EP1836100A1

EP1836100A1 - Tubular ram for a cartridge, used for expressing pasty substances

Info

Publication number: EP1836100A1
Application number: EP05850154A
Authority: EP
Inventors: Anton Topic
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-01-14
Filing date: 2005-12-15
Publication date: 2007-09-26
Anticipated expiration: 2025-12-15
Also published as: ATE393102T1; WO2006074626A1; SI1836100T1; PL1836100T3; DE502005003882D1; EP1836100B1; DK1836100T3; DE112005003501A5; DE202005000531U1; ES2308597T3

Abstract

The piston for cartridges of building sealant has a domed top (12) and vertical walls (14). Two peripheral ribs (16, 17) are mounted near the point where these join. The top rib is curved outwards and has slots (54) spaced around it. The lower rib is vertical and encloses a pocket (19) with the upper rib. An independent claim is included for a cartridge fitted with the piston.

Description

RING PISTON FOR A CARTRIDGE FOR PRESSING PASTIC SUBSTANCES

The present invention relates to a piston for a cartridge for extruding pasty substances according to the preamble of claim 1, a cartridge according to the preamble of claim 31, an annular piston according to the preamble of claim 32 and a coaxial cartridge according to the preamble of claim 60. The cylindrical Container or the cylindrical chamber may for example be made of plastic, aluminum or steel.

Cartridges are used for a variety of pasty substances to be ejected. Widely used z. As cartridges for acrylic or silicone, which are used in construction for sealing joints. Such cartridges are filled and sealed in automatic devices. Here, the heated substance is filled via a filling tube through the open end of the cylindrical container of the cartridge in the cylindrical container. Thereafter, the open end of the cylindrical container with a, in particular cup-shaped, piston is closed. The piston is inserted here, with its end wall in front of the device by means of a plunger in the cartridge. However, there are some problems here:

Remaining air between the filler and the piston has the consequence that it later or later in the later processing of the filling substance from the then open injection port of the cartridge, the cannula, exiting, whereby the flow of the pasty substance at a ejected joint filling is interrupted, that is, a rapid and continuous joint filling is no longer possible, but after the interruption by air leakage, the cannula must be rescheduled, which not only delays the workflow, but a smooth, complacent course of joint filling difficult. On the other hand, residual air also contains a proportion of water, namely in the form of water vapor. Some substances to be injected, such as. As silicone, react under the influence of moisture, they harden. The larger the enclosed, compressed quantity of residual air, the greater the proportion of the pasty filling substance which hardens within the cartridge and thus becomes unusable. As a result, the residual air must be removed from the cartridge as much as possible.

In the storage and transport state of the filled cartridge, the piston must on the one hand seal well, so that the enclosed substance is prevented from escaping. On the other hand, however, the piston must also be so movable, namely displaceable in the axial direction within the cartridge, so that in later pressing the pasty substance still acceptable forces are sufficient. Consequently, the piston must be displaceable within a certain range of forces after filling of the cartridge.

In addition, pasty substances are known to contain hydrocarbons. By acting on the hydrocarbons, the piston increases more in the circumferential direction than the cartridge. This can lead to a bursting of the container during or after a certain storage.

Furthermore, the piston must not sit too loose when inserting, because then inadmissibly much pasty substance passes out of its wall on the cartridge, which leads not only to loss of material, but from a contamination of the cartridge. On the other hand, if the piston is too tight, a more or less large quantity of residual air is trapped behind the filled substance when closing the filled cartridge.

Too tight a seat of the piston also means that it can not move sufficiently in the direction of the filled substance, if this subsequently cools and shrinks, the trapped volume is reduced accordingly. The consequence of the shrinkage is then that the container bulges. Such deformed cartridges are virtually unsalable, as in a potential buyer creates the impression that the cartridge has been filled some time ago and the pasty substance is at least partially unusable. On the other hand, such a deformation of the cartridge is disadvantageous, since it hinders a displacement of the piston, which is normally circular in cross-section, at a later ejection and can lead to a loss of pasty substance.

In addition, z. B. in the storage of the filled cartridge z. B. result of temperature changes, an increase in the diameter of the container, which is stronger than a caused by the same reason increase in the diameter of the piston. As a result, the sealing effect of the piston decreases and air can penetrate into the container and come into contact with the pasty substance, which can lead to a curing of the pasty substance.

Coaxial cartridges are used for 2-component masses, such as adhesives, sealants, etc. used, the two components are housed separately from each other in coaxial chambers of cylindrical cartridges and are mixed together for common use by a mouthpiece with mixing nozzle for use.

To express the pistons in a simple cartridge and a coaxial cartridge, a Preßstempelorgan (also known as piston setter) a Ausdrückpistole is used. To solve the abovementioned problems, a piston according to the preamble of claim 1 is proposed in the German utility model DE 20319464.0, wherein at least one of the two circumferential elastic lamellae is directed towards the end wall of the piston substantially obliquely outwards and with bias on the inner wall the container is present and on its side facing away from the wall of the piston side has at least one projection. The known piston already represents an improvement in terms of the smallest possible amount of residual air when inserting a piston into a cartridge and a good axial mobility of the piston used. Nevertheless, in some cases, the amount of residual air is not sufficiently low enough and the axial mobility is not sufficiently good enough.

