bar element, i.e. in particular transverse to the container lid plane or parallel thereto. 
     According to a further embodiment, the locking element is formed by a leaf spring. At least the spring portion of the locking element may be configured as a leaf spring. In such a leaf-spring-like locking element, the latching structure and the spring portion may be configured particularly efficiently and compactly in the form of a one-piece component, in particular may be shaped sheet metal parts made of a spring material, such as a spring steel. 
     In a further embodiment, the locking element may be a rocker lever arranged in a defined position on the container lid. In particular, this rocker lever may be pivotable relative to the bar element between a locking state that locks it in the closed position and a release position. The rocker lever is preferably pre-tensioned in the locking state, for example via a separate pre-tensioning element in the form of a spring/coil spring/leaf spring. It is of particular advantage if the rocker lever can be transferred from the locking state to its release position by an actuation pointing away from the container lid and the container pan, as in this way accidental unlocking of the closing mechanism by stacking several sterile containers on top of each other can be prevented in a simple and safe manner. 
     In summary, the invention can in particular bring about the following advantages:
         It provides a closure unit for closing an upper container part/container lid with a lower container part/container pan, wherein preferably on a front side of the lower container part/container lid, despite the closure unit, the largest possible area, for example for marking the container, is free and available.   In particular, there is not necessarily any risk of the closure unit opening accidentally or of accidental actuation on the front side as a result of gripping/gripping around or pulling on the front face of the container.   The effect of the locking element/compensating element/spring portion also enables the closure unit to advantageously compensate for tolerances between the upper container part/container lid and the lower container part/container pan. In particular, the upper container part/container lid can be pressed onto the lower container part/container pan with a defined minimum force.   In the scope of one embodiment of the invention, a rotary movement of a folding handle/actuation element of the closure unit can be transformed into a trajectory of the bar element/slider, in which the force exerted by the closure on the container seal can increasingly increase.   In one embodiment, if there is an excess pressure in the container interior relative to the container exterior (or, in other words, if the container exterior exhibits a negative pressure relative to the container interior), a relative movement of the upper container part/container lid relative to the lower container part/container pan can take place. In this way, a bypass can be advantageously released between the upper container part/container lid and the lower container part/container pan.   An actuation element/folding handle for opening can be located in particular on the upper side of the upper container part/container lid. This results in optimized space conditions at the front and corresponding options for marking the containers at the front.   The distance from the folding handle/actuation element to the container opening is dimensioned in such a way that sufficient distance to the container interior is ensured, which is important, for example, for so-called aseptic provision in the operating room. It thus improves aseptic provision of the contents of the container.   When the closure is closed, it is stabilized/fixed/secured/locked in the end position/closed position.   Accidental/unintentional opening of the closure can be easily and safely avoided/prevented.   Opening of the closure from the locking state is enabled particularly simply/user-friendly by actuating/unlocking the locking element.       

    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       Further features and advantages of the present invention will be apparent from the following exemplary and non-limiting description of the figures. These are merely schematic in nature and serve only to aid understanding of the invention. 
         FIG.  1    is a perspective view of a closing mechanism according to a first configuration example of the invention in the open position, i.e. in the completely unlocked state, 
         FIG.  2    is an enlarged detailed view of the closing mechanism of  FIG.  1   , 
         FIG.  3    is a perspective view of the closing mechanism of  FIGS.  1  and  2    in the closed position, i.e., in the fully closed state, 
         FIG.  4    is an enlarged detailed view of the closing mechanism of  FIG.  3   , 
         FIG.  5    is a perspective view of the closing mechanism of  FIGS.  1  to  4    with a cover cap, 
         FIG.  6    is a perspective view of a second configuration example in the open position, i.e. in the completely unlocked state, 
         FIG.  7    is a perspective view of a third configuration example in the open position, i.e., in the completely unlocked state, 
         FIG.  8    is a perspective view of a fourth configuration example in the open position, i.e. in the completely unlocked state, 
         FIG.  9    is a perspective view of a fifth configuration example in the open position, i.e. in the completely unlocked state, 
         FIG.  10    is a perspective view of a sixth configuration example in the open position, i.e. in the completely unlocked state, 
         FIG.  11    is a sectional view of a closing mechanism according to a further configuration example in the open position, and 
         FIG.  12    is a sectional view of the closing mechanism of  FIG.  11    in the closed position. 
