DE29812996U1 - Plate-shaped filter holder for a sterilization container - Google Patents

Description

PLATE-SHAPED FILTER HOLDER FOR A STERILIZING CONTAINER

The invention relates to a plate-shaped filter holder for a sterilization container with a circumferential outer pressure edge, a central pressure area, a fastening device for securing the filter holder to the sterilization container and with webs that are left free between the openings between the outer pressure edge and the central pressure area.

Such a filter holder for a sterilization container is known, for example, from DE 37 10 049 Bl. With the help of the plate-shaped filter holder, flat filter materials, for example paper filters or textile filters, can be pressed tightly against openings in the sterilization container, for example such openings are located in the lid of a sterilization container, in a side wall or in the base area of the same. To permanently fix the filter position, it is necessary to press the filter holder against the filter position with springs, and this is done in known arrangements by a central fastening device that presses the filter holder against the filter position with elastic deformation. Sealing is achieved in the known filter holder on the one hand by a seal along the outer pressure edge and on the other hand by a

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middle seal in the central pressure area. The known filter holders connect the outer pressure edge with the central pressure area via radial webs, which leave openings between them through which gas exchange can take place.

It has been found that tensions can occur in such filter holders, which lead to undesirable deformation of the filter holder. Such tensions arise, for example, when punching the openings or during deep-drawing processes, in which the filter holder is brought into the desired shape. These undesirable deformations lead to an uneven contact between the filter holder and the filter layer and thus to a seal that may not always be secure. To avoid this, it is necessary to eliminate the tensions by appropriate post-processing of the filter holders, for example by heat treatment.

It is the object of the invention to design a filter holder of this type in such a way that undesirable tensions are reliably avoided.

This object is achieved according to the invention in a filter holder of the type described at the beginning in that the webs run at least in sections in a direction that has a component in the circumferential direction. It has surprisingly been found that no tension occurs if care is taken that the webs are between the external

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printing edge and central pressure area do not run exactly in the radial direction, but if these webs run at least partially in the circumferential direction or at least in a direction that has a component in the circumferential direction. By running the webs in this way, the material can be
and any tensions that may occur during production are eliminated as soon as such
Reduce tensions again. This is the case with bridges that
run exclusively in radial direction, not
possible.

The webs can be designed in very different geometric forms, provided that they have a component pointing in the circumferential direction at least in sections.

For example, it can be provided that the webs between the central area and the outer pressure edge run in an arc shape.

It is also possible for the webs to run in a straight line between the central area and the outer pressure edge, whereby they then form an angle with respect to the radial direction.

The webs can run along their entire length with a circumferentially rectified component, but in a modified embodiment
It is also possible that the circumferential

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Component of the web over whose length its direction changes.

For example, the webs can be wavy or zigzag-shaped along their length.

In a particularly preferred embodiment, it is provided that the webs have sections along their longitudinal extent that run alternately radially and in the circumferential direction.

The webs can be designed as independent components between the outer pressure edge and the central pressure area, but it is also possible for adjacent webs to be connected to one another by connecting webs. This increases the strength of the filter holder, but still avoids undesirable tensions due to the peripheral components in the web path.

In a particularly preferred embodiment, it is provided that between the central pressure area and the outer pressure edge at least one central web is arranged running around in the circumferential direction and that between this and the outer pressure edge, the inner pressure area or an adjacent central web there are connecting webs with a radial component, which open into the central web on opposite sides offset from one another in the circumferential direction. In particular, the connecting webs can run in the radial direction. This gives a design in which radially running webs

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between the central pressure area and the outer pressure edge, but these do not extend over the entire distance between the outer pressure edge and the central pressure area, but only over a partial area, namely up to the next central web, and this central web runs in the circumferential direction, so that overall the web connection between the outer pressure edge and the central pressure area runs alternately radially and in the circumferential direction. This also ensures that undesirable tensions are avoided.

To ensure that the filter material is securely fixed, it is advisable to have a ring seal on the outer pressure edge. In addition, an elastically deformable pressure seal can also be arranged on the central pressure area.

