DE3005855A1 - FLOOR LOCK FOR A CAVITY EXTRUSION CONTAINER - Google Patents

Description

DIPL.-ING. HORST ROSE DIPL.-ING. PETER KOSEL PATENT ANWXtTE

Aki.n-No .: 245ö / 39 D-3353 Bad Gandersheim, February 15.

Alfred Fischbach KG

Bottom closure for a hollow cylindrical extruded container

The invention relates to a bottom seal serving as an ejection piston for viscoplastic masses elastic material for a hollow cylindrical extrusion container, in particular for a cartridge, with a for Storage space of the extrusion container directed closure plate and one facing the filling opening of the extrusion container extending hollow piston section guided on its inner wall and with at least one made of the material of the hollow piston section and surrounding its outer wall, butting against the inner wall of the container, elastic Sealing lip.

In the case of permanently elastic, permanently plastic, hardening and other similar pasty masses, in particular Sealing compounds, filled extrusion containers or cartridges are required such ejection pistons, which at the same time Serve as a bottom closure of the extrusion container until the application of the plastic mass. With such bottom closures it is of particular importance that when it is inserted into the extrusion container, it is in front of the sealing plate air can escape in order to avoid any detrimental influence of any trapped air on the to prevent absorbed mass. At the same time it is necessary to create a secure seal between the inner wall of the To ensure extruded container and the outer wall of the bottom closure or its hollow piston section if for a pressure medium is applied directly to the drive of the bottom closure as an ejection piston of the hollow piston section will. A passage of the print medium into the

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The oil storage space of the extrusion container would, on the one hand, lead to a change and, if necessary, to a hardening of the enclosed Lead mass and on the other hand to an uneven expression of the mass from the extrusion container.

With known bottom closures or ejector pistons of the type specified at the beginning (e.g. DE-PS 2 034 047 and DE-GM 74 00 492), the sealing lips used have an approximately triangular cross-section with one another to the apex inclined flanks, the apex of the sealing lips perpendicular to the inner wall of the extrusion container is pressed. In this way, on the one hand, there is a safe escape of the mass contained in the poured-in mass Air when inserting the bottom seal questioned because of the vertical pressure of the lip log if necessary, a seal against the air outlet is effected. On the other hand, however, the sealing effect is sufficient this sealing lips for the application of a pressure medium acting directly on the ejection piston is not sufficient, since the effect of the pressure medium easily leads to a lifting of the sealing lip from the inner wall of the extrusion container can lead, since a substantial part of the forces exerted by the pressure medium on the sealing lip act on the flank of the sealing lip which is inclined towards the storage space of the extruded container acts and pushes them away from the inner wall. A further complicating factor is that the known ejector piston sealing lips used only insufficiently any different inside diameters of the extrusion containers can adapt, however, such differences in diameter in the mass production of such extrusion containers are practically unavoidable.

The invention is based on the object of providing a floor seal of the type specified at the outset, in which both requirements outlined at the beginning are met with the greatest possible certainty, that is to say, on the one hand, a faultless one Ventilation of the storage space of the extrusion container when inserting the bottom seal or ejector piston

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Oil is guaranteed and on the other hand, and especially when it is safer Sealing between the inner wall and the bottom closure a direct exposure of the bottom seal by a pressure medium for its feed drive is made possible, even with manufacturing-related differences in the inner diameter the extruded container used in each case.

According to the invention, this is achieved above all in that on the one facing the open end of the hollow piston section Side surface of the at least one sealing lip an annularly extending open pressure pocket is shaped in such a way that that when air pressure builds up in the storage space of the extruded container, the peripheral edge of the sealing lip of the container inner wall lifted, but when a pressure medium acts from the open end of the hollow piston, the peripheral edge is pressed against the inner wall of the container. This ensures that the sealing lip is always in accordance with the desired Function behaves. If pressure is exerted on the sealing lip from the storage space by trapped air, so the sealing lip can deform inward in the direction of the pressure pocket and thus create a passage gap for the Form air between its peripheral edge and the inner wall of the extrusion container. On the other hand, it is used to drive the Bottom closure or ejection piston given the pressure medium, this acts on the pressure pocket in the sense of a Expansion and thus in the sense of pressing the peripheral edge of the sealing lip against the inner wall of the extrusion container, whereby an extremely increased sealing effect is achieved. As the sealing lip under warranty the described high sealing effect can be made relatively highly deformable, it can adapt well to any manufacturing-related fluctuations in the inner diameter of the extrusion container, as well any irregularities on the inner wall of the extrusion container. The pressure pocket always allows a corresponding sealing deformation of the sealing lip.

