Medicament delivery device

Abstract

A medicament delivery device is disclosed having a housing, an actuation mechanism capable of delivering doses of medicament from a medicament container and arranged with a delivery member, a shield, a guard movable within the housing, wherein the guard is operably connected to the actuation mechanism. A protective cap is releasably arranged on the housing and having a shield remover. A blocking element on the guard is movable between a blocking position and a release position and has an engagement surface to engage a proximal area of the housing. The blocking element engages with a surface of the shield remover to retain the blocking element in the blocking position. The engagement surface causes a blocking of the guard from movement and removal of the protective cap enables a movement of the blocking element to a release position when the engagement surface engages the proximal area allowing the member guard to move.

Claims

1. An activation mechanism for a medicament delivery device comprising; a. a housing having a proximal end terminating in a proximally directed surface; and b. a guard axially moveable relative to the housing and comprising a blocking element having a blocking position and a release position, wherein the blocking element comprises a flexible tongue that is fixed radially when the blocking element is in the blocking position wherein when the guard is in an initial position, the blocking element is not in contact with the proximally directed surface of the housing; wherein when the guard is pressed against a dose delivery site, the blocking element, when in the release position, will move distally and axially past the proximally directed surface of the housing; wherein when the blocking element is in the blocking position, the guard is free to move distally and axially relative to the housing until the blocking element engages the proximally directed surface of the housing such that the engagement of the blocking element with the proximally directed surface of the housing will prevent further axial movement of the guard in the distal direction.

2. The activation mechanism of claim 1 where the blocking element is located on an outside surface of the guard and the flexible tongue comprises an inwardly directed contact surface that is engaged with a needle shield remover when the flexible tongue is fixed radially.

3. The activation mechanism of claim 1 where the flexible tongue comprises an engagement surface projecting radially outward that prevents distal axial movement of the guard when the blocking element is in the blocking position and the guard has moved distally from the initial position relative to the proximally directed surface of the housing.

4. The activation mechanism of claim 1 where the flexible tongue is flexed radially inward when the guard moves distally and axially past the proximally directed surface of the housing as the guard is pressed against the dose delivery site.

5. The activation mechanism of claim 1 where the flexible tongue further comprises an outwardly directed protrusion having an inclined surface.

6. The activation mechanism of claim 1, wherein the flexible tongue comprises a radially outward directed protrusion having a distally directed surface.

7. The activation mechanism of claim 6, wherein the protrusion is not engaged with the proximally directed surface of the housing when the guard is in the initial position.

8. The activation mechanism of claim 7, wherein the protrusion is not engaged with the proximally directed surface of the housing when the guard is pressed against the dose delivery site and the blocking element is in the release position.

9. The activation mechanism of claim 7, wherein the protrusion will engaged with and will directly abut the proximally directed surface of the housing when the guard is moved axially and distally when the blocking element is in the blocking position.

10. The activation mechanism of claim 7, wherein the distally directed surface moves axially in a distal direction when the guard is pressed against the dose delivery site such that the distally directed surface contacts the proximally directed surface of the housing causing the protrusion to move radially inward and move past the proximally directed surface of the housing.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) In the following detailed description of the invention, reference will be made to the accompanying drawings, of which

(2) FIG. 1 shows a perspective view of a medicament delivery device comprising the present disclosure,

(3) FIG. 2 is an exploded view of the device of FIG. 1,

(4) FIG. 3 is a cross-sectional view of a proximal part of the device of FIG. 1, and

(5) FIGS. 4-6 each show detailed views of components comprised in the present disclosure.

DETAILED DESCRIPTION

(6) The embodiment shown in the drawings comprises a generally elongated, tubular housing 10 with a somewhat triangular shape in cross-section, and having a distal end 12 and a proximal end 14, FIG. 1. The housing is arranged to accommodate a medicament delivery actuation mechanism 16, FIG. 2, capable of, upon activation, effecting a delivery of a dose of medicament from a medicament container 18 arranged inside the housing via a medicament delivery member, such as e.g. an injection needle 20, FIG. 3. The injection needle may be protected before use by an appropriate medicament delivery member shield 22, FIG. 2, and in the embodiment shown a so called RNS (rigid needle shield) is utilized. The medicament delivery actuation mechanism may have a number of designs and functions that are not essential to the disclosure and will therefore not be described in detail.

(7) The proximal end of the housing is arranged with an end cover 24, FIGS. 2 and 4, of a generally tubular shape. A distal part 26 of the end cover 24 is arranged with dimensions and a shape generally corresponding to the proximally directed opening 28 of the housing 10. The distal part 26 is arranged with attachment members 30 in the embodiment shown as transversal ledges, which are to engage with transversal ledges 32 on the inner surface of the housing, FIG. 2.