In a particularly preferred embodiment, this pressure seal is a lip seal with a sealing lip that can be pressed against the central pressure area. Such a sealing lip can be deformed to a relatively large extent, so that even with sealing material of different thicknesses, a secure fit in the central area is always guaranteed, even if the filter holder is always the same distance from the sterilization container. Distance tolerances are accommodated by the sealing lip, which can be deformed to a large extent.

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It is advantageous if the lip seal has an annular bearing body onto which the annular sealing lip is formed.

In particular, it can be provided that the bearing body has a recess into which the lip seal immerses when it is pressed completely against the central pressure area.

A particularly simple attachment of this filter holder to the sterilization container is achieved if, according to a preferred embodiment, the fastening device has a housing with two locking bodies that can be pushed against each other in a circumferential direction in a resilient manner, which in a non-displaced locking position engage behind a holding member of the sterilization container that passes through the filter holder and release this in a displaced release position, that the housing can be secured to the filter holder in the central pressure area by a rotary movement in which projections and recesses on the filter holder or on the housing engage behind one another, and that at least one releasable catch is provided which, when the housing is secured to the filter holder, secures it against rotation relative to the filter holder. Such a fastening device with two locking bodies that can be moved against each other is known per se for filter holders of this type (DE 37 10 049 Bl), but in this case the housing is permanently connected to the filter holder, for example by riveting, screwing, etc. In the construction described, however, the

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The housing is connected to the filter holder by a rotating movement similar to a bayonet lock and is secured against accidental release by the removable catch. It is therefore possible to attach the housing to the filter holder using the two locking bodies without using any tools or additional parts.

It is particularly advantageous if the catch is formed by one of the two locking bodies, which secures the housing against rotation in its locking position and releases it in its release position. With this design, it is not necessary to provide a separate catch, but the locking body in the housing, which can be moved against spring force, also takes on the task of a catch that secures the housing against unintentional twisting and release.

It is also particularly advantageous if the other locking body secures the housing against twisting in its release position and releases it in its locking position. This ensures that when the locking body is moved into the release position, in which the filter holder releases the holding element of the sterilization container and can be removed from the sterilization container, the housing cannot be accidentally twisted and removed from the filter holder. To rotate the housing, one of the two locking bodies must be moved into the release position, but the other locking body must remain in the locking position. This prevents the housing from twisting.

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Housing is neither possible when both locking bodies are in the locking position, nor when both locking bodies are in the release position. Only these two positions will occur during normal operation of the filter holder, since the two locking bodies are moved from the locking position to the release position by diametrical pressure. If, on the other hand, the housing is to be turned relative to the filter holder in order to remove the housing, it must be ensured that only one of the two locking bodies is moved.

In a particularly preferred embodiment, it is provided that cam tracks and projections guided in them interact on the central pressure area or the locking bodies and thus allow rotation of the housing relative to the filter holder only in the specific positions of the locking bodies.

For example, it can be provided that a cam track for the locking body securing the housing in its locking position has a radially inward-facing section and a section adjoining its inner end and extending outward next to this section. Such a section ensures that rotation of the housing relative to the filter holder is only possible when the corresponding locking body is pushed into the release position.

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Furthermore, it is advantageous if a cam track for the locking body securing the housing in its release position has a radially inward-facing section and a section that runs in the circumferential direction and adjoins its outer end. This locking body therefore only allows the housing to be rotated when it is in the locking position itself; in all other positions, however, rotation of the housing relative to the filter holder is prevented.

In particular, it can be provided that the radially inward-facing sections of the cam tracks and the projections engaging in the cam tracks are arranged mirror-symmetrically with respect to the axis of rotation of the housing. This makes it possible to arrange the cam tracks and the projections in such a way that the housing can be placed on the filter holder in two positions rotated by 180". Depending on the orientation of the housing, both locking bodies can then take on the role of the locking body that secures the housing against rotation in the release position or in the locking position, i.e. a completely symmetrical structure of the locking bodies can be used and when placing the housing on, there is no need to pay attention to which projection is immersed in which cam track.

