Multi-chamber cartridge

Abstract

The invention relates to a multi-chamber cartridge (1) with an outer tube (2) and an inner tube (3) arranged coaxially in the outer tube (2) for the separate storage of two components, for example, a hardener and a binder of a two-component synthetic resin. For dispensing, the multi-chamber cartridge (1) has a dispensing element (14) with four cutting edges (21) which, when the multi-chamber cartridge (1) is dispensed, cut the inner tube (3) of the multi-chamber cartridge (1) into four strips that roll, fold, and / or crumple into four receiving spaces (23) in the dispensing element (14). For sealing in the inner tube (3), the dispensing element (14) has a head pin (19) whose head (42) seals in the inner tube (3).In order to be able to injection mold the ejector element (14) from plastic, a collar (48) surrounding the head pin (19) of the ejector element (14) has two collar openings (49) opposite each other, through which two slides (50) of an injection molding tool are pulled out to demold the ejector element (14) after injection molding, forming a shaft (41) of the head pin (19).

Description

[0001] The invention relates to a multi-chamber cartridge having the features of the preamble of claim 1.

[0002] Multi-chamber cartridges are used for the separate storage of flowable, for example, liquid, and especially viscous or pasty components of a compound that sets, solidifies, or hardens when its components are mixed. The compound, for example, is a resin with a binder as one component and a hardener as the other. In this case, the compound is a two-component compound, with both components contained separately in two chambers of the multi-chamber cartridge. In this case, the multi-chamber cartridge is a two-chamber cartridge.

[0003] Patent application DE 10 2018 117 143 A1 discloses a two-chamber cartridge with a cylindrical outer tube, in which an inner chamber is separated by a partition wall that is V-shaped in a cross-section through the two-chamber cartridge. To extrude components contained in the outer tube and the inner chamber, the known two-chamber cartridge has a piston as an extrusion element, which is displaced toward a front end of the two-chamber cartridge for extrusion. The two-chamber cartridge has an outlet for the outer tube and the inner chamber, through which the components exit the outer tube and the inner chamber and are mixed, for example, in a static mixer mounted on the outlet.The piston forming the ejection element has two cutting edges on its circumference. These cut through the V-shaped partition on an inner circumference of the outer tube when the piston is moved toward the front end of the dual-chamber cartridge. A central cutting edge cuts through the V-shaped partition at its apex, cutting the V-shaped partition into two strips that roll up inside the piston. The familiar dual-chamber cartridge can be ejected using a conventional cartridge gun for a single-chamber cartridge. Such cartridge guns are also called cartridge presses or ejection guns.

[0004] The object of the invention is to propose a multi-chamber cartridge with an inner tube which can be pressed out using a conventional cartridge gun for a single-chamber cartridge and which has a good seal in the inner tube.

[0005] This object is achieved according to the invention by the features of claim 1. The multi-chamber cartridge according to the invention is intended for the separate storage and joint dispensing of several components of a mass. The multi-chamber cartridge according to the invention has a longitudinal axis, an outer tube which is parallel to the longitudinal axis and in particular concentric with the longitudinal axis, and an inner tube which is arranged parallel and preferably concentric with the longitudinal axis in the outer tube. When the multi-chamber cartridge is filled, one component of the mass is contained in the inner tube and another component is contained in a space between the inner tube and the outer tube. At one end of the multi-chamber cartridge, which is referred to here as the front end, the multi-chamber cartridge has an outlet for the outer tube and for the inner tube.The outlet for the outer tube communicates with the space between the outer tube and the inner tube such that, when the multi-chamber cartridge is pressed out, the component of the mass contained in the space between the outer tube and the inner tube exits through the outlet for the outer tube. The outlet for the inner tube communicates with the inner tube such that, when the multi-chamber cartridge is pressed out, the component of the mass contained in the inner tube exits through the outlet for the inner tube. The outlets for the outer tube can, for example, be arranged next to one another or inside one another, open into one another, or the multi-chamber cartridge can have a common outlet for the outer tube and the inner tube.

[0006] To extrude the components of the compound, the multi-chamber cartridge according to the invention has a piston or the like, which is generally referred to here as an "extrusion element." The extrusion element is displaceable in the outer tube along the longitudinal axis of the multi-chamber cartridge and is displaced toward the front end of the multi-chamber cartridge to extrude the multi-chamber cartridge. The extrusion element presses the components contained in the inner tube and in the space between the outer tube and the inner tube toward the front end of the multi-chamber cartridge, where the components exit the multi-chamber cartridge through the outlet(s).

