Coaxial cartridge having an integrated reinforcement for dispensing a flowable multi-component composition without restoring force

Abstract

A coaxial cartridge for storing and discharging a flowable multi-component composition, contains a hollow-cylindrical inner wall and a hollow-cylindrical outer wall arranged coaxially around the inner wall. The coaxial cartridge has an inner chamber for a first component, which is delimited radially by the inner wall, and an outer chamber for a second component, which is arranged radially between the inner wall and the outer wall. The coaxial cartridge also contains a cartridge front wall, which firmly closes the inner and the outer chamber on one end face of the cartridge and has one discharge opening per chamber; an inner and an outer piston which each close the relevant chamber at the rear and are axially movable; and an integrated reinforcement embedded inside the outer wall or fastened to its surface and having a plurality of rings or spiral turns, made of a material that is stable against tensile stresses.

Claims

1. A coaxial cartridge designed to store and discharge a flowable multi-component composition, comprising: a hollow-cylindrical inner wall and a hollow-cylindrical outer wall arranged coaxially around said inner wall, an inner chamber, which is delimited radially by the inner wall, for receiving a first component of the multi-component composition; an outer chamber, which is arranged radially between the inner wall and the outer wall, for receiving a second component of the multi-component composition; a cartridge front wall, which firmly closes the inner chamber and the outer chamber on one end face of the coaxial cartridge and has one discharge opening per chamber; an inner piston, which closes the inner chamber at a rear and is axially movable therein, and an outer piston which closes the outer chamber at a rear and is axially movable therein; and an integrated reinforcement, embedded inside the outer wall or fastened to a surface of the outer wall, and having a plurality of rings that are overlapping or closed in a peripheral direction of the outer wall, or a plurality of spiral turns, and wherein the plurality of rings or the plurality of spiral turns are made of a material that is stable against tensile stresses.

2. The coaxial cartridge according to claim 1, wherein the material of the plurality of rings or the plurality of spiral turns and a number and distribution thereof along the outer wall are such that, when the multi-component composition is dispensed from the coaxial cartridge by axial displacement of the inner piston and of the outer piston, a shape and dimensions of the outer wall remain unchanged.

3. The coaxial cartridge according to claim 1, wherein the plurality of rings or the plurality of spiral turns are distributed substantially evenly over an entire axial length of the outer wall.

4. The coaxial cartridge according to claim 1, wherein the integrated reinforcement comprises a woven fabric made of the material that is stable against tensile stresses, and wherein the plurality of rings or the plurality of spiral turns are a component of the woven fabric.

5. The coaxial cartridge according to claim 1, wherein at least the outer wall of the coaxial cartridge is produced by injection molding or another casting process; and wherein the integrated reinforcement is embedded inside the outer wall by being cast therein.

6. The coaxial cartridge according to claim 5, wherein the integrated reinforcement has the plurality of rings that are closed in the peripheral direction of the outer wall, or wherein the integrated reinforcement has the plurality of spiral turns merging into one another without interruption.

7. The coaxial cartridge according to claim 1, wherein the integrated reinforcement is formed in a layer or film which is fastened to an inside or outside of the outer wall of the coaxial cartridge, with an overlap in the peripheral direction; and wherein the plurality of rings, if present, each overlap in the peripheral direction by extending in the peripheral direction into overlapping portions of the layer or film that are fastened to one another, and thereby have overlapping ends.

8. The coaxial cartridge according to claim 7, wherein the layer or film is glued to the outside of the outer wall of the coaxial cartridge and is designed as a label which, in addition to the integrated reinforcement, comprise predetermined identification elements for identifying or labeling the coaxial cartridge.

9. The coaxial cartridge according to claim 1, wherein the material of the plurality of rings or the plurality of spiral turns is or comprises aramid, glass fiber or carbon fiber.

10. A system for storing and discharging a flowable multi-component composition, comprising: the coaxial cartridge according to claim 1; and a support structure having a receptacle which is at least partially cylindrical on an inside, wherein a shape and size of the receptacle is dimensioned for inserting and holding the coaxial cartridge in order to dispense the multi-component composition therefrom, wherein an inner diameter of the receptacle of the support structure is greater than an outer diameter of the coaxial cartridge by a predetermined annular gap which is twice as wide.

11. The system according to claim 10, wherein the annular gap is wide enough to allow the coaxial cartridge to be inserted smoothly into the receptacle of the support structure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0061] The above aspects of the invention and the embodiments and specific designs thereof are explained in more detail below with reference to the examples shown in the accompanying drawings. The drawings are schematic. Said drawings may, but do not have to, be understood to be true to scale. In the drawings:

[0062] FIG. 1 is a longitudinal section of a system of the type presented herein with a coaxial cartridge inserted in a support structure with a cylindrical annular gap therebetween;

[0063] FIG. 2 is a longitudinal section of a coaxial cartridge of the type presented herein with an embedded reinforcement in its outer wall; and

[0064] FIG. 3 is a longitudinal section of a coaxial cartridge of the type presented herein with a reinforcement that is integrated in a sales label glued to the outer wall.