For this purpose, it is also advantageous if the end points of the sections adjoining the radially inward-facing sections are arranged mirror-symmetrically with respect to the axis of rotation of the housing.

·

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The following description of preferred embodiments of the invention serves to explain it in more detail in conjunction with the drawing. They show:

Figure 1: a perspective view of the inside of a sterilization container lid with a filter holder with the housing of the fastening device removed;

Figure 2: a top view of the filter holder of Figure 1 with the housing of the fastening device attached;

Figure 3: a sectional view taken along line 3-3 in Figure 2;

Figure 4: an enlarged detailed view of the

the central seal inserted into the filter holder in the undeformed state,

Figure 5: a partial view of another preferred embodiment of a filter holder with straight webs;

Figure 6: a view similar to Figure 5 with straight webs and a central web;

Figure 7: a view similar to Figure 5 with curved webs;

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Figure 8: a view similar to Figure 5 with curved webs tangentially entering the outer edge of the system;

Figure 9: a view similar to Figure 5 with corrugated webs;

Figure 10: a view similar to Figure 5 with zigzag-shaped webs;

Figure 11: a view similar to Figure 5 with radial webs and a central web;

Figure 12: a view similar to Figure 5 with radial webs and two central webs;

Figure 13: a cross-sectional view along line 13-13 in Figure 14 of the housing of the fastening device with two locking bodies mounted therein;

Figure 14: a sectional view taken along line 14-14 in Figure 13;

Figure 15: a sectional view taken along line 15-15 in Figure 13;

Figure 16: a sectional view similar to Figure 13 with locking bodies moved into the release position and

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Figure 17: a view similar to Figure 13 with a housing rotated relative to the filter holder and removable from it.

Figure 1 shows an inverted lid 1 of a sterilization container, which has a flat top 2 and a rim 3 that adjoins it at the bottom. The top 2 has openings that are covered by a flat filter layer 4, for example by a filter paper or a textile surface filter.

This filter layer 4 is pressed against the inside of the lid 1 by means of a filter holder. For this purpose, this filter holder 5 has an annular outer pressure edge 6 and a central pressure area 7, which are connected to one another via webs 8, with openings 9 being formed between the webs 8, through which gas exchange can take place.

The pressure edge 6 is U-shaped in cross section and thus forms an annular groove 10 into which an elastomeric ring seal 11 is inserted.

An annular groove 12 is formed in the central pressure area 7, which accommodates an annular body 13 of a central seal 14. An annular sealing lip 15 protruding obliquely towards the filter layer 4 is formed onto the annular body 13, which can be elastically bent against the annular body 13 and then into an annular

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recess 16 of the ring body 13 (Figures 3 and 4). The sealing lip 15 can thus bridge a relatively large sealing area and adapt to filter layers 4 of different thicknesses.

In the embodiment shown in Figures 1 to 4, the webs 8 are curved, whereby they have a component in the circumferential direction, i.e. parallel to the pressure edge 6, over their entire length, this component increases from the inside to the outside.

This course of the webs 8 with a clear component in the circumferential direction means that mechanical stresses in the filter holder 5 are avoided during production and also during subsequent operation; should these occur, for example, during production, they can be compensated for due to the described course of the webs 8.

The filter holder 5 can, for example, be manufactured as a deep-drawn part from a sheet metal plate, the openings 9 are created by punching processes.

Figures 5 to 12 show other possible courses of the webs 8. In Figure 5, the webs 8 run straight from the inside to the outside, but also with a clear component in the circumferential direction. In the embodiment of Figure 6, straight webs 8 are also provided, but in this case two different sets, namely an inner set and an outer set, which have a circumferentially extending component.

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running component with opposite direction. These webs 8 of the two sets both lead into a central web 17 running concentrically to the outer pressure edge 6, in such a way that the junction points of the webs 8 of the outer set and the inner set are offset from each other in the circumferential direction. This results in a connection between the central pressure area 7 and the outer pressure edge 6, which has a clear circumferential component in the entire area of the webs 8.