[0007] The ejection element of the multi-chamber cartridge according to the invention has at least one cutting edge which, when the ejection element is displaced in the outer tube of the multi-chamber cartridge toward the front end of the multi-chamber cartridge, cuts through the inner tube in a longitudinal direction. The longitudinal direction runs in particular parallel to the longitudinal axis of the multi-chamber cartridge or at least has a component parallel to the longitudinal axis of the multi-chamber cartridge. For example, it is possible to cut through the inner tube in a helical or wave-like manner. Preferably, the ejection element of the multi-chamber cartridge according to the invention has several cutting edges which, when the ejection element is displaced toward the front end of the multi-chamber cartridge, cut the inner tube at several points along its circumference in the longitudinal direction into strips which extend in the longitudinal direction of the multi-chamber cartridge and over a limited circumference of the inner tube.The strips can be rolled up, folded or crumpled in a cavity of the ejection element when the ejection element is moved towards the front end of the multi-chamber cartridge, although this is not essential for the invention.

[0008] The ejection element of the multi-chamber cartridge according to the invention has an inner piston which is at least partially located within the inner tube and which has a circumferential inner seal which bears circumferentially against an inner circumference of the inner tube. The inner seal is preferably an integral component of the inner piston. The inner seal preferably seals absolutely tightly against the inner circumference of the inner tube in order to prevent premature hardening or aging of the compound contained in the inner tube. However, the invention is also intended to encompass inner seals which are not absolutely tight, which, for example, permit or at least do not always prevent gas exchange between the inner tube and the environment, or which permit the inner piston to slide past residues of the component contained in the inner tube which adhere to the inner circumference of the inner tube.

[0009] Behind the inner seal, i.e., on the side of the inner seal facing away from the front end of the multi-chamber cartridge, the inner piston tapers, forming a preferably circumferential undercut. This allows for an axially short inner seal, which improves the seal in the inner tube and / or facilitates the movement of the inner piston within the inner tube and thus the movement of the ejection element in the multi-chamber cartridge.

[0010] In the space between the outer tube and the inner tube, the inner seal of the inner piston of the ejection element is surrounded by a tubular collar of the ejection element. According to the invention, the collar has an opening which is located radially outside the undercut on the taper of the inner piston behind the inner seal. Through the opening, the undercut of the inner piston behind the inner seal is radially accessible from the outside through the collar of the ejection element. This enables the ejection element to be injection molded together with the inner piston in one piece from plastic, with a slider which is radially movable in an injection mold forming the undercut behind the inner seal of the inner piston. After injection molding, the slider can be pulled radially out of the collar and the ejection element can then be demolded.

[0011] One embodiment of the invention provides that the inner seal or a sealing surface of the inner seal has the shape of a cylindrical ring. The sealing surface is a surface adjacent to the inner circumference of the inner tube. It is, in particular, an outer circumferential surface on the inner piston, which has a larger diameter than the inner piston behind the inner seal or behind the sealing surface. "Behind" means a section of the inner piston adjoining the inner seal or its sealing surface on a side facing away from the front end of the multi-chamber cartridge.

[0012] In particular, the inner seal or its sealing surface is axially short, i.e. it has an axial length of one or a few millimeters and / or is axially shorter than a diameter or a radius of the sealing surface.

[0013] One embodiment of the invention provides a head pin as the inner piston. The head pin has a head with a larger diameter or generally a larger circumference than a shaft of the head pin, which adjoins the head on the side facing away from the front end of the multi-chamber cartridge. The shaft of the head pin merges integrally into the ejection element at a base or is connected to the ejection element in some other way - preferably rigidly. The circumference of the head forms the inner seal or its sealing surface. At a transition from the head to the shaft of the head pin, the head pin forming the inner piston has the circumferential undercut with which the head pin tapers from its head to its shaft.

[0014] In a preferred embodiment of the invention, the collar of the ejection element has two openings that are opposite each other with respect to the longitudinal axis of the multi-chamber cartridge. This allows the circumferential undercut at the rear end of the inner seal, or the head of the head pin that forms the inner piston, to be formed with two slides arranged opposite each other during injection molding of the ejection element. These slides are pulled radially out of the collar after injection molding of the ejection element, after which the ejection element can be removed from the mold.

