Cartridge holder latch mating to axial through opening of bearing with central threaded opening

Abstract

A drug delivery device for administering a predefined dose of a medicament comprising a housing is presented where the housing includes a body to accommodate a drive mechanism, a cartridge holder to accommodate a cartridge having a piston slidably disposed therein in an axial direction (z), and an interconnection between cartridge holder and body. The interconnection has, at least one displaceable or resiliently deformable latch element to mate with a corresponding bearing, and the latch element is displaceable or deformable in a direction (z, w) extending substantially parallel to a circumferential side wall of the body or cartridge holder.

Claims

1. A drug delivery device for administering a predefined dose of a medicament comprising a housing having: a body to accommodate a drive mechanism, a cartridge holder to accommodate a cartridge having a piston slidably disposed therein in an axial direction (z), an interconnection between the cartridge holder and the body, said interconnection having at least one resiliently deformable latch element configured to mate with a bearing, wherein each latch element of the at least one latch element is resiliently deformable relative to the cartridge holder and relative to the body in a direction (z, w) extending substantially parallel to a circumferential side wall of the body or the cartridge holder, wherein the cartridge holder and the body comprise an insert portion and a corresponding receptacle portion for establishing an at least partially interleaved interconnection of the cartridge holder and the body, wherein the receptacle portion comprises the bearing, wherein the bearing comprises a solid structure extending in a lateral plane (x, y) with respect to a tubular shape of the cartridge holder or the body, wherein the solid structure extends radially inward from an inside facing side wall section of the receptacle portion and defines a lateral web, and wherein the lateral web comprises at least one axial through opening to receive the at least one latch element and wherein a radial center of the lateral web comprises a central and threaded through opening being threaded to cooperate with an outer thread of a piston rod of the drive mechanism.

2. The drug delivery device according to claim 1, wherein the cartridge holder comprises the insert portion to be inserted into the receptacle portion of the body, or vice versa.

3. The drug delivery device according to claim 1, wherein the insert portion comprises the at least one latch element extending in longitudinal direction (z) and having at least one resiliently deformable spreading piece extending in a circumferential direction (w).

4. The drug delivery device according to claim 1, wherein the bearing adjacently extends to the inside facing side wall section of the receptacle portion.

5. The drug delivery device according to claim 1, wherein side wall sections of the insert portion and/or of the receptacle portion comprise a closed surface structure, free of through openings.

6. The drug delivery device according to claim 1, wherein the interconnection is of non-releasable type.

7. The drug delivery device according to claim 1, further comprising a cartridge filled with a medicament disposed in the cartridge holder.

8. The drug delivery device according to claim 1, wherein the lateral web extends across an inner diameter of the receptacle portion.

9. The drug delivery device according to claim 1, wherein the bearing is integrally formed with the receptacle portion and wherein the bearing delimits the receptacle portion in an axial direction.

10. The drug delivery device according to claim 1, wherein the at least one axial through opening of the lateral web adjoins the inside facing side wall section of the receptacle portion.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following, preferred embodiments of the invention will be described by making reference to the drawings, in which:

(2) FIG. 1 schematically illustrates a drug delivery device according to the prior art in an exploded view,

(3) FIG. 2 separately illustrates a cartridge holder shown in FIG. 1, and

(4) FIG. 3 schematically depicts a cross section through the body component according to FIG. 1,

(5) FIG. 4 is illustrative of the interconnection of body and cartridge holder according to a first embodiment of the invention,

(6) FIG. 5 schematically shows an alternative design for a latch element,

(7) FIG. 6 schematically depicts a latch element integrated in a longitudinal rib of the cartridge holder, and

(8) FIG. 7 schematically shows a positive interlock attainable by way of a latch element according to FIG. 6.

DETAILED DESCRIPTION

(9) In FIG. 4, a receptacle portion 51 of a body housing component 50 is illustrated, which is adapted to receive a correspondingly shaped insert portion 66 of a cartridge holder 60. In contrast to the embodiment as illustrated in FIGS. 1 to 3, the side wall sections 52, 65 of body 50 and cartridge holder 60 substantially comprise an entirely closed surface structure, which is free of radial through openings.

