A cartridge equipped with a piston unit having a slotted internal piston.

Abstract

The present invention relates to a cartridge (1) for a viscous material (31) that can be attached to a caulking gun (100), the cartridge (1) comprising a cylindrical cartridge body (10) having a proximal end (11) and a distal end (12), a cartridge cap (20) positioned at the distal end (12) of the cartridge body (10) and equipped with a discharge port (21), and a piston unit (40) comprising an outer piston (41), an inner piston (42), and a spreader ring (49). The present invention also relates to a piston unit (40) in which the outer piston (41), the inner piston (42), and the spreader ring (49) are movable along the longitudinal axis (13) of the cartridge body (10), and when the inner piston (42) is pressed against the spreader ring (49) or the outer piston (41) by the caulking gun (100), the outer piston (41) is spread radially by the spreader ring (42). The present invention is characterized in that the inner piston (42) has a piston body (50) in which at least one slot (63) is provided, the slot extending axially from the spreader ring (49) to the positioning surface (62) of the thrust plate (101) of the caulking gun (100). The present invention also relates to a piston unit (40) for a cartridge (10).

Description

Technical Field

[0001] The present invention relates to a cartridge for a viscous material that can be disposed within a caulking gun. The present invention also relates to a piston unit for the cartridge.

[0002] For commercial and personal use, various viscous materials such as silicone, acrylic, and adhesives are standardly supplied in cartridges that allow the material to be dispensed using a caulking gun.

[0003] European Patent Application Publication No. 1514611 discloses a cartridge having a cylindrical cartridge body with a distal end and a proximal end. A cartridge cap disposed at the distal end has a discharge port through which a viscous material can be extruded using a caulking gun. The cartridge cap is integrally formed with the cylindrical cartridge body. The piston unit of the cartridge includes an outer piston and an inner piston. The inner piston can be pushed into the outer piston, and the outer diameter of the inner piston is slightly larger than the inner diameter of the inner space of the outer piston into which the inner piston is pushed. When a force generated by the caulking gun is applied to the inner piston, the inner piston is pushed in the direction of the cartridge cap, and the outer piston expands. As a result of the expansion, the outer piston forms a sealing contact with the inner wall of the cylindrical cartridge body. Thereby, it is possible to prevent the material from passing through the outer piston and reaching the proximal end of the cartridge body.

[0004] German Patent Application Publication No. 10029799 discloses a cartridge having a piston unit provided with a spreader ring between the outer piston and the inner piston. By expanding and contracting the inner piston and the outer piston, the spreader ring integrally formed with the outer piston expands the outer piston to enhance the sealing effect.

[0005] European Patent Application Publication No. 0004100 also discloses a cartridge comprising a multi-part piston unit including an outer piston and an inner piston. Similar to European Patent Application Publication No. 1514611, the diameters of the outer and inner pistons are adjusted so that the outer piston expands when axial pressure is applied to the inner piston, improving the sealing effect. The inner piston is in contact with the outer piston under tension. The inner and outer pistons constitute a compact unit.

[0006] Normally, the plastic cartridge body is being replaced in part with a cardboard cartridge body for environmental and sustainability reasons. The viscous material can be filled into a flexible film bag placed inside the cartridge body. The cartridge cap may have a cutting rod, blade, etc., so that when pressure is applied to the film bag inside the cartridge, the film bag is pressed against the cartridge cap and automatically cut open. This allows the viscous material to pass through the discharge opening. Once empty, the film bag can be folded and discarded together with the cartridge cap as needed.

[0007] Even when using a film bag for a cardboard cartridge body, it is important to ensure a certain seal or radial tension between the outer piston and the inner wall of the cartridge body so that when the film bag is empty, it does not get lodged between the cartridge body and the outer piston, preventing the caulking gun's thrust plate from being pushed back through the film bag and making it difficult for the user to remove.

[0008] Caulking guns come in a variety of designs and qualities. It cannot be ruled out that the thrust plate of a caulking gun may not be precisely centered on the inner piston, and / or that the thrust plate may exert a force on the inner piston that is not precisely coaxial with the cartridge body. The piston unit may enter the relatively soft cardboard cartridge body away from its longitudinal axis, causing bulging or cracking. The cartridge body may be damaged to the point where further discharge of viscous material from the cartridge is no longer possible.

