INJECTION NEEDLE ASSEMBLY

Abstract

The present invention relates to an injection needle assembly having opposite distal and proximal ends, and wherein the assembly comprises an injection needle having proximal and distal pointed ends, wherein the distal pointed end is arranged to penetrate a membrane arranged at the proximal end of a medicament container; a tubular needle holder comprising distal engagement means and proximal engagement means; a tubular cap comprising proximal outer engagement means and proximal inner engagement means; a tubular needle cover comprising first engagement means arranged to cooperate with the proximal engagement means, and second engagement means arranged to cooperate with the proximal outer engagement means of the cap; characterized in that said needle cover is arranged to be displaced from a first position wherein the second engagement means and the proximal outer engagement means prevents the needle cover and the needle holder to be axially displaced by a linear displacement, to a second position wherein the needle cover and the needle holder are distally displaced, and wherein the proximal inner engagement means of the cap and the distal engagement means of the needle holder prevents the needle holder to be proximally displaced but allows the needle cover to be distally displaced.

Claims

1. An injection needle assembly comprising: a) a tubular needle holder comprising: a proximal end and a distal end; a cut-out located on an outer surface of the proximal end, a first external engagement member located on the distal end, and an injection needle fixedly connected to and surrounded by the tubular needle holder such that a proximal pointed end of the injection needle extends axially from the proximal end and a distal pointed end of the injection needle extends axially from the distal end, b) a needle cover having an inside surface, where the needle cover comprises; an axially extending ledge protruding radially from the inside surface, where the ledge is slidably and removably positioned within the cut-out, and a first internal engagement member; and c) a tubular cap comprising: a second external engagement member located on a proximal end of the tubular cap and threadedly engaged with the first internal engagement member, and a second internal engagement located within a central passage of the tubular cap and threadedly engaged with the first external engagement member on the tubular needle holder.

2. The injection needle assembly of claim 1 where the first external engagement member comprises a first external screw thread, the first internal engagement member comprises a first internal screw thread having a first pitch, and the second external engagement member comprises a second external screw thread, where the first external screw thread has a second pitch and the second external screw thread are partially threadedly engaged.

3. The injection needle assembly of claim 1 where the tubular cap further comprises two legs extending distally from a distal end of the tubular cap.

4. The injection needle assembly of claim 3 where the two legs are separated by a distance sufficient to allow a proximal end of a container of medicament to be positioned between the two legs such that the proximal end of the container can abut the distal end of the tubular cap.

5. The injection needle assembly of claim 1 where the tubular needle holder has a first axial position relative to the tubular cap where the distal pointed end of the injection needle is not in fluid communication with an interior of a medicament container.

6. The injection needle assembly of claim 5 where the tubular needle holder has a second axial position relative to the tubular cap where the distal pointed end of the injection needle is in fluid communication with an interior of a medicament container.

7. The injection needle assembly of claim 5 where the needle cover has a first axial position when the tubular needle holder is in its first position.

8. The injection needle assembly of claim 5 where the needle cover has a second axial position when the tubular needle holder is in its second position, where the second external screw thread on the proximal end of the cap is no longer engaged with the first internal engagement member of the needle cover.

9. The injection needle assembly of claim 2 where the first pitch and the second pitch are different.

10. The injection needle assembly of claim 2 where the second pitch is greater than the first pitch.

11. The injection needle assembly of claim 1 where two axially extending ledges engage two cut-outs when the needle cover is rotated in a first direction, where rotation of the needle cover in the first direction causes the tubular needle holder to rotate in a second direction opposite the first direction.

12. The injection needle assembly of claim 11 where the rotation of the tubular needle holder in the second direction causes an axial movement of tubular needle holder in a distal linear direction such that the distal pointed end of the injection needle comes into fluid communication with an interior of a medicament container.

14. The injection needle assembly of claim 3 where each of the two legs have distal ends configured to connect and attach to a container holder of a medicament delivery device.

15. The injection needle assembly of claim 2 where the first pitch is in a first direction and the second pitch is in second direction that is opposite of the first direction.

16. The injection needle assembly of claim 2 where the first pitch is large enough such that the first internal screw thread disengages from the second external screw thread when the needle cover is rotated approximately 180 degrees.

17. The injection needle assembly of claim 16 where the rotation of the needle cover causes linear displacement of the tubular needle holder such that the distal pointed end of the injection needle comes into fluid communication with an interior of a container of medicament abutting the distal end of the tubular cap.

18. The injection needle assembly of claim 1 where the tubular needle holder comprises two cut-outs located on the outer surface of the proximal end, where the cut-outs are operatively engaged by two axially extending ledges of the needle cover.