[0015] In one embodiment of the invention, the head pin forming the inner piston, or the collar of the ejection element of the multi-chamber cartridge according to the invention surrounding the head of the head pin forming the inner piston, forms a seal holder for a central seal and / or for an outer seal. The central seal seals against an outer circumference of the inner tube, and the outer seal seals against an inner circumference of the outer tube of the multi-chamber cartridge.

[0016] The cutting edge of the ejection element, which cuts through the inner tube longitudinally when the ejection element is moved toward the front end of the multi-chamber cartridge, is preferably offset rearward relative to the inner seal. This means that the cutting edge is at a greater distance from the front end of the multi-chamber cartridge than the inner seal. This allows the inner seal to seal in a section of the inner tube not yet cut through by the cutting edge.

[0017] In embodiments of the invention, the cutting edge is located in an axial plane of the longitudinal axis of the multi-chamber cartridge or in a plane parallel to the axial plane.

[0018] In a preferred embodiment of the invention, the ejection element has a plurality of cutting edges that are offset from one another in the circumferential direction. The cutting edges can be evenly or unevenly distributed over the circumference. They cut the inner tube into a plurality of strips, which, when the ejection element is moved toward the front end of the multi-chamber cartridge, roll up, fold up, or bunch up, for example, in a cavity of the ejection element.

[0019] At a front end facing the front end of the multi-chamber cartridge, the inner piston tapers in front of the inner seal with an insertion bevel, which facilitates insertion of the inner piston into the inner tube of the multi-chamber cartridge.

[0020] The features and combinations of features, embodiments and configurations of the invention mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or drawn in a figure can be used not only in the respective combination specified or drawn, but also in principle any other combinations or individually. Embodiments of the invention are possible which do not have all the features of a dependent claim. Individual features of a claim can also be replaced by other disclosed features or combinations of features. Embodiments of the invention which do not have all the features of the exemplary embodiment, but basically any part of the identified features of the exemplary embodiment, are possible.

[0021] The invention is explained in more detail below using an exemplary embodiment illustrated in the drawing. In the drawings: Figure 1 shows a multi-chamber cartridge according to the invention in a perspective axial section; and Figure 2 shows an ejection element of the multi-chamber cartridge from Figure 1 as a single part in a perspective view.

[0022] The Figure 1The multi-chamber cartridge 1 according to the invention shown is a two-chamber cartridge with a longitudinal axis 40, an outer tube 2 coaxial with the longitudinal axis 40, and an inner tube 3 which is also coaxial with the longitudinal axis 40 and is arranged in the outer tube 2. An inner tube 3 arranged eccentrically and parallel to the longitudinal axis 40 in the outer tube 2 is also possible (not shown). The outer tube 2 has, at one end, which is referred to here as the front end 4 of the outer tube 2 and of the multi-chamber cartridge 1, a perforated disc-shaped end wall 5, from the central hole of which a tubular nozzle 6 protrudes coaxially outwards. The nozzle 6 has an external thread 7, onto which, in the drawing, a cover 8 is screwed, which closes the nozzle 6.

[0023] Coaxially arranged in the nozzle 6 is an outlet 9 for the inner tube 3—cylindrical in the exemplary embodiment—which is secured in the nozzle 6 by radially arranged ribs 10 arranged in a star shape. Via a perforated disc-shaped annular step 32, the inner tube 3 merges into the outlet 9 at the front end 4, whereby the inner tube 3 is held coaxially in the outer tube 2 of the two- or multi-chamber cartridge 1. The nozzle 6 surrounding the outlet 9 of the inner tube 3 or an annular space surrounding the outlet 9 of the inner tube 3 in the nozzle 6 forms an outlet 11 of the outer tube 2 or an outlet 11 of an annular space 12 surrounding the inner tube 3 in the outer tube 2. The cover 8 closes the outlet 11 of the outer tube 2 and the outlet 9 of the inner tube 3 when it is screwed onto the nozzle 6.

[0024] The outer tube 2, or the intermediate space 12 between the outer tube 2 and the inner tube 3, and the inner tube 3 serve for the separate storage of two flowable, particularly viscous or pasty, components of a compound that sets, solidifies, or hardens after their components have been mixed. For example, the outer tube 2 and the inner tube 3 serve for the separate storage of a binder and a hardener of a two-component synthetic resin. To dispense the two components, a hollow truncated cone-shaped dispensing nozzle (not shown) or a tubular static mixer (not shown) can be screwed onto the nozzle 6 of the multi-chamber cartridge 1 instead of the lid 8. This mixer mixes the components of the compound stored separately in the outer tube 2 and the inner tube 3 when the components are squeezed out through the outlets 9, 11 of the two- or multi-chamber cartridge 1 and flow through the static mixer (not shown).