[0009] The objective of the present invention is to provide a cartridge that can be manufactured using a resource-efficient method and can be reliably emptied using a conventional caulking gun.

[0010] The object of the present invention is achieved by the subject matter described in claim 1. Embodiments are described in the dependent claims of claim 1.

[0011] According to the present invention, the inner piston has a piston body provided with at least one slot (groove) extending axially from the spreader ring to the positioning surface of the thrust plate of the caulking gun. In one embodiment, the piston body is designed to be hollow and cylindrical with an inner wall and an outer wall, and the slot extends radially from the inner wall to the outer wall. Preferably, exactly one slot is provided. Multiple slots may be provided.

[0012] The slots in the caulking gun's cartridge, which can expand or contract during operation, allow the inner piston to exhibit some flexibility. As a result, any angular or positional offset of the thrust plate acting on the inner piston is not transmitted to the outer piston, or is not transmitted at all. In other words, the flexibility of the inner piston allows it to at least partially compensate for the angular and / or positional offset of the thrust plate, and as a result, the outer piston can maintain contact with the inner wall of the cylindrical cartridge body, preventing bulging or other damage to the cartridge body. Therefore, the cartridge body does not need to withstand very large forces and can thus be made of very thin walls and / or relatively soft materials. For example, the cartridge body can be made of cardboard, aluminum, plastic, or a combination thereof.

[0013] The cross-section of the cylindrical cartridge body is preferably circular. In principle, other cross-sections, such as elliptical or polygonal, are also possible. Therefore, the term "cartridge" covers not only cartridges with a circular cross-section, such as those widely used for silicones, adhesives, and similar building materials, but also containers for viscous materials that do not have a circular cross-section.

[0014] The cartridge according to the present invention can be mounted on a caulking gun or similar device. As already described above, caulking guns come in a variety of designs and qualities. Therefore, the term “caulking gun or similar device” refers to a device that can apply axial pressure to a piston unit by a thrust plate used to engage with the piston unit of the cartridge, thereby moving the piston unit along the longitudinal axis of the cartridge body and pushing a viscous material out of the discharge port. This device may also be a hand dispenser to which the cartridge according to the present invention can be mounted.

[0015] Preferably, the spreader ring is integrally formed with the piston body of the inner piston. Therefore, the piston body of the inner piston and the spreader ring can be a single injection-molded part made of plastic. Alternatively, the spreader ring can be integrally formed with the outer piston. Finally, the spreader ring may be a separately manufactured part that is mounted between the inner and outer pistons. The spreader ring can be secured to the inner or outer piston, for example, by snap-in or clip connections.

[0016] In one embodiment, the slot extends parallel to the longitudinal axis. The slot may have an angle of inclination with respect to the longitudinal axis, for example, in a helical manner. The slot can extend straight radially from the outer wall to the inner wall, and the virtual extension line of the slot can intersect the longitudinal axis.

[0017] The piston body of the inner piston may have an outer sleeve and an inner sleeve connected to each other by multiple radial webs. The wall thickness of the outer sleeve and the wall thickness of the inner sleeve can be 0.5 to 5 mm, respectively. The ratio of the outer diameter of the outer sleeve to the outer diameter of the inner sleeve can be in the range of 1.2 to 2.

[0018] A slot can be circumferentially divided by two opposing radial webs. The distance between these opposing, spaced radial webs defines the slot width. The slot width can be 0.5 to 3 mm, 0.6 to 2 mm, preferably 1 to 1.5 mm, regardless of the specific embodiment having a radial web.

[0019] In one embodiment, the spreader ring has a first circumferential edge having a smaller diameter and a second circumferential edge having a larger diameter, the first edge being attached to the piston body of the inner piston and the second edge being attached to the piston crown of the outer piston. Preferably, the edge having the smaller diameter is integrally attached to the piston body of the inner piston. Preferably, the spreader ring does not have slots.

[0020] The spreader ring has a frustoconical shape that widens in the direction of the piston crown of the outer piston, and the opening angle of the frustoconical (unloaded) is 40 to 80°, preferably 50 to 70°. In one embodiment, the opening angle is 60°. When the inner piston is pressed against the spreader ring, the two edges of the frustoconical are compressed axially, increasing the diameter of the larger edge and causing the outer piston to expand.