19. A combination of a medicament container and an injection needle assembly comprising: a medicament container and a injection needle assembly comprising, a) a tubular needle holder comprising: a proximal end and a distal end; two cut-outs located on an outer surface of the proximal end, a first external screw thread located on the distal end having a first pitch, and an injection needle fixedly connected to and surrounded by the tubular needle holder such that a proximal pointed end of the injection needle extends axially from the proximal end and a distal pointed end of the injection needle that extends axially from the distal end, b) a needle cover having an inside surface, where the tubular cap comprises; two axially extending ledges protruding radially from the inside surface, where each ledge is slidably and removably positioned within one of the cut-outs, and a first internal screw thread having a second pitch; and c) a tubular cap comprising: a second external screw thread located on a proximal end of the cap and engaged with the first internal screw thread, and a second internal screw thread located within a central passage of the tubular cap and engaged with the first external screw thread on the tubular needle holder,

20. The combination of claim 19 where the tubular cap further comprises two legs extending distally from a distal end of the tubular cap.

21. The combination of claim 20 where the medicament container is positioned between the legs and abuts the distal end of the tubular cap.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0020] In the following detailed description of the invention, reference will be made to the accompanying drawings, of which

[0021] FIG. 1 shows perspective view of a needle cover and of a protective cover of the needle assembly of the present invention,

[0022] FIG. 2 shows a side view of a tubular cap and of a needle holder of FIG. 1 without the needle cover,

[0023] FIG. 3 shows a side exploded view of FIG. 2,

[0024] FIG. 4 shows a perspective exploded view of FIG. 2,

[0025] FIG. 5 shows a perspective views of the needle cover and of the needle holder of FIG. 2 seen from their distal ends,

[0026] FIG. 6 shows a side view of a tubular cap and of a needle holder of a variant of the needle assembly,

[0027] FIG. 7 shows a perspective exploded view of FIG. 6,

[0028] FIG. 8 shows perspective views of the needle cover, of the needle holder and of the cap of FIG. 6 seen from their distal ends.

DETAILED DESCRIPTION

[0029] In the present application, when the term “distal part/end” is used, this refers to the part/end of the assembly, or the parts/ends of the members thereof, which is/are located the furthest away from the medicament delivery site of the patient. Correspondingly, when the term “proximal part/end” is used, this refers to the part/end of the assembly, or the parts/ends of the members thereof, which, is/are located closest to the medicament delivery site of the patient.

[0030] The present invention is intended to be used in medicament injection devices, which could be of any type from simple manual injectors to multi-function auto-injectors. However they do not form part of the present invention and are thus not shown in the drawings.

[0031] FIG. 1 shows a needle assembly 10 having opposite distal and proximal ends according to the present invention. The assembly comprises an injection needle 46 having proximal 48 and distal 50 pointed ends, wherein the distal pointed end is arranged to penetrate a membrane (not shown) arranged at the proximal end of a medicament container 24; a tubular needle holder 40 partially surrounding and fixedly connected to said injection needle 46, wherein said needle holder comprises on its outer circumferential surface distal engagement means 44; 70 and proximal engagement means 54; a tubular cap 26 comprising a distal part 28 having container attachment means 30, a proximal part 32 having proximal outer engagement means 60; 80 on its outer circumferential surface, and a central passage 34 having proximal inner engagement means 36, 38; 72 on its inner circumferential surface adapted for receiving the distal engagement means 44; 70 of the needle holder; a tubular needle cover 12 comprising on its inner circumferential surface, first engagement means 52 arranged to cooperate with the proximal engagement means 54 of the needle holder, and second engagement means 58; 78 arranged to cooperate with the proximal outer engagement means 60; 80 of the cap; wherein said needle cover is arranged to be displaced from a first position wherein the second engagement means 58; 78 and the proximal outer engagement means 60; 80 prevents the needle cover and the needle holder to be axially displaced by a linear displacement, to a second position wherein the needle cover and the needle holder are distally displaced, and wherein the proximal inner engagement means 36, 38; 72 of the cap and the distal engagement means 44; 70 of the needle holder prevents the needle holder to be proximally displaced but allows the needle cover to be distally displaced.

[0032] The needle cover 12 comprises a slightly conical proximal part 14, a generally tubular distal part 16 and a central tubular part between them, where the tubular distal part 16 has a somewhat larger diameter than the central tubular part.

[0033] The cap 26 is tubularly shaped and thus has the central passage 34, FIG. 4. The proximal inner engagement means on the central passage are at least one longitudinally extending groove 36 ending in a generally transversal groove 38, thereby forming a general T-shape, thus creating one part of a bayonet fitting, FIG. 4.

[0034] The outer diameter of the distal end 42 of the needle holder generally corresponds as the inner diameter of the passage 34, and is arranged with the distal engagement means as e.g. ledges 44, creating the other part of the bayonet fitting, intended to cooperate with the grooves 36, 38; FIG. 4.