[0025] At a rear end 13 of the multi-chamber cartridge 1, remote from the front end 4, the outer tube 2 and the inner tube 3 are open or closed by an ejection element 14, which is arranged in the rear end 13 of the multi-chamber cartridge 1 or the outer tube 2 and is displaceable forwards in the direction of the longitudinal axis 40 in the multi-chamber cartridge 1 or in the outer tube 2 of the multi-chamber cartridge 1 towards the front end 4. The ejection element 14 can also be understood as a stamp or piston for ejecting the multi-chamber cartridge 1. It is in Figure 2shown as an individual part. By displacing the ejection element 14 in the outer tube 2 toward the front end 4 of the multi-chamber cartridge 1, the ejection element 14 presses the components of the mass stored separately in the annular space 12 surrounding the inner tube 3 in the outer tube 2 and in the inner tube 3 out of the multi-chamber cartridge 1 through the outlets 9, 11 at the front end. Ejecting the components can also be considered ejecting the multi-chamber cartridge 1. Before ejection, the cover 8 must be removed.

[0026] In order to move the ejection element 14 in the outer tube 2 of the multi-chamber cartridge 1 and to eject the multi-chamber cartridge 1, the multi-chamber cartridge 1 is inserted into a cartridge gun, which is known per se and not shown here and is operated manually, by an electric motor, pneumatically or in some other way, which is also referred to as a cartridge press or ejection gun.

[0027] The ejection element 14 has a circular perforated disc-shaped rear wall 15, which is arranged coaxially to the longitudinal axis 40 of the multi-chamber cartridge 1 and in a radial plane of the longitudinal axis 40 in the outer tube 2 and extends to or close to an inner circumference of the outer tube 2. The rear wall 15 is located on a rear side of the ejection element 14, facing away from the front end 4 and the outlets 9, 10.

[0028] From a front side of the rear wall 15 facing the front end 4 of the multi-chamber cartridge 1, supports 16 project forward, parallel to the axis, toward the front end 4 of the multi-chamber cartridge 1. The supports 16 are arranged on an outer circumference of the rear wall 15 and guide the ejection element 14 axially displaceably in the outer tube 2 of the multi-chamber cartridge 1 such that they support the ejection element 14 against tilting about an imaginary radial axis in the outer tube 2.

[0029] In the exemplary embodiment, the ejection element 14 has four supports 16 that are offset from one another by 90° in a circumferential direction, i.e., are evenly distributed over the circumference. A different number of supports 16 and / or an unevenly distributed arrangement over the circumference are possible (not shown).

[0030] Between the supports 16, a hollow truncated cone-shaped post 18 projects in the direction of the front end 4 of the multi-chamber cartridge 1 at the center of the front side of the rear wall 15 of the ejection element 14. A head pin 19 projects from a smaller, front cover surface of the post 18, i.e., the surface facing the front end 4 of the multi-chamber cartridge 1, in the direction of the front end 4 of the multi-chamber cartridge 1. The head pin 19 is arranged coaxially in the inner tube 3 of the multi-chamber cartridge 1; in the exemplary embodiment, the head pin 19 is coaxial with the longitudinal axis 40 of the multi-chamber cartridge 1.

[0031] The head pin 19 has a shaft 41—in the exemplary embodiment, cylindrical in shape—and a head 42 at a front end facing the front end 4 of the multi-chamber cartridge 1. The head 42 has a larger diameter than the shaft 41, and the head 42 projects radially beyond the shaft 41. The head 42 is circular disk-shaped and has a cylindrical circumferential surface, which, as a sealing surface 43, bears circumferentially against an inner circumference of the inner tube 3 of the multi-chamber cartridge 1. The head pin 19 forms an inner piston 44 of the ejection element 14 for ejecting the inner tube 3 of the multi-chamber cartridge 1, and its head 42 or its sealing surface 43 forms a circumferential inner seal 45 of the ejection element 14 for sealing in the inner tube 3. The inner seal 45 is axially short; in the exemplary embodiment, it has an axial length of between approximately 2-3 mm.It therefore has a good sealing effect on the inner circumference of the inner tube 3 of the multi-chamber cartridge 1 and still slides easily in the inner tube 3.

