referring to the drawings in particular , fig1 shows as an example a sterilization container 1 , which has a box - shaped design in this exemplary embodiment and has a lower container part 2 . a container cover 3 is placed tightly on this lower container part 2 , and said container cover is held in this attached position by means of two container closures 4 , but only the “ front ” container closure 4 is visible in fig1 . further , it can be seen in fig1 that the container cover 3 has two wall areas 5 and 6 in the present exemplary embodiment , which are provided with a plurality of ventilation openings 7 each . the ventilation openings 7 of the wall area 6 are shown in the bottom view in fig2 . the two wall areas 5 and 6 with their ventilation openings 7 differ in that the ventilation openings in the second wall area 6 are covered by a cover plate 8 . this cover plate 8 is located at a vertically spaced location from the wall area 6 , so that ambient air can flow through the ventilation openings 7 visible from fig2 . furthermore , it is seen in fig1 that a flat lock nut 9 , whose significance will be explained in more detail below , is provided centrally within the ventilation openings 7 of the wall area 5 . the ventilation openings 7 are used for “ pressure equalization ” within the closed sterilization container 1 during operation . thus , such a sterilization container 1 is used , as was mentioned already in the introduction to the specification , for example , to sterilize surgical instruments . the surgical instruments are placed for this purpose into the sterilization container 1 , the container cover 3 is placed on the container part 2 and closed tightly . the sterilization container 1 is heated , as a rule , during the sterilization process , so that an overpressure develops within this sterilization container 1 . the air now flows through the ventilation openings 7 from the inside to the outside for pressure equalization . the sterilization container 1 is cooled again after the sterilization operation , so that ambient air flows through the ventilation openings 7 into the sterilization container 1 in the opposite direction . to prevent contamination within the container or of the sterilized medical instruments for hygienic reasons , a so - called sterile barrier is provided , which is in the form of a filter sheet 10 in the embodiment variant shown and is shown as a separate component in fig2 . as can be seen further from the bottom view of the container cover 3 in fig2 , a mounting pin 11 , which is screwed into a corresponding threaded hole of the wall area 6 of the container cover 3 , which said threaded hole is not visible in fig2 , is provided centrally in the wall area 6 or in the area of the ventilation openings 7 . the cover plate 8 , which is screwed onto a threaded section , which protrudes on the top side above the wall section 6 of the container cover 3 , is used in the area of the container cover 3 to secure this mounting pin 11 . after the mounting pin 11 has been positioned , the filter sheet 10 can be placed on same in the area of the ventilation openings 7 . as is shown for the wall area 5 in fig2 , a pressing disk 12 , which is braced on the top side against the filter sheet 10 via a special holding device 13 in the exemplary embodiment shown , is subsequently placed on the filter sheet 10 . the holding device 13 thus forms a filter holder together with the pressing disk 12 for stationarily holding the filter sheet 10 in the area of the ventilation openings 7 . fig3 shows for this a partial sectional view of the wall area 5 with the ventilation openings 7 . it can be recognized that an internal screw thread , into which a threaded pin 15 of the mounting pin 11 can be screwed , is provided centrally in the area of the ventilation openings 7 . the axial length of this threaded pin 15 is selected here to be such that this threaded pin passes through the wall area 5 in the mounted state . the lock nut 9 can be correspondingly screwed onto this threaded pin 15 , so that the mounting pin 11 is arranged stationarily in the wall area 5 . to make it possible to screw the lock nut 9 onto the threaded pin 15 in a tightly seated manner , said lock nut has , on the whole , three flat wrench contact surfaces 16 arranged uniformly distributed on the circumference in the exemplary embodiment being shown . further , it can be recognized from fig3 that the mounting pin 11 has , in its end area located towards the threaded pin 15 , a radially expanded profile web 17 , which forms a plurality of flat holding surfaces 18 distributed uniformly on the circumference . in the opposite end area of this profile web 17 , the mounting pin 11 has a circular locking groove 19 , which has an approximately partly cylindrical cross - sectional shape . as was already mentioned in connection with fig2 , the holding device 13 can be detachably placed on this mounting pin 11 in the mounted state . fig4 shows for this a partial perspective view of the pressing disk 12 from fig2 together with a holding pin 20 and with an adjusting sleeve 21 . this holding pin 20 and the adjusting sleeve 21 together form the holding device 13 mentioned in connection with fig2 for the pressing disk 12 . the pressing disk 12 has a plurality of perforations 22 , so that an air flow can flow correspondingly through these . the pressing disk 12 is provided centrally with an internal screw thread 23 , which is limited on the top side by means of a radially inwardly protruding stop web 24 . corresponding to the diameter of this stop web 24 , the holding pin 20 has a vertically upwardly projecting cylindrical bearing section 25 . in the lower end area of this bearing section 25 , the holding pin 20 forms a radially projecting , circular mounting web 26 , which is provided with a corresponding external screw thread 27 ( not shown explicitly in the drawing ). for mounting in the pressing disk 12 , the holding pin 20 can be passed with its cylindrical bearing section 25 through the stop web 24 and can be caused to stationarily mesh by its external screw thread 27 with the internal screw thread 23 of the pressing disk 12 . further , it can be seen in fig4 that the cylindrical bearing section 25 of the holding pin 20 has , in its jacket surface in the front left area , an l - shaped groove 28 , which has a vertical section 29 towards the upper end area , which said vertical section extends in parallel to the central longitudinal axis 30 of the bearing section 25 or of the holding pin 20 . the l - shaped groove 28 forms a horizontal section 31 extending at right angles in the lower end area of this vertical section 29 . further , it can be recognized from fig4 and also from the bottom view of the mounting pin 20 in fig5 that a through hole 32 is provided in the free end area of the bearing section 25 . this through hole 32 is used to receive two locking balls , between which an axial compression spring is provided , as this will be explained in more detail below . in the area located towards the mounting web 26 , the bearing section 25 has a total of three mounting holes 33 ( fig5 ), which are used to receive a fixing element in the form of a locking ball , as this will be explained in more detail below . further , it can be recognized from fig5 that the holding pin 20 has a central mounting hole 34 , with which this holding pin 20 can be placed fittingly onto the mounting pin 11 from fig3 . further , this mounting hole 34 in the axial end area of the mounting web 26 is provided with a bearing profile 35 , with which the holding pin 20 can be placed fittingly onto the holding surfaces 18 of the profile web 17 of the mounting pin 11 . the holding pin 20 can thus be arranged on the mounting pin 11 secured against rotation in the mounted state . further , it can also be seen in fig5 that two grooves 36 , which are used to firmly tighten the holding pin 20 in the internal screw thread 23 of the pressing disk 12 , are arranged in the area of the mounting web 26 on the underside in the front surface of said mounting web . further , it can be seen in fig4 that the adjusting sleeve 21 forms a central through hole 40 , which has an inner fixing groove 42 at an axially spaced location from its upper front surface in the direction of arrow 41 . in the upper end area , the adjusting sleeve 21 has a radially expanded , profiled actuating web 43 , which is used for the simplified operation of the adjusting sleeve 21 . in the area between the inner fixing groove 42 and the upper front surface or in the area of this actuating web 43 , the through hole 40 is provided with a milled recess 44 , diametrically opposed to which a second milled recess 44 , which is not recognizable in fig4 , may be arranged . this milled recess or these milled recesses 44 is / are used during operation to fix a preset , relative angular position of the adjusting sleeve 21 relative to the holding pin 20 . the milled recesses 44 will be overlapped with the through hole 32 in this position , so that the locking balls arranged in the through hole 32 under spring loading will come to mesh with these milled recesses 44 . further , it can be recognized from fig4 that the adjusting sleeve 21 has a through hole 46 in its cylindrical side wall 45 . as can be recognized from the sectional view of the adjusting sleeve 21 in fig6 , a fixing pin 47 , which is seated stationarily in the through hole 46 in the mounted state and , as this is shown by broken lines in fig6 , protrudes into the through hole 46 , can be caused to mesh with this through hole 46 . this fixing pin 47 is inserted after attaching the adjusting sleeve 21 to the holding pin 20 and meshes in the mounted state with the l - shaped groove 28 or with the vertical section 29 or horizontal section 31 thereof as desired . it is thus achieved that the adjusting sleeve 31 is adjustable , on the one hand , limited to the holding pin 20 in the axial direction of the double arrow 48 and is likewise rotatable to a limited extent in the direction of the double arrow 49 . the fixing pin 47 can be pressed , soldered or bonded into the through hole 46 . a “ clamping ” threaded connection is also conceivable , so that the fixing pin 47 cannot become detached by itself in the through hole , which is designed as a threaded hole in this case . concerning the preassembled state of the pressing disk 12 , of the holding pin 20 and of the adjusting sleeve 21 , fig7 shows an enlarged partial view of these components in the central area of the pressing disk 12 . it can be recognized from fig7 that the adjusting sleeve 21 with its through hole 40 is attached to the cylindrical bearing section 25 of the holding pin 20 . the adjusting sleeve 21 with its actuating web 43 is now located above the upper front surface 37 of the cylindrical bearing section 25 . the above - mentioned two locking balls 50 shown in fig7 mesh with the circular locking groove 42 of the adjusting sleeve 21 in this “ neutral ” position of the adjusting sleeve 21 relative to the holding