The invention is therefore based on the object to provide for even smaller amount of residual air when inserting a piston into a cartridge or coaxial cartridge and an annular piston in a coaxial cartridge and at the same time an even better axial mobility of the piston or piston used.

According to the invention, this object is achieved in the generic piston in that the front in the ejection direction lamella of the two slats is substantially arcuate outwardly, further comprising the front slat circumferentially spaced slits and in the Auspreßrichtung rear slat to the end wall of the piston out substantially runs obliquely outwards and forms a pocket with the front lamella.

Furthermore, this object is achieved by a cartridge according to claim 31.

According to a further aspect, this object is achieved in the generic annular piston characterized in that on the outer side of the radially outer wall of the annular piston in the vicinity of the end wall two circumferential in radial planes outer elastic blades made of plastic and on the inside of the radially inner wall of the annular piston in the vicinity of the end wall, two inner elastic lamellas of plastic revolving in radial planes are formed, wherein the front in the pressing direction of the two outer slats is substantially arcuate outwardly, further comprising the front slat of the two outer slats circumferentially spaced slots and the rear in Auspreßrichtung lamella of the two outer slats to the end wall of the annular piston in the essentially obliquely outwards and forms a pocket with the front lamella of the two outer lamellae, and wherein the front lamellae of the two inner lamellae is substantially arcuate inwardly, further comprising the front lamella of the two inner laminae circumferentially spaced slots and the rear lamella of the two inner lamellae in the pressing out direction extends essentially obliquely inwards toward the end wall of the annular piston and forms a pocket with the front lamella of the two inner lamellae.

Finally, this object is achieved by a coaxial cartridge according to claim 60.

According to a particular embodiment of the invention may be provided in the piston, that the front lamella projects radially outwardly beyond the lamella in the Auspreßrichtung.

In particular, the front lamella can be designed to rest with prestress against the inner wall of the container or the chamber.

Conveniently, the rear sipe is designed so as not to abut against the inner wall of the container or the chamber prior to the first squeezing of pasty substances from the cartridge.

Alternatively, it can be provided that the rear lamella has on its outer side a peripheral in a radial plane elevation. In particular, it can be provided that the rear blade is designed to abut against the inner wall of the container or the chamber before the first pressing of pasty substances from the cartridge.

Conveniently, the rear blade extends substantially arcuate obliquely outward.

Advantageously, the rear blade has an end whose surface is roughened. The roughened surface facilitates the venting of the piston.

Preferably, the roughness of the surface is about 30 microns.

A further particular embodiment of the invention is characterized in that on the inside of the end wall at least one of them substantially vertically extending web having a first land height and a first web thickness and at least one thereof substantially perpendicularly extending web with a second land height and a second Web thickness extends, wherein the first and second web heights are at least substantially identical and the first and second web thicknesses are different. If the piston sits plane-parallel at the beginning of extrusion by means of a plunger, deforms the web or deform the webs with the smaller web thickness in building an internal pressure rather than the web or the webs with greater web thickness, whereby the piston receives a tilt, which in turn deforms elliptical in plan view when pressing in the piston, the rear lip, so that a gap or gap to the wall arises / arise through which / can be done a vent. Then, it is not absolutely necessary that the rear fin has an end with a roughened surface.

Conveniently, the front slat on the outside in a radial plane circumferentially spaced webs. By the webs, the rear slat is pushed outwards more. Conveniently, the webs extend obliquely or transversely to the direction of rotation of the front blade.

According to a particular embodiment of the invention can be provided that the front blade has a rounded end.

Advantageously, the front sipe forms a pocket with the outside of the wall.

Furthermore, it can be provided that the defined by the outside of the wall, at right angles to the longitudinal axis of the piston extending cross-sectional area decreases towards the end wall.

In particular, it may be provided that the cross-sectional area decreases from a first wall section having a first cross-sectional area via a transition section to a second wall section having a second cross-sectional area.

Conveniently, the root portion of the front fin is arranged in the transition portion.

According to a particular embodiment of the invention, the slots are arranged in the root area of the front lamella.

Conveniently, the rear blade extends at an angle α of 0 to 10 degrees to the longitudinal axis of the piston obliquely outward.

More preferably, the angle α is in the range of 0 to 5 degrees. Most preferably, the angle α is 3 degrees. Conveniently, the root region of the rear lamella is arranged in the region of the transition between the first wall section and the transition section.

Advantageously, the rear lamella has a beveled outwardly to the end wall of the piston outward end.

Conveniently, the outside of the wall of the piston at least one circumferential in a radial plane, away from the end wall obliquely outwardly directed sealing lip.

More preferably, the outer side of the wall of the piston has two sealing lips running around in radial planes and directed obliquely outwards away from the end wall.

Conveniently, a circumferential in a radial plane, outwardly projecting guide rib is provided on the outside of the wall between the two sealing lips. The guide rib (s) serve to prevent deformation and / or tilting of the piston, particularly when using a compressed air gun.

More preferably, the outer side of the wall of the piston has three sealing lips extending in radial planes away from the end wall, wherein between the sealing lips on the outer side of the wall there is provided an outwardly projecting guide rib extending in a radial plane.

