Closure cap and combination of a closure cap and reusable container
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-04-26
- Publication Date
- 2026-03-04
AI Technical Summary
Existing screw caps for reusable bottles require complex and expensive injection molds due to their intricate design, making them costly to produce and difficult to manufacture, while also failing to reliably seal damaged or inaccurately dimensioned bottle necks.
A closure cap with a conical cross-sectional shape for both inner and outer seals that can be easily removed from a standard injection mold, allowing for cost-effective production and ensuring a reliable seal by bending and applying pressure to the bottle neck, even with dimensional inaccuracies or damage.
The closure cap effectively seals reusable bottles, including those with damaged or inaccurately dimensioned necks, while reducing manufacturing costs by eliminating the need for complex molds, and preventing leaks with its innovative seal design.
Smart Images
Figure EP2024061550_31102024_PF_FP_ABST
Abstract
Description
[0001] CAP AND COMBINATION OF A CAP AND
[0002] A REUSABLE CONTAINER
[0003] Field of the invention
[0004] The invention relates to a closure cap for closing the neck of a multi-
[0005] 5 disposable container according to the preamble of claim 1 and a combination of the closure cap and a reusable container according to claim 12.
[0006] State of the art
[0007] A screw cap made of HDPE is known from the prior art, which has an inner and an outer sealing lip, which protrude from the inside of the head plate of the screw cap. The inner sealing lip comprises a base section and a sealing section, which is connected to the base section by a defined bend. The cap is intended to reliably seal reusable glass bottles, even if their bottle neck has dimensional inaccuracies or is damaged. This is achieved by the double seal on the inside and outside, or rather the front side, of the bottle neck. However, the inner and outer sealing lips have a complicated shape, which can only be produced in a complex injection mold with slides. 0 Object of the invention
[0008] The disadvantages of the described prior art give rise to the object of creating a screw cap for reusable bottles which can be produced cost-effectively and which reliably seals a damaged bottle neck, as is typical for a reusable bottle, without the need for an expensive injection mold or an expensive molding tool for producing the cap.
[0009] Description
[0010] The stated object is achieved in a closure cap by the features recited in the characterizing portion of patent claim 1. Further developments and / or advantageous embodiments are the subject of the dependent patent claims. The invention is preferably characterized in that the sealing portion adjoins the base seamlessly and its cross-section tapers continuously to its open end. This cross-sectional shape, which is reminiscent of a cone or half a banana, enables the entire inner seal to be forcibly removed from an injection mold by pulling the inner seal out of its negative mold. The inner seal does not have shapes such as joints or sealing nubs, which can only be removed if the injection mold has sliders or other features of complex mold construction. The closure cap can therefore be produced in a cost-effective injection mold.
[0011] It has proven useful for the sealing section to have a first end connected to the base and a second open end. Because the first end connects to the base without a joint, the sealing section can be easily pulled out of its negative mold during demolding.
[0012] The sealing section conveniently extends radially outward and downward. This allows the container neck to reliably bend the sealing section upward when screwed on, without the sealing section kinking or being bent in the wrong direction.
[0013] The invention is also preferably characterized by the fact that the cross-section of the outer seal tapers continuously to its open end. This allows the outer seal to be forced demolded in the same way as the first seal, allowing the entire closure cap to be forced demolded. The conical cross-sectional shape also allows the outer seal to be pulled out of its negative mold.
[0014] The outer seal advantageously has a first end that connects to the transition between the head plate and the threaded part, and a second open end. Because the first end connects to the transition without a joint, there is no shaping of the outer seal that would make demolding difficult.
[0015] It proves advantageous if the open ends of the sealing section and the outer seal are rounded. This allows the open ends to slide along the container neck with little friction when the closure cap is screwed onto the container neck. In a particularly preferred embodiment of the invention, a concentric elevation is formed adjacent to the outer seal on the inside of the head plate. This increases the pressure of the outer seal on the outer edge of the end face of the container neck. This improves the seal between the outer seal and the container neck in a simple manner.
[0016] It is advantageous if the base has a constant cross-sectional width. This gives the base the shape of a cylindrical shell, which can be easily removed from the injection mold.
[0017] In a further preferred embodiment of the invention, the sealing section is bendable at its first end. This creates a high restoring force and a correspondingly high pressure on the container neck when the neck bends the sealing section outward.
[0018] It is also preferred if the outer seal can be bent at its first end. This creates a high restoring force and correspondingly high pressure on the container neck when the neck bends the outer seal inward.
[0019] The cap is conveniently injection-molded from high-density polyethylene (HDPE). HDPE is the preferred plastic for caps and is easy to demold from the injection mold.
[0020] A further aspect of the invention relates to a combination of the closure cap according to the above description and a reusable container with a neck on which an external thread is formed that interacts with the internal thread. The internal and external seals, as already described above, are designed such that they can be forced out of an injection mold, thus reducing the manufacturing costs of the injection mold.