[0032] On a front side facing the front end 4 of the multi-chamber cartridge 1, the head 42 of the head pin 19, which forms the inner piston 44, has a circumferential bevel as an insertion bevel 46, which facilitates insertion of the inner piston 44 into the rear end of the inner tube 3 of the multi-chamber cartridge 1. The insertion bevel 46 is a circumferential and annular inclined surface at a transition from the circumferential surface to a front end face of the head 42 of the head pin 19. The circumferential surface of the head 42 forms, as described, the circumferential sealing surface 43 or the inner seal 45.

[0033] On a rear side facing the shaft 41, the head 42 of the head pin 19 merges into the shaft 41 with an annular step. The annular step forms an undercut 47, at or with which the head pin 19 tapers at a transition from its head 42 to its shaft 41. In the exemplary embodiment, the undercut 47 is designed as a bevel-like, annular, circumferential inclined surface, although this is not mandatory for the invention. As described, the head pin 19 forms the inner piston 44 of the ejection element 14 of the multi-chamber cartridge 1 according to the invention, which tapers behind the inner seal 45, whereby "behind" means the rear side of the head 42 facing away from the front end 4 of the multi-chamber cartridge 1.

[0034] Partition walls 20 are arranged between the supports 16 and the column 18. In the exemplary embodiment, the partition walls 20 are located in two axial planes intersecting at right angles.

[0035] The front edges of the partition walls 20 facing away from the rear wall 15 of the ejection element 14 and facing the front end 4 of the multi-chamber cartridge 1 are designed as sharp-edged cutting edges 21 in radially inner sections adjoining the stand 18. Viewed axially, or in the direction of the longitudinal axis 40 of the multi-chamber cartridge 1, the cutting edges 21 cross a wall 22 of the inner tube 3 of the multi-chamber cartridge 1 such that when the ejection element 14 is displaced forward in the direction of the front end 4 of the multi-chamber cartridge 1 to eject the multi-chamber cartridge 1, the cutting edges 21 of the ejection element 14 cut the wall 22 of the inner tube 3 in the direction of the longitudinal axis 40 of the multi-chamber cartridge 1 into strips - four in the exemplary embodiment.

[0036] When the ejection element 14 is moved forward, the strips into which the cutting edges 21 of the ejection element 14 cut the inner tube 2 of the multi-chamber cartridge 1 enter receiving spaces 23 at or in front of the front side of the rear wall 15 of the ejection element 14. The receiving spaces 23 are delimited rearwardly, toward the rear end 13 of the multi-chamber cartridge 1, by the rear wall 15 and in the circumferential direction by the partition walls 20. When the ejection element 14 is moved toward or during the ejection of the multi-chamber cartridge 1, the strips into which the cutting edges 21 of the ejection element 14 cut the wall 22 of the inner tube 3 roll, fold, crumple, or deform into the receiving spaces 23 of the ejection element 14.

[0037] With respect to the inner seal 45, the cutting edges 21 are offset rearward, i.e. in the direction of the rear wall 15 of the ejection element 14 or in the direction of the rear end 13 of the multi-chamber cartridge 1, so that the inner seal 45 seals in an uncut section of the inner tube 3 of the multi-chamber cartridge 1.

[0038] Concentrically arranged at the front ends of the supports 16 of the ejection element 14 facing the front end 4 of the multi-chamber cartridge 1 is a cylindrical tube-shaped collar 48 serving as the outer seal holder 24, which encloses the head 42 of the head pin 19 forming the inner piston 44. Axially, the collar 48 projects both forwards and backwards beyond the head 42. The collar 48 forming the outer seal holder 24 is located in the intermediate space 12 between the outer tube 2 and the inner tube 3 of the multi-chamber cartridge 1. The collar 48 encloses the inner tube 3 at a radial distance; in the exemplary embodiment, the collar 48 is closer to the outer tube 2 than to the inner tube 3.

[0039] To enable the ejection element 14 to be injection-molded in one piece from plastic, the collar 48 has two collar openings 49 at opposite circumferential locations, which are sufficiently wide in a circumferential direction to radially cover the shaft 41 of the head pin 19. In the exemplary embodiment, the two collar openings 49 extend axially from the undercut 47 on the rear side of the head 42 of the head pin 19 to the front end of the post 18, from which the shaft 41 of the head pin 19 protrudes forward. The collar openings 49 can be higher axially toward the front and / or rear.