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The mechanical guidance of the hollow piston section can in the case of the bottom closure according to the invention at only a sealing lip designed according to the invention through known suitable designs of the hollow piston section, e.g. annular or axial projections on the outer wall of the hollow piston section, made or get supported.

It is particularly simple to manufacture and at the same time safe in terms of the functions described The formation of the sealing lip with its pressure pocket is achieved in a further embodiment of the invention by that both side surfaces of the at least one sealing lip viewed from the inside to the outside to the open end of the Hollow piston section are shaped inclined towards. The cross-section of the sealing lip is designed like a sawtooth, and there is a circumferential pressure pocket with an approximately triangular cross-section between the rear lip flank and outer wall of the hollow piston section. A sealing lip shaped in this way can be removed in the case of the storage room Moving air escaping slightly away from the inner wall, on the other hand, becomes wedge-shaped via the circumferential Pressure pocket in the event that the pressure medium is applied to drive the bottom seal and pressed securely against the inner wall of the extrusion container. Thus, it is surely avoided that the printing medium can get past the sealing lip into the storage space, which in turn reliably prevents When further expressing the enclosed mass, this pressure medium emerges together with the mass and e.g. to the Splashing of the product at the moment of the joint escape could lead.

According to a further embodiment of the invention, several sealing lips provided with the pressure pocket are one behind the other on the outer wall of the hollow piston section

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arranged. In this way, on the one hand, the described sealing effect of the bottom closure is significantly promoted. In addition to the venting and sealing effect described, this multiple arrangement of sealing lips such an effective mechanical guidance and support of the hollow piston section on the inner wall of the extrusion container achieved that separate guide means can be omitted entirely, which leads to a simplification the design leads. But it can also

-JO at least one of the to the open end of the hollow piston section located sealing lips be provided with edge recesses distributed on the circumference, so that this interrupted sealing lip only has a supporting and guiding effect. The one facing the locking plate Sealing lip or located sealing lips then take over the sealing functions described.

In a further embodiment of the invention, there is one on the outside in front of the sealing lip or in front of the sealing lips Edge of the closure plate circumferential scraper lip arranged. This is in addition to the effect of the sealing lips a stripping of the mass from the inner wall of the extrusion container as the bottom closure is advanced or ejection piston reached immediately after the sealing plate. It is particularly useful to if in a further embodiment of the invention within the hollow piston section and immediately afterwards the inner wall of the closure plate has an annular lip projecting towards the open side of the hollow piston section and the closure plate is opposite one another on its wall located inside the hollow piston section the ring lip bears backward ring stop. The ring lip and the ring stop work with the wiper lip then together, if with the help of a plunger or feed plate, which is inserted into the bottom seal or ejector piston is introduced, a mechanical feed through

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to be led. Such a stamp or ejector plate first rests against the ring lip and spreads so that the wiper lip against the inner wall of the extrusion container until it reaches the ring stop, after which the actual advance of the bottom seal or ejector piston takes place. This makes one extraordinary safe wiping action in conjunction with the venting and sealing action of the invention Sealing lips achieved. At the same time, the bottom seal or ejector piston designed in this way is the same as those described Advantages for the drive only suitable for the best possible use of pressure medium.

Another particularly advantageous embodiment of the invention results from the fact that the edge of the open The end of the hollow piston section is widened conically to the outside to form a further sealing lip. On the one hand takes over thus the edge the further ventilation, sealing and / or guiding effect of a sealing lip according to the invention, on the other hand, the advantage is achieved that with mechanical drive of the bottom closure or ejector piston with the help of a mechanical drive means, e.g. the plunger or the squeezing plate of a squeezing gun, also in the case of a drive means that is not precisely aligned, e.g. one that is not precisely aligned Express plate, it is ensured that the mechanical drive means on the conical widening of the edge of the hollow piston section can slide along into the piston and thus it is ensured that this mechanical drive member actually reaches the closure plate or the described stop means and itself cannot sit on the wall as in the case of a right-angled edge of the hollow piston section and thereby the The piston tilts when it is pushed out.