In particular, it may be provided that the or each guide rib has a first flank facing the end wall with a first pitch and a second flank facing away from the end wall with a second pitch, wherein the second pitch is greater than the first pitch. Furthermore, it is possible that the piston has a round cross-section in the region of the front and rear slats.

Alternatively, it is also conceivable that the piston has an oval cross-section in the region of the front and rear slats.

The dependent claims 33 to 59 relate to advantageous developments of the annular piston.

The invention is based on the surprising finding that the residual air can be removed more easily and to a greater extent than before by the special arrangement and design of the two elastic lamellae revolving in radial planes. At the beginning of venting, the residual air can escape through the slots in the front sipe through the bag to the outside. The front blade is used in the stage for stripping z. As silicone from the inner wall of the container in the direction of the slots. The silicone then enters the pocket and fills it gradually from bottom to top, d. H. from the bottom of the bag upwards. As a result, the rear slat is spread outwards and places it against the inner wall of the container. This causes a lock, so that the silicone can not escape to the rear.

The erfϊndungsgemäße piston and annular piston also allows a squeezing with higher pressures or the use of lower wall thicknesses of the cartridges or coaxial cartridges at the same pressures. This results in a weight reduction of up to 30% and a lower environmental impact and lower disposal costs. This provides a price advantage to consumers. Also, the piston or ring piston is more flexible, at least in a particular embodiment by the slats, so that the bursting described above is easier to avoid. Further features and advantages of the invention will become apparent from the claims and the following description in which an exemplary embodiment is explained in detail with reference to the schematic drawings. Showing:

Figure 1 is a plan view of a piston according to a particular

Embodiment of the invention from the front;

Figure 2 is a longitudinal sectional view of the piston of Figure 1;

FIG. 3 shows the detail X of FIG. 2;

Figure 4 is a longitudinal sectional view of a cartridge with the piston of Figure 2 in two different stages during the insertion of the piston.

FIG. 5 shows the detail X of FIG. 4;

Figure 6 is a plan view of a piston according to another particular

Embodiment of the invention from the front;

Figure 7 is a sectional view of the piston along the line VII-VII in Figure 6;

Figure 8 is a plan view of the piston of Figure 6 from behind;

Figure 9 is a longitudinal sectional view of a cartridge having a piston in four different stages during insertion of the piston along with details X, Y, Z, W; Figure 10 is a sectional view as Figure 7 of a piston according to another particular embodiment of the invention;

Figure 11 is a sectional view of the piston of Figure 10 along the line XI-XI in Figure 10;

Figures 12a) - i) embodiments of front and rear lamellae of pistons according to particular embodiments of the invention;

Figure 13 is a longitudinal sectional view of a coaxial cartridge with a piston and an annular piston according to a particular embodiment of the invention;

Figure 14 is a longitudinal sectional view of the annular piston of Figure 13; and

FIG. 15 is a longitudinal sectional view of the piston of FIG. 13.

The piston 10 shown individually in Figures 1 to 3 is made of plastic, cup-shaped and has an end wall 12 with a central tip 12a and a closed wall 14. On the outer side 15 of the wall 14 of the piston 10 in the vicinity of the end wall 12, two elastic lamellae 16 and 17 surrounding in radial planes are formed from plastic. The front in the extrusion direction lamella 17 extends substantially arcuately outward and projects beyond the rear in the extrusion direction 16 slat radially outward. The front louver 17 has circumferentially spaced slots 54 extending in the circumferential direction, and the rear lamella 16 extending in the direction of extrusion extends substantially obliquely outwardly toward the end wall 12 of the piston and forms a pocket 19 with the front louver 17. The front plate 17 facing _* t a rounded end 17a (see Figure 3). In addition, the front lamella 17 forms a pocket 21 with the outside 15 of the wall 14. The cross-sectional area of the wall 14 decreases from a first wall section 14a having a first cross-sectional area via a transition section 14b to a second wall section 14c having a second cross-sectional area (see FIG 3). The root portion 17b of the front fin 17 is disposed in the transition portion 14b. In the root area 17b are the slots 54 of the front lamella 17th

The rear blade 16 extends at an angle α of 3 degrees to the longitudinal axis of the piston obliquely outward (see Figure 3).

The root region 16a of the rear lamella 16 is arranged in the region of the transition between the first wall section 14a and the transition section 14b (see FIG. 3). The rear lamella 16 has an end 16b which is beveled outwardly towards the end wall 12 of the piston 10 (see FIG. 3).