[0040] During injection molding of the ejection element 14, there are two slides 50, which Figure 1are shown with dash-dotted lines, of an injection molding tool (not shown) in the collar openings 49 of the collar 48 of the ejection element 14. The slides 50 form the shaft 41 of the head pin 19 and the undercut 47 on the rear side of the head 42 of the head pin 19 during injection molding of the ejection element 14. In order to demold the ejection element 14 from the injection molding tool (not shown), the two slides 50 are pulled radially out of the collar openings 49 after injection molding, the injection molding tool is then opened and the ejection element 14 is demolded.

[0041] A perforated disc-shaped elastic sealing element 25 is arranged on a front edge of the outer seal holder 24 facing the front end 4 of the multi-chamber cartridge 1. This sealing element 25 seals against an inner circumference of the outer tube 2 and an outer circumference of the inner tube 3 of the multi-chamber cartridge 1. The sealing element 25 has an annular sealing base body 33 with circumferential sealing lips 26, 27 on an inner circumference and an outer circumference of the sealing base body 33. A tubular collar 34 protrudes from the sealing base body 33 of the sealing element 25 on a rear side of the annular sealing base body 33 of the sealing element 25 facing away from the front end 4 of the multi-chamber cartridge 1 and encloses the cylindrical outer seal holder 24 of the ejection element 14.

[0042] In the exemplary embodiment, the tubular collar 34 of the sealing base body 33 of the sealing element 25 rests against an outer circumference of the outer seal holder 24 of the ejection element 14 and has a smaller diameter than the outer tube 2 of the multi-chamber cartridge 1 such that an annular space exists around the outside of the tubular collar 34 of the sealing element 25 between the tubular collar 34 of the sealing element 25 and the outer tube 2 of the multi-chamber cartridge 1.

[0043] On an inner circumference of the tubular collar 34, the annular sealing base body 33 of the sealing element 25 has, in its rear side facing away from the front end 4 of the multi-chamber cartridge 1, an annular groove 35 with a groove cross-section corresponding to the cylindrical tubular outer seal holder 24 of the ejection element 14, into which the outer seal holder 24 engages.

[0044] The two sealing lips 26, 27 are hollow truncated cone-shaped, i.e., the sealing lips 26, 27 of the sealing element 25 have the shape of the outer surfaces of truncated cones. An inner of the two sealing lips 26 tapers toward the front end 4 of the multi-chamber cartridge 1 such that its circumferential front edge sealingly abuts the outer circumference of the inner tube 3. An outer of the two sealing lips 27 widens toward the front end 4 of the multi-chamber cartridge 1 such that its circumferential front edge sealingly abuts the inner circumference of the outer tube 2 of the multi-chamber cartridge 1.The circumferential lines or, in the axial direction of the multi-chamber cartridge 1, narrow, circumferential strip-shaped surfaces on which the sealing lips 26, 27 of the sealing element 25 sealingly bear against the outer circumference of the inner tube 3 or the inner circumference of the outer tube 2 of the multi-chamber cartridge 1 are referred to here as sealing lines 36 or as sealing surfaces.

[0045] The sealing lips 26, 27 can generally also be understood as seals 37, 38, whereby the outer sealing lip 27, which seals against the inner circumference of the outer tube 2 of the multi-chamber cartridge 1, is also referred to here as the outer seal 37 and the inner sealing lip 26, which seals against the outer circumference of the inner tube 3 of the multi-chamber cartridge 1, is also referred to here as the middle seal 38.

[0046] Due to the tapering of the inner sealing lip 26 and the widening of the outer sealing lip 27 in the direction of the front end 4 of the multi-chamber cartridge 1, a pressure which arises in the space between the outer tube 2 and the inner tube 3 when the multi-chamber cartridge 1 is pressed out, acts on the inner sealing lip 26 radially inward against the outer circumference of the inner tube 3 and the outer sealing lip 27 radially outward against the inner circumference of the outer tube 2, which improves sealing.