     
    
    
     DETAILED DESCRIPTION 
     A closing mechanism according to  FIGS.  1  to  5    has a base plate  1  which is arranged on the upper side of a container lid  2  and is fastened, for example, via rivets  3 . The base plate  1  is a punched, shaped sheet metal part and has collar portions  4  bent upwards on both sides by about 90° to the plane of the container lid  2 . Each of these collar portions has a respective elongated guide hole  5  or a guide groove  5 , the longitudinal direction of which extends essentially parallel to the plane of the container lid  2 . 
     The closing mechanism also comprises a hook-shaped bar element  6 , for example in the form of a pulling bracket/claw fastener/clamping jaw/locking slider  6 . The bar element  6  is mounted on the upper side of a container lid  2  via a rod  8 /axis  8 /shaft  8  passing through the elongated guide holes  5  of the base plate  1  so as to be displaceable parallel to the latter. It is also pivotable in a certain region about the longitudinal axis of the rod  8  transverse to the plane of the container lid  2 . Thus, it can be said that the collar portions  4  with the elongated guide holes  5  form guide motion links  7  or a support  7  for the bar element  6 . Through this support  7 , the bar element  6  can be positioned between an open position shown in  FIGS.  1  and  2    and a closed position shown in  FIGS.  3 ,  4  and  5   , wherein the rod  8  slides in the elongated guide holes  7 . 
     The bar element  6  has/forms a hook portion or claw portion  9  at its end projecting freely over the circumferential edge of the container lid  2 , said hook portion or claw portion  9  being bent in the direction of the lower lid side or of a container pan  10 , respectively. The hook portion or claw portion  9  is configured and provided to come into operative connection with a rail  11  formed on the circumferential side of the container pan  10  as an engagement element  11  undercutting the latter when the closing mechanism is in the closed position. When the closing mechanism is in the release position or open position, the hook portion or claw portion  9  and the engagement element  11  are not engaged with each other and the container lid  2  can be removed from the container pan  10 . In the closed position, the container lid  2  is secured/fastened to the container pan  10 . 
     The closing mechanism of the first embodiment of  FIGS.  1  to  5    furthermore has a shaped sheet metal part  12 . It contains several functions. On the one hand, it forms a locking element/locking portion  13  in the sense of the invention. On the other hand, it forms a leaf spring element/leaf spring portion  14  for pre-tensioning/tensioning the bar element  6  with respect to the engagement element  11 /the rail  11  of the container pan  10 . While the locking element  13  and the leaf spring element  14  are configured in one piece by the shaped sheet metal part in the present configuration example, they may also be configured in multiple parts, in particular in two parts, by a plurality of shaped sheet metal parts in the scope of the invention. 
     In the embodiment of  FIGS.  1  to  5   , the locking element  13  is formed by a freely projecting arm of the shaped sheet metal part  12 , which has spring properties. It has a latching structure  15 , here in the form of an indentation  15 , which forms an abutment shoulder  16 . The width of the indentation  15  is slightly greater than the thickness of the rod  8 . The distal free end of the locking element  13  is formed as an actuation element  17 . On the side of the indentation  15  opposite the distal free end, the locking element  13  is provided with a guiding ramp  18  for the rod  8 . Due to the spring properties of the locking element  13 , it is pre-tensioned in a resting position protruding from the base plate  1 . From this position, it can be resiliently displaced against its spring pre-tension in the direction of the base plate  1 . 
