CLOSING CAP AND METHOD FOR MANUFACTURING A CLOSING CAP

Abstract

The invention relates to a closure cap (1) for a hollow medical article (3), comprising an outer shell (5) and a sealing element (9) located in an interior (7) of the outer shell (5), wherein the outer shell (5) has a first form-fitting element (11) and the sealing element (9) has a second form-fitting element (13), wherein the first and second form-fitting elements (11, 13) interact to hold the sealing element (9) in the interior (7) of the outer shell (5) such that they carry along the sealing element, and wherein the first form-fitting element (11) is in the form of a thread (15).

Description

[0001] DESCRIPTION

[0002] Closure cap and method for producing a closure cap

[0003] The invention relates to a closure cap and a method for producing a closure cap.

[0004] Closure caps of the type discussed here serve to close medical hollow bodies, in particular prefilled medical hollow bodies and especially prefilled syringes or cartridges. For this purpose, such a closure cap typically has a harder outer shell and a typically softer sealing element, whereby the outer shell provides mechanical stability for the closure cap and the sealing element ensures a tight closure of the medical hollow body, in particular with regard to the long-term stability and sterility of the prefilled medical or pharmaceutical contents. To remove the closure cap, the outer shell must be pulled off the medical hollow body. To simplify opening, measures are taken to ensure that the sealing element is carried along by the outer shell.For this purpose, means must be provided that connect the sealing element to the outer shell in such a way that the sealing element is carried along by the outer shell when the outer shell is removed from the hollow medical device. This can be achieved by undercuts provided on one element and engaged by projections on the other element. However, this is difficult to implement, particularly in an injection molding process preferred for the production of such parts, especially in view of the small dimensions of the parts to be manufactured. Demolding in particular is difficult and - where it does not prove impossible - leads to considerable waste due to damage caused by the application of high forces.

[0005] The invention is therefore based on the object of providing a closure cap and a method for producing a closure cap, wherein the aforementioned disadvantages are at least reduced, preferably not occurring at all. This object is achieved by providing the present technical teaching, in particular the teaching of the independent claims and the embodiments disclosed in the dependent claims and the description.

[0006] The object is achieved in particular by creating a closure cap for a medical hollow body, which closure cap has an outer shell and a sealing element arranged in an interior of the outer shell, wherein the outer shell has a first positive locking element and the sealing element has a second positive locking element, wherein the first and second positive locking elements cooperate to hold the sealing element removably in the interior of the outer shell, and wherein the first positive locking element is designed as a thread. By designing the first positive locking element as a thread, the outer shell can be manufactured easily, and in particular when manufactured using an injection molding process, can advantageously be demolded easily, preferably by simply screwing an injection molding core, which then has a complementary thread, out of the interior of the outer shell along the thread turns of the thread.This means that no brute force is required for demoulding, so that no damage occurs to the formed back section.

[0007] The closure cap is designed in particular as a closure cap for a syringe, a carpule, a vial or a phial as the medical hollow body, in particular for a prefilled syringe, a prefilled carpule, a prefilled vial or a prefilled phial as the medical hollow body.

[0008] In one embodiment, the outer shell comprises, at least in some regions, a first, harder material, while the sealing element comprises, at least in some regions, a second, softer, particularly elastic material. Advantageously, the outer shell can thus serve as a support body for the sealing element and absorb mechanical supporting or holding forces, whereby the sealing element can fulfill a sealing function in the region of the medical hollow body. In one embodiment, the sealing element consists of an elastic material, in particular a pharmaceutical rubber.

[0009] According to a further development of the invention, the first form-locking element is designed as an internal thread. This represents a particularly advantageous embodiment, wherein the second form-locking element of the sealing element can be designed as a projection that engages the internal thread, in particular between the thread turns of the internal thread. The injection-molded core for producing the outer shell then has a correspondingly complementary external thread, which can be easily unscrewed from the internal thread to demold the outer shell.

[0010] According to a further development of the invention, the first form-locking element has two threads. This advantageously ensures sufficient stability and easy demolding.

[0011] In one embodiment, the first form-locking element has exactly two threads. Alternatively, the form-locking element can have exactly one thread or more than two threads.