[0047] At their circumferential front ends remote from the front end 4 of the multi-chamber cartridge 1, the two sealing lips 26, 27 merge integrally into the sealing base body 33 of the sealing element 25. Viewed in the axial direction of the multi-chamber cartridge 1 according to the invention, the circumferential sealing lines 36 or sealing surfaces of the two sealing lips 26, 27 are located in front of a circumferential front end edge of the outer seal holder 24 facing the front end 4 of the multi-chamber cartridge 1, i.e., the sealing lines 36 or sealing surfaces of the sealing lips 26, 27 are closer to the front end 4 of the multi-chamber cartridge 1 than the front end edge of the outer seal holder 24, which axially supports the sealing element 25 when the multi-chamber cartridge 1 is pressed out.

[0048] The circumferential rear ends of the sealing lips 26, 27 are located behind the front end edge of the outer seal holder 24 of the ejection element 14, viewed in the axial direction of the multi-chamber cartridge 1. This means that the annular transitions of the sealing lips 26, 27 into the sealing base body 33 of the sealing element 25 are spaced a greater distance from the front end 4 of the multi-chamber cartridge 1 than the circumferential front end edge of the outer seal holder 24 of the ejection element 14. This causes the sealing lips 26, 27 to be "pulled" when the multi-chamber cartridge 1 is ejected. "Pulled" means that an axial force is introduced at the front end edge of the outer seal holder 24 axially in front of the transitions of the sealing lips 26, 27 into the sealing base body 33 when the multi-chamber cartridge 1 is ejected.

[0049] In addition, the sealing element 25 has a rear sealing lip 28 on its outer circumference, which is offset relative to the inner and outer sealing lips 26, 27 toward the rear end 13 of the multi-chamber cartridge 1. The rear sealing lip 28 is located on the tubular collar 34 of the sealing element 25, has a sawtooth-shaped cross-section, and also sealingly bears against the inner circumference of the outer tube 2 of the multi-chamber cartridge 1.

[0050] The outer seal holder 24 - in the exemplary embodiment cylindrical in shape - has a distance in the longitudinal direction or in the axial direction of the multi-chamber cartridge 1 from the front side of the rear wall 15 of the ejection element 14 such that openings 29 are formed on the circumferences of the receiving spaces 23 and thus also on a circumference of the ejection element 14 between a circumferential rear edge of the annular outer seal holder 24 facing the rear wall 15 of the ejection element 14, the front side of the rear wall 15 of the ejection element 14 and the supports 16 which connect the outer seal holder 24 on the circumference of the rear wall 15 of the ejection element 14 - in the exemplary embodiment in one piece - to the rear wall 15.Through the openings 29 of each receiving space 23 on the circumference of the ejection element 14, the outer tube 2 delimits the receiving spaces 23 on the outside, whereby the receiving spaces 23 have more volume for receiving the inner tube 3 of the multi-chamber cartridge 1 cut into strips than if the ejection element 14 had its own closed peripheral wall enclosing the receiving spaces 23 without the openings 29.

[0051] The perforated disc-shaped sealing element 25 has a circumferential, radially outwardly projecting bead 30, which is snapped onto hook-shaped holders 31 that protrude from the front ends of the supports 16 of the ejection element 14 and that hold the sealing element 25 axially on the outer seal holder 24. The hook-shaped holders 31 and the bead 30 form a locking mechanism 39 that holds the sealing element 25 axially on the ejection element 14 and on the outer seal holder 24 of the ejection element 14, respectively.

[0052] With respect to the openings 29 on the circumference of the ejection element 14 and with respect to the cutting edges 21, the outer seal holder 24 or at least its front end edge is offset axially or in the longitudinal direction of the multi-chamber cartridge 1 forwards in the direction of the front end 4 of the multi-chamber cartridge 1. List of reference symbols Multi-chamber cartridge

[0053] 1 Multi-chamber cartridge 2 Outer tube 3 Inner tube 4 Front end of multi-chamber cartridge 1 or outer tube 2 5 End wall 6 Nozzle 7 External thread 8 Cover 9 Outlet of inner tube 3 10 Rib 11 Outlet of outer tube 2 12 Intermediate space 13 Rear end of multi-chamber cartridge 1 or outer tube 2 14 Ejection element 15 Rear wall 16 Support 17 free18Post 19Head pin 20Partition wall 21Cutting edge 22Wall 23Holding space 24Outer seal holder 25Sealing element 26Inner sealing lip 27Outer sealing lip 28Rear sealing lip 29Opening 30Bead 31Holder 32Annular step 33Seal body 34Tubular collar 35Groove 36Sealing line 37Outer seal 38Middle seal 39Locking 40Longitudinal axis 41Shaft 42Head 43Sealing surface 44Inner piston 45Inner seal 46Introduction chamfer 47Undercut 48Collar 49Collar opening 50Slide