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Further features, advantages and details of the invention emerge from the claims and from the following Description of two exemplary embodiments of the invention with reference to the drawing. In the drawing are jeveils the bottom closure according to the invention and to simplify the representation of the extrusion container only a section shown. Show it

1 shows a longitudinal section through a first embodiment of an otherwise rotationally symmetrical one Bottom closure according to the invention,

2 shows a partial longitudinal section through a filled extrusion container with an inserted bottom seal according to Flg. 1, but before a pressure medium is applied to it,

Flg. 3 shows the longitudinal section according to FIG. 2, but after a pressure medium has acted on the bottom seal,

4 shows a longitudinal section through an otherwise rotationally symmetrical bottom closure the invention,

5 shows a longitudinal section through part of a filled one Extruded container after the insertion of the bottom closure according to FIG. 4, but before it is acted upon by pressure medium or by a mechanical drive element,

6 shows the longitudinal section according to FIG. 3, but after the bottom closure has been acted upon by a not shown mechanical drive element that spreads the ring lip with the wiper lip and the ring stop applied,

7 shows a detailed section through a bottom closure according to the invention in the area of the sealing lip for clarification.

The bottom closures shown in FIGS. 1 and 4 serve as ejection pistons for viscoplastic ones Masses in a hollow cylindrical extrusion container, in particular a cartridge.

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Both of the bottom closures shown in Fig. 1 and 4 are made of elastic material, in particular one Injection molded elastic plastic, and have one to the storage space of the extrusion container directed closure plate 1 as well as one extending to the filling opening of the extrusion container Hollow piston section 2, which, as can be seen from FIGS. 2 and 3 or FIGS. 5 and 6, on the inner wall of the Extrusion container 3 is performed.

In both embodiments according to FIGS. 1 to 3 and 4 to 6, elastic sealing lips 4, which are formed from the material of the hollow piston section 2 and surround the outer wall and lie against the inner wall of the extruded container, are provided. In the case of each sealing lip 4, an annularly extending open pressure pocket 5 is formed on the side surface facing the open end of the hollow piston section 2. For this purpose, both side surfaces of the sealing lips 4 are formed so as to be inclined towards the open end of the hollow piston section 2, viewed from the inside outwards from the longitudinal axis. As inebes · Pig.7 shows, this results in an approximately triangular cross-section towards the open

End of the hollow piston section 2 and thus also for pressing
filling of the strand container 3 open towards the cone-shaped or ring-wedge-shaped pocket. The sealing lips 4 are arranged one behind the other on the outer wall of the hollow piston section 2, as the drawing clearly shows.

In both of the embodiments according to FIGS. 1 to 3 and FIGS. 4 to 6 is also on the outer edge of the closure plate 1 each has a circumferential wiper lip 6 formed from the material of the bottom closure. aside from that is in the bottom closure according to FIGS. 4 to 6 within the hollow piston section 2 and immediately thereafter to the inner wall of the closure plate 1 to

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The annular lip 7 protruding on the open side of the hollow piston section is arranged, and the closure plate 1 carries it on its wall located in the interior of the hollow piston section 2, a protruding opposite the annular lip Ring stop 7a. This training of the bottom closure is used with the help of a mechanical drive member, in particular a press-out plate or - ^ stamp. Becomes such a drive member Introduced into the bottom seal, it initially deforms the annular lip 7, whereby the wiper lip 6 is spread outwards against the inner wall of the extrusion container 3 until it reaches the annular stop 7a attainable after the actual advance of the bottom seal or ejector piston. As a result, the in the storage space of the extrusion container 3 is filled Mass 8 stripped securely from the inner wall of the extrusion container.

Is the floor seal described and shown in the drawing in its two embodiments after filling the extrusion container with the mass 8 inserted into the extrusion container, so are how Fig. 2 and Fig. 5 show the sealing lips 4 with compression of the respective pressure pocket 5 inward elastically deformed, with the side surface facing the storage space of the extrusion container 3 let it press inwards. Any in the anteroom of the mass 8 enclosed air can with further elastic deformation of the sealing lips 4 against the pressure pocket 5 looks easy. exit the storage room to the outside.