pin 20 . the neutral , axial relative position of the adjusting sleeve 21 relative to the holding pin 20 is thus secured . further , it can be recognized from fig7 that the fixing pin 47 is arranged in the through hole 46 in a tightly seated manner and meshes with the vertical section 29 of the l - shaped groove 28 in the upper end area thereof . the adjusting sleeve 21 is thus fixed in this position against rotation against the holding pin 20 based on the functional connection of the fixing pin 47 with the vertical section 29 of the l - shaped groove 28 . further , one of the three radial through holes 33 of the bearing section 25 from fig5 , in which a corresponding holding ball 51 is arranged , can also be recognized from fig7 . further holding balls 51 are correspondingly inserted into the other two through holes not recognizable in fig7 as well . in this axial relative position of the adjusting sleeve 21 in relation to the holding pin 20 , this holding ball 51 ( or locking balls ) is ( are ) located in an axial area of a radial expansion 52 of the through hole 40 of the adjusting sleeve 21 , which is arranged in the lower end area of the adjusting sleeve 21 , as this can also be recognized especially from the sectional view in fig6 . the holding ball 51 ( or holding balls ) can thus be moved radially to the outside until this comes into contact with this radial expansion 52 on the inside and does not protrude into the mounting hole 34 of the holding pin 20 any longer . furthermore , it can be recognized from fig7 that the holding pin 20 with its external screw thread 27 of its mounting web 26 meshes with the internal screw thread 23 of the pressing disk 12 in a stationary manner . the pressing disk 12 with the holding device 13 comprising the holding pin 20 and the adjusting sleeve 21 can be placed in this preassembled state onto the mounting pin 11 according to fig3 . furthermore , fig7 also shows the axial compression spring 60 , by which the two locking balls 50 arranged in the end area of the through hole 32 extending at right angles are pressed radially outwardly under prestress . fig8 shows the view from fig7 with the pressing disk 12 of the holding device 13 in the state in which it is placed on the mounting pin 11 . the mounting pin 11 is screwed into the wall section 5 , and the lock nut 9 is screwed stationarily onto the threaded pin 15 of the mounting pin 11 on the underside . the mounting pin 11 is fixed nonrotatably on the wall area 5 in this mounted state of the mounting pin 11 in the wall area 5 . further , it can be recognized that the holding ball 51 is located in the axial area of the circular locking groove 19 of the mounting pin 11 in this state in which the pressing disk 12 with the holding device 13 is placed “ loosely ” on the mounting pin 11 . in this attached state , the holding pin 20 meshes with the holding surfaces 18 of the profile web 17 of the mounting pin 11 in a positive - locking manner and hence nonrotatably by its bearing profile 35 , which can be recognized as a suggestion only in fig8 . thus , the pressing disk 12 is also held nonrotatably in the wall area 5 based on the stationary threaded connection with the holding pin 20 . further , it can be recognized from fig8 that the filter sheet 10 shown as a separate component in fig2 is arranged between the pressing disk 12 and the wall area 5 . furthermore , it can also be recognized from fig8 that a sealing ring 55 is provided under the filter sheet 10 . reference should briefly also be made in this connection to the view in fig3 , from which it can be recognized that a mounting groove 56 , in which a second sealing ring , which is not shown explicitly in fig3 , is provided in the mounted state , is arranged in the outer circumferential area of the ventilation openings 7 . to receive the sealing ring 55 from fig8 , the wall area 5 likewise has a circular mounting groove 57 in the area located radially within the ventilation openings 7 . to now press the pressing disk 12 at least slightly against the surface of the filter sheet 10 and especially to achieve a sealing action of the sealing ring 55 , the adjusting sleeve 21 can be adjusted manually downwardly in the direction of arrow 41 . the holding ball 51 ( or holding balls ) now enters ( enter ) the radially tapered through hole 40 from the area of the radial expansion 52 of the through hole 40 , so that an adjusting motion of the holding ball 51 is brought about in the radial direction indicated by arrow 58 . the holding ball 51 is thus pressed inevitably into the circular locking groove 19 , as a result of which adjusting forces are , in turn , generated in the direction of arrow 41 . since a total of three such holding balls 51 are provided in the through holes 33 recognizable in fig5 , uniform pressing of the pressing disk 12 is brought about via these holding balls 51 and the locking groove 19 in the direction of arrow 41 . the fixing pin 47 “ slides ” along the vertical section 29 of the l - shaped groove 28 during this adjusting motion in the direction of arrow 41 . when the “ lower ” end position of the adjusting sleeve 21 is reached , this fixing pin 47 is located in the axial area of the lower horizontal section 31 of the l - shaped groove 28 . the fixing pin 47 can thus now be caused to mesh with the horizontal section 31 to fix this axial securing position of the adjusting sleeve 21 by rotating same in the direction of arrow 59 into its fixing position . this fixed fixing position of the adjusting