The outer side 15 of the wall 14 of the piston has three circumferential in radial planes, away from the end wall 12 obliquely outwardly directed sealing lips 20, 50 and 62, wherein between the sealing lips 20 and 50 and 50 and 62 on the outer side 15 of the wall 14 respectively a circumferential in a radial plane, outwardly projecting guide rib 25 and 27 is provided (see Figure 2). Each guide rib 25 and 27 has a first flank 25a or 27a facing the end wall 12 with a first pitch and a second flank 25b or 27b facing away from the end wall 12 with a second pitch, wherein the second pitch is greater than the first pitch ,

As is apparent from Figure 1, the piston 10 in the region of the front and rear slats 16 and 17 has a round cross-section. Next, reference is made to FIGS. 4 and 5. When inserting the piston 10 by pushing into the open end 28 of the cylindrical container 30, which is closed at its end opposite the open end 28 with a bottom (not marked) with a mouthpiece (not marked) for dispensing pasty substances, the cartridge the front lamella 17 applies under bias to the inner wall 32 of the container 30, since the outer diameter resulting from the front lamella 17 is greater than the inner diameter of the container 30, while of course the outer diameter of the wall 14 is less than the inner diameter of the container 30th is. At this stage, on the other hand, the rear sipe 16 does not abut on the inner wall 32 of the container 30 because the outer diameter resulting from the rear sipe 16 is smaller than the inner diameter of the container. This results in a gap 31 between the rear sipe 16 and the wall 14 at this stage (see Figure 4 below).

As can be seen from FIG. 4, pushing the piston 10 into the open end 28 creates an overpressure which causes residual air to flow through the slots 54 in the front lamella 17 into the pocket 19 and subsequently around the end 16b can escape through the gap 31 (see Figure 4 below). The front louver 17 strips the material 40 from the inner wall 32 and directs it through the slots 54 into the pocket 19. The pocket 19 fills gradually from bottom to top, whereby the rear lamella 16 is pushed outward / spread and to rest comes to the inner wall 32. This prevents the material from getting past the rear sipe 16. As it were, there is a locking towards the rear (see the upper piston in FIG. 4 and FIG. 5). In summary, it is achieved by the arrangement and design of the front plate 17 and rear plate 16 that first the residual air is discharged and then the escape of material 40 is prevented to the rear.

In the case of particularly high pressures, the front lamella 17 is even pressed against the rear lamella 16, at least in this embodiment. In the detail X of Figure 4 and Figure 5, the Restlufit has already escaped and entered a portion of the pasty substance 40 through the slots 54 in the pocket 19, whereby the rear blade 16 is pressed to the outside and the inside wall 32 of the container seals inside. In the present case, this follows selectively on average.

The piston 10 shown in FIGS. 6 to 8, like the piston shown in FIGS. 1 to 5, is made of plastic and is pot-shaped and has an end face 12 with a central tip 12 a and a closed wall 14. In addition, on the outside 15 of the wall 14 of the piston 10 in the vicinity of the end wall 12 are formed two elastic lamellae 16 and 17 made of plastic encircling radial planes. The front in the extrusion direction lamella 17 extends substantially arcuately obliquely outwards, but at least not yet inserted into a cartridge state does not protrude beyond the in the pressing direction rear blade 16 radially outward. The rear slat 16 in Auspreßrichtung is rather on the front in the extrusion direction lamella 17 radially outward. The front lamella 17 has circumferentially spaced slots 54 which extend in the circumferential direction, and the rear lamella 16 extends substantially arcuately obliquely outwardly towards the end wall 12 of the piston and forms a pocket 19 with the front lamella 17.

The front louver 17 has a rounded end 17a (see FIG. 9). In addition, the front lamella 17 forms a pocket 21 with the outside 15 of the wall 14. The cross-sectional area of the wall 14 decreases from a first wall section 14a having a first cross-sectional area via a transition section 14b to a second wall section 14c having a second cross-sectional area (see FIG 9). The root portion 17b of the front fin 17 is located in the transition portion 14b (see FIG. 9). In the root area 17b are the slots 54 of the front lamella 17 (see FIG. 9). Starting from the root region 17b to the end 17a, the front lamella 17 has a substantially constant thickness. The root region 16a of the rear lamella 16 is arranged in the region of the transition between the first wall section 14a and the transition section 14b (see FIG. 9). The rear lamella 16 has an end 16b which is beveled outwardly towards the end wall 12 of the piston 10 (see FIG. 9). The surface of the end 16b is roughened, wherein the roughness is about 30μm. Furthermore, on the outside of the rear lamella 16, a circumferential elevation 16c is provided in a radial plane (see FIG. 9). Starting from the root region 16a of the rear lamella 16 in the direction of the end 16b, the thickness of the rear lamella 16 increases and then decreases in the area of the elevation 16c, becoming even less than the thickness in the root area 16a due to a weakening 16d, and then grows again approximately to the thickness in the root area 16a.

On the inside of the end wall 12 inner reinforcing ribs 22 are molded. Furthermore, two webs 23 are arranged on the inside of the end wall 12 with a first web height 1I ₁ and a first web thickness d _ϊ , which extend concentrically to the inner reinforcing ribs 22. On the side facing radially to the two webs 24 are provided with a second web height h ₂ and a second web thickness d ₂ , which also extend concentrically to the inner reinforcing ribs 22. The first land height hi and the second land height h ₂ are identical and selected such that the lands 23 and 24 protrude from the inside of the end wall 12 rearwardly beyond the inner reinforcing ribs. However, the second web thickness d ₂ is smaller than the first web thickness di selected. If thus by means of a plunger from the open side 28 is acted on the piston 12 in a straight line, from a certain pressure, the webs 24 yield due to the smaller web thickness d ₂ , that bend or buckle, so that the piston 12 in the Pressure sets obliquely to the plunger. As already described above, this leads to a better venting of the cartridge.