In the embodiment of Figure 7, the webs 8 run in an arc shape, whereby in the area near the edge they have a component in the circumferential direction, the direction of which is different from the component in the area near the center.

In the embodiment of Figure 8, the webs 8 run in an arc-shaped manner similar to the embodiment of Figures 1 to 4, but they are more curved than in the embodiment of Figure 2, so that the webs 8 run essentially tangentially into the outer pressure edge 6.

In the embodiment of Figure 9, the webs 8 are designed to be corrugated, i.e. the directions of the components alternate in the circumferential direction.

The same applies to the embodiment of Figure 10, in which the webs 8 are formed by straight,

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sections are formed that adjoin one another at an angle.

In the embodiment of Figure 11, similar to the embodiment of Figure 6, a concentric central web 17 is provided, into which the webs 8 open offset from one another. In contrast to the embodiment of Figure 6, the webs 8 in this case run exactly radially, so that the component in the circumferential direction is formed by the central web 17. The connecting lines from the central pressure area 7 to the outer pressure edge 6 run on the one hand over the radial webs 8 and on the other hand over the central web 17 running in the circumferential direction, so that these connecting lines as a whole have components in the circumferential direction at least in sections, and this component in the circumferential direction ensures that tension can be avoided.

The embodiment of Figure 12 corresponds largely to that of Figure 11 with the difference that in this case two concentric central webs 17 are provided which are connected to one another via three sets of radial webs 8. In this case too, the webs 8 are arranged offset from one another in the circumferential direction in the areas where they join the central webs 17.

To fix the filter position 4 on the cover 1, the cover has a vertically projecting pin 18 with a step-shaped widening head 19. This pin

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18 projects through a central opening 20 in the central pressure area 7 of the filter layer 4 and ends in a pot-shaped housing 21, which is connected to the filter holder 5 on the side facing away from the filter layer 4.

The housing 21 accommodates two locking bodies 23 and 24 in a diametrical guide 22 that can be moved along this guide, which protrude from the housing 21 in the form of push buttons 25 and 26, respectively, and which are moved into the maximum extended position by compression springs 27 and 28 acting between them. In this position, both locking bodies 23 and 24 engage around the pin 18 with a cross arm 29, 30 and thereby engage under the stepped, projecting head 19 of the pin 18. This fixes the housing 21 with the filter holder 5 in the axial direction to the pin 18 and thus also to the cover 1, in a position in which the filter holder 5 is clamped against the inside of the cover 1. This position of the locking bodies 23 and 24 is therefore referred to as the locking position.

Both locking bodies 23 and 24 can be pressed into the housing 21 by pressing the push buttons 25 and 26 against the effects of the compression springs 27 and 28, in the process they move away from the pin 18 with their cross arms 29 and 30 and thus enable the housing with the filter holder 5 to be removed from the pin 18 and thus also from the cover 1. This position of the locking bodies 23 and 24 is therefore referred to as the release position.

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The design is selected in such a way that removal of the housing 21 and the filter holder 5 from the pin 18 is only possible if both locking bodies 23 and 24 are inserted into the housing 21 in the same way. If only one locking body is moved into the release position, removal of the housing and the filter holder is not possible.

The housing 21 with the locking bodies 23 and 24 guided therein has two inwardly projecting projections 31 on its inner casing, which engage under outwardly projecting projections 32 on the filter holder 5 and thereby fix the housing 21 to the filter holder 5. The engagement of the projections 31 and 32 can be released by rotating the housing 1 about an axis of rotation that runs concentrically to the pin 18. As soon as the projections 31 and 32 are then next to one another, the housing 21 can be removed from the filter holder 5 (Figure 17). This is therefore a bayonet lock between the housing 21 and the filter holder 5.

In the central pressure area 7 of the filter holder 5, two cam tracks 33 and 34 are arranged, which are simply formed by slots in the central pressure area 7. The cam track 33 has a section 35 that runs radially inwards from the outside and a section 36 that adjoins its inner end and runs obliquely outwards from there, the other cam track 34 also has a radially inwards

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extending section 37 and a section 38 extending in the circumferential direction adjoining the outer end of this section 37. The radially inwardly extending sections 35 and 37 of the two cam tracks 33 and 34 are arranged mirror-symmetrically with respect to the pin 18, the sections 36 and run in the same circumferential direction and both end in positions which are also arranged mirror-symmetrically with respect to the pin 18 (Figure 13).