[0012] According to a further development of the invention, the outer shell comprises a distal part and a proximal part, wherein the first form-fitting element is formed in the distal part, and wherein a Luer thread is formed in the proximal part. Advantageously, the Luer thread enables versatile and universal connectivity to the medical hollow body, particularly to connecting parts such as a cannula.

[0013] In the context of the present technical teaching, "distal" and "proximal" are understood to mean directions or positions with reference to the intended use of the medical hollow body on which the closure cap is arranged. In accordance with the general technical understanding of these terms, "proximal" refers to a direction or position that, when the medical hollow body is used as intended by an operator, faces a hand of the operator holding the hollow body, points towards this hand, or is arranged closer to this hand than the distal position, whereas "distal" refers to a direction or position that is facing away from the hand, points away from this hand, or is arranged further from this hand than the proximal position.

[0014] An axial direction of the outer shell and thus also of the closure cap extends in the direction of an imaginary connecting line between a distal position and a proximal position on the closure cap. Typically, the axial direction thus also extends along a longitudinal axis of a medical hollow body that has the closure cap. A circumferential direction concentrically encompasses the axial direction. A radial direction is perpendicular to the axial direction. In one embodiment, the distal part and the proximal part of the outer shell are formed integrally, in particular from the same material. In one configuration, the distal part and the proximal part are connected to one another via at least one predetermined breaking point.This simultaneously enables simple and cost-effective production of the closure cap and easy separation of the distal part from the proximal part, whereby the sealing element is carried along with the distal part, while the proximal part remains attached to the medical hollow body. The predetermined breaking point can be designed, for example, as a circumferentially extending material weakening or as at least one retaining web, in particular a plurality of retaining webs arranged at a distance from one another in the circumferential direction.

[0015] According to a further development of the invention, the first form-locking element, designed as a thread, in particular as an internal thread, has the same thread pitch as the Luer thread. This advantageously enables particularly simple production of the outer shell, in particular using a one-piece injection-molded core on which complementary threads are formed, on the one hand, for the first form-locking element and, on the other hand, for the Luer thread. The injection-molded core can be easily unscrewed from the outer shell for demolding.

[0016] According to a further development of the invention, the second form-locking element is designed as a radial projection. This advantageously results in a particularly simple and cost-effective design of the second form-locking element and thus also of the sealing element.

[0017] In one embodiment, the second form-locking element is designed as an annular collar. In this case, the second form-locking element, and thus also the sealing element, is particularly simple and cost-effective to manufacture.

[0018] In one embodiment, the second form-fitting element is rotationally symmetrical, in particular when the sealing element is arranged as intended in the outer shell, rotationally symmetrical about the axial direction as the axis of symmetry. Preferably, the sealing element - possibly except for the optionally asymmetrical arrangement of at least one end-face spacer projection or any trademarks, inscriptions, or the like - is overall rotationally symmetrical, in particular about the axial direction as the axis of symmetry. According to a further development of the invention, the sealing element has at least one spacer projection on a distal end face. The spacer projection advantageously enables axial tolerance and / or length compensation within the closure cap, in particular between the sealing element and the outer shell, when arranging the closure cap on a medical hollow body.This advantageously relieves the strain on the predetermined breaking point and / or, in particular, further advantageously enables the closure cap to be used with a plurality of different medical hollow bodies. The at least one spacer projection has the additional advantage that a plurality of common sealing elements transported separately from outer shells in a bag do not stick to one another at their distal end faces. The at least one spacer projection is designed, in particular, as a spacer nub.

[0019] In one embodiment, the spacer projection is elastic in the axial direction, preferably as a whole. In one configuration, the spacer projection is formed integrally and of the same material as the sealing element, in particular molded onto the sealing element, especially if the sealing element consists entirely of an elastic material, in particular a pharmaceutical rubber.

[0020] In one embodiment, the sealing element has a plurality of preferably spaced-apart spacer projections on its distal end face. In one configuration, the sealing element has three spaced-apart spacer projections on the distal end face, which are preferably arranged at the corners of an imaginary triangle.