If the respective bottom seal is now applied from the open side of the hollow piston section with a driving Pressure medium applied when the mass contained in the extrusion container is to be expressed, so

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the pressure medium acts on the rare surface of the sealing lips facing the open side of the hollow piston section 4, so into the pressure pocket 5 formed in such a way that the peripheral edge of the sealing lips 4 firmly against the inner wall of the container is pressed. Fig. 3 shows in comparison to FIG. 2, the deformation of the achieved thereby Sealing lips 4 reducing the size of the pressure pockets 5. The increased pressure of the pressure medium leads, as shown in the drawing clearly shows, always to an increase in the

«I0 contact pressure of the peripheral edge of the sealing lips 4 against the inner wall of the extruded container 3 and thus to an increase in the sealing effect.

If it turns out in a particular application that the Use of a sealing lip with pressure pocket is sufficient, so in the exemplary embodiment the to the open end of the Sealing lip 4 located in the hollow piston section 2 is provided with edge recesses distributed around the circumference be, so that this sealing lip only has a support function, while the front, so to the closure plate 1 facing sealing lip 4 performs the sealing function described.

The embodiments shown in the drawing also clearly show that the inventive Design of the sealing lips 4 a particularly good and extensive adaptation to different inside diameters of the extrusion container 3 or any unevenness on this inner wall is reached, and in comparison to the known sealing lips described in the introduction, which are e.g. formed in a shape are, as shown in the drawing by the shape of the wiper lips 6.

4 to 6 show a further advantageous embodiment of the bottom closure according to the invention. It is

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while the edge of the open end of the Hohlkolbenabs chni tts 2 widened conically to the outside to form a further sealing lip 9. This edge therefore takes on the one hand Effect of a sealing lip and, on the other hand, ensures the proper insertion of a mechanical drive element, in particular a push-out plate or punch a squeeze gun or the like.

Patent attorneys Dipl.-lng. Horst Rose Djpl.-Ing. Peter Kosel

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Claims (7)

DlPL-ING. HORST ROSE DIPL.-ING. PETER KOSEL PATENT LAWYERS un «.r. File number: 2468/39 D-3353 Bad Gandersheim, February ^{1, 1980} Alfred Fischbach KG Claims / 1.) Serving as an ejection piston for viscoplastic masses Bottom closure made of elastic material for a hollow cylindrical Extruded container, in particular for a cartridge, with one to the storage space of the extruded container directed closure plate and one extending to the filling opening of the extrusion container, on the inner wall guided hollow piston section and with at least one formed from the material of the hollow piston section and The elastic sealing lip surrounding its outer wall and resting against the inner wall of the container, characterized in that on the side surface of the at least one sealing lip (4) facing the open end of the hollow piston section (2) an annularly extending open pressure pocket (5) in this way is shaped that when the air pressure builds up in the storage space (8) of the extruded container (3), the peripheral edge of the sealing lip (4) lifted from the inner wall of the container when a pressure medium acts on the open end of the hollow piston section (2) ago, however, the peripheral edge is pressed against the inner wall of the container. 2. Bottom closure according to claim 1, characterized in that both side surfaces of the at least one Sealing lip (4), viewed from the inside to the outside, is shaped inclined towards the open end of the hollow piston section (2) are. 3. Bottom closure according to claim 1 or 2, characterized in that several provided with the pressure pocket (5) Sealing lips (4) are arranged one behind the other on the outer wall of the hollow piston section (2). 1 30034/0554 4. Bottom closure according to claim 3, characterized in that at least one of the open end of the Sealing lips located in the hollow piston section are provided with edge recesses distributed around the circumference ^is 5. Bottom closure according to one of claims 1 to 4, characterized in that in front of the sealing lip or in front the sealing lips (4) are arranged on the outer edge of the closure plate (1) circumferential wiping lip (6). 6. Bottom closure according to claim 5, characterized in that within the hollow piston section (2) and immediately following the inner wall of the closure plate (1) an annular lip projecting to the open side of the hollow piston section (7) is arranged and the closure plate on its inside of the wall located on the hollow piston section carries an annular stop (7a) projecting back from the annular lip. 7. Bottom closure according to one of claims 1 to 6, characterized in that the edge of the open end of the hollow piston section (2) is widened conically to the outside to form a further sealing lip (9). Patent attorneys Dipl.-Ing. Horst Rose Dipk-lng. Peter Kos & l 130034/0554