[0065] FIG. 1 shows, in an axial longitudinal section, an example of a system 1 of the type presented herein, in which a coaxial cartridge 2 is inserted into a hollow-cylindrical receptacle 13 of a support structure 3 in order to dispense the multi-component composition contained therein. In this example, the coaxial cartridge 2 is made of plastics material. The same can also apply to the support structure 3.

[0066] The cartridge 2 comprises a hollow-cylindrical inner wall 4 and a hollow-cylindrical outer wall 5 having a common cylinder axis A, which outer wall is arranged around said inner wall, whereby an inner chamber 6, which is delimited radially by the inner wall 4, and an outer chamber 7, which is arranged radially between the inner wall 4 and the outer wall 5, are formed. A first component of the multi-component composition to be discharged is accommodated in the inner chamber 6, while a second component of the multi-component composition is accommodated in the outer chamber 7 (not shown).

[0067] On one end face of the cartridge 2, which is on the right in FIG. 1, the cartridge front wall 8 closes the inner chamber 6 and the outer chamber 7, one discharge opening per chamber being formed in the cartridge front wall 8. The two discharge openings open into a connecting piece 9 which is formed in the cartridge front wall 8 on its side facing away from the inner and the outer chamber 6, 7 and for connecting (e.g. by screwing onto an external thread indicated in FIGS. 2 and 3) a mixer, not shown separately, for mixing the first and the second component of the multi-component composition during the dispensing process.

[0068] Furthermore, the cartridge 2 comprises an inner piston 10 which closes the inner chamber 6 at the rear and is axially movable therein, and an outer piston 11 which closes the outer chamber 7 at the rear and is axially movable therein, it being possible for the multi-component composition to be discharged from the cartridge 2 through the dispensing openings in the cartridge front wall 8 (dispensing process) by means of the simultaneous axial movement of said pistons to the right in FIG. 1.

[0069] The diameter of the coaxial cartridge 2 is slightly smaller than the support structure 3, such that a cylindrical annular gap 12 remains between the outer wall 5 of the cartridge and the cylindrical receptacle 13 of the support structure 3, which annular gap facilitates the insertion of the cartridge 2 into the receptacle 13. The cartridge 2 has a reinforcement 14 integrated in/on its outer wall 5 (only shown in FIGS. 2 and 3), which reinforcement reduces or completely prevents an elastic expansion of the outer wall 5 into the annular gap 12 during the dispensing process, whereby the disturbing elastic restoring behavior (pumping) of the cartridge 2 can be reduced or even entirely prevented.

[0070] FIGS. 2 and 3 show, each in a highly simplified schematic representation, two embodiments of a coaxial cartridge 2 of the type presented herein, which differ in the design of the integrated reinforcement 14. Moreover, reference is made to the above general description of the cartridge 2 in FIG. 1. The cartridge 2 of FIGS. 2 and 3 can in particular be part of the system 1 of FIG. 1, the axial longitudinal section shown in FIGS. 2 and 3 being rotated by 90° about the cylinder axis A with respect to FIG. 1, such that the position of the connecting piece 9, which position is clearly visible in FIG. 1 from the middle of the cartridge front wall 8, is not visible in FIGS. 2 and 3.

[0071] FIG. 2 shows a reinforcement 14 cast into the cartridge outer wall 5 which can absorb tensile loads in the peripheral direction of the cartridge 2 and thus prevents the outer wall 5 from expanding and increasing in diameter during a dispensing process. The reinforcement 14 can be designed, for example, as a plurality of rings that are closed in the peripheral direction or as a spiral or as a woven fabric structure and can be made of various materials suitable for the stated purpose (aramid, glass fiber, carbon fiber, etc.).

[0072] In order to avoid a more cost-intensive production of such cartridges 2, which are reinforced by means of an injected woven fabric or injected rings or spiral turns, the reinforcement 14 can also be subsequently applied to the cartridge 2. For this purpose, FIG. 3 shows a possibility of integrating the reinforcement 14 into a sales label 15 that is to be applied anyway. The label 15 is to be overlappingly applied at its ends in the peripheral direction of the cartridge 2, for example by being glued on. The adhesive effect of the label 15 in the overlapping region (not shown separately), together with the corresponding overlapping rings or woven fabric structures of the reinforcement 14, causes a reliable reinforcement of the cartridge outer wall 5 in its peripheral direction, thus preventing its expansion and thus preventing unfavorable pumping with associated mixing problems. Moreover, the same can apply to FIG. 3 as explained above in relation to FIGS. 1 and 2.

[0073] By means of an integrated reinforcement 14, it is possible both in FIG. 2 and in FIG. 3 to stabilize the cartridge 2 sufficiently for pressurization that can occur during a dispensing process, such that there is no elastic or plastic expansion or other deformation of the outer wall 5. In this case, a support structure 3 of FIG. 1 comprising the cartridge 2 can therefore be dispensed with entirely for a dispensing process.