sleeve 21 with its fixing pin 47 can be recognized in the perspective sectional view shown in fig9 . it can also be recognized in this view that the locking ball 50 meshes with the milled recess 44 of the through hole 40 of the adjusting sleeve 21 and is held in this meshing position by the axial compression spring 60 . the second locking ball 50 correspondingly meshes with the second milled recess not recognizable in fig9 . this meshing position of the second locking ball 50 with the second milled recess 44 is indicated by broken lines in fig1 , because this is not “ actually ” recognizable in fig1 based on the section orientation from fig9 , because this is located “ in front of ” the plane of the drawing sheet . as can also be determined from fig9 , the fixing pin 47 meshes with the horizontal section 31 of the l - shaped groove 28 . based on the positive - locking connection of the mounting pin 11 with the holding surfaces 18 of the profile web 17 with the inner bearing profile 35 of the holding pin 20 , the holding pin 20 is likewise fixed nonrotatably relative to the wall section 5 on the mounting pin 11 . it is thus ensured that the holding pin 20 cannot co - rotate during the rotary adjusting motion of the adjusting sleeve 21 in the direction of arrow 59 . based on the meshing of the two locking balls 50 with the corresponding milled recesses 44 of the adjusting sleeve 21 , the adjusting sleeve 21 is secured in this “ locked ” position . further , it can be determined from fig1 that the holding ball 51 , three of which are arranged distributed uniformly on the circumference , meshes with the locking groove 19 of the mounting pin 11 . this locking ball 51 is supported at the inner wall of the through hole 40 of the adjusting sleeve 21 , so that the locked position of the holding pin 20 is fixed securely together with the pressing disk 12 . for example , the sealing ring 55 is compressed at least slightly in the wall area 5 in this fixed position , so that an optimal sealing action can be achieved here , as this can be recognized from fig1 . by a correspondingly opposite rotary motion against arrow 59 from the locking position shown in fig1 and 9 and subsequently raising the adjusting sleeve 21 against arrow 41 , the adjusting sleeve 21 with its radial expansion 52 will again reach the axial area of the locking balls 51 , so that these are adjustable against arrow 58 radially outwardly until they come into contact with the inner wall of the radial expansion 52 . the axial path of adjustment of the adjusting sleeve 21 to the holding pin 20 against arrow 41 is defined now by the axial length of the vertical section 29 of the l - shaped groove 28 . due to the radial adjusting motion of the holding balls 51 , the positive - locking connection between these holding balls 51 and the locking groove 19 of the mounting pin 11 is eliminated , so that the entire holding device 13 is lifted off together with the cover disk 12 that is stationarily in connection with this and the filter sheet 10 located under it can be replaced . it can be easily imagined that based on the special embodiment , especially of the holding device 13 , the pressing disk 12 can be mounted and removed in an extremely simple manner . for mounting , the pressing disk 12 is ultimately placed simply on the mounting pin 11 together with the holding device 13 until the holding surfaces 18 of the profile web 17 come to mesh with the bearing profile 35 of the holding pin 20 in a positive - locking manner . since a connection of this holding pin 20 with the mounting pin 11 is now achieved , which connection rotates in unison , the pressing disk 12 is likewise arranged on this nonrotatably in relation to the wall section 5 . this position can be fixed in a very simple manner by subsequently adjusting the adjusting sleeve 21 in the axial direction indicated by arrow 41 and subsequent rotation in the direction of arrow 59 . the pressing disk 12 can , in turn , be lifted off from the filter sheet 10 in a very simple manner by correspondingly reversing these motions , so that the filter sheet can be replaced in a simple manner . based on the fixation of the pressing disk 12 via the holding surfaces 18 of the profile web 17 of the mounting pin 11 and the bearing profile 35 of the holding pin 20 , the pressing disk 12 is fixed nonrotatably relative to the wall section 5 and hence to the filter sheet 10 , so that damage , especially during the mounting of the filter sheet 10 , is ruled out with certainty . while specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention , it will be understood that the invention may be embodied otherwise without departing from such principles .
a filter holder , for a sterilization container , has a wall area with ventilation openings , through which an exchange of air takes place between the interior space of the sterilization container and the surrounding area , covered by a filter sheet to form a sterile barrier , sterilizing air entering the interior space . the filter sheet is held on the wall area by an air - permeable pressing disk . a holding pin , with a mounting hole , by which the pressing disk can be pressed against the wall area in the axial direction , can be attached to a mounting pin , which is stationary relative to the wall area . the holding pin is connected with the mounting pin in a pressed position via a detachable positive - locking connection . the connection can be secured by an adjusting sleeve mounted displaceably on the holding pin .