     When the closing mechanism and thus the bar element  6  are in the release position/open position, the rod  8  and the locking element  13  are disengaged. This situation is shown in  FIGS.  1  and  2   . The rod  8  is positioned on the side of the indentation  15  and the guiding ramp  18  opposite from the actuation element  17 . As shown in particular in  FIGS.  3  and  4   , the rod  8  comes to rest in the indentation  15  when the bar element  6  is in the closed position. When the bar element  6  is moved from the release position to the closed position, the rod  8  is displaced together with the bar element  6  in the direction towards the locking element  13 . The rod  8  runs onto the guiding ramp  18  of the locking element  13 . Since the bar element  6  and the rod  8  in the guide motion link  7  are preferably guided parallel to the plane of the container lid  2 , the locking element  13  is displaced by the rod  8  against its pre-tension in the direction of the container lid  2  and the base plate  1  during continued movement into the closed position. It can also be said that the locking element  13  deflects in the direction towards the base plate  1  or towards the container lid  2 , respectively. As soon as the rod  8  overlaps with the indentation  15 , the locking element  13  springs back into its resting position at a distance from the base plate as a result of its spring properties. The rod  8  then comes to rest in the indentation  15  and in contact with the shoulder  16 . The bar element  6  is thus secured in the closed position by the locking element  13 . In this way, the indentation  15  forms a latching structure with the shoulder  16 , and the rod  8  forms a counter latching structure in the sense of the invention that interacts with it. 
     The closing mechanism also has two coil springs  19  as spring elements  19 , which pre-tension in the release position/open position. The coil springs  19  are each supported on the one hand on the bar element  6  and on the other hand on the base plate  1 . When the bar element  6  is moved into the closed position, the coil springs  19  are compressed against their spring tension. In order to move the closing mechanism and the bar element  6  from the closed position to the release position, the user has to actuate the actuation element  17 , which is pressed and displaced against the spring tension of the locking element  13  in the direction of the base plate  1  or of the container lid  2 , respectively. As a result of this displacement, the shoulder  16  and the rod  8  are disengaged and, due to the tension of the coil springs  19 , the bar element  6  is displaced from the closed position back into the release position. 
     The leaf spring element  14  formed by the shaped sheet metal part  12  has a ramp surface  20  projecting away from the plane of the container lid  2 , which is formed by a wave-shaped or roof-shaped region  21 . This roof-shaped region  21  also projects from the plane of the container lid  2  or of the base plate  1 , respectively, and into a recess  22 /window  22  formed in the bar element  6 . When the bar element  6  is moved into the closed position, an edge  22   a  bounding the recess  22  interacts with the ramp surface  20  of the region  21  and runs onto it. On the one hand, this may result in elastic deformation of the roof-shaped region  21  or of the ramp surface  20  in the direction of the base plate and, on the other hand, in displacement of the hook portion or claw portion  9 , since the bar element  6  is guided relative to the base plate  1  and the container lid  2  only on its distal free side via the rod  8  and the guide  7 , but is otherwise rotatable about the rod  8 . The kinematics are configured and adjusted in such a way that the hook portion or claw portion  9  does not result in or start pivoting away from the base plate  1  as a result of the interaction with the ramp surface  20  until the hook portion or claw portion  9  engages behind the rail  11  of the container pan  10 . In this way, the closing mechanism on the one hand causes the hook portion or claw portion  9  to be tensioned with the rail  11  (and thus a tight fit) and on the other hand, due to the elasticity of the roof-shaped region  21 , has a type of overload protection which defines pressing of the container lid  2  against the container pan  10  by the spring force acting in the process. 
       FIG.  5    shows that the closing mechanism shown in  FIGS.  1  to  4    is largely covered via a cover  23 , which leaves only the actuation element  17  free. 
       FIG.  6    shows a perspective view of a further configuration example of the closing mechanism in the open position, which differs from the embodiment of  FIGS.  1  to  5    only in the configuration of the locking element. In this embodiment, a shaped sheet metal part  12  forms only the leaf spring element  14 . A rocker lever  24  is formed separately from the shaped sheet metal part  12  and constitutes a locking element in the sense of the invention. The rocker lever  24  is arranged on the base plate  1  (or on the container lid  2 ) so as to be fixed in position and pivotable about a pivot axis  25 . It is positionable between a resting position/locking position, in which it is pre-tensioned via a compression spring  26 , and a release position, into which it can be brought by user actuation against the force of the compression spring  26 . The rocker lever  24  has an indentation  27  or a hook  27  open in the direction away from the base plate and configured and intended to receive/interact with the rod  8  when the bar element  6  is in the closed position. The end of the rocker lever  24  remote from the pivot axis  25  is configured as an actuation element  28  for pressure actuation by a user. Accordingly, the rocker lever  24  can lock the bar element  6  in the locking position and releases it for movement in the release position. 