[0021] In a further preferred embodiment of the invention, when the closure cap is screwed onto the container neck, the sealing section is bent outward at its first end, and the sealing section rests against the inside of the container neck with a defined surface area due to the restoring force generated by the bending. This creates the largest possible sealing surface between the inside of the container neck and the sealing section.
[0022] In a further preferred embodiment of the invention, when the closure cap is screwed onto the container neck, the outer seal is bent inward at its first end and rests against the outer edge of the front side of the container neck, with the raised portion amplifying or focusing the pressure on the outer edge. The outer edge of the front side and the raised portion lie on a straight line that forms an angle of approximately 45 degrees to the horizontal. This increases the pressure of the outer seal on the edge and improves the seal. The tighter the closure cap is tightened onto the container neck, the greater the contact pressure of the outer edge and the raised portion on the outer seal.
[0023] The reusable container is expediently made of plastic, in particular PET or PEF. It is also preferred if the reusable container is a reusable bottle. Reusable plastic bottles are typically made of PET (polyethylene terephthalate) or PEF (polyethylene furanoate). The unavoidable damage and wear to the necks of reusable containers can be compensated for by the closure cap according to the invention and the inner and outer seals. Leaks that would otherwise occur with conventional closure caps are therefore reliably prevented by the present closure cap.
[0024] Further advantages and features will become apparent from the following description of an embodiment of the invention with reference to the schematic representations. These are not to scale:
[0025] Figure 1 : a closure cap in a side view;
[0026] Figure 2: a longitudinal section through the closure cap from Figure 1;
[0027] Figure 3: a schematic detailed view of the cap and a container neck before the cap is screwed onto the neck;
[0028] Figure 4: a detailed view of the cap and the container neck while the cap is screwed onto the neck and
[0029] Figure 5: a detailed view of the cap and the container neck when the cap is screwed onto the neck.
[0030] Figures 1 to 5 show a closure cap, preferably injection-molded from HDPE, which is designated overall by the reference numeral 11. The closure cap 11 is intended to be screwed onto a container neck 13 of a reusable container. The container has the container neck 13 with an external thread that interacts with the internal thread 21. The container neck 13 defines a container opening 22 through which the contents are poured into and out of the container. The container neck 13 is indicated in Figures 3 to 5.
[0031] The cap 11 has a circular head plate 15 and a cylindrical threaded portion 17 surrounding the head plate 15. The threaded portion 17 has an open edge 19 and an internal thread 21. The internal thread 21 can be interrupted, as shown in Figure 2. An inner seal 23 protrudes from the inside of the head plate 15. A concentrically extending outer seal 25 protrudes from the inner transition 26 of the head plate 15 to the threaded portion 17. The inner seal 23 consists of a base 27, which has a cylindrical shape and is attached to the head plate 15. A sealing section 29 adjoins the base 27. The base 27 has a constant cross-sectional width and accordingly has the shape of a cylinder jacket.
[0032] Both the outer seal 25 and the sealing section 29 have a first end 25a, 29a and a second open end 25b, 29b. The first end 25a adjoins the inner transition 26 between the head plate 15 and the threaded part 17. The first end 29a adjoins the base 27.
[0033] The outer seal 25 is arranged concentrically around the rotational axis 31 of the closure cap 11 and extends radially inward and downward, i.e., diagonally downward. The sealing section 29 is also arranged concentrically around the rotational axis 31 and extends radially outward and downward, i.e., diagonally downward. Adjacent to the outer seal 25, a concentric elevation 33 is formed on the inside of the head plate 15.
[0034] Both the cross-section of the outer seal 25 and the sealing section 29 taper towards their open ends 25b, 29b. The open ends 25b and 29b are rounded. The cross-sectional shapes of the outer seal 25 and the sealing section 29 are reminiscent of the shape of half a banana. This special shape allows the closure cap 11 to be forced out of an injection mold. The injection mold can therefore be designed simply and inexpensively and is accordingly cost-effective to manufacture. Compared to an injection mold in which a closure cap of the prior art described above is produced, slides or other complex mold construction features can therefore be dispensed with.Although the closure cap 11 according to the invention can be produced in a cost-effective injection mold, it reliably seals the bottle neck 13 of a reusable container, even if carbonated beverages are filled therein, which lead to excess pressure.
[0035] Figures 3 to 5 show how the inner and outer seals 23,25 interact sealingly with the neck 13: In Figure 3, the neck 13 is still spaced apart from the two seals 23,25.
[0036] As the cap 11 is further screwed onto the neck 13, the end face 35 of the neck first comes into contact with the sealing portion 29 via its inner edge 37. Since the sealing portion 29 is bendable at its first end 29a, the sealing portion 29 is bent outward from the neck (Figure 4).
[0037] When the closure cap 11 is fully screwed onto the neck 13, the flexible sealing section 29 is bent outward, generating a restoring force. As a result, the sealing section 29 rests sealingly against the inside of the container neck with a defined surface area 34. Almost the entire surface of the side of the sealing section 29 facing the neck 13 serves as the sealing surface.