On their underside, both locking bodies 23 and pins 39 and 40, respectively, which project downwards and are directed towards the open side of the housing 21 and which penetrate into the cam tracks 33 and 34.

In order to connect the housing 21 to the filter holder 5, the housing 21 with the locking bodies 23 and 24 mounted therein is first placed in an angular position on the central pressure area 7 of the filter holder 5, in which the two pins 39 and 40 at the free ends of the sections 36 and 38 can penetrate into them (Figure 17). In this angular position, the projections 31 and 32 lie next to one another and do not overlap.

If the housing 21 is rotated about the axis of rotation concentric with the pin 18, the projections 31 and 32 are brought into their overlapping position (Figure 16), i.e. the bayonet lock is locked. This is easily possible, with this rotational movement the pin 40 of the locking body 24 runs in the circumferential direction.

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ing section 38 of the cam track 34 without the locking body 24 being displaced relative to the housing 21. The pin 39 of the locking body 23 runs in the section 36 of the cam track 33 directed obliquely towards the center and thereby displaces the locking body 23 against the effect of the two compression springs 27 and 28 until the inner end of the radial section 35 of the cam track 33 is reached. The locking body 23 is then displaced radially outwards by the compression springs 27 and 28, the pin 39 then moves outwards in the radial section 35 of the cam track 33 and thereby locks the housing 21 against rotation.

In this position, the housing 21 and the filter holder 5 are permanently connected to one another. When the two locking bodies 23 and 24 are moved together into the release position in the manner described, the pins 39 and 40 run in the radial sections 35 or the cam tracks 33 and 34, and in any case the housing 21 is thereby secured against undesired rotation. In the locking position, this rotational protection is provided by the locking body 23, while in the release position it is provided by the locking body 24.

In order to be able to release the bayonet connection between the housing 21 and the filter holder 5, it is necessary to insert the locking body 23 into the housing 21 alone, in order to push the pin 39 of the locking body 23 forward to the inner end of the section 35 of the cam track 33. Only then is it possible to twist

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of the housing 21, which can then be carried out without further ado until the projections 31 and 32 again lie next to one another in the manner shown in Figure 17 and removal of the housing 21 becomes possible.

Due to the arrangement described, it is irrelevant which of the two locking bodies 23, 24 engages with which cam track 33 or 34. The housing 21 and the locking bodies 23 and 24, including the pins 39 and 40, are constructed completely symmetrically, and the different function of the locking bodies 23 and 24 in securing the housing 21 against rotation is achieved solely by the asymmetrical arrangement of the cam tracks 33 and 34. The user is therefore not forced to pay attention to the direction in which the housing 21 is placed when putting the housing on; it is sufficient if he inserts the pins 39 and 40 into the ends of the sections 36 and 38 when putting it on.

Claims (23)