[0021] The piston unit is fixed to the proximal end of the cartridge body and may have a connecting component that connects to the inner piston via a connecting web in the initial state of the piston unit. The connecting web is designed with a predetermined break point. When the inner piston is moved along the longitudinal direction of the cartridge body together with the outer piston, it can be separated without applying a large axial force. The connecting component fixed axially at the proximal end securely connects the piston unit to the cartridge body and prevents loss during distribution, retail, or when handling the cartridge before loading it into a caulking gun.

[0022] The adhesive material is preferably filled in a bag disposed within the cartridge body. When the inner piston and the outer piston move axially, the bag is compressed. Before taking out the adhesive material, it is necessary to open the bag, preferably cut or make a notch. This can be automatically performed by a pointed rod or blade on the inside of the cartridge cap, and when the film bag is pressed against the cartridge cap, the film bag is torn. The bag can be, for example, a plastic film bag. Alternatively, the bag can also be made of silicone - processed or coated paper. The material of the bag can be single - layer or multi - layer.

[0023] A further object of the present invention, namely the provision of a piston unit for the above - mentioned cartridge, is achieved by the subject matter of claim 12.

Brief Description of the Drawings

[0024] The present invention will be described in more detail with reference to the embodiments shown in the drawings.

[0025] [Figure 1] FIG. 1 schematically shows a cartridge equipped with the illustrated caulking gun. [Figure 2] FIG. 2 shows a side view of the piston unit for the cartridge of FIG. 1. [Figure 3] FIG. 3 shows a cross - sectional view taken along the line A - A of FIG. 2. [Figure 4] FIG. 4 is a cross - sectional view of FIG. 3 showing the state where the inner piston and the outer piston are assembled. [Figure 5] FIG. 5 shows a perspective view of the piston unit. [Figure 6] FIG. 6 shows a perspective view of the piston unit. [Figure 7] FIG. 7 shows a perspective view of the piston unit. [Figure 8] FIG. 8 shows a view of the piston unit seen from below. [Figure 9] FIG. 9 shows another side view of the piston unit rotated 90° with respect to the side view of FIG. 2. [Figure 10] Figure 10 shows a view of the piston unit as seen from above.

[0026] Figure 1 shows a cartridge indicated as 1 as a whole. The cartridge 1 includes a cylindrical cartridge body 10 having a proximal end portion 11 and a distal end portion 12. A cartridge cap 20 having a discharge port 21 is disposed at the distal end portion 12. The cartridge cap 20 is preferably a separate component that can be firmly connected to the distal end portion 12 of the cartridge body 10. However, it is also conceivable that the cartridge cap 20 and the cartridge body 10 form an integral component.

[0027] In Figure 1, the cartridge body 10 is shown broken, and a bag in the shape of a film bag 30 inserted into the cartridge body 10 and a piston unit 40 disposed at the proximal end portion 11 of the cartridge body 10 can be seen. The film bag 30 contains a viscous or paste-like material 31 such as, for example, silicone, acrylic, a sealing compound, an adhesive, or the like. Inside the cartridge cap 20, a sharp edge or point (not shown) for tearing the film bag 30 when the film bag 30 is pressed against the cartridge cap 2 by the piston unit 40 may be provided. Figure 1 shows the piston unit 40 in an initial state where no pressure is yet applied to the film bag 30.

[0028] As is further evident from Figures 2 to 10, the piston unit 40 has an outer piston 41, an inner piston 42, and a connecting component 43. By applying pressure to the inner piston 42, the inner piston 42 and the outer piston 41 can be moved axially along the longitudinal axis 13 of the cartridge body 10. This compresses the film bag 30, causing the viscous material 31 to be discharged from the outlet 21. The pressure required for the inner piston 42 can be provided by a conventional caulking gun 100. Figure 1 shows only the thrust plate 101 and push rod 102 of the caulking gun 100. The film bag 30 may be a tubular bag held at both ends by small metal clips (not shown).

[0029] Figure 2 shows a side view of the piston unit 40, and Figure 3 shows a cross-sectional view along line AA in Figure 2. Figure 4 is also a cross-sectional view, in which a portion of the inner piston 42 is located within the internal space 44 of the outer piston 41. The internal space 44 is partitioned by a slightly curved piston crown 45 and a cylindrical side wall 46. The piston crown 45 is provided with a circular recess, preferably a circular opening 47, which serves to receive one of the two metal clips of the film bag 30. A circumferential seal lip 48 is provided on the outside of the side wall 46, and when the piston unit 40 is inserted, the seal lip 48 contacts the inner wall 14 of the cartridge body 10.