[0038] The end face 35 bends the outer seal 25 upward until it abuts the raised portion 33. The raised portion 33 is arranged on the inside of the head plate 15 such that it lies essentially on a 45° line passing through the outer edge 39. As a result, the pressure of the outer seal 25 on the outer edge is increased by the raised portion. This further improves the sealing of the neck 13.
[0039] The design of the two seals 23, 25 ensures that the closure cap reliably seals the neck 13 of a reusable container that has become damaged or worn through repeated use. The two seals are also capable of compensating for dimensional inaccuracies in the neck 13. This is preferred if the reusable container is a reusable bottle made of PET or PEF. Use with reusable glass bottles, whose necks are prone to dimensional inaccuracies and damage due to chipping, is also conceivable.
[0040] The closure cap 11 can also function as a tamper-evident seal. For this purpose, a tamper-evident ring 41 with predetermined breaking ribs 43 can be held on the open edge 19. When the closure cap 11 is first unscrewed, the tamper-evident ring 41 is held to the neck 13 by retaining elements 45. The predetermined breaking ribs 43 break when the threaded part 17 moves axially away from the tamper-evident ring 41.
[0041] Legend:
[0042] 11 Cap
[0043] 13 Container neck
[0044] 15 Headstock
[0045] 17 Threaded part
[0046] 19 Open edge
[0047] 21 internal thread
[0048] 23 Internal seal
[0049] 25 External seal
[0050] 25a, 25b First and second end of the outer seal
[0051] 26 Transition of the head plate to the threaded part
[0052] 27 feet
[0053] 29 Sealing section
[0054] 29a, 29b First and second end of the sealing section
[0055] 31 Rotation axis
[0056] 33 Survey
[0057] 34 surface support
[0058] 35 Frontal side of the neck
[0059] 37 Inner edge of the front side
[0060] 39 Outer edge of the front side
[0061] 41 Guarantee ring
[0062] 43 predetermined breaking bars
[0063] 45 holding elements
Claims
1. A closure cap (11) for closing the neck (13) of a reusable container, comprising a circular head plate (15), a cylindrical threaded part (17) surrounding the head plate (15) with an open edge (19) and an internal thread (21), an inner seal (23) projecting concentrically from the inside of the head plate (15), which seal comprises a foot (27) and a sealing section (29) adjoining the foot (27) and extending radially outwards, and an outer seal (25) projecting concentrically from the inner transition (26) of the head plate (15) to the threaded part (17), which seal extends radially inwards and downwards, characterized in that the sealing section (29) adjoins the foot (27) without a shoulder and its cross-section tapers continuously up to its open end (29b).
2. Closure cap according to claim 1, characterized in that the sealing section (29) has a first end (29a) which adjoins the foot (27) and has a second open end (29b).
3. Closure cap according to claim 1 or 2, characterized in that the sealing section (29) extends radially outwards and downwards.
4. Closure cap according to one of the preceding claims, characterized in that the cross-section of the outer seal (25) tapers continuously up to its open end (25b).
5. Closure cap according to one of the preceding claims, characterized in that the outer seal (25) has a first end (25a) which adjoins the transition (26) between the head plate (15) and the threaded part (17) and has a second open end (25b).
6. Closure cap according to claim 5, characterized in that the open ends (25b, 29b) of the sealing portion (29) and the outer seal (25) are rounded.
7. Closure cap according to one of the preceding claims, characterized in that a concentric elevation (33) is formed adjacent to the outer seal (25) on the inside of the head plate (15).
8. Closure cap according to one of the preceding claims, characterized in that the foot (27) has a constant cross-sectional width.
9. Closure cap according to one of claims 2 to 8, characterized in that the sealing section (29) is bendable at its first end (29a).
10. Closure cap according to one of claims 5 to 9, characterized in that the outer seal (25) is bendable at its first end (25a). 11 . Closure cap according to one of the preceding claims, characterized in that the closure cap (11) is injection-molded from a high-density polyethylene.
12. Combination of the closure cap (11) according to one of the preceding claims and a reusable container with a neck (13) on which an external thread cooperating with the internal thread (21) is formed.
13. Combination according to claim 12, characterized in that when the closure cap (11) is screwed onto the container neck (13), the sealing section (29) is bent outwards at its first end (29a) and rests against the inside of the container neck (13) with a defined surface support (34) with the restoring force generated by the bending.
14. Combination according to claim 12 or 13, characterized in that when the closure cap (11) is screwed onto the container neck (11), the outer seal (25) is bent inwards at its first end (25a) and rests against the outer edge (39) of the end face of the container neck (13), the elevation amplifying or focusing the pressure on the outer edge (39).
15. Combination according to claim 12 to 14, characterized in that the reusable container is made of plastic, in particular PET or PEF.