FIG. 9 shows various stages in the use of a piston 10, substantially identical to the piston shown in FIGS. 6 to 8, in a cartridge. The cartridge has a cylindrical container 30 with an open end 28 and a bottom 34 with a mouthpiece 36 shown closed. When inserting the piston 10 by pushing into the open end 28 of the cylindrical container 30 of the cartridge, the front lamella 17 contacts the inner wall 32. The rear lamella 16 is biased against the inner wall 32 (see detail X). In the detail Y, the rear sipe 16 is pressed inward, wherein between the annular protrusion 16 c and the inner wall 32, a gap 33 is generated.

In detail W, the piston 10 is set and generates an internal pressure. As a result, the rear lamella 16 yields in the area of the constriction 16d, so that the elevation 16c abuts against the inner wall 32 of the container 30 and seals.

Detail Z shows an extreme situation when pressing out, in which the front lamella 17 and the rear lamella 16 bend outward. In this extreme situation, the front lamella 17 can lean on the rear lamella 16 and locks the piston 10 at least almost 100% and thus leaves no pasty substance, such as silicone, back out.

The rear blade 16 has in the sealing area (see detail X) such a selected rough surface that the air can flow out to the rear when setting the piston. This makes it possible to set the piston plane-parallel. The piston 10 shown in Figure 9 therefore has no webs 23 and 24 in deviation from the piston shown in Figures 6 to 8. In principle, these are only necessary if the end 16b of the rear lamella 16 has no roughened surface.

The piston 10 shown in FIGS. 10 and 11 differs from the piston 10 shown in FIG. 9 in that the front lamella 17 has ridges 60 arranged circumferentially at a constant spacing on the outside thereof in a radial plane. The webs 60 extend at right angles to the direction of rotation of the front blade 17. The webs 60 are designed so that they rest against the inner wall of the rear blade 16 when setting the piston. As a result, the rear sipe 16 becomes stronger toward the outside Inner wall 32 of the container 30 is pressed. This in turn provides a better stripping behavior, especially when using a pure air gun.

Figures 12a) to 12i) show by way of example possible configurations, arrangements and combinations of front fins 17 and rear fins 16 of a piston or rotary piston according to the present invention, wherein the embodiment shown in Figure 12a) corresponds to the embodiment shown in Figures 6 to 8 ,

As can be seen from FIGS. 12a) to 12i), the front lamella 17 can also extend in a straight line in cross section, for example, and the rear lamella 16 can also run in a straight line and in particular at least almost in the direction of extrusion.

13 shows a coaxial cartridge 100 for pressing pasty substances according to a particular embodiment of the present invention, which has a cylindrical container 130 made of plastic, which is closed at its one end with a bottom 134 and open at its other end 128 and an inner, Circular in cross-section chamber 160 and an outer, annular in cross-section chamber 162 which surrounds the inner chamber concentrically. In the chamber 160 is a piston 110, which is shown in Figure 15 and apart from the shape of the end wall very much similar to the piston shown in Figure 9, so the other components have the same reference numerals and reference is made to the above description becomes. In the annular chamber 162 is an annular piston 170, as shown in Figure 14. The annular piston 170 is elastic and made of plastic and in the outer, annular chamber 162 slidably disposed with a radially outer cylindrical wall 172, a radially inner cylindrical wall 174 and a connecting these two end wall 176 at the front end of the annular piston. On the outer side 178 of the radially outer wall 172 of the annular piston 170 are in the vicinity of the end wall 176 two circumferential in radial planes outer elastic lamellae 180 and 182 formed of plastic and on the inside of the radially inner wall 174 of the Annular piston 170 are formed in the vicinity of the end wall 176 two circumferential in radial planes inner elastic lamellae 186 and 188 made of plastic. The front in the pressing direction lamella 182 of the two outer plates 180 and 182 is like the lamella 17 of Figure 7 formed and arranged and has slots 183. The slat 180 of the two outer slats 180 and 182 which is in the direction of extrusion is formed and arranged like the slat 16 of FIG. Reference is therefore made in this respect to the above description.

The leading in Auspreßrichtung lamella 188 of the two inner plates 186 and 188 extends substantially arcuately inwardly and has circumferentially spaced slots 183 on. The squeezing out in the rear plate 186 of the two inner plates 186 and 188 extends to the end wall 176 of the annular piston 170 in substantially obliquely inward and forms with the front plate 188 of the two inner plates 186 and 188 a pocket 190. The rear plate 186 of the two inner sipes 186 and 188 project radially inwardly beyond the front sipe 188. Furthermore, the rear lamella 186 on its outer side a circumferential in a radial plane elevation 192 and further to the end of a constriction 194 on.

The outer fins 180 and 182 and the inner fins 186 and 180 cooperate with the respective adjacent walls 162a and 162b of the annular chamber 162, as shown in Figure 9 and set forth in the description above.

The features of the invention disclosed in the foregoing description, in the drawings and in the claims may be essential both individually and in any combination for the realization of the invention in its various embodiments.