[0021] According to a further development of the invention, the spacer projection rests against a proximal end face of the outer shell when the second form-locking element interacts with the first form-locking element. In particular, the spacer projection rests against the proximal end face of the outer shell when the radial projection engages the internal thread. In this way, the previously described tolerance and / or length compensation can be advantageously achieved.

[0022] According to a further development of the invention, the outer shell is produced by injection molding. This advantageously represents a particularly simple and cost-effective way of producing the outer shell. The object is also achieved by providing a method for producing a closure cap according to the invention or a closure cap according to one or more of the previously described embodiments, wherein an outer shell of the closure cap is produced by injection molding, wherein a thread is formed as a first form-fitting element in an interior of the outer shell during the injection molding. In connection with the method, in particular those advantages arise which were already described above in connection with the closure cap.

[0023] According to a further development of the invention, a sealing element is arranged inside the outer shell, which sealing element has a second form-locking element. The sealing element is arranged inside the outer shell in such a way that the second form-locking element cooperates with the first form-locking element to hold the sealing element in the outer shell. Preferably, the sealing element is simply pressed or clipped into the outer shell, so that the second form-locking element engages behind the first form-locking element or engages with the first form-locking element.

[0024] The invention is explained in more detail below with reference to the drawings, which show:

[0025] Figure 1 shows an embodiment of a closure cap for a medical hollow body, and

[0026] Figure 2 Detailed representations of the embodiment of the closure cap according to Figure 1.

[0027] Fig. 1 shows an illustration of an embodiment of a closure cap 1 for a medical hollow body 3.

[0028] The closure cap 1 has an outer shell 5 and a sealing element 9 arranged in an interior 7 of the outer shell 5. The outer shell 5 has a first form-locking element 11, and the sealing element 9 has a second form-locking element 13. The first and second form-locking elements 11, 13 cooperate to hold the sealing element 9 removably in the interior 7 of the outer shell 5. The first form-locking element 11 is designed as a thread 15. In this way, the outer shell 5 can be easily demolded, particularly during production using the injection molding process, in particular by then screwing an injection molding core, which has a complementary thread, out of the interior 7 of the outer shell 5 along the thread turns of the thread 15. In the illustrated embodiment, the first form-locking element 11 is designed as an internal thread.The second form-locking element 13 can then be designed, in particular, as a projection 17 that engages between threads 19 of the internal thread. The injection-molded core for producing the outer shell 5 preferably has a complementary external thread, which can be easily unscrewed from the internal thread to demold the outer shell 5.

[0029] Preferably, the first form-locking element 11 has two, in particular exactly two thread turns 19.

[0030] Fig. 2 shows detailed representations of the embodiment of the closure cap 1 according to Figure 1.

[0031] Identical and functionally identical elements are provided with the same reference symbols in all figures, so that reference is made to the preceding description in each case.

[0032] In a) the outer shell 5 is shown in isolation.

[0033] The outer shell 5 here has a distal part 21 and a proximal part 23, wherein the first form-fitting element 11 is formed in the distal part 21, and wherein a Luer thread 25 is formed in the proximal part 23.

[0034] In particular, the distal part 21 and the proximal part 23 are formed in one piece, in particular of a uniform material. Preferably, the distal part 21 and the proximal part 23 are connected to one another via at least one predetermined breaking point 27, which may be formed in particular as a circumferentially circumferentially extending material weakening, or as at least one retaining web 29, in particular as a plurality of retaining webs 29 arranged spaced apart from one another in the circumferential direction. The sectional plane of the view in Figure 2a) runs through a retaining web 29 on the right and left.

[0035] Preferably, the first form-locking element 11 formed as a thread 15 has the same thread pitch as the Luer thread 25.

[0036] The outer shell 5 is preferably produced by injection molding.

[0037] In b), the sealing element 9 is shown in isolation. The second form-locking element 13 is preferably designed as a radial projection 31, in particular as an annular collar 33.

[0038] Preferably, the sealing element 9 has at least one preferably elastic spacer projection 37 on a distal end face 35, which in particular enables axial tolerance and / or length compensation within the closure cap 1.