(8) The end cover 24 further comprises a proximal part 34 with a somewhat lesser diameter than the distal part 28. The distal part 26 and the proximal part 34 of the end cover 24 are separated by a generally proximally directed transition surface 36. Further, the end cover 24 is arranged with a first holding member 38 comprised in a protective cap holding mechanism, FIG. 4, on the outer surface of the proximal part 34, that in the embodiment shown is arranged as a ledge or protrusion positioned generally in line with the longitudinal direction 40 of the device. The protrusion 38 may have somewhat inclined side surfaces as seen in FIG. 4.

(9) A protective cap 42, FIGS. 2, and 5, is further arranged to the device. The protective cap 42, is generally tubular in shape and with a similar form as the housing 10. It has a distally directed opening 44, which has a diameter somewhat larger than the outer diameter of the proximal part 34 of the end cover 24, such that the protective cap 42 will fit around the proximal part 34. On the inner surface of the protective cap 42 a second holding member 46 is arranged, designed to interact with the first holding member 38, comprised in the protective cap holding mechanism. In the embodiment shown it is arranged as a number of ledges 46 I-IV, forming a space 48 where the first holding member 38 is positioned when the protective cap is attached to the housing and the end cover. Two of the ledges 46 I and II have a lesser height, the function of which will be explained below.

(10) The protective cap 42 is further arranged with a medicament delivery member shield remover, in the embodiment shown in the form of a tubular needle shield remover 50 attached to a distally directed wall surface. The needle shield remover 50 is arranged with inwardly extending inclined tongues 52, which are capable of gripping into the outer surface of the RNS 22, FIG. 3.

(11) The device further comprises a medicament delivery member guard 54, FIGS. 2 and 4, in the form of a generally elongated tubular member where the proximal part has a diameter only somewhat smaller than the inner diameter of an opening 56 at the proximal end of the end cover 24. The medicament delivery member guard 54 is arranged slidable in the longitudinal direction of the device from positions where the medicament delivery member 20 is covered to positions where the medicament delivery member is exposed during delivery of medicament. An actuator (not shown) may be arranged to force the medicament delivery member guard 54 in the proximal direction.

(12) The outer surface of the medicament delivery member guard 54 is arranged with a blocking element 58, FIG. 4. In the embodiment shown it is arranged as a tongue 60 by a U-shaped cut-out in the medicament delivery member guard 54, having a free end of the tongue 60 facing the proximal direction. An outwardly facing surface of the tongue 60 is arranged with a protrusion 62. The protrusion 62 is arranged with a distally directed surface 64 having a certain inclination in relation to the longitudinal direction 40 of the device. The free end of the tongue is further arranged with an inwardly directed protrusion 66, FIGS. 3 and 6, the function of which will be explained below.

(13) When the device is in an initial state with the medicament delivery member guard 54 in an initial position in relation to the housing 10 and the protective cap 42 is attached to the device, the first and second holding members 38, 46 interact to releasibly hold the protective cap 42 to the housing 10 such that the protrusion 38 of the first holding member is within the area 48 of the ledges 46 of the second holding member. Further, the needle shield remover 50 is surrounding the needle shield 22 and the inwardly directed protrusion 66 of the tongue 60 is in contact with the outer surface of the needle shield remover 50, FIG. 3. Thus the tongue 60 of the blocking element 58 is prevented from moving inwardly radially. Further, the outwardly directed protrusion 62 of the tongue 60 is arranged to block any movement in the distal direction of the medicament delivery member guard 54 in that the protrusion 62 will engage a contact surface in the form of a proximally directed surface 68 of the end cover 24. Thus, the medicament delivery device guard 54 is prevented from moving if the device should accidentally be dropped on a hard surface such as a floor, thereby preventing unintended activation of the device.

(14) When the device is to be used, the protective cap 42 may be turned whereby the protrusion 38 of the first holding member will pass over the lower ledge 46.sub.I, after which the protective cap is free to be removed. As an alternative, the protective cap 42 may be pulled in the proximal direction whereby the protrusion 38 will pass over the lower ledge 46.sub.II. Due to the connection of the needle shield remover 50 with the RNS 22, the RNS 22 will be removed when the protective cap 42 is removed, thus rendering the medicament delivery member 20 ready for use, FIG. 6. When the protective cap 42 is removed, the proximal end of the device, which preferably is the proximal end of the medicament delivery member guard 54, can be pressed against a dose delivery site.

(15) The pressing of the medicament delivery guard 54 will cause it to move in the distal direction in relation to the housing and the end cover 24. Due to that the tongue now is free to move in the radial direction because the inwardly directed protrusion 66 is no longer in contact with the needle shield remover 50, FIG. 6, the outwardly directed protrusion 62 of the tongue 60 can pass the proximally directed surface 68 of the end cover. The passing is facilitated by the inclined surface 64 of the outwardly directed protrusion. Thus, the distal movement of the medicament delivery member guard 54 in the distal direction will cause an activation of the device for delivering a dose of medicament.

(16) 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 disclosure and that it may be modified in many ways within the scope of the patent claims.