Claims

claims

A piston (10; 110) for a cartridge for extruding pasty substances (40) having an approximately cylindrical container (30) or an approximately cylindrical chamber (160) at its one end with a bottom (34; 134) is closed and open at its other end (28; 128), wherein the piston (10; 110) is elastic and made of plastic and in the container (30) and the chamber (160) slidably with an end wall (12) facing the bottom of the container (30) or the chamber (160) and a closed wall (14) can be arranged on the outside (15) of the wall (14) of the piston (10) in the vicinity the end wall (12) is formed of two elastic lamellae (16; 17) made of plastic running around in radial planes,

characterized in that

the front lamella (17) of the two lamellae (16; 17) extends substantially arcuately outwards, furthermore the front lamella (17) comprises circumferentially spaced slots (54) and the lamella (16) in the direction of extrusion faces the end wall (12) of the piston (10; 110) extends substantially obliquely outwards and with the front lamella (17) forms a pocket (19).

2. Piston (10; 110) according to claim 1, characterized in that the front lamella (17) projects radially outward beyond the lamella (16) which is in the direction of extrusion.

3. Piston (10; 110) according to claim 1 or 2, characterized in that the front lamella (17) is designed to bias against the inner wall (32) of the container (30) and the chamber (160).

4. piston (10; 110) according to one of claims 1 to 3, characterized in that the rear lamella (16) is designed to not on the inner wall (32) of the container before the first pressing of pasty substances from the cartridge (16). 30) and the chamber (160) abut.

5. piston (10; 110) according to one of claims 1 to 3, characterized in that the rear blade (16) on the outside thereof in a radial plane surrounding elevation (16c).

6. Piston (10; 110) according to claim 5, characterized in that the rear lamella (16) is designed to prevent the first pressing of pasty substances from the cartridge on the inner wall (32) of the container (30) or the Chamber (160) to rest.

7. piston (10; 110) according to any one of the preceding claims, characterized in that the rear blade (16) extends substantially arcuately obliquely outwards.

8. Piston (10; 110) according to one of the preceding claims, characterized in that the rear blade (16) has an end (16b) whose surface is roughened.

9. piston (10; 110) according to claim 8, characterized in that the roughness of the surface is about 30 microns.

10. Piston (10; 110) according to one of the preceding claims, characterized in that on the inside of the end wall (12) at least one of them substantially vertically extending web (23) having a first web height Ji ₁ and a first web thickness and at least one web (24) extending substantially vertically therefrom with a second web height h ₂ and a second web thickness d ₂ , wherein the first and second web heights h _1? h _{2 are} at least substantially identical and the first and second web thicknesses d _ls d _{2 are} different.

11. piston (10; 110) according to one of the preceding claims, characterized in that the front lamella (17) on the outside in a radial plane circumferentially spaced webs (60).

12. piston (10; 110) according to claim 11, characterized in that the webs (60) obliquely or transversely to the direction of rotation of the front plate (17) extend.

13. Piston (10; 110) according to one of the preceding claims, characterized in that the front lamella (17) has a rounded end (17a).

14. Piston (10; 110) according to one of the preceding claims, characterized in that the front lamella (17) forms a pocket (21) with the outside (15) of the wall (14).

15. Piston (10; 110) according to one of the preceding claims, characterized in that the cross-sectional area defined by the outer side (15) of the wall (14) extends at right angles to the longitudinal axis of the piston (10) towards the end wall (12) decreases.

16. piston (10; 110) according to claim 15, characterized in that the cross-sectional area of a first wall portion (14 a) having a first cross-sectional area over a Transition portion (14 b) decreases to a second wall portion (14 c) having a second cross-sectional area.

17. piston (10; 110) according to claim 16, characterized in that the root portion (17b) of the front lamella (17) in the transition portion (14b) is arranged.

18. Piston (10; 110) according to any one of the preceding claims, characterized in that the slots (54) are arranged in the root area (17b) of the front lamella (17).

Piston (10; 110) according to one of the preceding claims, characterized in that the rear blade (16) extends obliquely outwards at an angle α of 0 to 10 degrees to the longitudinal axis of the piston (10;

20. Piston (10; 110) according to claim 19, characterized in that the angle α is in the range of 0 to 5 degrees.

21. Piston (10; 110) according to claim 20, characterized in that the angle α is 3 degrees.

22. Piston (10; 110) according to any one of claims 16 to 21, characterized in that the root portion (16a) of the rear sipe (16) in the region of the transition between the first wall portion (14a) and the transition portion (14b) is arranged ,

23. Piston (10; 110) according to one of the preceding claims, characterized in that the rear lamella (16) has an end (16b) tapered outwards towards the end wall (12) of the piston (10).

24. Piston (10) according to any one of the preceding claims, characterized in that the outer side (15) of the wall (14) of the piston (10) at least one circumferential in a radial plane, of the end wall (12) obliquely outwardly directed sealing lip (20).

25. Piston (10) according to claim 24, characterized in that the outer side (15) of the wall (14) of the piston (10) revolving in radial planes, from the end wall (12) obliquely outwardly directed sealing lips (20; ) having.

26. Piston (10) according to claim 25, characterized in that on the outer side (15) of the wall (14) between the two sealing lips (20; 50) is provided a circumferential in a radial plane, outwardly projecting guide rib (25).