[0039] It is possible for the sealing element 9 to have a plurality of spaced-apart spacing projections 37 on its distal end face 35, in particular three spaced-apart spacing projections 37, which are preferably arranged at the corners of an imaginary triangle. In the sectional plane of the illustration in Figure 2b), only one of the three spacer projections 37 located behind the sectional plane is visible; the other two spacer projections 37 are located in front of the sectional plane and are thus hidden from the viewer.

[0040] The at least one spacer projection 37 preferably rests - as can be seen in Figure 1 - on a proximal end face 39 of the outer shell 5, provided with a reference number in Figure 2a), when the sealing element 9 is arranged in the interior 7 of the outer shell 5 and the second form-locking element 13 interacts with the first form-locking element 11.

[0041] In particular, the second form-locking element 13 is at least substantially rotationally symmetrical - except, where appropriate, for the optionally asymmetrically arranged spacer projections 37, and / or inscriptions or the like.

[0042] Within the scope of an embodiment of a method for producing the closure cap 1, the outer shell 5 is produced by injection molding, wherein during injection molding the thread 15 is formed as the first form-locking element 11 in the interior 7 of the outer shell 5.

[0043] The sealing element 9 is then arranged in the interior 7 of the outer shell 5 such that the second form-locking element 13 cooperates with the first form-locking element 11 to hold the sealing element 9 in the outer shell 5. Preferably, the sealing element 9 is simply pressed or clipped into the outer shell 5 so that the second form-locking element 13 engages behind the first form-locking element 11 or engages in the first form-locking element 11.

Claims

1. A locking cap (1) for a hollow medical article (3) comprising an outer shell (5) and a sealing element (9) located in the inner part (7) of the outer shell (5), wherein the outer shell (5) comprises a first element (11) of geometric closure and the sealing element (9) comprises a second element (13) of geometric closure, wherein the first and second elements (11, 13) of geometric closure interact with each other to retain the sealing element (9) with the possibility of being captured in the inner part (7) of the outer shell (5), and wherein the first element (11) of geometric closure is made in the form of a thread (15).

2. The locking cap (1) according to item 1, wherein the first element (11) of the geometric closure is made in the form of an internal thread.

3. A locking cap (1) according to any of the preceding claims, wherein the first element (11) of the geometric closure comprises two, in particular exactly two, thread turns (19).

4. A locking cap (1) according to any of the preceding claims, wherein the outer shell (5) has a distal part (21) and a proximal part (23), wherein the first geometric closure element (11) is formed in the distal part (21), and wherein a Luer thread (25) is formed in the proximal part (23).

5. The locking cap (1) according to item 4, wherein the first element (11) of the geometric closure, made in the form of a thread (15), has the same thread pitch as the Luer thread (25).

6. A locking cap (1) according to any of the preceding claims, wherein the second element (13) of the geometric closure is designed in the form of a radial protrusion (31), in particular in the form of an annular flange (33).

7. A locking cap (1) according to any of the preceding claims, wherein the sealing element (9) on the distal end side (35) comprises at least one spacer projection (37).

8. The locking cap (1) according to claim 7, wherein the distance projection (37) is adjacent to the proximal end side (39) of the outer shell (5) when the second element (13) of the geometric closure interacts with the first element (11) of the geometric closure, in particular when the radial projection (31) is engaged in the internal thread.

9. A sealing cap (1) according to any of the preceding claims, wherein the outer shell (5) is manufactured by injection moulding.

10. A method for manufacturing a locking cap (1) according to any of the preceding claims, wherein the outer shell (5) of the locking cap (1) is manufactured by injection molding, wherein during injection molding a thread (15) is made in the inner part (7) of the outer shell (5) as a first element (11) of the geometric closure.

11. The method according to claim 10, wherein a sealing element (9) is positioned in the inner part (7) of the outer shell (5) which contains a second element (13) of geometric closure, wherein the sealing element (9) is positioned in the inner part of the outer shell (5) in such a way that the second element (13) of geometric closure interacts with the first element of geometric closure (11) to retain the sealing element (9) in the outer shell (5).