Claims

1. Multi-chamber cartridge (1) having a longitudinal axis (40), having an outer tube (2) parallel to the longitudinal axis (40) of the multi-chamber cartridge (1), and an inner tube (3) arranged in the outer tube (2) and parallel to the longitudinal axis (40) of the multi-chamber cartridge (1), having an outlet (9, 11) for the outer tube (2) and the inner tube (3) at a front end (4) of the multi-chamber cartridge (1), and having a pushing-out element (14) for pushing out the multi-chamber cartridge (1) which is displaceably arranged in the outer tube (2) for pushing out the multi-chamber cartridge (1) in the direction of the longitudinal axis (40) in the multi-chamber cartridge (1) such that the pushing-out element (14) pushes out contents of the outer tube (2) and the inner tube (3) through the outlet (9, 11) of the multi-chamber cartridge (1) when the pushing-out element (14) is displaced in the direction of the front end (4) of the multi-chamber cartridge (1) in the outer tube (2) of the multi-chamber cartridge (1), wherein the pushing-out element (14) has at least one cutting edge (21) such that, upon displacement of the pushing-out element (14) in the direction of the longitudinal axis (40) of the multi-chamber cartridge (1) in the direction of the front end of the multi-chamber cartridge (1) in the outer tube (2), the cutting edge (21) of the pushing-out element (14) cuts through the inner tube (3) in a longitudinal direction, wherein the pushing-out element (14) has an inner plunger (44) for pushing out the inner tube (3) and a circumferential inner seal (45) which rests in a circumferentially sealing manner against an inner circumference of the inner tube (3), characterized in that behind the inner seal (45) the inner plunger (44) tapers to form an undercut (47), and in that the inner seal (45) of the inner plunger (44) in the outer tube (2) of the multi-chamber cartridge (1) is surrounded by a cylindrical collar (48) of the pushing-out element (14) which surrounds the inner tube (3) and which has a collar opening (49) radially outside the undercut (47) at the taper behind the inner seal (45) of the inner plunger (44) such that the undercut (47) is accessible radially from outside through the collar opening (49) in the collar (48) of the pushing-out element (14).

2. Multi-chamber cartridge (1) according to claim 1, characterized in that the inner seal (45) has the shape of a cylindrical ring.

3. Multi-chamber cartridge (1) according to claim 1 or claim 2, characterized in that the pushing-out element (14) has a head pin (19) as an inner plunger (44) whose head (42) is located at an end, facing the front end (4) of the multi-chamber cartridge (1), of the head pin (19), wherein the head (42) of the head pin (19) is located in the collar (48) of the pushing-out element (14), and a circumferential surface of the head (42) of the head pin (19) forms the inner seal (45) of the inner plunger (44).

4. Multi-chamber cartridge (1) according to one or more of the preceding claims, characterized in that the collar (48) of the pushing-out element (14) has two collar openings (49) which are opposite one another in relation to the longitudinal axis (40) of the multi-chamber cartridge (1).

5. Multi-chamber cartridge (1) according to one or more of the preceding claims, characterized in that the collar (48) of the pushing-out element (14) forms a seal holder (24) for a central seal (38) which is arranged on the seal holder (24) of the pushing-out element (14) and which rests circumferentially sealingly against an outer circumference of the inner tube (3) of the multi-chamber cartridge (1), and / or for an outer seal (37), which is arranged on the seal holder (24), which rests circumferentially sealingly against an inner circumference of the outer tube (2).

6. Multi-chamber cartridge (1) according to one or more of the preceding claims, characterized in that the cutting edge (21) is arranged offset to the rear on the inner plunger (44) with respect to the inner seal (45) of the inner plunger (44) parallel to the longitudinal axis (40) of the multi-chamber cartridge (1).

7. Multi-chamber cartridge (1) according to one or more of the preceding claims, characterized in that the cutting edge (21) is located in an axial plane or in a plane parallel to the axial plane.

8. Multi-chamber cartridge (1) according to one or more of the preceding claims, characterized in that the pushing-out element (14) has several cutting edges (21) offset relative to one another in a circumferential direction.

9. Multi-chamber cartridge (1) according to one or more of the preceding claims, characterized in that the inner plunger (44) tapers with an insertion bevel (46) before the inner seal (45).

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