Autoinjector housing

1 . A housing assembly for a drug delivery device, comprising:

a first housing part comprising:

a first proximal end comprising a first engagement portion comprising a resiliently-biased clip comprising a radially-outward extending protrusion, and a second engagement portion,

a first distal end, and

a first sidewall therebetween defining a first longitudinal axis and a first interior, the first sidewall comprising one or more windows therethrough; and

a second housing part comprising:

a second proximal end,

a second distal end comprising a third engagement portion and a fourth engagement portion, and

a second sidewall therebetween defining a second longitudinal axis and a second interior, wherein the third engagement portion comprises an opening within and surrounded by the second sidewall,

wherein, when the first housing part is connected to the second housing part, the first engagement portion is biased such that the radially-outward extending protrusion is received within the third engagement portion, thereby forming a positive lock with the third engagement portion and joining the first housing part and the second housing part such that the first longitudinal axis and the second longitudinal axis are coaxial, and

wherein, when the first housing part and the second housing part are joined, the second engagement portion abuts the fourth engagement portion, such that the first housing part cannot rotate relative to the second housing part.

2 . The housing assembly of claim 1 , wherein the first distal end comprises an opening.

3 . The housing assembly of claim 1 , wherein the first distal end comprises a moveable needle shield comprising a sidewall having proximal and distal ends, the needle shield comprising an opening at the distal end thereof and being slidable relative to the first housing part.

4 . The housing assembly claim 1 , wherein the first engagement portion and the third engagement portion form an irreversible lock.

5 . The housing assembly of claim 1 , wherein the radially-outward extending protrusion comprises a first beam and a second beam spaced apart from the first beam, the second beam extending substantially parallel to the first beam along the first longitudinal axis.

6 . The housing assembly of claim 5 , wherein the first and second beam comprise:

an insertion contact surface that extends radially outward from proximal to distal ends thereof along the first longitudinal axis; and

a removal contact surface longitudinally spaced from and angled with respect to the insertion contact surface.

7 . The housing assembly of claim 1 , wherein the resiliently-biased flexible clip is deflected radially inward from an initial biased position as the insertion contact surface engages the third engagement portion.

8 . The housing assembly of claim 7 , wherein, when the first housing part and the second housing part are joined, the resiliently-biased clip returns to the initial biased position.

9 . The housing assembly of claim 6 , wherein, when the first housing part and the second housing part are joined, the removal contact surface and the third engagement portion prevent separation of the first housing part and the second housing part.

10 . The housing assembly of claim 1 , wherein the second engagement portion and the fourth engagement portion comprise circumferentially-arranged contact surfaces in the first sidewall and the second sidewall, respectively.

11 . The housing assembly of claim 1 , wherein the second engagement portion comprises one or more walls of the window.

12 . The housing assembly of claim 1 , wherein the second engagement portion and the fourth engagement portion comprise one or more steps in the first sidewall and the second sidewall, respectively.

13 . The housing assembly of claim 1 , wherein the fourth engagement portion comprises a u-shaped recess configured to receive the first proximal end therein.

14 . The housing assembly of claim 13 , wherein the u-shaped recess receives at least a portion of the window therein.

15 . An injection device comprising:

a housing assembly comprising:

a first housing part comprising:

a first proximal end comprising a first engagement portion comprising a resiliently-biased clip comprising a radially-outward extending outward protrusion, and a second engagement portion,

a first distal end, and

a first sidewall therebetween defining a first longitudinal axis and a first interior, the first sidewall comprising one or more windows therethrough; and

a second housing part comprising:

a second proximal end,

a second distal end comprising a third engagement portion and a fourth engagement portion, and

a second sidewall therebetween defining a second longitudinal axis and a second interior, wherein the third engagement portion comprises an opening within and surrounded by the second sidewall,

wherein, when the first housing part and the second housing part are joined, the first engagement portion is biased such that the radially-outward extending protrusion is received within the third engagement portion, thereby forming a positive lock with the third engagement portion and joining the first housing part and the second housing part such that the first longitudinal axis and the second longitudinal axis are coaxial, and

wherein, when the first housing part and the second housing part are joined, the second engagement portion abuts the fourth engagement portion, such that the first housing part cannot rotate relative to the second housing part;

a syringe comprising a reservoir and a needle in fluid communication therewith, the syringe received within the first interior and/or the second interior; and

a driver received within the second interior and configured to, upon actuation, expel medicament from the reservoir through the needle.