[0030] The piston unit 40 further includes a frustoconical spreader ring 49 integrally formed with the piston body 50 of the inner piston 42. The opening angle 51 of the spreader ring 49 is 60°. The spreader ring 49 has a first circumferential edge 52 with a smaller diameter and a second circumferential and free edge 53 with a larger diameter. In the assembled or initial state (see Figure 4), the second edge 53 is in contact with the piston crown 45 in the transition region to the side wall 46. When the inner piston 42 and the outer piston 41 are compressed axially, that is, when the inner piston 42 is pushed toward the cartridge cap 20 by the caulking gun 100 and the outer piston 41 receives a reaction force from the filled film bag 30, the second edge 53 presses the outer piston 41 radially outward, causing the outer piston 41 to (slightly) expand. This causes the seal lip 48 of the outer piston 41 to press against the inner wall 14 of the cartridge body 10. This prevents any part of the compressed film bag 30 from getting stuck between the outer piston 41 and the inner wall 13 when the cartridge is empty.

[0031] In its initial state, the connecting component 43 is connected to the piston body 50 via a thin connecting web 54. The connecting component 43 has a cylindrical side wall 55 with a circumferential projection 56, which engages with the inner wall 14 of the cartridge body 10 when the piston unit 40 is pressed into the proximal end 11 of the cartridge body 10. The outer diameter of the cylindrical side wall 55 corresponds to the inner diameter of the cartridge body 10. A circumferential end stopper or flange 57 determines the axial position of the connecting component 43 relative to the proximal end 11 of the cartridge body 10. The outer diameter of the flange 27 may be flush with the outside of the cartridge body 10. The interaction between the connecting component 43 and the cartridge body 10 prevents the piston unit 40 from falling out of the cartridge body 10 and being lost after it has been inserted and before it can be used in the caulking gun 100. The connecting web 54 is designed as a predetermined break point that breaks under low load when the inner piston 42 moves toward the cartridge cap 20, while the connecting component 43 is prevented from moving axially by the end stopper 57.

[0032] As can be seen from the combination of Figures 3, 7, and 8, the piston body 50 of the inner piston 42 has a cylindrical outer sleeve 58 and a cylindrical inner sleeve 59, with an annular cavity 60 defined between them. The cylindrical outer sleeve 58 and the cylindrical inner sleeve 59 are connected to each other via a plurality of radial webs 61 that bridge the cavity 60. The lower ends of the cylindrical outer sleeve 58, the cylindrical inner sleeve 59 and the radial webs 61 form a positioning surface 62 to which the thrust plate 101 contacts when the caulking gun 100 pushes the piston unit 40 into the cartridge body 10.

[0033] The piston body 50 is provided with a slot 63, which extends axially (along the longitudinal axis 13) parallel to the positioning surface 62 from the spreader ring 49. The slot 63 is circumferentially divided by two opposing radial webs 61a and 61b (see Figures 7 and 8). Thus, radially, the slot 63 extends continuously from the inner wall 64 (corresponding to the inside of the inner sleeve 59) to the outer wall 65 (corresponding to the outside of the outer sleeve 58). In Figure 8, a slot width of approximately 1.5 mm is shown by 66. The circumference of the piston body 50 is completely divided by the slot 63. Figure 2 clearly shows that the slot extends to the spreader ring 49 but does not open its closed circumference.

[0034] Because the inner piston 42 is flexible due to the slot 63, stresses and undesirable forces generated by the thrust plate 101, which is mounted obliquely and / or off-center to the positioning surface 62, are not transmitted to the outer piston 41, or if they are transmitted, the extent of such transmission is reduced. Therefore, the outer piston 41 is easily guided longitudinally within the cartridge body 10. Thus, even if the wall thickness of the cartridge body is thin or a soft material such as cardboard is selected for the cartridge body, damage to the cartridge body 10 caused by larger radial forces via the outer piston 41 (e.g., in the form of bulging or cracking) can be avoided.