     When the bar element  6  is brought into the closed position, the rod  8  runs onto the rocker lever  24 . As a result, the rocker lever  24  pivots against the force of the compression spring  26  in the direction of the container lid  2 /base platel until the rod  8  overlaps with the indentation  27  and the rocker lever  24  pivots back into its resting position due to the action of the compression spring  26 . In this position, the rod  8  lies in the indentation  27  so that the bar element  6  is locked in the closed position. When the actuation element  28  is pressed in the direction of the base plate  1 , the indentation  27  releases the rod  8  and the bar element  6  automatically returns from the closed position to the release position due to the pre-tension of the coil springs  19 . 
       FIG.  7    shows a perspective view of the closing mechanism according to a further configuration example in the open position. This is essentially similar to that of  FIG.  6   , but differs in the arrangement of the pivot axis  25  and the orientation of the indentation  27  of the rocker levers  24 , which is open in the direction of the base plate. 
       FIG.  8    shows another configuration example in which the indentation  27  of the rocker lever  24  is still open at the top (i.e. open on the side facing away from the base plate  1 ), and the compression spring  26  and the indentation  27  are arranged on one side of the pivot axis  25 , and the actuation element  28  is arranged on the side of the pivot axis  25 . It is a particular advantage of this embodiment that the actuation element  28  is not pressure actuable in the direction of the base plate  1  and the container lid  2 , but is actuable by a pull actuation in a direction away from the base plate  1  and the container lid  2 . This prevents accidental actuation of the actuation element  28  and unlocking of the bar element  6  and the closing mechanism when several sterile containers  10  are stacked on top of each other. 
       FIG.  9    shows a perspective view of a further configuration example of the invention in the open position. Here, instead of a rocker lever  24 , a press button  29  is provided as a locking element, which is configured and intended to interact with the rod in a manner already described with reference to the other configuration examples and is pre-tensioned with a compression spring  30  into a locking state that locks the rod  8 . 
       FIG.  10    shows a configuration example of the invention in which the locking element is formed in the form of a locking element  31  that is positionable transversely to the plane of the container lid  2  and the base plate  1 . The locking element  31  is mounted on the rod  8  in the longitudinal direction thereof so as to be relatively positionable between a locking state and a release position. It is also pre-tensioned into the locking state via the spring element  32 . Compared to the other configuration examples, the collar section  4  of the base plate  1  is configured to be elongated and has a locking recess  33  into which the locking element  31  automatically engages/can engage when the closing mechanism/bar element  6  is in the closed position due to the pre-tensioning by the spring element  32 . In order to move the closing mechanism from the closed position to the release position, the locking element  31  is actuated against the spring pre-tension by the user and the locking recess  33  is disengaged, so that the bar element  6  changes independently to the release position due to the tension of the coil springs  19 . While  FIG.  10    shows only one locking element  31  on one side of the closing mechanism, a variant of this configuration example may have two such locking elements  31  arranged on both sides of the closing mechanism. 
       FIG.  11    shows a sectional view of a further configuration example in the open position, which differs from the configuration example of  FIGS.  1  to  5    in that the shaped sheet metal part  12  is not stationarily fixed to the container lid  2 , but is fixed stationarily to the bar element  6 .  FIG.  12    shows a sectional view of the closing mechanism of  FIG.  11    in the closed position. The shaped sheet metal part  12  can, for example, be connected to the bar element  6  by a rivet connection or screw connection  34  or a material connection  34  (spot welding, etc.). A latching element  35  may be arranged on the container lid  2  or on the base plate  1 , which is configured to interact with the locking element  13  of the shaped sheet metal part  12 . Moreover, the configuration example of  FIGS.  11  and  12    corresponds to that of  FIGS.  1  to  5   , so that reference is made to the description of further details given there. A particular advantage of this configuration example is that the shaped sheet metal part  12  is almost completely covered and protected by the bar element  6 , irrespective of its functional position, and that the locking element  13  is unlocked by a pull actuation of the actuation element  17  (unlike the configuration example of  FIGS.  1  to  5   , in which a push actuation takes place in the direction of the container lid), so that unintentional unlocking can be safely avoided when several sterile containers are stacked on top of each other.