- 21 A 54 516 u 20 July 1998 u-234 PROTECTION CLAIMS 1. Plate-shaped filter holder for a sterilization container with a circumferential outer pressure edge, a central pressure area, a fastening device for securing the filter holder on the sterilization container and with webs that are left open between openings between the outer pressure edge and the central pressure area, characterized in that the webs (8; 17) run at least in sections in a direction that has a component in the circumferential direction. 2. Filter holder according to claim 1, characterized in that the webs (8) run in an arc shape between the central pressure area (7) and the outer pressure edge (6). 3. Filter holder according to claim 1, characterized in that the webs (8) run in a straight line between the central pressure area (7) and the outer pressure edge (6). - 22A
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u-234 4. Filter holder according to one of the preceding claims, characterized in that the webs (8) run over their entire length with a component that is aligned in the circumferential direction. 5. Filter holder according to one of claims 1 to 3, characterized in that the component of the web (8) running in the circumferential direction changes its direction over its length. 6. Filter holder according to claim 5, characterized in that the webs (8) run in a wave-like or zigzag shape along their longitudinal extent. 7. Filter holder according to claim 5, characterized in that the webs (8; 17) have sections along their longitudinal extension which run alternately radially and in the circumferential direction. 8. Filter holder according to one of the preceding claims, characterized in that adjacent webs (8) are connected to one another by connecting webs (17). - 23A
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u-234 9. Filter holder according to claims 7 and 8, characterized in that between the central pressure area (7) and the outer pressure edge (6) at least one central web (17) running around in the circumferential direction is arranged and that between this and the outer pressure edge (6), the inner pressure area (7) or an adjacent central web (17) connecting webs (8) with a radial component are arranged, which open into a central web (17) on opposite sides offset from one another in the circumferential direction. 10. Filter holder according to claim 9, characterized in that the connecting webs (8) run in the radial direction. 11. Filter holder according to one of the preceding claims, characterized in that an annular seal (11) is held on the outer pressure edge (6). 12. Filter holder according to one of the preceding claims, characterized in that an elastically deformable pressure seal (14) is arranged on the central pressure area (7). - 24A
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u-234 13. Filter holder according to claim 12, characterized in that the pressure seal (14) is a lip seal with a sealing lip (15) that can be pressed elastically onto the central pressure area (7). 14. Filter holder according to claim 13, characterized in that the lip seal (15) has an annular bearing body (13) onto which the annular sealing lip (15) is formed. 15. Filter holder according to claim 14, characterized in that the bearing body (13) has a recess (16) into which the lip seal (15) is immersed when it is pressed completely against the central pressure area (7). 16. Filter holder according to one of the preceding claims, characterized in that the fastening device has a housing with two locking bodies (23, 24) which can be diametrically pushed against one another in a resilient manner and which, in a non-displaced locking position, engage behind a holding member (18, 19) of the sterilization container (1) which passes through the filter holder (5) and release this in a displaced release position, that the housing (12) on the filter holder (5) in the central pressure area (7) by a rotary movement - 25A
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u-234 can be fixed, in which projections (32) and recesses (31) on the filter holder (5) or on the housing (21) engage behind one another, and that at least one releasable catch (23) is provided which, when the housing (21) is fixed to the filter holder (5), secures it against rotation relative to the filter holder (5). 17. Filter holder according to claim 16, characterized in that the catch is formed by one of the two locking bodies (23), which secures the housing (21) against rotation in its locking position and releases it in its release position. 18. Filter holder according to claim 17, characterized in that the other locking body (24) secures the housing (21) against rotation in its release position and releases it in its locking position. 19. Filter holder according to one of claims 17 or 18, characterized in that cam tracks (33, 34) and projections (39, 40) guided in these interact on the central pressure area (7) or the locking bodies (23, 24) and thereby prevent rotation of the housing (21) relative to the filter holder. - 26A
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u-234 locking mechanism (5) only in the specific positions of the locking bodies (23, 24). 20. Filter holder according to claim 19, characterized in that a cam track (33) for the locking body (23) securing the housing (21) in its locking position has a radially inwardly directed section (35) and a section (36) adjoining its inner end and extending outwardly next to this section (35). 21. Filter holder according to claim 19 or 20, characterized in that a cam track (34) for the locking body (24) securing the housing (21) in its release position has a radially inwardly directed section (37) and a section (38) adjoining its outer end and running in the circumferential direction. 22. Filter holder according to claims 20 and 21, characterized in that the radially inwardly directed sections (35, 37) of the cam tracks (33, 34) and the projections (39, 40) engaging in the cam tracks (33, 34) are arranged mirror-symmetrically with respect to the axis of rotation of the housing (21). -&tgr;&igr; &kgr; 54 516 u
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u-234 23. Filter holder according to claim 22, characterized in that the end points of the sections (36, 38) adjoining the radially inwardly directed sections (35, 37) are arranged orthogonally symmetrically with respect to the axis of rotation of the housing (21).