(10) The latch mechanism 59 attainable by the embodiment as illustrated in FIG. 4 is based on arrow-like latch elements 68 extending in longitudinal direction (z) from a proximalend of the insert portion 66. The body 50 comprises a tubular or cylindrically shaped side wall 52 having a bearing 54 extending in a lateral plane (x, y). The bearing 54, which also serves as a lateral web is a solid structure integrally formed with the lateral side wall 52 of the body 50 and comprises at least one axial through opening 58 which is adapted to receive and to mate with the longitudinally extending latch elements 68 of the insert portion 66.

(11) The latch elements 68 as illustrated in FIG. 4 comprise two oppositely and circumferentially extending spreading pieces or barbs 70 that may squeeze or circumferentially deform when urged through the through openings 58 of the bearing 54. Resilient or elastic deformation of the barbs 70 can be supported by a longitudinal slit 72 extending between the circumferentially extending spreading pieces 70.

(12) Position and circumferential distribution of the latch elements 68 corresponds with the circumferential size and position of the axial through openings 58 of the bearing 54. The bearing 54 as further illustrated in FIG. 4 also comprises a central and threaded through opening 56, that serves to axially guide a piston rod of a drive mechanism being not further illustrated here.

(13) The latch elements 68 as shown in FIG. 4 extend in longitudinal direction (z) as well as in circumferential direction (w). They are particularly adapted to resiliently or elastically deform in circumferential direction (w) in order to establish a positive interlock with the bearing 54. This way, a mutual interconnection of body 50 and cartridge holder 60 can be attained on the basis of a positive snap-in solution without the necessity to provide through openings or other structurally weakened portions in the side wall sections 52, 65 of receptacle portion 51 and insert portion 66.

(14) Typically, the longitudinal extension of the insert portion 66 substantially matches with the longitudinal extension of the receptacle portion 51. When a final assembly configuration of the drug delivery device is attained, cartridge holder 60 and body 50 not only abut in radial direction but also in longitudinal direction (z). It is intended, that a distal and lower end face of the body abuts 50 in longitudinal direction with a radially extending circumferential rim 64 of the cartridge holder 60. Correspondingly, also a proximally located end face of the insert portion 66 may but against the transverse or laterally extending bearing 54 in final assembly configuration. The circumferential rim 64 further separates a distal and substantially tubular shaped portion 62 of the cartridge holder 12 and the insert portion 66.

(15) FIG. 5 shows an alternative embodiment of a latch element 74 comprising a somewhat arrow-like shape and having two beveled barbs 78 at the free end of an elongated socket portion 76. The barbs 78 are intended to mate and to abut with the proximally located surface of the bearing 54 as illustrated in FIG. 4.

(16) The embodiment according to FIGS. 6 and 7 is illustrative of another snap-in configuration. Here, the insert portion 66 of the cartridge holder 60 comprises substantially longitudinally extending ribs or tongues 80 with circumferentially extending latch elements 82 comprising circumferentially extending barbs 84 that mate with correspondingly shaped recesses 88 of a longitudinal groove 86 provided in the inside facing side wall section 52 of the receptacle 51 of the body component 50.

(17) Here, it is of further benefit, when the circumferentially protruding barbs or spreading pieces 84 comprise a sufficient elasticity that allows to urge the latch elements 82 through the groove 86 in longitudinal direction (z) until a final assembly configuration as illustrated in FIG. 7 is reached. The recess 88 which is adapted to accommodate a relaxed latch element 82 comprises an undercutting 90 substantially extending in the lateral plane (z, w). However, also other embodiments are conceivable, wherein the undercutting 90 and the circumferentially protruding barbs comprise mutually corresponding abutment faces extending at an angle, substantially smaller than 90° with respect to the direction of assembly (z).

(18) The embodiment according to FIGS. 6 and 7 can be arbitrarily combined with the embodiment according to FIG. 4 and may therefore provide an additional fixation of cartridge holder 60 and body 50 of a drug delivery device, e.g. of pen-injector type.