27. Piston (10) according to any one of claims 23 to 26, characterized in that the outer side (15) of the wall (14) of the piston (10) three in radial planes encircling, of the end wall (12) obliquely outwardly directed sealing lips (20, 50, 62), wherein between the sealing lips (20 and 50 and 50 and 62) on the outer side (15) of the wall (14) each one in a radial plane, outwardly projecting guide rib (25, 27) provided is.

28. Piston (10) according to claim 26 or 27, characterized in that the or each guide rib (25; 27) has an end wall (12) facing first flank (25a; 27a) with a first slope and one of the end wall ( 12) facing away from the second edge (25b, 27b) having a second pitch, wherein the second pitch is greater than the first pitch.

29. Piston (10; 110) according to one of the preceding claims, characterized in that the piston (10) in the region of the front and rear slats (16; 17) has a round cross section.

30. Piston (10) according to any one of claims 1 to 28, characterized in that the piston (10) in the region of the front and rear slats (16; 17) has an oval cross-section.

31. A cartridge for dispensing pasty substances, comprising a cylindrical container (30) which is closed at its one end with a bottom (34) and at its other end (28) open, characterized in that in the cartridge, a piston (10; 110) according to one of the preceding claims.

32. annular piston (170) for a coaxial cartridge (100) for pressing pasty substances, which has an approximately cylindrical container (130) at one end (128) with a bottom (134) completed and at its other end (128 ) is open and an inner, circular in cross section chamber (160) and an outer annular in cross section chamber (162) which surrounds the inner chamber (160) concentrically, wherein the annular piston (170) is elastic and made of plastic and in the outer, annular chamber (162) slidably with a radially outer, approximately cylindrical wall (172), a radially inner, approximately cylindrical wall (174) and an end wall connecting these two (176) at the front end face of the annular piston (170) can be arranged .

characterized in that

on the outer side (178) of the radially outer wall (172) of the annular piston (170) in the vicinity of the end wall (176) two outer elastic lamellae circulating in radial planes (180, 182) are formed of plastic and on the inside of the radially inner wall (174) of the annular piston (170) in the vicinity of the end wall (176) are formed in two radial planes inner elastic plate (186, 188) made of plastic, wherein the front in the pressing direction lamella (182) of the two outer plates (180, 182) extends substantially arcuately outwardly, further comprising the front lamella (182) of the two outer plates (180, 182) circumferentially spaced slots (183) and the rearward slat (180) of the two outer slats (180, 182) extends substantially obliquely outwards towards the end wall (176) of the annular piston (170) and engages with the front slat (182) of the two outer slats (180, 180). 182) forms a pocket (190) and wherein the squeezing out front lamella (188) of the two inner lamellae (186, 188) is substantially arcuate inwardly, further the front lamella (188) of the inner lamellae (186, 188) circumferentially spaced slots (183) and the rear in Auspreßrichtung lamella (186) of the two inner plates (186, 188) to the end wall (176) of the annular piston (170) out substantially obliquely extends inside and with the front lamella (188) of the two inner slats (186, 188) forms a pocket (190).

33. annular piston (170) according to claim 32, characterized in that the front lamella (182) of the two outer plates (180, 182) on the rear in Auspreßrichtung lamella (180) of the two outer plates (180, 182) radially outward protrudes and / or the front lamella (188) of the two inner lamellae (186, 188) projects radially inwardly beyond the discharge lamella (186) of the two inner lamellae (186, 188).

34. Annular piston (170) according to any one of claims 32 to 33, characterized in that the front lamella (182) of the two outer plates (180, 182) is designed to bias against the outer wall (162 a) of the annular chamber (162 ) and / or the front blade (182) of the two inner blades (186, 188) is designed to bias against the inner wall (162b) of the annular chamber (162).

35. annular piston (170) according to any one of claims 32 to 34, characterized in that the rear blade (180) of the two outer plates (180, 182) is designed to prior to the first pressing of pasty substances from the coaxial cartridge (100). not abutting the outer wall (162a) of the annular chamber (162) and / or the rear sipe (186) of the two inner sipes (186, 188) is designed not to be prior to the first squeezing of pasty substances from the coaxial cartridge (100) on the inner wall (162b) of the annular chamber (162) abut.

36. annular piston (170) according to any one of claims 32 to 35, characterized in that the respective rear slats (180, 186) of the inner and outer slats (180, 182, 186, 188) on the outer sides thereof in each case a circumferential in a radial plane Survey (192).

37. annular piston (170) according to claim 36, characterized in that the respective rear slats (180, 186) of the inner and outer slats (180, 182, 186, 188) are designed to be prior to the first pressing of pasty substances from the Coaxial cartridge (100) on the outer wall (162a) of the annular chamber (162) or on the inner wall (162b) of the annular chamber (162) abut.

38. Ring piston (170) according to any one of claims 32 to 37, characterized in that the rear blade (180) of the two outer blades (180, 182) extends substantially arcuate obliquely outwards and / or the rear blade (186) of both inner slats (186, 188) extends substantially arcuate obliquely inwards.

39. Ring piston (170) according to any one of claims 32 to 38, characterized in that the rear lamellae (180, 186) of the inner and outer plates (180, 182, 186, 188) each have an end (128) whose surface roughened.

40. annular piston (170) according to any one of claims 32 to 39, characterized in that the roughness of the surface is about 30μm.