[0035] Information to simplify the recycling of various components of the cartridge 10 may be optionally provided on the upper side of the piston crown 45. Figure 10 also shows the injection point 68 of the outer piston 41 located on the upper side of the piston crown 45. Like the inner piston 42 (including the connecting component 43 and spreader ring 49), this outer piston can be an injection-molded plastic part. [Explanation of Symbols]

[0036] 1 cartridge 10 Cartridge Body 11 Proximal end 12 Distal end 13 Longitudinal axis 14 Inner wall 20 Cartridge Caps 21 Discharge port 30 film bags 31 Viscous materials 40 Piston Unit 41 Outer piston 42 Inner piston 43 Connecting parts 44 Interior space 45 Piston Crown 46 Side wall 47 Opening 48 Seal Lip 49. Spreading 50 Piston body 51 Aperture angle 52 First edge 53 Second edge 54 Connect to the Web 55 Side wall 56 Protrusion 57 End stopper / flange 58 Outer sleeve 59 Inner sleeve 60 Cavity 61 Radial web 62 Positioning surface 63 slots 64 Inner wall 65 Exterior Wall 66 slot width 67 Information 68 injection point

Claims

1. It can be attached to a caulking gun (100) or a similar device. A cylindrical cartridge body (10) having a proximal end (11) and a distal end (12), A cartridge cap (20) is provided with a discharge port (21) and is located at the distal end (12) of the cartridge body (10). A piston unit (40) comprising an outer piston (41), an inner piston (42), and a spreader ring (49), wherein the outer piston (41), the inner piston (42), and the spreader ring (49) are movable along the longitudinal axis (13) of the cartridge body (10), and the outer piston (41) is radially spread by the spreader ring (42) when the inner piston (42) is pressed against the spreader ring (49) or the outer piston (41) by the caulking gun (100), The cartridge (1) for a viscous material (31) has an inner piston (42) having a piston body (50), the piston body (50) having at least one slot (63) extending axially from the spreader ring (49) to the positioning surface (62) of the thrust plate (101) of the caulking gun (100).

2. The piston body (50) is hollow and cylindrical, and has an inner wall (64) and an outer wall (65). The cartridge (1) according to claim 1, wherein the slot (63) extends radially from the inner wall (64) to the outer wall (65).

3. The cartridge (1) according to claim 1 or 2, wherein the spreader ring (49) is integrally formed with the piston body (50) of the inner piston (42).

4. The cartridge (1) according to any one of claims 1 to 3, wherein the slot (63) extends parallel to the longitudinal axis (13).

5. The cartridge (1) according to any one of claims 1 to 4, wherein the piston body (50) of the inner piston (42) has an outer sleeve (58) and an inner sleeve (59) connected to each other by a plurality of radial webs (61).

6. The cartridge (1) according to claim 5, wherein the slot (63) is circumferentially separated by two opposing radial webs (61a, 61b).

7. A cartridge (1) according to any one of claims 1 to 6, wherein the circumferential slot width (66) is 0.5 to 2 mm, preferably 1 to 1.5 mm.

8. The spreader ring (49) has a first circumferential edge portion (52) having a smaller diameter and a second circumferential edge portion (53) having a larger diameter. The first circumferential edge portion (52) is attached to the piston body (50) of the inner piston (42). The cartridge (1) according to any one of claims 1 to 7, wherein the second circumferential edge portion (53) is attached to the piston crown (45) of the outer piston.

9. The spreader ring (49) has a frustoconical shape that widens in the direction of the piston crown (45) of the outer piston (41). The cartridge (1) according to claim 8, wherein the opening angle (51) of the frustum of the cone is 40 to 80°, preferably 50 to 70°.

10. The piston unit (40) is fixed to the proximal end (11) of the cartridge body (10) and, in its initial state, has a connecting component (43) that is connected to the inner piston (42) via a connecting web (54). The cartridge (1) according to any one of claims 1 to 9, wherein the connecting web (54) is designed as a predetermined break point that can be separated when the inner piston (42) moves together with the outer piston (41) along the longitudinal direction (13) of the cartridge body (10).

11. The cartridge (1) according to any one of claims 1 to 10, wherein the viscous material (31) is filled in a bag (30) placed inside the cartridge body (10).

12. A piston unit (40) for a cartridge (1) according to any one of claims 1 to 11.

Images