[0035] The tubular distal part 16 of the needle cover has a diameter that surround the container attachment means and the central part of the needle cover has an inner diameter somewhat larger than the outer diameter of the distal tubular part 28 of the cap 26, but such that central part of the needle cover is press fitted onto the distal tubular part 28 of the cap. The inner circumferential surface of the distal tubular part of the needle cover is provided with the first engagement means as e.g. three axially extending ledges, where each has a first radial inwardly directed ledge 52, FIG. 5. These ledges 52 fit into the proximal engagement means of the needle holder e.g. cut-outs 54. Further the inner circumferential surface of the distal tubular part of the needle cover is arranged with the second engagement means 58 as e.g. an inwardly directed ledge, which is intended to fit into the proximal outer engagement means 60 of the cap as e.g. an-shaped groove having a first transversal part, a first longitudinal part, a second transversal part and a second longitudinal part.

[0036] The distal part 28 of the cap 26 is either attached to the proximal end of the container or attached to both the proximal end of the container and to a housing part or container holder of a delivery device by the container attachment means 30.

[0037] When the needle assembly is delivered to the user a portion of the distal part of the needle holder is partially press fitted into the cap and the radial distal front surface of the distal engagement means 44 of the needle holder abuts the radial proximal surface of the proximal part 32 of the cap. Also, the inwardly directed ledge 58 of the needle cover 12 is in engagement with the first transversal part of the bayonet fitting groove 60 and thereby an axial movement of both the needle holder and the needle cover is prevented.

[0038] For penetrating the membrane of the container with the distal pointed end 50 of the needle 46, the user twists the needle cover 12, whereby the needle holder 40 also twists due to the connection between them via the inwardly directed ledges 52 fitting into the cut-outs 54 of the needle holder. This twisting also causes the inwardly directed ledge 58 of the needle cover 12 to move out of the first transversal part of the bayonet fitting groove 60 on the outside of the cap 26, and the ledges 44 of the needle holder 40 to fit into the longitudinal grooves 36 of the cap 26, thereby enabling both the needle cover 12 and the needle holder to be linearly pushed towards the distal end of the assembly. During the linear motion of the needle holder into the cap, the distal pointed end 50 of the injection needle 46 penetrates the membrane of the medicament container, thereby creating a passage from the interior of the container to the proximal pointed end 48 of the injection needle 46.

[0039] When the ledges 44 have reached the end of the longitudinal grooves 36 the user twists further the needle cover 12, whereby the needle holder 40 also twists due to the connection between them via the inwardly directed ledges 52 fitting into the cut-outs 54 of the needle holder. The further twisting then causes the ledges 44 to fit into the transversal groove 38, thereby causing a bayonet locking of the needle holder with the cap whereby the needle holder cannot be axially displaced. The further twisting also causes and the inwardly directed ledge 58 of the needle cover 12 to move through and out of the second transversal part of the bayonet fitting groove 60 on the outside of the cap 26. Now, the needle cover 12 may be pulled off the needle holder 40 and the cap 26. The injection needle assembly is now ready for injection.

[0040] FIGS. 6-8 show a variant of the embodiment of FIG. 1. Instead of bayonet fittings between the needle holder and the cap, and between the needle cover and the cap, the distal engagement of the needle holder 70 and the proximal inner engagement means 72 of the cap are threads 70, and the proximal outer engagement means 80 of the cap and the second engagement means 78 of the needle cover are also threads. Thus, when the needle cover is turned, the needle holder is screwed into the cap, which movement causes the distal pointed end 50 of the injection needle 46 to penetrate the membrane of the medicament container. It is however to be noticed that the threads 80, 78 between the needle cover and the cap, has a different direction of the pitch than the threads 70, 72 between the needle holder and the cap.

[0041] When the needle assembly is delivered to the user the needle cover is partially screwed onto the cap and the needle holder is also partially screwed into the cap as shown in FIG. 6, with just a few threads in engagement with the cap. When the user then starts to turn the needle cover, this turning causes the needle holder to be screwed into the cap whereby the pointed distal end of the injection needle penetrates the membrane of the medicament holder and due to the different direction of the pitch the needle cover is screwed off the cap and may be removed. Preferably the pitches of the threads are chosen such that there is a major longitudinal movement of the needle holder into the cap for a small turning angle in order to prevent as much as possible turning or “drilling” of the distal end of the injection needle in the membrane. At the same time the pitch of the threads between the needle cover and the hub is preferably chosen such that the user only needs to turn the needle cover about half a turn in order to perform the operation so as to avoid having to change grip in order to finish the operation.

[0042] In the previous embodiments, the cap 26 has previously been attached in a proper manner to the proximal end of the medicament container in a sterile form.

[0043] In another embodiment, the injection needle assembly according to the present invention has the appearance of FIG. 1. Thus the distal pointed end of the injection needle is kept sterile by a protective cover 20, such as an aluminium foil or plastic foil or the like arranged on a distal opening 18 of the needle cover. The protective cover 20 is preferably arranged with a grip means, such as a tab 22, for facilitating the removal of the protective cover. When the injection needle assembly is to be attached to the medicament container/injection device, the protective cover is torn away and the needle cap is attached to the container and to the delivery.

[0044] It is to be understood that the embodiment described above and shown in the drawings is to be regarded only as a non-limiting example of the invention and that it may be modified in many ways within the scope of the patent claims.