41. annular piston (170) according to any one of claims 32 to 40, characterized in that the respective front fins (182, 188) of the inner and outer fins (180, 182, 186, 188) respectively on the outer side (178) in a Radial level circumferentially spaced ridges have.

42. annular piston (170) according to claim 45, characterized in that the webs extend obliquely or transversely to the direction of rotation of the front slats.

43. annular piston (170) according to any one of claims 32 to 42, characterized in that the respective front fins (182, 188) of the inner and outer fins (180, 182, 186, 188) each have a rounded end.

44. annular piston (170) according to any one of claims 32 to 43, characterized in that the respective front fins (182, 188) of the inner and outer fins (180, 182, 186, 188) each with the radially outer wall (172) or the radially inner wall (174) form a pocket (191).

45. annular piston (170) according to any one of claims 32 to 44, characterized in that the by the radially outer wall (172) defined outer diameter to the end wall (176) decreases towards.

46. annular piston (170) according to any one of claims 32 to 45, characterized in that by the radially inner wall (174) defined inner diameter to the end wall (176) increases towards.

47. annular piston (170) according to claim 45 or 46, characterized in that the outer and inner diameter of a first portion of the radially outer and inner walls (172, 174) having a first outer diameter and a first inner diameter via a transition section to a second Remove portion of the radially outer and inner walls (172, 174) having a second outer diameter and a second inner diameter.

48. annular piston (170) according to claim 47, characterized in that the root portions of the front fins (182, 188) of the inner and outer fins (180, 182, 186, 188) are arranged in the transition section.

49. annular piston (170) according to any one of claims 32 to 48, characterized in that the slots (183) in the root regions of the front slats (182, 188) are arranged.

50. Ring piston (170) according to any one of claims 32 to 49, characterized in that the rear blade (180) of the outer plates (180, 182) at an angle α of 0 to 10 degrees to the longitudinal axis of the annular piston (170) obliquely extends outside and / or the rear blade (186) of the inner blades (186, 188) at an angle α of 0 to 10 degrees to the longitudinal axis of the annular piston (170) extends obliquely inwards.

51. annular piston (170) according to claim 50, characterized in that the angle α is in the range of 0 to 5 degrees.

52. annular piston (170) according to claim 51, characterized in that the angle α is 3 degrees.

53. annular piston (170) according to one of claims 47 to 52, characterized in that the root portions of the rear slats (180, 186) in the region of the transition between the first portion of the radially outer and inner walls (172, 174) and the transition portion are arranged.

54. annular piston (170) according to one of claims 32 to 53, characterized in that the rear blade (180) of the outer plates (180, 182) has an end wall (176) of the annular piston (170) outwardly bevelled end and or the rear lamella (186) of the inner lamellae (186, 188) has an end which is tapered inwards towards the end wall (176) of the annular piston (170).

55. annular piston (170) according to any one of claims 32 to 54, characterized in that the outer side (178) of the radially outer wall (172) of the annular piston (170) at least one in a radial plane, obliquely from the end wall (176) away has outwardly directed sealing lip and / or the inside (184) of the radially inner wall (174) of the annular piston (170) has at least one circumferential in a radial plane, from the end wall (176) obliquely inwardly directed sealing lip.

56. annular piston (170) according to claim 55, characterized in that the outer side (178) of the radially outer wall (172) of the annular piston (170) has two in radial planes, circumferential, of the end wall (176) obliquely outwardly directed sealing lips and / or the inner side (184) of the radially inner wall (174) of the annular piston (170) has two circumferential in radial planes of the end wall (176) obliquely inwardly directed sealing lips.

57. annular piston (170) according to claim 56, characterized in that on the outer side (178) of the radially outer wall (172) between the two sealing lips a circumferential in a radial plane, outwardly projecting guide rib is provided and / or on the inside (17 184) of the radially inner wall (174) is provided between the two sealing lips a circumferential in a radial plane, inwardly projecting guide rib.

58. annular piston (170) according to one of claims 55 to 57, characterized in that the outer side (178) of the radially outer wall (172) of the annular piston (170) three in radial planes encircling, from the end wall (176) away obliquely outwards directed sealing lips, wherein between the sealing lips on the outer side (178) of the radially outer wall (172) each have a circumferential in a radial plane, outwardly projecting guide rib is provided, and / or the inside (184) of the radially inner wall (174) the annular piston (170) has three sealing lips running in radial planes away from the end wall (176), wherein between the sealing lips on the inside of the radially inner wall (174) there is provided an inwardly projecting guide rib extending in a radial plane is.

59. The annular piston (170) according to claim 57 or 58, characterized in that the or each guide rib has a first flank facing the end wall (176) with a first pitch and a second flank facing away from the end wall (176) with a second pitch wherein the second slope is greater than the first slope.

60. A coaxial cartridge (100) for pressing pasty substances, which has an approximately cylindrical container (130) which is closed at its one end (128) having a bottom (134) and at its other end (128) open and an inner , Circular in cross-section chamber (160) and an outer, annular in cross-section chamber (162) concentrically surrounding the inner chamber (160), characterized in that in the coaxial cartridge (100) has an annular piston (170) according to one of claims 32 to 59 and / or a piston (10; 110) according to one of claims 1 to 30 is provided.